Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

15 files changed, 6109 insertions, 0 deletions

diff --git a/init/.gitignore b/init/.gitignore
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+++ b/init/.gitignore
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+# SPDX-License-Identifier: GPL-2.0-only
+/utsversion-tmp.h
diff --git a/init/Kconfig b/init/Kconfig
new file mode 100644
index 0000000000..6d35728b94
--- /dev/null
+++ b/init/Kconfig
@@ -0,0 +1,1986 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config CC_VERSION_TEXT
+	string
+	default "$(CC_VERSION_TEXT)"
+	help
+	  This is used in unclear ways:
+
+	  - Re-run Kconfig when the compiler is updated
+	    The 'default' property references the environment variable,
+	    CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd.
+	    When the compiler is updated, Kconfig will be invoked.
+
+	  - Ensure full rebuild when the compiler is updated
+	    include/linux/compiler-version.h contains this option in the comment
+	    line so fixdep adds include/config/CC_VERSION_TEXT into the
+	    auto-generated dependency. When the compiler is updated, syncconfig
+	    will touch it and then every file will be rebuilt.
+
+config CC_IS_GCC
+	def_bool $(success,test "$(cc-name)" = GCC)
+
+config GCC_VERSION
+	int
+	default $(cc-version) if CC_IS_GCC
+	default 0
+
+config CC_IS_CLANG
+	def_bool $(success,test "$(cc-name)" = Clang)
+
+config CLANG_VERSION
+	int
+	default $(cc-version) if CC_IS_CLANG
+	default 0
+
+config AS_IS_GNU
+	def_bool $(success,test "$(as-name)" = GNU)
+
+config AS_IS_LLVM
+	def_bool $(success,test "$(as-name)" = LLVM)
+
+config AS_VERSION
+	int
+	# Use clang version if this is the integrated assembler
+	default CLANG_VERSION if AS_IS_LLVM
+	default $(as-version)
+
+config LD_IS_BFD
+	def_bool $(success,test "$(ld-name)" = BFD)
+
+config LD_VERSION
+	int
+	default $(ld-version) if LD_IS_BFD
+	default 0
+
+config LD_IS_LLD
+	def_bool $(success,test "$(ld-name)" = LLD)
+
+config LLD_VERSION
+	int
+	default $(ld-version) if LD_IS_LLD
+	default 0
+
+config RUST_IS_AVAILABLE
+	def_bool $(success,$(srctree)/scripts/rust_is_available.sh)
+	help
+	  This shows whether a suitable Rust toolchain is available (found).
+
+	  Please see Documentation/rust/quick-start.rst for instructions on how
+	  to satisfy the build requirements of Rust support.
+
+	  In particular, the Makefile target 'rustavailable' is useful to check
+	  why the Rust toolchain is not being detected.
+
+config CC_CAN_LINK
+	bool
+	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT
+	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag))
+
+config CC_CAN_LINK_STATIC
+	bool
+	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT
+	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static)
+
+config CC_HAS_ASM_GOTO_OUTPUT
+	def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
+
+config CC_HAS_ASM_GOTO_TIED_OUTPUT
+	depends on CC_HAS_ASM_GOTO_OUTPUT
+	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
+	def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $CC -x c - -c -o /dev/null)
+
+config TOOLS_SUPPORT_RELR
+	def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
+
+config CC_HAS_ASM_INLINE
+	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
+
+config CC_HAS_NO_PROFILE_FN_ATTR
+	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
+
+config PAHOLE_VERSION
+	int
+	default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))
+
+config CONSTRUCTORS
+	bool
+
+config IRQ_WORK
+	bool
+
+config BUILDTIME_TABLE_SORT
+	bool
+
+config THREAD_INFO_IN_TASK
+	bool
+	help
+	  Select this to move thread_info off the stack into task_struct.  To
+	  make this work, an arch will need to remove all thread_info fields
+	  except flags and fix any runtime bugs.
+
+	  One subtle change that will be needed is to use try_get_task_stack()
+	  and put_task_stack() in save_thread_stack_tsk() and get_wchan().
+
+menu "General setup"
+
+config BROKEN
+	bool
+
+config BROKEN_ON_SMP
+	bool
+	depends on BROKEN || !SMP
+	default y
+
+config INIT_ENV_ARG_LIMIT
+	int
+	default 32 if !UML
+	default 128 if UML
+	help
+	  Maximum of each of the number of arguments and environment
+	  variables passed to init from the kernel command line.
+
+config COMPILE_TEST
+	bool "Compile also drivers which will not load"
+	depends on HAS_IOMEM
+	help
+	  Some drivers can be compiled on a different platform than they are
+	  intended to be run on. Despite they cannot be loaded there (or even
+	  when they load they cannot be used due to missing HW support),
+	  developers still, opposing to distributors, might want to build such
+	  drivers to compile-test them.
+
+	  If you are a developer and want to build everything available, say Y
+	  here. If you are a user/distributor, say N here to exclude useless
+	  drivers to be distributed.
+
+config WERROR
+	bool "Compile the kernel with warnings as errors"
+	default COMPILE_TEST
+	help
+	  A kernel build should not cause any compiler warnings, and this
+	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
+	  to enforce that rule by default. Certain warnings from other tools
+	  such as the linker may be upgraded to errors with this option as
+	  well.
+
+	  However, if you have a new (or very old) compiler or linker with odd
+	  and unusual warnings, or you have some architecture with problems,
+	  you may need to disable this config option in order to
+	  successfully build the kernel.
+
+	  If in doubt, say Y.
+
+config UAPI_HEADER_TEST
+	bool "Compile test UAPI headers"
+	depends on HEADERS_INSTALL && CC_CAN_LINK
+	help
+	  Compile test headers exported to user-space to ensure they are
+	  self-contained, i.e. compilable as standalone units.
+
+	  If you are a developer or tester and want to ensure the exported
+	  headers are self-contained, say Y here. Otherwise, choose N.
+
+config LOCALVERSION
+	string "Local version - append to kernel release"
+	help
+	  Append an extra string to the end of your kernel version.
+	  This will show up when you type uname, for example.
+	  The string you set here will be appended after the contents of
+	  any files with a filename matching localversion* in your
+	  object and source tree, in that order.  Your total string can
+	  be a maximum of 64 characters.
+
+config LOCALVERSION_AUTO
+	bool "Automatically append version information to the version string"
+	default y
+	depends on !COMPILE_TEST
+	help
+	  This will try to automatically determine if the current tree is a
+	  release tree by looking for git tags that belong to the current
+	  top of tree revision.
+
+	  A string of the format -gxxxxxxxx will be added to the localversion
+	  if a git-based tree is found.  The string generated by this will be
+	  appended after any matching localversion* files, and after the value
+	  set in CONFIG_LOCALVERSION.
+
+	  (The actual string used here is the first 12 characters produced
+	  by running the command:
+
+	    $ git rev-parse --verify HEAD
+
+	  which is done within the script "scripts/setlocalversion".)
+
+config BUILD_SALT
+	string "Build ID Salt"
+	default ""
+	help
+	  The build ID is used to link binaries and their debug info. Setting
+	  this option will use the value in the calculation of the build id.
+	  This is mostly useful for distributions which want to ensure the
+	  build is unique between builds. It's safe to leave the default.
+
+config HAVE_KERNEL_GZIP
+	bool
+
+config HAVE_KERNEL_BZIP2
+	bool
+
+config HAVE_KERNEL_LZMA
+	bool
+
+config HAVE_KERNEL_XZ
+	bool
+
+config HAVE_KERNEL_LZO
+	bool
+
+config HAVE_KERNEL_LZ4
+	bool
+
+config HAVE_KERNEL_ZSTD
+	bool
+
+config HAVE_KERNEL_UNCOMPRESSED
+	bool
+
+choice
+	prompt "Kernel compression mode"
+	default KERNEL_GZIP
+	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_ZSTD || HAVE_KERNEL_UNCOMPRESSED
+	help
+	  The linux kernel is a kind of self-extracting executable.
+	  Several compression algorithms are available, which differ
+	  in efficiency, compression and decompression speed.
+	  Compression speed is only relevant when building a kernel.
+	  Decompression speed is relevant at each boot.
+
+	  If you have any problems with bzip2 or lzma compressed
+	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
+	  version of this functionality (bzip2 only), for 2.4, was
+	  supplied by Christian Ludwig)
+
+	  High compression options are mostly useful for users, who
+	  are low on disk space (embedded systems), but for whom ram
+	  size matters less.
+
+	  If in doubt, select 'gzip'
+
+config KERNEL_GZIP
+	bool "Gzip"
+	depends on HAVE_KERNEL_GZIP
+	help
+	  The old and tried gzip compression. It provides a good balance
+	  between compression ratio and decompression speed.
+
+config KERNEL_BZIP2
+	bool "Bzip2"
+	depends on HAVE_KERNEL_BZIP2
+	help
+	  Its compression ratio and speed is intermediate.
+	  Decompression speed is slowest among the choices.  The kernel
+	  size is about 10% smaller with bzip2, in comparison to gzip.
+	  Bzip2 uses a large amount of memory. For modern kernels you
+	  will need at least 8MB RAM or more for booting.
+
+config KERNEL_LZMA
+	bool "LZMA"
+	depends on HAVE_KERNEL_LZMA
+	help
+	  This compression algorithm's ratio is best.  Decompression speed
+	  is between gzip and bzip2.  Compression is slowest.
+	  The kernel size is about 33% smaller with LZMA in comparison to gzip.
+
+config KERNEL_XZ
+	bool "XZ"
+	depends on HAVE_KERNEL_XZ
+	help
+	  XZ uses the LZMA2 algorithm and instruction set specific
+	  BCJ filters which can improve compression ratio of executable
+	  code. The size of the kernel is about 30% smaller with XZ in
+	  comparison to gzip. On architectures for which there is a BCJ
+	  filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
+	  will create a few percent smaller kernel than plain LZMA.
+
+	  The speed is about the same as with LZMA: The decompression
+	  speed of XZ is better than that of bzip2 but worse than gzip
+	  and LZO. Compression is slow.
+
+config KERNEL_LZO
+	bool "LZO"
+	depends on HAVE_KERNEL_LZO
+	help
+	  Its compression ratio is the poorest among the choices. The kernel
+	  size is about 10% bigger than gzip; however its speed
+	  (both compression and decompression) is the fastest.
+
+config KERNEL_LZ4
+	bool "LZ4"
+	depends on HAVE_KERNEL_LZ4
+	help
+	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
+	  A preliminary version of LZ4 de/compression tool is available at
+	  <https://code.google.com/p/lz4/>.
+
+	  Its compression ratio is worse than LZO. The size of the kernel
+	  is about 8% bigger than LZO. But the decompression speed is
+	  faster than LZO.
+
+config KERNEL_ZSTD
+	bool "ZSTD"
+	depends on HAVE_KERNEL_ZSTD
+	help
+	  ZSTD is a compression algorithm targeting intermediate compression
+	  with fast decompression speed. It will compress better than GZIP and
+	  decompress around the same speed as LZO, but slower than LZ4. You
+	  will need at least 192 KB RAM or more for booting. The zstd command
+	  line tool is required for compression.
+
+config KERNEL_UNCOMPRESSED
+	bool "None"
+	depends on HAVE_KERNEL_UNCOMPRESSED
+	help
+	  Produce uncompressed kernel image. This option is usually not what
+	  you want. It is useful for debugging the kernel in slow simulation
+	  environments, where decompressing and moving the kernel is awfully
+	  slow. This option allows early boot code to skip the decompressor
+	  and jump right at uncompressed kernel image.
+
+endchoice
+
+config DEFAULT_INIT
+	string "Default init path"
+	default ""
+	help
+	  This option determines the default init for the system if no init=
+	  option is passed on the kernel command line. If the requested path is
+	  not present, we will still then move on to attempting further
+	  locations (e.g. /sbin/init, etc). If this is empty, we will just use
+	  the fallback list when init= is not passed.
+
+config DEFAULT_HOSTNAME
+	string "Default hostname"
+	default "(none)"
+	help
+	  This option determines the default system hostname before userspace
+	  calls sethostname(2). The kernel traditionally uses "(none)" here,
+	  but you may wish to use a different default here to make a minimal
+	  system more usable with less configuration.
+
+config SYSVIPC
+	bool "System V IPC"
+	help
+	  Inter Process Communication is a suite of library functions and
+	  system calls which let processes (running programs) synchronize and
+	  exchange information. It is generally considered to be a good thing,
+	  and some programs won't run unless you say Y here. In particular, if
+	  you want to run the DOS emulator dosemu under Linux (read the
+	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
+	  you'll need to say Y here.
+
+	  You can find documentation about IPC with "info ipc" and also in
+	  section 6.4 of the Linux Programmer's Guide, available from
+	  <http://www.tldp.org/guides.html>.
+
+config SYSVIPC_SYSCTL
+	bool
+	depends on SYSVIPC
+	depends on SYSCTL
+	default y
+
+config SYSVIPC_COMPAT
+	def_bool y
+	depends on COMPAT && SYSVIPC
+
+config POSIX_MQUEUE
+	bool "POSIX Message Queues"
+	depends on NET
+	help
+	  POSIX variant of message queues is a part of IPC. In POSIX message
+	  queues every message has a priority which decides about succession
+	  of receiving it by a process. If you want to compile and run
+	  programs written e.g. for Solaris with use of its POSIX message
+	  queues (functions mq_*) say Y here.
+
+	  POSIX message queues are visible as a filesystem called 'mqueue'
+	  and can be mounted somewhere if you want to do filesystem
+	  operations on message queues.
+
+	  If unsure, say Y.
+
+config POSIX_MQUEUE_SYSCTL
+	bool
+	depends on POSIX_MQUEUE
+	depends on SYSCTL
+	default y
+
+config WATCH_QUEUE
+	bool "General notification queue"
+	default n
+	help
+
+	  This is a general notification queue for the kernel to pass events to
+	  userspace by splicing them into pipes.  It can be used in conjunction
+	  with watches for key/keyring change notifications and device
+	  notifications.
+
+	  See Documentation/core-api/watch_queue.rst
+
+config CROSS_MEMORY_ATTACH
+	bool "Enable process_vm_readv/writev syscalls"
+	depends on MMU
+	default y
+	help
+	  Enabling this option adds the system calls process_vm_readv and
+	  process_vm_writev which allow a process with the correct privileges
+	  to directly read from or write to another process' address space.
+	  See the man page for more details.
+
+config USELIB
+	bool "uselib syscall (for libc5 and earlier)"
+	default ALPHA || M68K || SPARC
+	help
+	  This option enables the uselib syscall, a system call used in the
+	  dynamic linker from libc5 and earlier.  glibc does not use this
+	  system call.  If you intend to run programs built on libc5 or
+	  earlier, you may need to enable this syscall.  Current systems
+	  running glibc can safely disable this.
+
+config AUDIT
+	bool "Auditing support"
+	depends on NET
+	help
+	  Enable auditing infrastructure that can be used with another
+	  kernel subsystem, such as SELinux (which requires this for
+	  logging of avc messages output).  System call auditing is included
+	  on architectures which support it.
+
+config HAVE_ARCH_AUDITSYSCALL
+	bool
+
+config AUDITSYSCALL
+	def_bool y
+	depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
+	select FSNOTIFY
+
+source "kernel/irq/Kconfig"
+source "kernel/time/Kconfig"
+source "kernel/bpf/Kconfig"
+source "kernel/Kconfig.preempt"
+
+menu "CPU/Task time and stats accounting"
+
+config VIRT_CPU_ACCOUNTING
+	bool
+
+choice
+	prompt "Cputime accounting"
+	default TICK_CPU_ACCOUNTING
+
+# Kind of a stub config for the pure tick based cputime accounting
+config TICK_CPU_ACCOUNTING
+	bool "Simple tick based cputime accounting"
+	depends on !S390 && !NO_HZ_FULL
+	help
+	  This is the basic tick based cputime accounting that maintains
+	  statistics about user, system and idle time spent on per jiffies
+	  granularity.
+
+	  If unsure, say Y.
+
+config VIRT_CPU_ACCOUNTING_NATIVE
+	bool "Deterministic task and CPU time accounting"
+	depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
+	select VIRT_CPU_ACCOUNTING
+	help
+	  Select this option to enable more accurate task and CPU time
+	  accounting.  This is done by reading a CPU counter on each
+	  kernel entry and exit and on transitions within the kernel
+	  between system, softirq and hardirq state, so there is a
+	  small performance impact.  In the case of s390 or IBM POWER > 5,
+	  this also enables accounting of stolen time on logically-partitioned
+	  systems.
+
+config VIRT_CPU_ACCOUNTING_GEN
+	bool "Full dynticks CPU time accounting"
+	depends on HAVE_CONTEXT_TRACKING_USER
+	depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
+	depends on GENERIC_CLOCKEVENTS
+	select VIRT_CPU_ACCOUNTING
+	select CONTEXT_TRACKING_USER
+	help
+	  Select this option to enable task and CPU time accounting on full
+	  dynticks systems. This accounting is implemented by watching every
+	  kernel-user boundaries using the context tracking subsystem.
+	  The accounting is thus performed at the expense of some significant
+	  overhead.
+
+	  For now this is only useful if you are working on the full
+	  dynticks subsystem development.
+
+	  If unsure, say N.
+
+endchoice
+
+config IRQ_TIME_ACCOUNTING
+	bool "Fine granularity task level IRQ time accounting"
+	depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
+	help
+	  Select this option to enable fine granularity task irq time
+	  accounting. This is done by reading a timestamp on each
+	  transitions between softirq and hardirq state, so there can be a
+	  small performance impact.
+
+	  If in doubt, say N here.
+
+config HAVE_SCHED_AVG_IRQ
+	def_bool y
+	depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
+	depends on SMP
+
+config SCHED_THERMAL_PRESSURE
+	bool
+	default y if ARM && ARM_CPU_TOPOLOGY
+	default y if ARM64
+	depends on SMP
+	depends on CPU_FREQ_THERMAL
+	help
+	  Select this option to enable thermal pressure accounting in the
+	  scheduler. Thermal pressure is the value conveyed to the scheduler
+	  that reflects the reduction in CPU compute capacity resulted from
+	  thermal throttling. Thermal throttling occurs when the performance of
+	  a CPU is capped due to high operating temperatures.
+
+	  If selected, the scheduler will be able to balance tasks accordingly,
+	  i.e. put less load on throttled CPUs than on non/less throttled ones.
+
+	  This requires the architecture to implement
+	  arch_update_thermal_pressure() and arch_scale_thermal_pressure().
+
+config BSD_PROCESS_ACCT
+	bool "BSD Process Accounting"
+	depends on MULTIUSER
+	help
+	  If you say Y here, a user level program will be able to instruct the
+	  kernel (via a special system call) to write process accounting
+	  information to a file: whenever a process exits, information about
+	  that process will be appended to the file by the kernel.  The
+	  information includes things such as creation time, owning user,
+	  command name, memory usage, controlling terminal etc. (the complete
+	  list is in the struct acct in <file:include/linux/acct.h>).  It is
+	  up to the user level program to do useful things with this
+	  information.  This is generally a good idea, so say Y.
+
+config BSD_PROCESS_ACCT_V3
+	bool "BSD Process Accounting version 3 file format"
+	depends on BSD_PROCESS_ACCT
+	default n
+	help
+	  If you say Y here, the process accounting information is written
+	  in a new file format that also logs the process IDs of each
+	  process and its parent. Note that this file format is incompatible
+	  with previous v0/v1/v2 file formats, so you will need updated tools
+	  for processing it. A preliminary version of these tools is available
+	  at <http://www.gnu.org/software/acct/>.
+
+config TASKSTATS
+	bool "Export task/process statistics through netlink"
+	depends on NET
+	depends on MULTIUSER
+	default n
+	help
+	  Export selected statistics for tasks/processes through the
+	  generic netlink interface. Unlike BSD process accounting, the
+	  statistics are available during the lifetime of tasks/processes as
+	  responses to commands. Like BSD accounting, they are sent to user
+	  space on task exit.
+
+	  Say N if unsure.
+
+config TASK_DELAY_ACCT
+	bool "Enable per-task delay accounting"
+	depends on TASKSTATS
+	select SCHED_INFO
+	help
+	  Collect information on time spent by a task waiting for system
+	  resources like cpu, synchronous block I/O completion and swapping
+	  in pages. Such statistics can help in setting a task's priorities
+	  relative to other tasks for cpu, io, rss limits etc.
+
+	  Say N if unsure.
+
+config TASK_XACCT
+	bool "Enable extended accounting over taskstats"
+	depends on TASKSTATS
+	help
+	  Collect extended task accounting data and send the data
+	  to userland for processing over the taskstats interface.
+
+	  Say N if unsure.
+
+config TASK_IO_ACCOUNTING
+	bool "Enable per-task storage I/O accounting"
+	depends on TASK_XACCT
+	help
+	  Collect information on the number of bytes of storage I/O which this
+	  task has caused.
+
+	  Say N if unsure.
+
+config PSI
+	bool "Pressure stall information tracking"
+	select KERNFS
+	help
+	  Collect metrics that indicate how overcommitted the CPU, memory,
+	  and IO capacity are in the system.
+
+	  If you say Y here, the kernel will create /proc/pressure/ with the
+	  pressure statistics files cpu, memory, and io. These will indicate
+	  the share of walltime in which some or all tasks in the system are
+	  delayed due to contention of the respective resource.
+
+	  In kernels with cgroup support, cgroups (cgroup2 only) will
+	  have cpu.pressure, memory.pressure, and io.pressure files,
+	  which aggregate pressure stalls for the grouped tasks only.
+
+	  For more details see Documentation/accounting/psi.rst.
+
+	  Say N if unsure.
+
+config PSI_DEFAULT_DISABLED
+	bool "Require boot parameter to enable pressure stall information tracking"
+	default n
+	depends on PSI
+	help
+	  If set, pressure stall information tracking will be disabled
+	  per default but can be enabled through passing psi=1 on the
+	  kernel commandline during boot.
+
+	  This feature adds some code to the task wakeup and sleep
+	  paths of the scheduler. The overhead is too low to affect
+	  common scheduling-intense workloads in practice (such as
+	  webservers, memcache), but it does show up in artificial
+	  scheduler stress tests, such as hackbench.
+
+	  If you are paranoid and not sure what the kernel will be
+	  used for, say Y.
+
+	  Say N if unsure.
+
+endmenu # "CPU/Task time and stats accounting"
+
+config CPU_ISOLATION
+	bool "CPU isolation"
+	depends on SMP || COMPILE_TEST
+	default y
+	help
+	  Make sure that CPUs running critical tasks are not disturbed by
+	  any source of "noise" such as unbound workqueues, timers, kthreads...
+	  Unbound jobs get offloaded to housekeeping CPUs. This is driven by
+	  the "isolcpus=" boot parameter.
+
+	  Say Y if unsure.
+
+source "kernel/rcu/Kconfig"
+
+config IKCONFIG
+	tristate "Kernel .config support"
+	help
+	  This option enables the complete Linux kernel ".config" file
+	  contents to be saved in the kernel. It provides documentation
+	  of which kernel options are used in a running kernel or in an
+	  on-disk kernel.  This information can be extracted from the kernel
+	  image file with the script scripts/extract-ikconfig and used as
+	  input to rebuild the current kernel or to build another kernel.
+	  It can also be extracted from a running kernel by reading
+	  /proc/config.gz if enabled (below).
+
+config IKCONFIG_PROC
+	bool "Enable access to .config through /proc/config.gz"
+	depends on IKCONFIG && PROC_FS
+	help
+	  This option enables access to the kernel configuration file
+	  through /proc/config.gz.
+
+config IKHEADERS
+	tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
+	depends on SYSFS
+	help
+	  This option enables access to the in-kernel headers that are generated during
+	  the build process. These can be used to build eBPF tracing programs,
+	  or similar programs.  If you build the headers as a module, a module called
+	  kheaders.ko is built which can be loaded on-demand to get access to headers.
+
+config LOG_BUF_SHIFT
+	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
+	range 12 25
+	default 17
+	depends on PRINTK
+	help
+	  Select the minimal kernel log buffer size as a power of 2.
+	  The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
+	  parameter, see below. Any higher size also might be forced
+	  by "log_buf_len" boot parameter.
+
+	  Examples:
+		     17 => 128 KB
+		     16 => 64 KB
+		     15 => 32 KB
+		     14 => 16 KB
+		     13 =>  8 KB
+		     12 =>  4 KB
+
+config LOG_CPU_MAX_BUF_SHIFT
+	int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
+	depends on SMP
+	range 0 21
+	default 12 if !BASE_SMALL
+	default 0 if BASE_SMALL
+	depends on PRINTK
+	help
+	  This option allows to increase the default ring buffer size
+	  according to the number of CPUs. The value defines the contribution
+	  of each CPU as a power of 2. The used space is typically only few
+	  lines however it might be much more when problems are reported,
+	  e.g. backtraces.
+
+	  The increased size means that a new buffer has to be allocated and
+	  the original static one is unused. It makes sense only on systems
+	  with more CPUs. Therefore this value is used only when the sum of
+	  contributions is greater than the half of the default kernel ring
+	  buffer as defined by LOG_BUF_SHIFT. The default values are set
+	  so that more than 16 CPUs are needed to trigger the allocation.
+
+	  Also this option is ignored when "log_buf_len" kernel parameter is
+	  used as it forces an exact (power of two) size of the ring buffer.
+
+	  The number of possible CPUs is used for this computation ignoring
+	  hotplugging making the computation optimal for the worst case
+	  scenario while allowing a simple algorithm to be used from bootup.
+
+	  Examples shift values and their meaning:
+		     17 => 128 KB for each CPU
+		     16 =>  64 KB for each CPU
+		     15 =>  32 KB for each CPU
+		     14 =>  16 KB for each CPU
+		     13 =>   8 KB for each CPU
+		     12 =>   4 KB for each CPU
+
+config PRINTK_INDEX
+	bool "Printk indexing debugfs interface"
+	depends on PRINTK && DEBUG_FS
+	help
+	  Add support for indexing of all printk formats known at compile time
+	  at <debugfs>/printk/index/<module>.
+
+	  This can be used as part of maintaining daemons which monitor
+	  /dev/kmsg, as it permits auditing the printk formats present in a
+	  kernel, allowing detection of cases where monitored printks are
+	  changed or no longer present.
+
+	  There is no additional runtime cost to printk with this enabled.
+
+#
+# Architectures with an unreliable sched_clock() should select this:
+#
+config HAVE_UNSTABLE_SCHED_CLOCK
+	bool
+
+config GENERIC_SCHED_CLOCK
+	bool
+
+menu "Scheduler features"
+
+config UCLAMP_TASK
+	bool "Enable utilization clamping for RT/FAIR tasks"
+	depends on CPU_FREQ_GOV_SCHEDUTIL
+	help
+	  This feature enables the scheduler to track the clamped utilization
+	  of each CPU based on RUNNABLE tasks scheduled on that CPU.
+
+	  With this option, the user can specify the min and max CPU
+	  utilization allowed for RUNNABLE tasks. The max utilization defines
+	  the maximum frequency a task should use while the min utilization
+	  defines the minimum frequency it should use.
+
+	  Both min and max utilization clamp values are hints to the scheduler,
+	  aiming at improving its frequency selection policy, but they do not
+	  enforce or grant any specific bandwidth for tasks.
+
+	  If in doubt, say N.
+
+config UCLAMP_BUCKETS_COUNT
+	int "Number of supported utilization clamp buckets"
+	range 5 20
+	default 5
+	depends on UCLAMP_TASK
+	help
+	  Defines the number of clamp buckets to use. The range of each bucket
+	  will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
+	  number of clamp buckets the finer their granularity and the higher
+	  the precision of clamping aggregation and tracking at run-time.
+
+	  For example, with the minimum configuration value we will have 5
+	  clamp buckets tracking 20% utilization each. A 25% boosted tasks will
+	  be refcounted in the [20..39]% bucket and will set the bucket clamp
+	  effective value to 25%.
+	  If a second 30% boosted task should be co-scheduled on the same CPU,
+	  that task will be refcounted in the same bucket of the first task and
+	  it will boost the bucket clamp effective value to 30%.
+	  The clamp effective value of a bucket is reset to its nominal value
+	  (20% in the example above) when there are no more tasks refcounted in
+	  that bucket.
+
+	  An additional boost/capping margin can be added to some tasks. In the
+	  example above the 25% task will be boosted to 30% until it exits the
+	  CPU. If that should be considered not acceptable on certain systems,
+	  it's always possible to reduce the margin by increasing the number of
+	  clamp buckets to trade off used memory for run-time tracking
+	  precision.
+
+	  If in doubt, use the default value.
+
+endmenu
+
+#
+# For architectures that want to enable the support for NUMA-affine scheduler
+# balancing logic:
+#
+config ARCH_SUPPORTS_NUMA_BALANCING
+	bool
+
+#
+# For architectures that prefer to flush all TLBs after a number of pages
+# are unmapped instead of sending one IPI per page to flush. The architecture
+# must provide guarantees on what happens if a clean TLB cache entry is
+# written after the unmap. Details are in mm/rmap.c near the check for
+# should_defer_flush. The architecture should also consider if the full flush
+# and the refill costs are offset by the savings of sending fewer IPIs.
+config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
+	bool
+
+config CC_HAS_INT128
+	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
+
+config CC_IMPLICIT_FALLTHROUGH
+	string
+	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
+	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
+
+# Currently, disable gcc-11+ array-bounds globally.
+# It's still broken in gcc-13, so no upper bound yet.
+config GCC11_NO_ARRAY_BOUNDS
+	def_bool y
+
+config CC_NO_ARRAY_BOUNDS
+	bool
+	default y if CC_IS_GCC && GCC_VERSION >= 110000 && GCC11_NO_ARRAY_BOUNDS
+
+#
+# For architectures that know their GCC __int128 support is sound
+#
+config ARCH_SUPPORTS_INT128
+	bool
+
+# For architectures that (ab)use NUMA to represent different memory regions
+# all cpu-local but of different latencies, such as SuperH.
+#
+config ARCH_WANT_NUMA_VARIABLE_LOCALITY
+	bool
+
+config NUMA_BALANCING
+	bool "Memory placement aware NUMA scheduler"
+	depends on ARCH_SUPPORTS_NUMA_BALANCING
+	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
+	depends on SMP && NUMA && MIGRATION && !PREEMPT_RT
+	help
+	  This option adds support for automatic NUMA aware memory/task placement.
+	  The mechanism is quite primitive and is based on migrating memory when
+	  it has references to the node the task is running on.
+
+	  This system will be inactive on UMA systems.
+
+config NUMA_BALANCING_DEFAULT_ENABLED
+	bool "Automatically enable NUMA aware memory/task placement"
+	default y
+	depends on NUMA_BALANCING
+	help
+	  If set, automatic NUMA balancing will be enabled if running on a NUMA
+	  machine.
+
+menuconfig CGROUPS
+	bool "Control Group support"
+	select KERNFS
+	help
+	  This option adds support for grouping sets of processes together, for
+	  use with process control subsystems such as Cpusets, CFS, memory
+	  controls or device isolation.
+	  See
+		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
+		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
+					  and resource control)
+
+	  Say N if unsure.
+
+if CGROUPS
+
+config PAGE_COUNTER
+	bool
+
+config CGROUP_FAVOR_DYNMODS
+        bool "Favor dynamic modification latency reduction by default"
+        help
+          This option enables the "favordynmods" mount option by default
+          which reduces the latencies of dynamic cgroup modifications such
+          as task migrations and controller on/offs at the cost of making
+          hot path operations such as forks and exits more expensive.
+
+          Say N if unsure.
+
+config MEMCG
+	bool "Memory controller"
+	select PAGE_COUNTER
+	select EVENTFD
+	help
+	  Provides control over the memory footprint of tasks in a cgroup.
+
+config MEMCG_KMEM
+	bool
+	depends on MEMCG
+	default y
+
+config BLK_CGROUP
+	bool "IO controller"
+	depends on BLOCK
+	default n
+	help
+	Generic block IO controller cgroup interface. This is the common
+	cgroup interface which should be used by various IO controlling
+	policies.
+
+	Currently, CFQ IO scheduler uses it to recognize task groups and
+	control disk bandwidth allocation (proportional time slice allocation)
+	to such task groups. It is also used by bio throttling logic in
+	block layer to implement upper limit in IO rates on a device.
+
+	This option only enables generic Block IO controller infrastructure.
+	One needs to also enable actual IO controlling logic/policy. For
+	enabling proportional weight division of disk bandwidth in CFQ, set
+	CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
+	CONFIG_BLK_DEV_THROTTLING=y.
+
+	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
+
+config CGROUP_WRITEBACK
+	bool
+	depends on MEMCG && BLK_CGROUP
+	default y
+
+menuconfig CGROUP_SCHED
+	bool "CPU controller"
+	default n
+	help
+	  This feature lets CPU scheduler recognize task groups and control CPU
+	  bandwidth allocation to such task groups. It uses cgroups to group
+	  tasks.
+
+if CGROUP_SCHED
+config FAIR_GROUP_SCHED
+	bool "Group scheduling for SCHED_OTHER"
+	depends on CGROUP_SCHED
+	default CGROUP_SCHED
+
+config CFS_BANDWIDTH
+	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
+	depends on FAIR_GROUP_SCHED
+	default n
+	help
+	  This option allows users to define CPU bandwidth rates (limits) for
+	  tasks running within the fair group scheduler.  Groups with no limit
+	  set are considered to be unconstrained and will run with no
+	  restriction.
+	  See Documentation/scheduler/sched-bwc.rst for more information.
+
+config RT_GROUP_SCHED
+	bool "Group scheduling for SCHED_RR/FIFO"
+	depends on CGROUP_SCHED
+	default n
+	help
+	  This feature lets you explicitly allocate real CPU bandwidth
+	  to task groups. If enabled, it will also make it impossible to
+	  schedule realtime tasks for non-root users until you allocate
+	  realtime bandwidth for them.
+	  See Documentation/scheduler/sched-rt-group.rst for more information.
+
+endif #CGROUP_SCHED
+
+config SCHED_MM_CID
+	def_bool y
+	depends on SMP && RSEQ
+
+config UCLAMP_TASK_GROUP
+	bool "Utilization clamping per group of tasks"
+	depends on CGROUP_SCHED
+	depends on UCLAMP_TASK
+	default n
+	help
+	  This feature enables the scheduler to track the clamped utilization
+	  of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
+
+	  When this option is enabled, the user can specify a min and max
+	  CPU bandwidth which is allowed for each single task in a group.
+	  The max bandwidth allows to clamp the maximum frequency a task
+	  can use, while the min bandwidth allows to define a minimum
+	  frequency a task will always use.
+
+	  When task group based utilization clamping is enabled, an eventually
+	  specified task-specific clamp value is constrained by the cgroup
+	  specified clamp value. Both minimum and maximum task clamping cannot
+	  be bigger than the corresponding clamping defined at task group level.
+
+	  If in doubt, say N.
+
+config CGROUP_PIDS
+	bool "PIDs controller"
+	help
+	  Provides enforcement of process number limits in the scope of a
+	  cgroup. Any attempt to fork more processes than is allowed in the
+	  cgroup will fail. PIDs are fundamentally a global resource because it
+	  is fairly trivial to reach PID exhaustion before you reach even a
+	  conservative kmemcg limit. As a result, it is possible to grind a
+	  system to halt without being limited by other cgroup policies. The
+	  PIDs controller is designed to stop this from happening.
+
+	  It should be noted that organisational operations (such as attaching
+	  to a cgroup hierarchy) will *not* be blocked by the PIDs controller,
+	  since the PIDs limit only affects a process's ability to fork, not to
+	  attach to a cgroup.
+
+config CGROUP_RDMA
+	bool "RDMA controller"
+	help
+	  Provides enforcement of RDMA resources defined by IB stack.
+	  It is fairly easy for consumers to exhaust RDMA resources, which
+	  can result into resource unavailability to other consumers.
+	  RDMA controller is designed to stop this from happening.
+	  Attaching processes with active RDMA resources to the cgroup
+	  hierarchy is allowed even if can cross the hierarchy's limit.
+
+config CGROUP_FREEZER
+	bool "Freezer controller"
+	help
+	  Provides a way to freeze and unfreeze all tasks in a
+	  cgroup.
+
+	  This option affects the ORIGINAL cgroup interface. The cgroup2 memory
+	  controller includes important in-kernel memory consumers per default.
+
+	  If you're using cgroup2, say N.
+
+config CGROUP_HUGETLB
+	bool "HugeTLB controller"
+	depends on HUGETLB_PAGE
+	select PAGE_COUNTER
+	default n
+	help
+	  Provides a cgroup controller for HugeTLB pages.
+	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
+	  The limit is enforced during page fault. Since HugeTLB doesn't
+	  support page reclaim, enforcing the limit at page fault time implies
+	  that, the application will get SIGBUS signal if it tries to access
+	  HugeTLB pages beyond its limit. This requires the application to know
+	  beforehand how much HugeTLB pages it would require for its use. The
+	  control group is tracked in the third page lru pointer. This means
+	  that we cannot use the controller with huge page less than 3 pages.
+
+config CPUSETS
+	bool "Cpuset controller"
+	depends on SMP
+	help
+	  This option will let you create and manage CPUSETs which
+	  allow dynamically partitioning a system into sets of CPUs and
+	  Memory Nodes and assigning tasks to run only within those sets.
+	  This is primarily useful on large SMP or NUMA systems.
+
+	  Say N if unsure.
+
+config PROC_PID_CPUSET
+	bool "Include legacy /proc/<pid>/cpuset file"
+	depends on CPUSETS
+	default y
+
+config CGROUP_DEVICE
+	bool "Device controller"
+	help
+	  Provides a cgroup controller implementing whitelists for
+	  devices which a process in the cgroup can mknod or open.
+
+config CGROUP_CPUACCT
+	bool "Simple CPU accounting controller"
+	help
+	  Provides a simple controller for monitoring the
+	  total CPU consumed by the tasks in a cgroup.
+
+config CGROUP_PERF
+	bool "Perf controller"
+	depends on PERF_EVENTS
+	help
+	  This option extends the perf per-cpu mode to restrict monitoring
+	  to threads which belong to the cgroup specified and run on the
+	  designated cpu.  Or this can be used to have cgroup ID in samples
+	  so that it can monitor performance events among cgroups.
+
+	  Say N if unsure.
+
+config CGROUP_BPF
+	bool "Support for eBPF programs attached to cgroups"
+	depends on BPF_SYSCALL
+	select SOCK_CGROUP_DATA
+	help
+	  Allow attaching eBPF programs to a cgroup using the bpf(2)
+	  syscall command BPF_PROG_ATTACH.
+
+	  In which context these programs are accessed depends on the type
+	  of attachment. For instance, programs that are attached using
+	  BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
+	  inet sockets.
+
+config CGROUP_MISC
+	bool "Misc resource controller"
+	default n
+	help
+	  Provides a controller for miscellaneous resources on a host.
+
+	  Miscellaneous scalar resources are the resources on the host system
+	  which cannot be abstracted like the other cgroups. This controller
+	  tracks and limits the miscellaneous resources used by a process
+	  attached to a cgroup hierarchy.
+
+	  For more information, please check misc cgroup section in
+	  /Documentation/admin-guide/cgroup-v2.rst.
+
+config CGROUP_DEBUG
+	bool "Debug controller"
+	default n
+	depends on DEBUG_KERNEL
+	help
+	  This option enables a simple controller that exports
+	  debugging information about the cgroups framework. This
+	  controller is for control cgroup debugging only. Its
+	  interfaces are not stable.
+
+	  Say N.
+
+config SOCK_CGROUP_DATA
+	bool
+	default n
+
+endif # CGROUPS
+
+menuconfig NAMESPACES
+	bool "Namespaces support" if EXPERT
+	depends on MULTIUSER
+	default !EXPERT
+	help
+	  Provides the way to make tasks work with different objects using
+	  the same id. For example same IPC id may refer to different objects
+	  or same user id or pid may refer to different tasks when used in
+	  different namespaces.
+
+if NAMESPACES
+
+config UTS_NS
+	bool "UTS namespace"
+	default y
+	help
+	  In this namespace tasks see different info provided with the
+	  uname() system call
+
+config TIME_NS
+	bool "TIME namespace"
+	depends on GENERIC_VDSO_TIME_NS
+	default y
+	help
+	  In this namespace boottime and monotonic clocks can be set.
+	  The time will keep going with the same pace.
+
+config IPC_NS
+	bool "IPC namespace"
+	depends on (SYSVIPC || POSIX_MQUEUE)
+	default y
+	help
+	  In this namespace tasks work with IPC ids which correspond to
+	  different IPC objects in different namespaces.
+
+config USER_NS
+	bool "User namespace"
+	default n
+	help
+	  This allows containers, i.e. vservers, to use user namespaces
+	  to provide different user info for different servers.
+
+	  When user namespaces are enabled in the kernel it is
+	  recommended that the MEMCG option also be enabled and that
+	  user-space use the memory control groups to limit the amount
+	  of memory a memory unprivileged users can use.
+
+	  If unsure, say N.
+
+config PID_NS
+	bool "PID Namespaces"
+	default y
+	help
+	  Support process id namespaces.  This allows having multiple
+	  processes with the same pid as long as they are in different
+	  pid namespaces.  This is a building block of containers.
+
+config NET_NS
+	bool "Network namespace"
+	depends on NET
+	default y
+	help
+	  Allow user space to create what appear to be multiple instances
+	  of the network stack.
+
+endif # NAMESPACES
+
+config CHECKPOINT_RESTORE
+	bool "Checkpoint/restore support"
+	depends on PROC_FS
+	select PROC_CHILDREN
+	select KCMP
+	default n
+	help
+	  Enables additional kernel features in a sake of checkpoint/restore.
+	  In particular it adds auxiliary prctl codes to setup process text,
+	  data and heap segment sizes, and a few additional /proc filesystem
+	  entries.
+
+	  If unsure, say N here.
+
+config SCHED_AUTOGROUP
+	bool "Automatic process group scheduling"
+	select CGROUPS
+	select CGROUP_SCHED
+	select FAIR_GROUP_SCHED
+	help
+	  This option optimizes the scheduler for common desktop workloads by
+	  automatically creating and populating task groups.  This separation
+	  of workloads isolates aggressive CPU burners (like build jobs) from
+	  desktop applications.  Task group autogeneration is currently based
+	  upon task session.
+
+config RELAY
+	bool "Kernel->user space relay support (formerly relayfs)"
+	select IRQ_WORK
+	help
+	  This option enables support for relay interface support in
+	  certain file systems (such as debugfs).
+	  It is designed to provide an efficient mechanism for tools and
+	  facilities to relay large amounts of data from kernel space to
+	  user space.
+
+	  If unsure, say N.
+
+config BLK_DEV_INITRD
+	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
+	help
+	  The initial RAM filesystem is a ramfs which is loaded by the
+	  boot loader (loadlin or lilo) and that is mounted as root
+	  before the normal boot procedure. It is typically used to
+	  load modules needed to mount the "real" root file system,
+	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
+
+	  If RAM disk support (BLK_DEV_RAM) is also included, this
+	  also enables initial RAM disk (initrd) support and adds
+	  15 Kbytes (more on some other architectures) to the kernel size.
+
+	  If unsure say Y.
+
+if BLK_DEV_INITRD
+
+source "usr/Kconfig"
+
+endif
+
+config BOOT_CONFIG
+	bool "Boot config support"
+	select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED
+	help
+	  Extra boot config allows system admin to pass a config file as
+	  complemental extension of kernel cmdline when booting.
+	  The boot config file must be attached at the end of initramfs
+	  with checksum, size and magic word.
+	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
+
+	  If unsure, say Y.
+
+config BOOT_CONFIG_FORCE
+	bool "Force unconditional bootconfig processing"
+	depends on BOOT_CONFIG
+	default y if BOOT_CONFIG_EMBED
+	help
+	  With this Kconfig option set, BOOT_CONFIG processing is carried
+	  out even when the "bootconfig" kernel-boot parameter is omitted.
+	  In fact, with this Kconfig option set, there is no way to
+	  make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
+	  parameters.
+
+	  If unsure, say N.
+
+config BOOT_CONFIG_EMBED
+	bool "Embed bootconfig file in the kernel"
+	depends on BOOT_CONFIG
+	help
+	  Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the
+	  kernel. Usually, the bootconfig file is loaded with the initrd
+	  image. But if the system doesn't support initrd, this option will
+	  help you by embedding a bootconfig file while building the kernel.
+
+	  If unsure, say N.
+
+config BOOT_CONFIG_EMBED_FILE
+	string "Embedded bootconfig file path"
+	depends on BOOT_CONFIG_EMBED
+	help
+	  Specify a bootconfig file which will be embedded to the kernel.
+	  This bootconfig will be used if there is no initrd or no other
+	  bootconfig in the initrd.
+
+config INITRAMFS_PRESERVE_MTIME
+	bool "Preserve cpio archive mtimes in initramfs"
+	default y
+	help
+	  Each entry in an initramfs cpio archive carries an mtime value. When
+	  enabled, extracted cpio items take this mtime, with directory mtime
+	  setting deferred until after creation of any child entries.
+
+	  If unsure, say Y.
+
+choice
+	prompt "Compiler optimization level"
+	default CC_OPTIMIZE_FOR_PERFORMANCE
+
+config CC_OPTIMIZE_FOR_PERFORMANCE
+	bool "Optimize for performance (-O2)"
+	help
+	  This is the default optimization level for the kernel, building
+	  with the "-O2" compiler flag for best performance and most
+	  helpful compile-time warnings.
+
+config CC_OPTIMIZE_FOR_SIZE
+	bool "Optimize for size (-Os)"
+	help
+	  Choosing this option will pass "-Os" to your compiler resulting
+	  in a smaller kernel.
+
+endchoice
+
+config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	bool
+	help
+	  This requires that the arch annotates or otherwise protects
+	  its external entry points from being discarded. Linker scripts
+	  must also merge .text.*, .data.*, and .bss.* correctly into
+	  output sections. Care must be taken not to pull in unrelated
+	  sections (e.g., '.text.init'). Typically '.' in section names
+	  is used to distinguish them from label names / C identifiers.
+
+config LD_DEAD_CODE_DATA_ELIMINATION
+	bool "Dead code and data elimination (EXPERIMENTAL)"
+	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	depends on EXPERT
+	depends on $(cc-option,-ffunction-sections -fdata-sections)
+	depends on $(ld-option,--gc-sections)
+	help
+	  Enable this if you want to do dead code and data elimination with
+	  the linker by compiling with -ffunction-sections -fdata-sections,
+	  and linking with --gc-sections.
+
+	  This can reduce on disk and in-memory size of the kernel
+	  code and static data, particularly for small configs and
+	  on small systems. This has the possibility of introducing
+	  silently broken kernel if the required annotations are not
+	  present. This option is not well tested yet, so use at your
+	  own risk.
+
+config LD_ORPHAN_WARN
+	def_bool y
+	depends on ARCH_WANT_LD_ORPHAN_WARN
+	depends on $(ld-option,--orphan-handling=warn)
+	depends on $(ld-option,--orphan-handling=error)
+
+config LD_ORPHAN_WARN_LEVEL
+        string
+        depends on LD_ORPHAN_WARN
+        default "error" if WERROR
+        default "warn"
+
+config SYSCTL
+	bool
+
+config HAVE_UID16
+	bool
+
+config SYSCTL_EXCEPTION_TRACE
+	bool
+	help
+	  Enable support for /proc/sys/debug/exception-trace.
+
+config SYSCTL_ARCH_UNALIGN_NO_WARN
+	bool
+	help
+	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
+	  Allows arch to define/use @no_unaligned_warning to possibly warn
+	  about unaligned access emulation going on under the hood.
+
+config SYSCTL_ARCH_UNALIGN_ALLOW
+	bool
+	help
+	  Enable support for /proc/sys/kernel/unaligned-trap
+	  Allows arches to define/use @unaligned_enabled to runtime toggle
+	  the unaligned access emulation.
+	  see arch/parisc/kernel/unaligned.c for reference
+
+config HAVE_PCSPKR_PLATFORM
+	bool
+
+# interpreter that classic socket filters depend on
+config BPF
+	bool
+	select CRYPTO_LIB_SHA1
+
+menuconfig EXPERT
+	bool "Configure standard kernel features (expert users)"
+	# Unhide debug options, to make the on-by-default options visible
+	select DEBUG_KERNEL
+	help
+	  This option allows certain base kernel options and settings
+	  to be disabled or tweaked. This is for specialized
+	  environments which can tolerate a "non-standard" kernel.
+	  Only use this if you really know what you are doing.
+
+config UID16
+	bool "Enable 16-bit UID system calls" if EXPERT
+	depends on HAVE_UID16 && MULTIUSER
+	default y
+	help
+	  This enables the legacy 16-bit UID syscall wrappers.
+
+config MULTIUSER
+	bool "Multiple users, groups and capabilities support" if EXPERT
+	default y
+	help
+	  This option enables support for non-root users, groups and
+	  capabilities.
+
+	  If you say N here, all processes will run with UID 0, GID 0, and all
+	  possible capabilities.  Saying N here also compiles out support for
+	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
+	  setgid, and capset.
+
+	  If unsure, say Y here.
+
+config SGETMASK_SYSCALL
+	bool "sgetmask/ssetmask syscalls support" if EXPERT
+	def_bool PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
+	help
+	  sys_sgetmask and sys_ssetmask are obsolete system calls
+	  no longer supported in libc but still enabled by default in some
+	  architectures.
+
+	  If unsure, leave the default option here.
+
+config SYSFS_SYSCALL
+	bool "Sysfs syscall support" if EXPERT
+	default y
+	help
+	  sys_sysfs is an obsolete system call no longer supported in libc.
+	  Note that disabling this option is more secure but might break
+	  compatibility with some systems.
+
+	  If unsure say Y here.
+
+config FHANDLE
+	bool "open by fhandle syscalls" if EXPERT
+	select EXPORTFS
+	default y
+	help
+	  If you say Y here, a user level program will be able to map
+	  file names to handle and then later use the handle for
+	  different file system operations. This is useful in implementing
+	  userspace file servers, which now track files using handles instead
+	  of names. The handle would remain the same even if file names
+	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
+	  syscalls.
+
+config POSIX_TIMERS
+	bool "Posix Clocks & timers" if EXPERT
+	default y
+	help
+	  This includes native support for POSIX timers to the kernel.
+	  Some embedded systems have no use for them and therefore they
+	  can be configured out to reduce the size of the kernel image.
+
+	  When this option is disabled, the following syscalls won't be
+	  available: timer_create, timer_gettime: timer_getoverrun,
+	  timer_settime, timer_delete, clock_adjtime, getitimer,
+	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
+	  clock_getres and clock_nanosleep syscalls will be limited to
+	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
+
+	  If unsure say y.
+
+config PRINTK
+	default y
+	bool "Enable support for printk" if EXPERT
+	select IRQ_WORK
+	help
+	  This option enables normal printk support. Removing it
+	  eliminates most of the message strings from the kernel image
+	  and makes the kernel more or less silent. As this makes it
+	  very difficult to diagnose system problems, saying N here is
+	  strongly discouraged.
+
+config BUG
+	bool "BUG() support" if EXPERT
+	default y
+	help
+	  Disabling this option eliminates support for BUG and WARN, reducing
+	  the size of your kernel image and potentially quietly ignoring
+	  numerous fatal conditions. You should only consider disabling this
+	  option for embedded systems with no facilities for reporting errors.
+	  Just say Y.
+
+config ELF_CORE
+	depends on COREDUMP
+	default y
+	bool "Enable ELF core dumps" if EXPERT
+	help
+	  Enable support for generating core dumps. Disabling saves about 4k.
+
+
+config PCSPKR_PLATFORM
+	bool "Enable PC-Speaker support" if EXPERT
+	depends on HAVE_PCSPKR_PLATFORM
+	select I8253_LOCK
+	default y
+	help
+	  This option allows to disable the internal PC-Speaker
+	  support, saving some memory.
+
+config BASE_FULL
+	default y
+	bool "Enable full-sized data structures for core" if EXPERT
+	help
+	  Disabling this option reduces the size of miscellaneous core
+	  kernel data structures. This saves memory on small machines,
+	  but may reduce performance.
+
+config FUTEX
+	bool "Enable futex support" if EXPERT
+	depends on !(SPARC32 && SMP)
+	default y
+	imply RT_MUTEXES
+	help
+	  Disabling this option will cause the kernel to be built without
+	  support for "fast userspace mutexes".  The resulting kernel may not
+	  run glibc-based applications correctly.
+
+config FUTEX_PI
+	bool
+	depends on FUTEX && RT_MUTEXES
+	default y
+
+config EPOLL
+	bool "Enable eventpoll support" if EXPERT
+	default y
+	help
+	  Disabling this option will cause the kernel to be built without
+	  support for epoll family of system calls.
+
+config SIGNALFD
+	bool "Enable signalfd() system call" if EXPERT
+	default y
+	help
+	  Enable the signalfd() system call that allows to receive signals
+	  on a file descriptor.
+
+	  If unsure, say Y.
+
+config TIMERFD
+	bool "Enable timerfd() system call" if EXPERT
+	default y
+	help
+	  Enable the timerfd() system call that allows to receive timer
+	  events on a file descriptor.
+
+	  If unsure, say Y.
+
+config EVENTFD
+	bool "Enable eventfd() system call" if EXPERT
+	default y
+	help
+	  Enable the eventfd() system call that allows to receive both
+	  kernel notification (ie. KAIO) or userspace notifications.
+
+	  If unsure, say Y.
+
+config SHMEM
+	bool "Use full shmem filesystem" if EXPERT
+	default y
+	depends on MMU
+	help
+	  The shmem is an internal filesystem used to manage shared memory.
+	  It is backed by swap and manages resource limits. It is also exported
+	  to userspace as tmpfs if TMPFS is enabled. Disabling this
+	  option replaces shmem and tmpfs with the much simpler ramfs code,
+	  which may be appropriate on small systems without swap.
+
+config AIO
+	bool "Enable AIO support" if EXPERT
+	default y
+	help
+	  This option enables POSIX asynchronous I/O which may by used
+	  by some high performance threaded applications. Disabling
+	  this option saves about 7k.
+
+config IO_URING
+	bool "Enable IO uring support" if EXPERT
+	select IO_WQ
+	default y
+	help
+	  This option enables support for the io_uring interface, enabling
+	  applications to submit and complete IO through submission and
+	  completion rings that are shared between the kernel and application.
+
+config ADVISE_SYSCALLS
+	bool "Enable madvise/fadvise syscalls" if EXPERT
+	default y
+	help
+	  This option enables the madvise and fadvise syscalls, used by
+	  applications to advise the kernel about their future memory or file
+	  usage, improving performance. If building an embedded system where no
+	  applications use these syscalls, you can disable this option to save
+	  space.
+
+config MEMBARRIER
+	bool "Enable membarrier() system call" if EXPERT
+	default y
+	help
+	  Enable the membarrier() system call that allows issuing memory
+	  barriers across all running threads, which can be used to distribute
+	  the cost of user-space memory barriers asymmetrically by transforming
+	  pairs of memory barriers into pairs consisting of membarrier() and a
+	  compiler barrier.
+
+	  If unsure, say Y.
+
+config KALLSYMS
+	bool "Load all symbols for debugging/ksymoops" if EXPERT
+	default y
+	help
+	  Say Y here to let the kernel print out symbolic crash information and
+	  symbolic stack backtraces. This increases the size of the kernel
+	  somewhat, as all symbols have to be loaded into the kernel image.
+
+config KALLSYMS_SELFTEST
+	bool "Test the basic functions and performance of kallsyms"
+	depends on KALLSYMS
+	default n
+	help
+	  Test the basic functions and performance of some interfaces, such as
+	  kallsyms_lookup_name. It also calculates the compression rate of the
+	  kallsyms compression algorithm for the current symbol set.
+
+	  Start self-test automatically after system startup. Suggest executing
+	  "dmesg | grep kallsyms_selftest" to collect test results. "finish" is
+	  displayed in the last line, indicating that the test is complete.
+
+config KALLSYMS_ALL
+	bool "Include all symbols in kallsyms"
+	depends on DEBUG_KERNEL && KALLSYMS
+	help
+	  Normally kallsyms only contains the symbols of functions for nicer
+	  OOPS messages and backtraces (i.e., symbols from the text and inittext
+	  sections). This is sufficient for most cases. And only if you want to
+	  enable kernel live patching, or other less common use cases (e.g.,
+	  when a debugger is used) all symbols are required (i.e., names of
+	  variables from the data sections, etc).
+
+	  This option makes sure that all symbols are loaded into the kernel
+	  image (i.e., symbols from all sections) in cost of increased kernel
+	  size (depending on the kernel configuration, it may be 300KiB or
+	  something like this).
+
+	  Say N unless you really need all symbols, or kernel live patching.
+
+config KALLSYMS_ABSOLUTE_PERCPU
+	bool
+	depends on KALLSYMS
+	default X86_64 && SMP
+
+config KALLSYMS_BASE_RELATIVE
+	bool
+	depends on KALLSYMS
+	default !IA64
+	help
+	  Instead of emitting them as absolute values in the native word size,
+	  emit the symbol references in the kallsyms table as 32-bit entries,
+	  each containing a relative value in the range [base, base + U32_MAX]
+	  or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either
+	  an absolute value in the range [0, S32_MAX] or a relative value in the
+	  range [base, base + S32_MAX], where base is the lowest relative symbol
+	  address encountered in the image.
+
+	  On 64-bit builds, this reduces the size of the address table by 50%,
+	  but more importantly, it results in entries whose values are build
+	  time constants, and no relocation pass is required at runtime to fix
+	  up the entries based on the runtime load address of the kernel.
+
+# end of the "standard kernel features (expert users)" menu
+
+# syscall, maps, verifier
+
+config ARCH_HAS_MEMBARRIER_CALLBACKS
+	bool
+
+config ARCH_HAS_MEMBARRIER_SYNC_CORE
+	bool
+
+config KCMP
+	bool "Enable kcmp() system call" if EXPERT
+	help
+	  Enable the kernel resource comparison system call. It provides
+	  user-space with the ability to compare two processes to see if they
+	  share a common resource, such as a file descriptor or even virtual
+	  memory space.
+
+	  If unsure, say N.
+
+config RSEQ
+	bool "Enable rseq() system call" if EXPERT
+	default y
+	depends on HAVE_RSEQ
+	select MEMBARRIER
+	help
+	  Enable the restartable sequences system call. It provides a
+	  user-space cache for the current CPU number value, which
+	  speeds up getting the current CPU number from user-space,
+	  as well as an ABI to speed up user-space operations on
+	  per-CPU data.
+
+	  If unsure, say Y.
+
+config CACHESTAT_SYSCALL
+	bool "Enable cachestat() system call" if EXPERT
+	default y
+	help
+	  Enable the cachestat system call, which queries the page cache
+	  statistics of a file (number of cached pages, dirty pages,
+	  pages marked for writeback, (recently) evicted pages).
+
+	  If unsure say Y here.
+
+config DEBUG_RSEQ
+	default n
+	bool "Enabled debugging of rseq() system call" if EXPERT
+	depends on RSEQ && DEBUG_KERNEL
+	help
+	  Enable extra debugging checks for the rseq system call.
+
+	  If unsure, say N.
+
+config HAVE_PERF_EVENTS
+	bool
+	help
+	  See tools/perf/design.txt for details.
+
+config GUEST_PERF_EVENTS
+	bool
+	depends on HAVE_PERF_EVENTS
+
+config PERF_USE_VMALLOC
+	bool
+	help
+	  See tools/perf/design.txt for details
+
+config PC104
+	bool "PC/104 support" if EXPERT
+	help
+	  Expose PC/104 form factor device drivers and options available for
+	  selection and configuration. Enable this option if your target
+	  machine has a PC/104 bus.
+
+menu "Kernel Performance Events And Counters"
+
+config PERF_EVENTS
+	bool "Kernel performance events and counters"
+	default y if PROFILING
+	depends on HAVE_PERF_EVENTS
+	select IRQ_WORK
+	help
+	  Enable kernel support for various performance events provided
+	  by software and hardware.
+
+	  Software events are supported either built-in or via the
+	  use of generic tracepoints.
+
+	  Most modern CPUs support performance events via performance
+	  counter registers. These registers count the number of certain
+	  types of hw events: such as instructions executed, cachemisses
+	  suffered, or branches mis-predicted - without slowing down the
+	  kernel or applications. These registers can also trigger interrupts
+	  when a threshold number of events have passed - and can thus be
+	  used to profile the code that runs on that CPU.
+
+	  The Linux Performance Event subsystem provides an abstraction of
+	  these software and hardware event capabilities, available via a
+	  system call and used by the "perf" utility in tools/perf/. It
+	  provides per task and per CPU counters, and it provides event
+	  capabilities on top of those.
+
+	  Say Y if unsure.
+
+config DEBUG_PERF_USE_VMALLOC
+	default n
+	bool "Debug: use vmalloc to back perf mmap() buffers"
+	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
+	select PERF_USE_VMALLOC
+	help
+	  Use vmalloc memory to back perf mmap() buffers.
+
+	  Mostly useful for debugging the vmalloc code on platforms
+	  that don't require it.
+
+	  Say N if unsure.
+
+endmenu
+
+config SYSTEM_DATA_VERIFICATION
+	def_bool n
+	select SYSTEM_TRUSTED_KEYRING
+	select KEYS
+	select CRYPTO
+	select CRYPTO_RSA
+	select ASYMMETRIC_KEY_TYPE
+	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+	select ASN1
+	select OID_REGISTRY
+	select X509_CERTIFICATE_PARSER
+	select PKCS7_MESSAGE_PARSER
+	help
+	  Provide PKCS#7 message verification using the contents of the system
+	  trusted keyring to provide public keys.  This then can be used for
+	  module verification, kexec image verification and firmware blob
+	  verification.
+
+config PROFILING
+	bool "Profiling support"
+	help
+	  Say Y here to enable the extended profiling support mechanisms used
+	  by profilers.
+
+config RUST
+	bool "Rust support"
+	depends on HAVE_RUST
+	depends on RUST_IS_AVAILABLE
+	depends on !MODVERSIONS
+	depends on !GCC_PLUGINS
+	depends on !RANDSTRUCT
+	depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE
+	select CONSTRUCTORS
+	help
+	  Enables Rust support in the kernel.
+
+	  This allows other Rust-related options, like drivers written in Rust,
+	  to be selected.
+
+	  It is also required to be able to load external kernel modules
+	  written in Rust.
+
+	  See Documentation/rust/ for more information.
+
+	  If unsure, say N.
+
+config RUSTC_VERSION_TEXT
+	string
+	depends on RUST
+	default $(shell,command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n)
+
+config BINDGEN_VERSION_TEXT
+	string
+	depends on RUST
+	default $(shell,command -v $(BINDGEN) >/dev/null 2>&1 && $(BINDGEN) --version || echo n)
+
+#
+# Place an empty function call at each tracepoint site. Can be
+# dynamically changed for a probe function.
+#
+config TRACEPOINTS
+	bool
+
+source "kernel/Kconfig.kexec"
+
+endmenu		# General setup
+
+source "arch/Kconfig"
+
+config RT_MUTEXES
+	bool
+	default y if PREEMPT_RT
+
+config BASE_SMALL
+	int
+	default 0 if BASE_FULL
+	default 1 if !BASE_FULL
+
+config MODULE_SIG_FORMAT
+	def_bool n
+	select SYSTEM_DATA_VERIFICATION
+
+source "kernel/module/Kconfig"
+
+config INIT_ALL_POSSIBLE
+	bool
+	help
+	  Back when each arch used to define their own cpu_online_mask and
+	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
+	  with all 1s, and others with all 0s.  When they were centralised,
+	  it was better to provide this option than to break all the archs
+	  and have several arch maintainers pursuing me down dark alleys.
+
+source "block/Kconfig"
+
+config PREEMPT_NOTIFIERS
+	bool
+
+config PADATA
+	depends on SMP
+	bool
+
+config ASN1
+	tristate
+	help
+	  Build a simple ASN.1 grammar compiler that produces a bytecode output
+	  that can be interpreted by the ASN.1 stream decoder and used to
+	  inform it as to what tags are to be expected in a stream and what
+	  functions to call on what tags.
+
+source "kernel/Kconfig.locks"
+
+config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+	bool
+
+config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
+	bool
+
+# It may be useful for an architecture to override the definitions of the
+# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
+# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
+# different calling convention for syscalls. They can also override the
+# macros for not-implemented syscalls in kernel/sys_ni.c and
+# kernel/time/posix-stubs.c. All these overrides need to be available in
+# <asm/syscall_wrapper.h>.
+config ARCH_HAS_SYSCALL_WRAPPER
+	def_bool n
diff --git a/init/Makefile b/init/Makefile
new file mode 100644
index 0000000000..cbac576c57
--- /dev/null
+++ b/init/Makefile
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+
+ccflags-y := -fno-function-sections -fno-data-sections
+
+obj-y                          := main.o version.o mounts.o
+ifneq ($(CONFIG_BLK_DEV_INITRD),y)
+obj-y                          += noinitramfs.o
+else
+obj-$(CONFIG_BLK_DEV_INITRD)   += initramfs.o
+endif
+obj-$(CONFIG_GENERIC_CALIBRATE_DELAY) += calibrate.o
+
+obj-y                          += init_task.o
+
+mounts-y			:= do_mounts.o
+mounts-$(CONFIG_BLK_DEV_RAM)	+= do_mounts_rd.o
+mounts-$(CONFIG_BLK_DEV_INITRD)	+= do_mounts_initrd.o
+
+#
+# UTS_VERSION
+#
+
+smp-flag-$(CONFIG_SMP)			:= SMP
+preempt-flag-$(CONFIG_PREEMPT_BUILD)	:= PREEMPT
+preempt-flag-$(CONFIG_PREEMPT_DYNAMIC)	:= PREEMPT_DYNAMIC
+preempt-flag-$(CONFIG_PREEMPT_RT)	:= PREEMPT_RT
+
+build-version = $(or $(KBUILD_BUILD_VERSION), $(build-version-auto))
+build-timestamp = $(or $(KBUILD_BUILD_TIMESTAMP), $(build-timestamp-auto))
+
+# Maximum length of UTS_VERSION is 64 chars
+filechk_uts_version = \
+	utsver=$$(echo '$(pound)'"$(build-version)" $(smp-flag-y) $(preempt-flag-y) "$(build-timestamp)" | cut -b -64); \
+	echo '$(pound)'define UTS_VERSION \""$${utsver}"\"
+
+#
+# Build version.c with temporary UTS_VERSION
+#
+
+$(obj)/utsversion-tmp.h: FORCE
+	$(call filechk,uts_version)
+
+clean-files += utsversion-tmp.h
+
+$(obj)/version.o: $(obj)/utsversion-tmp.h
+CFLAGS_version.o := -include $(obj)/utsversion-tmp.h
+
+#
+# Build version-timestamp.c with final UTS_VERSION
+#
+
+include/generated/utsversion.h: build-version-auto = $(shell $(srctree)/$(src)/build-version)
+include/generated/utsversion.h: build-timestamp-auto = $(shell LC_ALL=C date)
+include/generated/utsversion.h: FORCE
+	$(call filechk,uts_version)
+
+$(obj)/version-timestamp.o: include/generated/utsversion.h
+CFLAGS_version-timestamp.o := -include include/generated/utsversion.h
+KASAN_SANITIZE_version-timestamp.o := n
+KCSAN_SANITIZE_version-timestamp.o := n
+GCOV_PROFILE_version-timestamp.o := n
diff --git a/init/build-version b/init/build-version
new file mode 100755
index 0000000000..537d458150
--- /dev/null
+++ b/init/build-version
@@ -0,0 +1,10 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+
+prev_ver=$(cat .version 2>/dev/null) &&
+ver=$(expr ${prev_ver} + 1 2>/dev/null) ||
+ver=1
+
+echo ${ver} > .version
+
+echo ${ver}
diff --git a/init/calibrate.c b/init/calibrate.c
new file mode 100644
index 0000000000..f3831272f1
--- /dev/null
+++ b/init/calibrate.c
@@ -0,0 +1,316 @@
+// SPDX-License-Identifier: GPL-2.0
+/* calibrate.c: default delay calibration
+ *
+ * Excised from init/main.c
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/timex.h>
+#include <linux/smp.h>
+#include <linux/percpu.h>
+
+unsigned long lpj_fine;
+unsigned long preset_lpj;
+static int __init lpj_setup(char *str)
+{
+	preset_lpj = simple_strtoul(str,NULL,0);
+	return 1;
+}
+
+__setup("lpj=", lpj_setup);
+
+#ifdef ARCH_HAS_READ_CURRENT_TIMER
+
+/* This routine uses the read_current_timer() routine and gets the
+ * loops per jiffy directly, instead of guessing it using delay().
+ * Also, this code tries to handle non-maskable asynchronous events
+ * (like SMIs)
+ */
+#define DELAY_CALIBRATION_TICKS			((HZ < 100) ? 1 : (HZ/100))
+#define MAX_DIRECT_CALIBRATION_RETRIES		5
+
+static unsigned long calibrate_delay_direct(void)
+{
+	unsigned long pre_start, start, post_start;
+	unsigned long pre_end, end, post_end;
+	unsigned long start_jiffies;
+	unsigned long timer_rate_min, timer_rate_max;
+	unsigned long good_timer_sum = 0;
+	unsigned long good_timer_count = 0;
+	unsigned long measured_times[MAX_DIRECT_CALIBRATION_RETRIES];
+	int max = -1; /* index of measured_times with max/min values or not set */
+	int min = -1;
+	int i;
+
+	if (read_current_timer(&pre_start) < 0 )
+		return 0;
+
+	/*
+	 * A simple loop like
+	 *	while ( jiffies < start_jiffies+1)
+	 *		start = read_current_timer();
+	 * will not do. As we don't really know whether jiffy switch
+	 * happened first or timer_value was read first. And some asynchronous
+	 * event can happen between these two events introducing errors in lpj.
+	 *
+	 * So, we do
+	 * 1. pre_start <- When we are sure that jiffy switch hasn't happened
+	 * 2. check jiffy switch
+	 * 3. start <- timer value before or after jiffy switch
+	 * 4. post_start <- When we are sure that jiffy switch has happened
+	 *
+	 * Note, we don't know anything about order of 2 and 3.
+	 * Now, by looking at post_start and pre_start difference, we can
+	 * check whether any asynchronous event happened or not
+	 */
+
+	for (i = 0; i < MAX_DIRECT_CALIBRATION_RETRIES; i++) {
+		pre_start = 0;
+		read_current_timer(&start);
+		start_jiffies = jiffies;
+		while (time_before_eq(jiffies, start_jiffies + 1)) {
+			pre_start = start;
+			read_current_timer(&start);
+		}
+		read_current_timer(&post_start);
+
+		pre_end = 0;
+		end = post_start;
+		while (time_before_eq(jiffies, start_jiffies + 1 +
+					       DELAY_CALIBRATION_TICKS)) {
+			pre_end = end;
+			read_current_timer(&end);
+		}
+		read_current_timer(&post_end);
+
+		timer_rate_max = (post_end - pre_start) /
+					DELAY_CALIBRATION_TICKS;
+		timer_rate_min = (pre_end - post_start) /
+					DELAY_CALIBRATION_TICKS;
+
+		/*
+		 * If the upper limit and lower limit of the timer_rate is
+		 * >= 12.5% apart, redo calibration.
+		 */
+		if (start >= post_end)
+			printk(KERN_NOTICE "calibrate_delay_direct() ignoring "
+					"timer_rate as we had a TSC wrap around"
+					" start=%lu >=post_end=%lu\n",
+				start, post_end);
+		if (start < post_end && pre_start != 0 && pre_end != 0 &&
+		    (timer_rate_max - timer_rate_min) < (timer_rate_max >> 3)) {
+			good_timer_count++;
+			good_timer_sum += timer_rate_max;
+			measured_times[i] = timer_rate_max;
+			if (max < 0 || timer_rate_max > measured_times[max])
+				max = i;
+			if (min < 0 || timer_rate_max < measured_times[min])
+				min = i;
+		} else
+			measured_times[i] = 0;
+
+	}
+
+	/*
+	 * Find the maximum & minimum - if they differ too much throw out the
+	 * one with the largest difference from the mean and try again...
+	 */
+	while (good_timer_count > 1) {
+		unsigned long estimate;
+		unsigned long maxdiff;
+
+		/* compute the estimate */
+		estimate = (good_timer_sum/good_timer_count);
+		maxdiff = estimate >> 3;
+
+		/* if range is within 12% let's take it */
+		if ((measured_times[max] - measured_times[min]) < maxdiff)
+			return estimate;
+
+		/* ok - drop the worse value and try again... */
+		good_timer_sum = 0;
+		good_timer_count = 0;
+		if ((measured_times[max] - estimate) <
+				(estimate - measured_times[min])) {
+			printk(KERN_NOTICE "calibrate_delay_direct() dropping "
+					"min bogoMips estimate %d = %lu\n",
+				min, measured_times[min]);
+			measured_times[min] = 0;
+			min = max;
+		} else {
+			printk(KERN_NOTICE "calibrate_delay_direct() dropping "
+					"max bogoMips estimate %d = %lu\n",
+				max, measured_times[max]);
+			measured_times[max] = 0;
+			max = min;
+		}
+
+		for (i = 0; i < MAX_DIRECT_CALIBRATION_RETRIES; i++) {
+			if (measured_times[i] == 0)
+				continue;
+			good_timer_count++;
+			good_timer_sum += measured_times[i];
+			if (measured_times[i] < measured_times[min])
+				min = i;
+			if (measured_times[i] > measured_times[max])
+				max = i;
+		}
+
+	}
+
+	printk(KERN_NOTICE "calibrate_delay_direct() failed to get a good "
+	       "estimate for loops_per_jiffy.\nProbably due to long platform "
+		"interrupts. Consider using \"lpj=\" boot option.\n");
+	return 0;
+}
+#else
+static unsigned long calibrate_delay_direct(void)
+{
+	return 0;
+}
+#endif
+
+/*
+ * This is the number of bits of precision for the loops_per_jiffy.  Each
+ * time we refine our estimate after the first takes 1.5/HZ seconds, so try
+ * to start with a good estimate.
+ * For the boot cpu we can skip the delay calibration and assign it a value
+ * calculated based on the timer frequency.
+ * For the rest of the CPUs we cannot assume that the timer frequency is same as
+ * the cpu frequency, hence do the calibration for those.
+ */
+#define LPS_PREC 8
+
+static unsigned long calibrate_delay_converge(void)
+{
+	/* First stage - slowly accelerate to find initial bounds */
+	unsigned long lpj, lpj_base, ticks, loopadd, loopadd_base, chop_limit;
+	int trials = 0, band = 0, trial_in_band = 0;
+
+	lpj = (1<<12);
+
+	/* wait for "start of" clock tick */
+	ticks = jiffies;
+	while (ticks == jiffies)
+		; /* nothing */
+	/* Go .. */
+	ticks = jiffies;
+	do {
+		if (++trial_in_band == (1<<band)) {
+			++band;
+			trial_in_band = 0;
+		}
+		__delay(lpj * band);
+		trials += band;
+	} while (ticks == jiffies);
+	/*
+	 * We overshot, so retreat to a clear underestimate. Then estimate
+	 * the largest likely undershoot. This defines our chop bounds.
+	 */
+	trials -= band;
+	loopadd_base = lpj * band;
+	lpj_base = lpj * trials;
+
+recalibrate:
+	lpj = lpj_base;
+	loopadd = loopadd_base;
+
+	/*
+	 * Do a binary approximation to get lpj set to
+	 * equal one clock (up to LPS_PREC bits)
+	 */
+	chop_limit = lpj >> LPS_PREC;
+	while (loopadd > chop_limit) {
+		lpj += loopadd;
+		ticks = jiffies;
+		while (ticks == jiffies)
+			; /* nothing */
+		ticks = jiffies;
+		__delay(lpj);
+		if (jiffies != ticks)	/* longer than 1 tick */
+			lpj -= loopadd;
+		loopadd >>= 1;
+	}
+	/*
+	 * If we incremented every single time possible, presume we've
+	 * massively underestimated initially, and retry with a higher
+	 * start, and larger range. (Only seen on x86_64, due to SMIs)
+	 */
+	if (lpj + loopadd * 2 == lpj_base + loopadd_base * 2) {
+		lpj_base = lpj;
+		loopadd_base <<= 2;
+		goto recalibrate;
+	}
+
+	return lpj;
+}
+
+static DEFINE_PER_CPU(unsigned long, cpu_loops_per_jiffy) = { 0 };
+
+/*
+ * Check if cpu calibration delay is already known. For example,
+ * some processors with multi-core sockets may have all cores
+ * with the same calibration delay.
+ *
+ * Architectures should override this function if a faster calibration
+ * method is available.
+ */
+unsigned long __attribute__((weak)) calibrate_delay_is_known(void)
+{
+	return 0;
+}
+
+/*
+ * Indicate the cpu delay calibration is done. This can be used by
+ * architectures to stop accepting delay timer registrations after this point.
+ */
+
+void __attribute__((weak)) calibration_delay_done(void)
+{
+}
+
+void calibrate_delay(void)
+{
+	unsigned long lpj;
+	static bool printed;
+	int this_cpu = smp_processor_id();
+
+	if (per_cpu(cpu_loops_per_jiffy, this_cpu)) {
+		lpj = per_cpu(cpu_loops_per_jiffy, this_cpu);
+		if (!printed)
+			pr_info("Calibrating delay loop (skipped) "
+				"already calibrated this CPU");
+	} else if (preset_lpj) {
+		lpj = preset_lpj;
+		if (!printed)
+			pr_info("Calibrating delay loop (skipped) "
+				"preset value.. ");
+	} else if ((!printed) && lpj_fine) {
+		lpj = lpj_fine;
+		pr_info("Calibrating delay loop (skipped), "
+			"value calculated using timer frequency.. ");
+	} else if ((lpj = calibrate_delay_is_known())) {
+		;
+	} else if ((lpj = calibrate_delay_direct()) != 0) {
+		if (!printed)
+			pr_info("Calibrating delay using timer "
+				"specific routine.. ");
+	} else {
+		if (!printed)
+			pr_info("Calibrating delay loop... ");
+		lpj = calibrate_delay_converge();
+	}
+	per_cpu(cpu_loops_per_jiffy, this_cpu) = lpj;
+	if (!printed)
+		pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
+			lpj/(500000/HZ),
+			(lpj/(5000/HZ)) % 100, lpj);
+
+	loops_per_jiffy = lpj;
+	printed = true;
+
+	calibration_delay_done();
+}
diff --git a/init/do_mounts.c b/init/do_mounts.c
new file mode 100644
index 0000000000..21d065a55a
--- /dev/null
+++ b/init/do_mounts.c
@@ -0,0 +1,519 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/ctype.h>
+#include <linux/fd.h>
+#include <linux/tty.h>
+#include <linux/suspend.h>
+#include <linux/root_dev.h>
+#include <linux/security.h>
+#include <linux/delay.h>
+#include <linux/mount.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/initrd.h>
+#include <linux/async.h>
+#include <linux/fs_struct.h>
+#include <linux/slab.h>
+#include <linux/ramfs.h>
+#include <linux/shmem_fs.h>
+#include <linux/ktime.h>
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_fs_sb.h>
+#include <linux/nfs_mount.h>
+#include <linux/raid/detect.h>
+#include <uapi/linux/mount.h>
+
+#include "do_mounts.h"
+
+int root_mountflags = MS_RDONLY | MS_SILENT;
+static char __initdata saved_root_name[64];
+static int root_wait;
+
+dev_t ROOT_DEV;
+
+static int __init load_ramdisk(char *str)
+{
+	pr_warn("ignoring the deprecated load_ramdisk= option\n");
+	return 1;
+}
+__setup("load_ramdisk=", load_ramdisk);
+
+static int __init readonly(char *str)
+{
+	if (*str)
+		return 0;
+	root_mountflags |= MS_RDONLY;
+	return 1;
+}
+
+static int __init readwrite(char *str)
+{
+	if (*str)
+		return 0;
+	root_mountflags &= ~MS_RDONLY;
+	return 1;
+}
+
+__setup("ro", readonly);
+__setup("rw", readwrite);
+
+static int __init root_dev_setup(char *line)
+{
+	strscpy(saved_root_name, line, sizeof(saved_root_name));
+	return 1;
+}
+
+__setup("root=", root_dev_setup);
+
+static int __init rootwait_setup(char *str)
+{
+	if (*str)
+		return 0;
+	root_wait = -1;
+	return 1;
+}
+
+__setup("rootwait", rootwait_setup);
+
+static int __init rootwait_timeout_setup(char *str)
+{
+	int sec;
+
+	if (kstrtoint(str, 0, &sec) || sec < 0) {
+		pr_warn("ignoring invalid rootwait value\n");
+		goto ignore;
+	}
+
+	if (check_mul_overflow(sec, MSEC_PER_SEC, &root_wait)) {
+		pr_warn("ignoring excessive rootwait value\n");
+		goto ignore;
+	}
+
+	return 1;
+
+ignore:
+	/* Fallback to indefinite wait */
+	root_wait = -1;
+
+	return 1;
+}
+
+__setup("rootwait=", rootwait_timeout_setup);
+
+static char * __initdata root_mount_data;
+static int __init root_data_setup(char *str)
+{
+	root_mount_data = str;
+	return 1;
+}
+
+static char * __initdata root_fs_names;
+static int __init fs_names_setup(char *str)
+{
+	root_fs_names = str;
+	return 1;
+}
+
+static unsigned int __initdata root_delay;
+static int __init root_delay_setup(char *str)
+{
+	root_delay = simple_strtoul(str, NULL, 0);
+	return 1;
+}
+
+__setup("rootflags=", root_data_setup);
+__setup("rootfstype=", fs_names_setup);
+__setup("rootdelay=", root_delay_setup);
+
+/* This can return zero length strings. Caller should check */
+static int __init split_fs_names(char *page, size_t size)
+{
+	int count = 1;
+	char *p = page;
+
+	strscpy(p, root_fs_names, size);
+	while (*p++) {
+		if (p[-1] == ',') {
+			p[-1] = '\0';
+			count++;
+		}
+	}
+
+	return count;
+}
+
+static int __init do_mount_root(const char *name, const char *fs,
+				 const int flags, const void *data)
+{
+	struct super_block *s;
+	struct page *p = NULL;
+	char *data_page = NULL;
+	int ret;
+
+	if (data) {
+		/* init_mount() requires a full page as fifth argument */
+		p = alloc_page(GFP_KERNEL);
+		if (!p)
+			return -ENOMEM;
+		data_page = page_address(p);
+		/* zero-pad. init_mount() will make sure it's terminated */
+		strncpy(data_page, data, PAGE_SIZE);
+	}
+
+	ret = init_mount(name, "/root", fs, flags, data_page);
+	if (ret)
+		goto out;
+
+	init_chdir("/root");
+	s = current->fs->pwd.dentry->d_sb;
+	ROOT_DEV = s->s_dev;
+	printk(KERN_INFO
+	       "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
+	       s->s_type->name,
+	       sb_rdonly(s) ? " readonly" : "",
+	       MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
+
+out:
+	if (p)
+		put_page(p);
+	return ret;
+}
+
+void __init mount_root_generic(char *name, char *pretty_name, int flags)
+{
+	struct page *page = alloc_page(GFP_KERNEL);
+	char *fs_names = page_address(page);
+	char *p;
+	char b[BDEVNAME_SIZE];
+	int num_fs, i;
+
+	scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
+		  MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
+	if (root_fs_names)
+		num_fs = split_fs_names(fs_names, PAGE_SIZE);
+	else
+		num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
+retry:
+	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) {
+		int err;
+
+		if (!*p)
+			continue;
+		err = do_mount_root(name, p, flags, root_mount_data);
+		switch (err) {
+			case 0:
+				goto out;
+			case -EACCES:
+			case -EINVAL:
+				continue;
+		}
+	        /*
+		 * Allow the user to distinguish between failed sys_open
+		 * and bad superblock on root device.
+		 * and give them a list of the available devices
+		 */
+		printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
+				pretty_name, b, err);
+		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
+		printk_all_partitions();
+
+		if (root_fs_names)
+			num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
+		if (!num_fs)
+			pr_err("Can't find any bdev filesystem to be used for mount!\n");
+		else {
+			pr_err("List of all bdev filesystems:\n");
+			for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
+				pr_err(" %s", p);
+			pr_err("\n");
+		}
+
+		panic("VFS: Unable to mount root fs on %s", b);
+	}
+	if (!(flags & SB_RDONLY)) {
+		flags |= SB_RDONLY;
+		goto retry;
+	}
+
+	printk("List of all partitions:\n");
+	printk_all_partitions();
+	printk("No filesystem could mount root, tried: ");
+	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
+		printk(" %s", p);
+	printk("\n");
+	panic("VFS: Unable to mount root fs on %s", b);
+out:
+	put_page(page);
+}
+ 
+#ifdef CONFIG_ROOT_NFS
+
+#define NFSROOT_TIMEOUT_MIN	5
+#define NFSROOT_TIMEOUT_MAX	30
+#define NFSROOT_RETRY_MAX	5
+
+static void __init mount_nfs_root(void)
+{
+	char *root_dev, *root_data;
+	unsigned int timeout;
+	int try;
+
+	if (nfs_root_data(&root_dev, &root_data))
+		goto fail;
+
+	/*
+	 * The server or network may not be ready, so try several
+	 * times.  Stop after a few tries in case the client wants
+	 * to fall back to other boot methods.
+	 */
+	timeout = NFSROOT_TIMEOUT_MIN;
+	for (try = 1; ; try++) {
+		if (!do_mount_root(root_dev, "nfs", root_mountflags, root_data))
+			return;
+		if (try > NFSROOT_RETRY_MAX)
+			break;
+
+		/* Wait, in case the server refused us immediately */
+		ssleep(timeout);
+		timeout <<= 1;
+		if (timeout > NFSROOT_TIMEOUT_MAX)
+			timeout = NFSROOT_TIMEOUT_MAX;
+	}
+fail:
+	pr_err("VFS: Unable to mount root fs via NFS.\n");
+}
+#else
+static inline void mount_nfs_root(void)
+{
+}
+#endif /* CONFIG_ROOT_NFS */
+
+#ifdef CONFIG_CIFS_ROOT
+
+#define CIFSROOT_TIMEOUT_MIN	5
+#define CIFSROOT_TIMEOUT_MAX	30
+#define CIFSROOT_RETRY_MAX	5
+
+static void __init mount_cifs_root(void)
+{
+	char *root_dev, *root_data;
+	unsigned int timeout;
+	int try;
+
+	if (cifs_root_data(&root_dev, &root_data))
+		goto fail;
+
+	timeout = CIFSROOT_TIMEOUT_MIN;
+	for (try = 1; ; try++) {
+		if (!do_mount_root(root_dev, "cifs", root_mountflags,
+				   root_data))
+			return;
+		if (try > CIFSROOT_RETRY_MAX)
+			break;
+
+		ssleep(timeout);
+		timeout <<= 1;
+		if (timeout > CIFSROOT_TIMEOUT_MAX)
+			timeout = CIFSROOT_TIMEOUT_MAX;
+	}
+fail:
+	pr_err("VFS: Unable to mount root fs via SMB.\n");
+}
+#else
+static inline void mount_cifs_root(void)
+{
+}
+#endif /* CONFIG_CIFS_ROOT */
+
+static bool __init fs_is_nodev(char *fstype)
+{
+	struct file_system_type *fs = get_fs_type(fstype);
+	bool ret = false;
+
+	if (fs) {
+		ret = !(fs->fs_flags & FS_REQUIRES_DEV);
+		put_filesystem(fs);
+	}
+
+	return ret;
+}
+
+static int __init mount_nodev_root(char *root_device_name)
+{
+	char *fs_names, *fstype;
+	int err = -EINVAL;
+	int num_fs, i;
+
+	fs_names = (void *)__get_free_page(GFP_KERNEL);
+	if (!fs_names)
+		return -EINVAL;
+	num_fs = split_fs_names(fs_names, PAGE_SIZE);
+
+	for (i = 0, fstype = fs_names; i < num_fs;
+	     i++, fstype += strlen(fstype) + 1) {
+		if (!*fstype)
+			continue;
+		if (!fs_is_nodev(fstype))
+			continue;
+		err = do_mount_root(root_device_name, fstype, root_mountflags,
+				    root_mount_data);
+		if (!err)
+			break;
+	}
+
+	free_page((unsigned long)fs_names);
+	return err;
+}
+
+#ifdef CONFIG_BLOCK
+static void __init mount_block_root(char *root_device_name)
+{
+	int err = create_dev("/dev/root", ROOT_DEV);
+
+	if (err < 0)
+		pr_emerg("Failed to create /dev/root: %d\n", err);
+	mount_root_generic("/dev/root", root_device_name, root_mountflags);
+}
+#else
+static inline void mount_block_root(char *root_device_name)
+{
+}
+#endif /* CONFIG_BLOCK */
+
+void __init mount_root(char *root_device_name)
+{
+	switch (ROOT_DEV) {
+	case Root_NFS:
+		mount_nfs_root();
+		break;
+	case Root_CIFS:
+		mount_cifs_root();
+		break;
+	case Root_Generic:
+		mount_root_generic(root_device_name, root_device_name,
+				   root_mountflags);
+		break;
+	case 0:
+		if (root_device_name && root_fs_names &&
+		    mount_nodev_root(root_device_name) == 0)
+			break;
+		fallthrough;
+	default:
+		mount_block_root(root_device_name);
+		break;
+	}
+}
+
+/* wait for any asynchronous scanning to complete */
+static void __init wait_for_root(char *root_device_name)
+{
+	ktime_t end;
+
+	if (ROOT_DEV != 0)
+		return;
+
+	pr_info("Waiting for root device %s...\n", root_device_name);
+
+	end = ktime_add_ms(ktime_get_raw(), root_wait);
+
+	while (!driver_probe_done() ||
+	       early_lookup_bdev(root_device_name, &ROOT_DEV) < 0) {
+		msleep(5);
+		if (root_wait > 0 && ktime_after(ktime_get_raw(), end))
+			break;
+	}
+
+	async_synchronize_full();
+
+}
+
+static dev_t __init parse_root_device(char *root_device_name)
+{
+	int error;
+	dev_t dev;
+
+	if (!strncmp(root_device_name, "mtd", 3) ||
+	    !strncmp(root_device_name, "ubi", 3))
+		return Root_Generic;
+	if (strcmp(root_device_name, "/dev/nfs") == 0)
+		return Root_NFS;
+	if (strcmp(root_device_name, "/dev/cifs") == 0)
+		return Root_CIFS;
+	if (strcmp(root_device_name, "/dev/ram") == 0)
+		return Root_RAM0;
+
+	error = early_lookup_bdev(root_device_name, &dev);
+	if (error) {
+		if (error == -EINVAL && root_wait) {
+			pr_err("Disabling rootwait; root= is invalid.\n");
+			root_wait = 0;
+		}
+		return 0;
+	}
+	return dev;
+}
+
+/*
+ * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
+ */
+void __init prepare_namespace(void)
+{
+	if (root_delay) {
+		printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
+		       root_delay);
+		ssleep(root_delay);
+	}
+
+	/*
+	 * wait for the known devices to complete their probing
+	 *
+	 * Note: this is a potential source of long boot delays.
+	 * For example, it is not atypical to wait 5 seconds here
+	 * for the touchpad of a laptop to initialize.
+	 */
+	wait_for_device_probe();
+
+	md_run_setup();
+
+	if (saved_root_name[0])
+		ROOT_DEV = parse_root_device(saved_root_name);
+
+	if (initrd_load(saved_root_name))
+		goto out;
+
+	if (root_wait)
+		wait_for_root(saved_root_name);
+	mount_root(saved_root_name);
+out:
+	devtmpfs_mount();
+	init_mount(".", "/", NULL, MS_MOVE, NULL);
+	init_chroot(".");
+}
+
+static bool is_tmpfs;
+static int rootfs_init_fs_context(struct fs_context *fc)
+{
+	if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
+		return shmem_init_fs_context(fc);
+
+	return ramfs_init_fs_context(fc);
+}
+
+struct file_system_type rootfs_fs_type = {
+	.name		= "rootfs",
+	.init_fs_context = rootfs_init_fs_context,
+	.kill_sb	= kill_litter_super,
+};
+
+void __init init_rootfs(void)
+{
+	if (IS_ENABLED(CONFIG_TMPFS)) {
+		if (!saved_root_name[0] && !root_fs_names)
+			is_tmpfs = true;
+		else if (root_fs_names && !!strstr(root_fs_names, "tmpfs"))
+			is_tmpfs = true;
+	}
+}
diff --git a/init/do_mounts.h b/init/do_mounts.h
new file mode 100644
index 0000000000..15e372b00c
--- /dev/null
+++ b/init/do_mounts.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/syscalls.h>
+#include <linux/unistd.h>
+#include <linux/slab.h>
+#include <linux/mount.h>
+#include <linux/major.h>
+#include <linux/root_dev.h>
+#include <linux/init_syscalls.h>
+
+void  mount_root_generic(char *name, char *pretty_name, int flags);
+void  mount_root(char *root_device_name);
+extern int root_mountflags;
+
+static inline __init int create_dev(char *name, dev_t dev)
+{
+	init_unlink(name);
+	return init_mknod(name, S_IFBLK | 0600, new_encode_dev(dev));
+}
+
+#ifdef CONFIG_BLK_DEV_RAM
+
+int __init rd_load_disk(int n);
+int __init rd_load_image(char *from);
+
+#else
+
+static inline int rd_load_disk(int n) { return 0; }
+static inline int rd_load_image(char *from) { return 0; }
+
+#endif
+
+#ifdef CONFIG_BLK_DEV_INITRD
+bool __init initrd_load(char *root_device_name);
+#else
+static inline bool initrd_load(char *root_device_name)
+{
+	return false;
+	}
+
+#endif
diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
new file mode 100644
index 0000000000..425f4bcf4b
--- /dev/null
+++ b/init/do_mounts_initrd.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/unistd.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/minix_fs.h>
+#include <linux/romfs_fs.h>
+#include <linux/initrd.h>
+#include <linux/sched.h>
+#include <linux/freezer.h>
+#include <linux/kmod.h>
+#include <uapi/linux/mount.h>
+
+#include "do_mounts.h"
+
+unsigned long initrd_start, initrd_end;
+int initrd_below_start_ok;
+static unsigned int real_root_dev;	/* do_proc_dointvec cannot handle kdev_t */
+static int __initdata mount_initrd = 1;
+
+phys_addr_t phys_initrd_start __initdata;
+unsigned long phys_initrd_size __initdata;
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table kern_do_mounts_initrd_table[] = {
+	{
+		.procname       = "real-root-dev",
+		.data           = &real_root_dev,
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec,
+	},
+	{ }
+};
+
+static __init int kernel_do_mounts_initrd_sysctls_init(void)
+{
+	register_sysctl_init("kernel", kern_do_mounts_initrd_table);
+	return 0;
+}
+late_initcall(kernel_do_mounts_initrd_sysctls_init);
+#endif /* CONFIG_SYSCTL */
+
+static int __init no_initrd(char *str)
+{
+	mount_initrd = 0;
+	return 1;
+}
+
+__setup("noinitrd", no_initrd);
+
+static int __init early_initrdmem(char *p)
+{
+	phys_addr_t start;
+	unsigned long size;
+	char *endp;
+
+	start = memparse(p, &endp);
+	if (*endp == ',') {
+		size = memparse(endp + 1, NULL);
+
+		phys_initrd_start = start;
+		phys_initrd_size = size;
+	}
+	return 0;
+}
+early_param("initrdmem", early_initrdmem);
+
+static int __init early_initrd(char *p)
+{
+	return early_initrdmem(p);
+}
+early_param("initrd", early_initrd);
+
+static int __init init_linuxrc(struct subprocess_info *info, struct cred *new)
+{
+	ksys_unshare(CLONE_FS | CLONE_FILES);
+	console_on_rootfs();
+	/* move initrd over / and chdir/chroot in initrd root */
+	init_chdir("/root");
+	init_mount(".", "/", NULL, MS_MOVE, NULL);
+	init_chroot(".");
+	ksys_setsid();
+	return 0;
+}
+
+static void __init handle_initrd(char *root_device_name)
+{
+	struct subprocess_info *info;
+	static char *argv[] = { "linuxrc", NULL, };
+	extern char *envp_init[];
+	int error;
+
+	pr_warn("using deprecated initrd support, will be removed in 2021.\n");
+
+	real_root_dev = new_encode_dev(ROOT_DEV);
+	create_dev("/dev/root.old", Root_RAM0);
+	/* mount initrd on rootfs' /root */
+	mount_root_generic("/dev/root.old", root_device_name,
+			   root_mountflags & ~MS_RDONLY);
+	init_mkdir("/old", 0700);
+	init_chdir("/old");
+
+	info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
+					 GFP_KERNEL, init_linuxrc, NULL, NULL);
+	if (!info)
+		return;
+	call_usermodehelper_exec(info, UMH_WAIT_PROC|UMH_FREEZABLE);
+
+	/* move initrd to rootfs' /old */
+	init_mount("..", ".", NULL, MS_MOVE, NULL);
+	/* switch root and cwd back to / of rootfs */
+	init_chroot("..");
+
+	if (new_decode_dev(real_root_dev) == Root_RAM0) {
+		init_chdir("/old");
+		return;
+	}
+
+	init_chdir("/");
+	ROOT_DEV = new_decode_dev(real_root_dev);
+	mount_root(root_device_name);
+
+	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
+	error = init_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
+	if (!error)
+		printk("okay\n");
+	else {
+		if (error == -ENOENT)
+			printk("/initrd does not exist. Ignored.\n");
+		else
+			printk("failed\n");
+		printk(KERN_NOTICE "Unmounting old root\n");
+		init_umount("/old", MNT_DETACH);
+	}
+}
+
+bool __init initrd_load(char *root_device_name)
+{
+	if (mount_initrd) {
+		create_dev("/dev/ram", Root_RAM0);
+		/*
+		 * Load the initrd data into /dev/ram0. Execute it as initrd
+		 * unless /dev/ram0 is supposed to be our actual root device,
+		 * in that case the ram disk is just set up here, and gets
+		 * mounted in the normal path.
+		 */
+		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
+			init_unlink("/initrd.image");
+			handle_initrd(root_device_name);
+			return true;
+		}
+	}
+	init_unlink("/initrd.image");
+	return false;
+}
diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
new file mode 100644
index 0000000000..ac021ae6e6
--- /dev/null
+++ b/init/do_mounts_rd.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/minix_fs.h>
+#include <linux/ext2_fs.h>
+#include <linux/romfs_fs.h>
+#include <uapi/linux/cramfs_fs.h>
+#include <linux/initrd.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+
+#include "do_mounts.h"
+#include "../fs/squashfs/squashfs_fs.h"
+
+#include <linux/decompress/generic.h>
+
+static struct file *in_file, *out_file;
+static loff_t in_pos, out_pos;
+
+static int __init prompt_ramdisk(char *str)
+{
+	pr_warn("ignoring the deprecated prompt_ramdisk= option\n");
+	return 1;
+}
+__setup("prompt_ramdisk=", prompt_ramdisk);
+
+int __initdata rd_image_start;		/* starting block # of image */
+
+static int __init ramdisk_start_setup(char *str)
+{
+	rd_image_start = simple_strtol(str,NULL,0);
+	return 1;
+}
+__setup("ramdisk_start=", ramdisk_start_setup);
+
+static int __init crd_load(decompress_fn deco);
+
+/*
+ * This routine tries to find a RAM disk image to load, and returns the
+ * number of blocks to read for a non-compressed image, 0 if the image
+ * is a compressed image, and -1 if an image with the right magic
+ * numbers could not be found.
+ *
+ * We currently check for the following magic numbers:
+ *	minix
+ *	ext2
+ *	romfs
+ *	cramfs
+ *	squashfs
+ *	gzip
+ *	bzip2
+ *	lzma
+ *	xz
+ *	lzo
+ *	lz4
+ */
+static int __init
+identify_ramdisk_image(struct file *file, loff_t pos,
+		decompress_fn *decompressor)
+{
+	const int size = 512;
+	struct minix_super_block *minixsb;
+	struct romfs_super_block *romfsb;
+	struct cramfs_super *cramfsb;
+	struct squashfs_super_block *squashfsb;
+	int nblocks = -1;
+	unsigned char *buf;
+	const char *compress_name;
+	unsigned long n;
+	int start_block = rd_image_start;
+
+	buf = kmalloc(size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	minixsb = (struct minix_super_block *) buf;
+	romfsb = (struct romfs_super_block *) buf;
+	cramfsb = (struct cramfs_super *) buf;
+	squashfsb = (struct squashfs_super_block *) buf;
+	memset(buf, 0xe5, size);
+
+	/*
+	 * Read block 0 to test for compressed kernel
+	 */
+	pos = start_block * BLOCK_SIZE;
+	kernel_read(file, buf, size, &pos);
+
+	*decompressor = decompress_method(buf, size, &compress_name);
+	if (compress_name) {
+		printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
+		       compress_name, start_block);
+		if (!*decompressor)
+			printk(KERN_EMERG
+			       "RAMDISK: %s decompressor not configured!\n",
+			       compress_name);
+		nblocks = 0;
+		goto done;
+	}
+
+	/* romfs is at block zero too */
+	if (romfsb->word0 == ROMSB_WORD0 &&
+	    romfsb->word1 == ROMSB_WORD1) {
+		printk(KERN_NOTICE
+		       "RAMDISK: romfs filesystem found at block %d\n",
+		       start_block);
+		nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS;
+		goto done;
+	}
+
+	if (cramfsb->magic == CRAMFS_MAGIC) {
+		printk(KERN_NOTICE
+		       "RAMDISK: cramfs filesystem found at block %d\n",
+		       start_block);
+		nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
+		goto done;
+	}
+
+	/* squashfs is at block zero too */
+	if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) {
+		printk(KERN_NOTICE
+		       "RAMDISK: squashfs filesystem found at block %d\n",
+		       start_block);
+		nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1)
+			 >> BLOCK_SIZE_BITS;
+		goto done;
+	}
+
+	/*
+	 * Read 512 bytes further to check if cramfs is padded
+	 */
+	pos = start_block * BLOCK_SIZE + 0x200;
+	kernel_read(file, buf, size, &pos);
+
+	if (cramfsb->magic == CRAMFS_MAGIC) {
+		printk(KERN_NOTICE
+		       "RAMDISK: cramfs filesystem found at block %d\n",
+		       start_block);
+		nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
+		goto done;
+	}
+
+	/*
+	 * Read block 1 to test for minix and ext2 superblock
+	 */
+	pos = (start_block + 1) * BLOCK_SIZE;
+	kernel_read(file, buf, size, &pos);
+
+	/* Try minix */
+	if (minixsb->s_magic == MINIX_SUPER_MAGIC ||
+	    minixsb->s_magic == MINIX_SUPER_MAGIC2) {
+		printk(KERN_NOTICE
+		       "RAMDISK: Minix filesystem found at block %d\n",
+		       start_block);
+		nblocks = minixsb->s_nzones << minixsb->s_log_zone_size;
+		goto done;
+	}
+
+	/* Try ext2 */
+	n = ext2_image_size(buf);
+	if (n) {
+		printk(KERN_NOTICE
+		       "RAMDISK: ext2 filesystem found at block %d\n",
+		       start_block);
+		nblocks = n;
+		goto done;
+	}
+
+	printk(KERN_NOTICE
+	       "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n",
+	       start_block);
+
+done:
+	kfree(buf);
+	return nblocks;
+}
+
+static unsigned long nr_blocks(struct file *file)
+{
+	struct inode *inode = file->f_mapping->host;
+
+	if (!S_ISBLK(inode->i_mode))
+		return 0;
+	return i_size_read(inode) >> 10;
+}
+
+int __init rd_load_image(char *from)
+{
+	int res = 0;
+	unsigned long rd_blocks, devblocks;
+	int nblocks, i;
+	char *buf = NULL;
+	unsigned short rotate = 0;
+	decompress_fn decompressor = NULL;
+#if !defined(CONFIG_S390)
+	char rotator[4] = { '|' , '/' , '-' , '\\' };
+#endif
+
+	out_file = filp_open("/dev/ram", O_RDWR, 0);
+	if (IS_ERR(out_file))
+		goto out;
+
+	in_file = filp_open(from, O_RDONLY, 0);
+	if (IS_ERR(in_file))
+		goto noclose_input;
+
+	in_pos = rd_image_start * BLOCK_SIZE;
+	nblocks = identify_ramdisk_image(in_file, in_pos, &decompressor);
+	if (nblocks < 0)
+		goto done;
+
+	if (nblocks == 0) {
+		if (crd_load(decompressor) == 0)
+			goto successful_load;
+		goto done;
+	}
+
+	/*
+	 * NOTE NOTE: nblocks is not actually blocks but
+	 * the number of kibibytes of data to load into a ramdisk.
+	 */
+	rd_blocks = nr_blocks(out_file);
+	if (nblocks > rd_blocks) {
+		printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n",
+		       nblocks, rd_blocks);
+		goto done;
+	}
+
+	/*
+	 * OK, time to copy in the data
+	 */
+	if (strcmp(from, "/initrd.image") == 0)
+		devblocks = nblocks;
+	else
+		devblocks = nr_blocks(in_file);
+
+	if (devblocks == 0) {
+		printk(KERN_ERR "RAMDISK: could not determine device size\n");
+		goto done;
+	}
+
+	buf = kmalloc(BLOCK_SIZE, GFP_KERNEL);
+	if (!buf) {
+		printk(KERN_ERR "RAMDISK: could not allocate buffer\n");
+		goto done;
+	}
+
+	printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ",
+		nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : "");
+	for (i = 0; i < nblocks; i++) {
+		if (i && (i % devblocks == 0)) {
+			pr_cont("done disk #1.\n");
+			rotate = 0;
+			fput(in_file);
+			break;
+		}
+		kernel_read(in_file, buf, BLOCK_SIZE, &in_pos);
+		kernel_write(out_file, buf, BLOCK_SIZE, &out_pos);
+#if !defined(CONFIG_S390)
+		if (!(i % 16)) {
+			pr_cont("%c\b", rotator[rotate & 0x3]);
+			rotate++;
+		}
+#endif
+	}
+	pr_cont("done.\n");
+
+successful_load:
+	res = 1;
+done:
+	fput(in_file);
+noclose_input:
+	fput(out_file);
+out:
+	kfree(buf);
+	init_unlink("/dev/ram");
+	return res;
+}
+
+int __init rd_load_disk(int n)
+{
+	create_dev("/dev/root", ROOT_DEV);
+	create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));
+	return rd_load_image("/dev/root");
+}
+
+static int exit_code;
+static int decompress_error;
+
+static long __init compr_fill(void *buf, unsigned long len)
+{
+	long r = kernel_read(in_file, buf, len, &in_pos);
+	if (r < 0)
+		printk(KERN_ERR "RAMDISK: error while reading compressed data");
+	else if (r == 0)
+		printk(KERN_ERR "RAMDISK: EOF while reading compressed data");
+	return r;
+}
+
+static long __init compr_flush(void *window, unsigned long outcnt)
+{
+	long written = kernel_write(out_file, window, outcnt, &out_pos);
+	if (written != outcnt) {
+		if (decompress_error == 0)
+			printk(KERN_ERR
+			       "RAMDISK: incomplete write (%ld != %ld)\n",
+			       written, outcnt);
+		decompress_error = 1;
+		return -1;
+	}
+	return outcnt;
+}
+
+static void __init error(char *x)
+{
+	printk(KERN_ERR "%s\n", x);
+	exit_code = 1;
+	decompress_error = 1;
+}
+
+static int __init crd_load(decompress_fn deco)
+{
+	int result;
+
+	if (!deco) {
+		pr_emerg("Invalid ramdisk decompression routine.  "
+			 "Select appropriate config option.\n");
+		panic("Could not decompress initial ramdisk image.");
+	}
+
+	result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
+	if (decompress_error)
+		result = 1;
+	return result;
+}
diff --git a/init/init_task.c b/init/init_task.c
new file mode 100644
index 0000000000..ff6c4b9bfe
--- /dev/null
+++ b/init/init_task.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init_task.h>
+#include <linux/export.h>
+#include <linux/mqueue.h>
+#include <linux/sched.h>
+#include <linux/sched/sysctl.h>
+#include <linux/sched/rt.h>
+#include <linux/sched/task.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/audit.h>
+#include <linux/numa.h>
+#include <linux/scs.h>
+
+#include <linux/uaccess.h>
+
+static struct signal_struct init_signals = {
+	.nr_threads	= 1,
+	.thread_head	= LIST_HEAD_INIT(init_task.thread_node),
+	.wait_chldexit	= __WAIT_QUEUE_HEAD_INITIALIZER(init_signals.wait_chldexit),
+	.shared_pending	= {
+		.list = LIST_HEAD_INIT(init_signals.shared_pending.list),
+		.signal =  {{0}}
+	},
+	.multiprocess	= HLIST_HEAD_INIT,
+	.rlim		= INIT_RLIMITS,
+	.cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
+	.exec_update_lock = __RWSEM_INITIALIZER(init_signals.exec_update_lock),
+#ifdef CONFIG_POSIX_TIMERS
+	.posix_timers = LIST_HEAD_INIT(init_signals.posix_timers),
+	.cputimer	= {
+		.cputime_atomic	= INIT_CPUTIME_ATOMIC,
+	},
+#endif
+	INIT_CPU_TIMERS(init_signals)
+	.pids = {
+		[PIDTYPE_PID]	= &init_struct_pid,
+		[PIDTYPE_TGID]	= &init_struct_pid,
+		[PIDTYPE_PGID]	= &init_struct_pid,
+		[PIDTYPE_SID]	= &init_struct_pid,
+	},
+	INIT_PREV_CPUTIME(init_signals)
+};
+
+static struct sighand_struct init_sighand = {
+	.count		= REFCOUNT_INIT(1),
+	.action		= { { { .sa_handler = SIG_DFL, } }, },
+	.siglock	= __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
+	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
+};
+
+#ifdef CONFIG_SHADOW_CALL_STACK
+unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)]
+		__init_task_data = {
+	[(SCS_SIZE / sizeof(long)) - 1] = SCS_END_MAGIC
+};
+#endif
+
+/*
+ * Set up the first task table, touch at your own risk!. Base=0,
+ * limit=0x1fffff (=2MB)
+ */
+struct task_struct init_task
+#ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
+	__init_task_data
+#endif
+	__aligned(L1_CACHE_BYTES)
+= {
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+	.thread_info	= INIT_THREAD_INFO(init_task),
+	.stack_refcount	= REFCOUNT_INIT(1),
+#endif
+	.__state	= 0,
+	.stack		= init_stack,
+	.usage		= REFCOUNT_INIT(2),
+	.flags		= PF_KTHREAD,
+	.prio		= MAX_PRIO - 20,
+	.static_prio	= MAX_PRIO - 20,
+	.normal_prio	= MAX_PRIO - 20,
+	.policy		= SCHED_NORMAL,
+	.cpus_ptr	= &init_task.cpus_mask,
+	.user_cpus_ptr	= NULL,
+	.cpus_mask	= CPU_MASK_ALL,
+	.nr_cpus_allowed= NR_CPUS,
+	.mm		= NULL,
+	.active_mm	= &init_mm,
+	.restart_block	= {
+		.fn = do_no_restart_syscall,
+	},
+	.se		= {
+		.group_node 	= LIST_HEAD_INIT(init_task.se.group_node),
+	},
+	.rt		= {
+		.run_list	= LIST_HEAD_INIT(init_task.rt.run_list),
+		.time_slice	= RR_TIMESLICE,
+	},
+	.tasks		= LIST_HEAD_INIT(init_task.tasks),
+#ifdef CONFIG_SMP
+	.pushable_tasks	= PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
+#endif
+#ifdef CONFIG_CGROUP_SCHED
+	.sched_task_group = &root_task_group,
+#endif
+	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
+	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
+	.real_parent	= &init_task,
+	.parent		= &init_task,
+	.children	= LIST_HEAD_INIT(init_task.children),
+	.sibling	= LIST_HEAD_INIT(init_task.sibling),
+	.group_leader	= &init_task,
+	RCU_POINTER_INITIALIZER(real_cred, &init_cred),
+	RCU_POINTER_INITIALIZER(cred, &init_cred),
+	.comm		= INIT_TASK_COMM,
+	.thread		= INIT_THREAD,
+	.fs		= &init_fs,
+	.files		= &init_files,
+#ifdef CONFIG_IO_URING
+	.io_uring	= NULL,
+#endif
+	.signal		= &init_signals,
+	.sighand	= &init_sighand,
+	.nsproxy	= &init_nsproxy,
+	.pending	= {
+		.list = LIST_HEAD_INIT(init_task.pending.list),
+		.signal = {{0}}
+	},
+	.blocked	= {{0}},
+	.alloc_lock	= __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
+	.journal_info	= NULL,
+	INIT_CPU_TIMERS(init_task)
+	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
+	.timer_slack_ns = 50000, /* 50 usec default slack */
+	.thread_pid	= &init_struct_pid,
+	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),
+	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
+#ifdef CONFIG_AUDIT
+	.loginuid	= INVALID_UID,
+	.sessionid	= AUDIT_SID_UNSET,
+#endif
+#ifdef CONFIG_PERF_EVENTS
+	.perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
+	.perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
+#endif
+#ifdef CONFIG_PREEMPT_RCU
+	.rcu_read_lock_nesting = 0,
+	.rcu_read_unlock_special.s = 0,
+	.rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
+	.rcu_blocked_node = NULL,
+#endif
+#ifdef CONFIG_TASKS_RCU
+	.rcu_tasks_holdout = false,
+	.rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
+	.rcu_tasks_idle_cpu = -1,
+#endif
+#ifdef CONFIG_TASKS_TRACE_RCU
+	.trc_reader_nesting = 0,
+	.trc_reader_special.s = 0,
+	.trc_holdout_list = LIST_HEAD_INIT(init_task.trc_holdout_list),
+	.trc_blkd_node = LIST_HEAD_INIT(init_task.trc_blkd_node),
+#endif
+#ifdef CONFIG_CPUSETS
+	.mems_allowed_seq = SEQCNT_SPINLOCK_ZERO(init_task.mems_allowed_seq,
+						 &init_task.alloc_lock),
+#endif
+#ifdef CONFIG_RT_MUTEXES
+	.pi_waiters	= RB_ROOT_CACHED,
+	.pi_top_task	= NULL,
+#endif
+	INIT_PREV_CPUTIME(init_task)
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+	.vtime.seqcount	= SEQCNT_ZERO(init_task.vtime_seqcount),
+	.vtime.starttime = 0,
+	.vtime.state	= VTIME_SYS,
+#endif
+#ifdef CONFIG_NUMA_BALANCING
+	.numa_preferred_nid = NUMA_NO_NODE,
+	.numa_group	= NULL,
+	.numa_faults	= NULL,
+#endif
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+	.kasan_depth	= 1,
+#endif
+#ifdef CONFIG_KCSAN
+	.kcsan_ctx = {
+		.scoped_accesses	= {LIST_POISON1, NULL},
+	},
+#endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+	.softirqs_enabled = 1,
+#endif
+#ifdef CONFIG_LOCKDEP
+	.lockdep_depth = 0, /* no locks held yet */
+	.curr_chain_key = INITIAL_CHAIN_KEY,
+	.lockdep_recursion = 0,
+#endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	.ret_stack		= NULL,
+	.tracing_graph_pause	= ATOMIC_INIT(0),
+#endif
+#if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION)
+	.trace_recursion = 0,
+#endif
+#ifdef CONFIG_LIVEPATCH
+	.patch_state	= KLP_UNDEFINED,
+#endif
+#ifdef CONFIG_SECURITY
+	.security	= NULL,
+#endif
+#ifdef CONFIG_SECCOMP_FILTER
+	.seccomp	= { .filter_count = ATOMIC_INIT(0) },
+#endif
+};
+EXPORT_SYMBOL(init_task);
+
+/*
+ * Initial thread structure. Alignment of this is handled by a special
+ * linker map entry.
+ */
+#ifndef CONFIG_THREAD_INFO_IN_TASK
+struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
+#endif
diff --git a/init/initramfs.c b/init/initramfs.c
new file mode 100644
index 0000000000..8d0fd946cd
--- /dev/null
+++ b/init/initramfs.c
@@ -0,0 +1,755 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <linux/async.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/dirent.h>
+#include <linux/syscalls.h>
+#include <linux/utime.h>
+#include <linux/file.h>
+#include <linux/kstrtox.h>
+#include <linux/memblock.h>
+#include <linux/mm.h>
+#include <linux/namei.h>
+#include <linux/init_syscalls.h>
+#include <linux/task_work.h>
+#include <linux/umh.h>
+
+static __initdata bool csum_present;
+static __initdata u32 io_csum;
+
+static ssize_t __init xwrite(struct file *file, const unsigned char *p,
+		size_t count, loff_t *pos)
+{
+	ssize_t out = 0;
+
+	/* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
+	while (count) {
+		ssize_t rv = kernel_write(file, p, count, pos);
+
+		if (rv < 0) {
+			if (rv == -EINTR || rv == -EAGAIN)
+				continue;
+			return out ? out : rv;
+		} else if (rv == 0)
+			break;
+
+		if (csum_present) {
+			ssize_t i;
+
+			for (i = 0; i < rv; i++)
+				io_csum += p[i];
+		}
+
+		p += rv;
+		out += rv;
+		count -= rv;
+	}
+
+	return out;
+}
+
+static __initdata char *message;
+static void __init error(char *x)
+{
+	if (!message)
+		message = x;
+}
+
+#define panic_show_mem(fmt, ...) \
+	({ show_mem(); panic(fmt, ##__VA_ARGS__); })
+
+/* link hash */
+
+#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
+
+static __initdata struct hash {
+	int ino, minor, major;
+	umode_t mode;
+	struct hash *next;
+	char name[N_ALIGN(PATH_MAX)];
+} *head[32];
+
+static inline int hash(int major, int minor, int ino)
+{
+	unsigned long tmp = ino + minor + (major << 3);
+	tmp += tmp >> 5;
+	return tmp & 31;
+}
+
+static char __init *find_link(int major, int minor, int ino,
+			      umode_t mode, char *name)
+{
+	struct hash **p, *q;
+	for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
+		if ((*p)->ino != ino)
+			continue;
+		if ((*p)->minor != minor)
+			continue;
+		if ((*p)->major != major)
+			continue;
+		if (((*p)->mode ^ mode) & S_IFMT)
+			continue;
+		return (*p)->name;
+	}
+	q = kmalloc(sizeof(struct hash), GFP_KERNEL);
+	if (!q)
+		panic_show_mem("can't allocate link hash entry");
+	q->major = major;
+	q->minor = minor;
+	q->ino = ino;
+	q->mode = mode;
+	strcpy(q->name, name);
+	q->next = NULL;
+	*p = q;
+	return NULL;
+}
+
+static void __init free_hash(void)
+{
+	struct hash **p, *q;
+	for (p = head; p < head + 32; p++) {
+		while (*p) {
+			q = *p;
+			*p = q->next;
+			kfree(q);
+		}
+	}
+}
+
+#ifdef CONFIG_INITRAMFS_PRESERVE_MTIME
+static void __init do_utime(char *filename, time64_t mtime)
+{
+	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
+	init_utimes(filename, t);
+}
+
+static void __init do_utime_path(const struct path *path, time64_t mtime)
+{
+	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
+	vfs_utimes(path, t);
+}
+
+static __initdata LIST_HEAD(dir_list);
+struct dir_entry {
+	struct list_head list;
+	time64_t mtime;
+	char name[];
+};
+
+static void __init dir_add(const char *name, time64_t mtime)
+{
+	size_t nlen = strlen(name) + 1;
+	struct dir_entry *de;
+
+	de = kmalloc(sizeof(struct dir_entry) + nlen, GFP_KERNEL);
+	if (!de)
+		panic_show_mem("can't allocate dir_entry buffer");
+	INIT_LIST_HEAD(&de->list);
+	strscpy(de->name, name, nlen);
+	de->mtime = mtime;
+	list_add(&de->list, &dir_list);
+}
+
+static void __init dir_utime(void)
+{
+	struct dir_entry *de, *tmp;
+	list_for_each_entry_safe(de, tmp, &dir_list, list) {
+		list_del(&de->list);
+		do_utime(de->name, de->mtime);
+		kfree(de);
+	}
+}
+#else
+static void __init do_utime(char *filename, time64_t mtime) {}
+static void __init do_utime_path(const struct path *path, time64_t mtime) {}
+static void __init dir_add(const char *name, time64_t mtime) {}
+static void __init dir_utime(void) {}
+#endif
+
+static __initdata time64_t mtime;
+
+/* cpio header parsing */
+
+static __initdata unsigned long ino, major, minor, nlink;
+static __initdata umode_t mode;
+static __initdata unsigned long body_len, name_len;
+static __initdata uid_t uid;
+static __initdata gid_t gid;
+static __initdata unsigned rdev;
+static __initdata u32 hdr_csum;
+
+static void __init parse_header(char *s)
+{
+	unsigned long parsed[13];
+	char buf[9];
+	int i;
+
+	buf[8] = '\0';
+	for (i = 0, s += 6; i < 13; i++, s += 8) {
+		memcpy(buf, s, 8);
+		parsed[i] = simple_strtoul(buf, NULL, 16);
+	}
+	ino = parsed[0];
+	mode = parsed[1];
+	uid = parsed[2];
+	gid = parsed[3];
+	nlink = parsed[4];
+	mtime = parsed[5]; /* breaks in y2106 */
+	body_len = parsed[6];
+	major = parsed[7];
+	minor = parsed[8];
+	rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
+	name_len = parsed[11];
+	hdr_csum = parsed[12];
+}
+
+/* FSM */
+
+static __initdata enum state {
+	Start,
+	Collect,
+	GotHeader,
+	SkipIt,
+	GotName,
+	CopyFile,
+	GotSymlink,
+	Reset
+} state, next_state;
+
+static __initdata char *victim;
+static unsigned long byte_count __initdata;
+static __initdata loff_t this_header, next_header;
+
+static inline void __init eat(unsigned n)
+{
+	victim += n;
+	this_header += n;
+	byte_count -= n;
+}
+
+static __initdata char *collected;
+static long remains __initdata;
+static __initdata char *collect;
+
+static void __init read_into(char *buf, unsigned size, enum state next)
+{
+	if (byte_count >= size) {
+		collected = victim;
+		eat(size);
+		state = next;
+	} else {
+		collect = collected = buf;
+		remains = size;
+		next_state = next;
+		state = Collect;
+	}
+}
+
+static __initdata char *header_buf, *symlink_buf, *name_buf;
+
+static int __init do_start(void)
+{
+	read_into(header_buf, 110, GotHeader);
+	return 0;
+}
+
+static int __init do_collect(void)
+{
+	unsigned long n = remains;
+	if (byte_count < n)
+		n = byte_count;
+	memcpy(collect, victim, n);
+	eat(n);
+	collect += n;
+	if ((remains -= n) != 0)
+		return 1;
+	state = next_state;
+	return 0;
+}
+
+static int __init do_header(void)
+{
+	if (!memcmp(collected, "070701", 6)) {
+		csum_present = false;
+	} else if (!memcmp(collected, "070702", 6)) {
+		csum_present = true;
+	} else {
+		if (memcmp(collected, "070707", 6) == 0)
+			error("incorrect cpio method used: use -H newc option");
+		else
+			error("no cpio magic");
+		return 1;
+	}
+	parse_header(collected);
+	next_header = this_header + N_ALIGN(name_len) + body_len;
+	next_header = (next_header + 3) & ~3;
+	state = SkipIt;
+	if (name_len <= 0 || name_len > PATH_MAX)
+		return 0;
+	if (S_ISLNK(mode)) {
+		if (body_len > PATH_MAX)
+			return 0;
+		collect = collected = symlink_buf;
+		remains = N_ALIGN(name_len) + body_len;
+		next_state = GotSymlink;
+		state = Collect;
+		return 0;
+	}
+	if (S_ISREG(mode) || !body_len)
+		read_into(name_buf, N_ALIGN(name_len), GotName);
+	return 0;
+}
+
+static int __init do_skip(void)
+{
+	if (this_header + byte_count < next_header) {
+		eat(byte_count);
+		return 1;
+	} else {
+		eat(next_header - this_header);
+		state = next_state;
+		return 0;
+	}
+}
+
+static int __init do_reset(void)
+{
+	while (byte_count && *victim == '\0')
+		eat(1);
+	if (byte_count && (this_header & 3))
+		error("broken padding");
+	return 1;
+}
+
+static void __init clean_path(char *path, umode_t fmode)
+{
+	struct kstat st;
+
+	if (!init_stat(path, &st, AT_SYMLINK_NOFOLLOW) &&
+	    (st.mode ^ fmode) & S_IFMT) {
+		if (S_ISDIR(st.mode))
+			init_rmdir(path);
+		else
+			init_unlink(path);
+	}
+}
+
+static int __init maybe_link(void)
+{
+	if (nlink >= 2) {
+		char *old = find_link(major, minor, ino, mode, collected);
+		if (old) {
+			clean_path(collected, 0);
+			return (init_link(old, collected) < 0) ? -1 : 1;
+		}
+	}
+	return 0;
+}
+
+static __initdata struct file *wfile;
+static __initdata loff_t wfile_pos;
+
+static int __init do_name(void)
+{
+	state = SkipIt;
+	next_state = Reset;
+	if (strcmp(collected, "TRAILER!!!") == 0) {
+		free_hash();
+		return 0;
+	}
+	clean_path(collected, mode);
+	if (S_ISREG(mode)) {
+		int ml = maybe_link();
+		if (ml >= 0) {
+			int openflags = O_WRONLY|O_CREAT;
+			if (ml != 1)
+				openflags |= O_TRUNC;
+			wfile = filp_open(collected, openflags, mode);
+			if (IS_ERR(wfile))
+				return 0;
+			wfile_pos = 0;
+			io_csum = 0;
+
+			vfs_fchown(wfile, uid, gid);
+			vfs_fchmod(wfile, mode);
+			if (body_len)
+				vfs_truncate(&wfile->f_path, body_len);
+			state = CopyFile;
+		}
+	} else if (S_ISDIR(mode)) {
+		init_mkdir(collected, mode);
+		init_chown(collected, uid, gid, 0);
+		init_chmod(collected, mode);
+		dir_add(collected, mtime);
+	} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
+		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
+		if (maybe_link() == 0) {
+			init_mknod(collected, mode, rdev);
+			init_chown(collected, uid, gid, 0);
+			init_chmod(collected, mode);
+			do_utime(collected, mtime);
+		}
+	}
+	return 0;
+}
+
+static int __init do_copy(void)
+{
+	if (byte_count >= body_len) {
+		if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len)
+			error("write error");
+
+		do_utime_path(&wfile->f_path, mtime);
+		fput(wfile);
+		if (csum_present && io_csum != hdr_csum)
+			error("bad data checksum");
+		eat(body_len);
+		state = SkipIt;
+		return 0;
+	} else {
+		if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count)
+			error("write error");
+		body_len -= byte_count;
+		eat(byte_count);
+		return 1;
+	}
+}
+
+static int __init do_symlink(void)
+{
+	collected[N_ALIGN(name_len) + body_len] = '\0';
+	clean_path(collected, 0);
+	init_symlink(collected + N_ALIGN(name_len), collected);
+	init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW);
+	do_utime(collected, mtime);
+	state = SkipIt;
+	next_state = Reset;
+	return 0;
+}
+
+static __initdata int (*actions[])(void) = {
+	[Start]		= do_start,
+	[Collect]	= do_collect,
+	[GotHeader]	= do_header,
+	[SkipIt]	= do_skip,
+	[GotName]	= do_name,
+	[CopyFile]	= do_copy,
+	[GotSymlink]	= do_symlink,
+	[Reset]		= do_reset,
+};
+
+static long __init write_buffer(char *buf, unsigned long len)
+{
+	byte_count = len;
+	victim = buf;
+
+	while (!actions[state]())
+		;
+	return len - byte_count;
+}
+
+static long __init flush_buffer(void *bufv, unsigned long len)
+{
+	char *buf = bufv;
+	long written;
+	long origLen = len;
+	if (message)
+		return -1;
+	while ((written = write_buffer(buf, len)) < len && !message) {
+		char c = buf[written];
+		if (c == '0') {
+			buf += written;
+			len -= written;
+			state = Start;
+		} else if (c == 0) {
+			buf += written;
+			len -= written;
+			state = Reset;
+		} else
+			error("junk within compressed archive");
+	}
+	return origLen;
+}
+
+static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */
+
+#include <linux/decompress/generic.h>
+
+static char * __init unpack_to_rootfs(char *buf, unsigned long len)
+{
+	long written;
+	decompress_fn decompress;
+	const char *compress_name;
+	static __initdata char msg_buf[64];
+
+	header_buf = kmalloc(110, GFP_KERNEL);
+	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
+	name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
+
+	if (!header_buf || !symlink_buf || !name_buf)
+		panic_show_mem("can't allocate buffers");
+
+	state = Start;
+	this_header = 0;
+	message = NULL;
+	while (!message && len) {
+		loff_t saved_offset = this_header;
+		if (*buf == '0' && !(this_header & 3)) {
+			state = Start;
+			written = write_buffer(buf, len);
+			buf += written;
+			len -= written;
+			continue;
+		}
+		if (!*buf) {
+			buf++;
+			len--;
+			this_header++;
+			continue;
+		}
+		this_header = 0;
+		decompress = decompress_method(buf, len, &compress_name);
+		pr_debug("Detected %s compressed data\n", compress_name);
+		if (decompress) {
+			int res = decompress(buf, len, NULL, flush_buffer, NULL,
+				   &my_inptr, error);
+			if (res)
+				error("decompressor failed");
+		} else if (compress_name) {
+			if (!message) {
+				snprintf(msg_buf, sizeof msg_buf,
+					 "compression method %s not configured",
+					 compress_name);
+				message = msg_buf;
+			}
+		} else
+			error("invalid magic at start of compressed archive");
+		if (state != Reset)
+			error("junk at the end of compressed archive");
+		this_header = saved_offset + my_inptr;
+		buf += my_inptr;
+		len -= my_inptr;
+	}
+	dir_utime();
+	kfree(name_buf);
+	kfree(symlink_buf);
+	kfree(header_buf);
+	return message;
+}
+
+static int __initdata do_retain_initrd;
+
+static int __init retain_initrd_param(char *str)
+{
+	if (*str)
+		return 0;
+	do_retain_initrd = 1;
+	return 1;
+}
+__setup("retain_initrd", retain_initrd_param);
+
+#ifdef CONFIG_ARCH_HAS_KEEPINITRD
+static int __init keepinitrd_setup(char *__unused)
+{
+	do_retain_initrd = 1;
+	return 1;
+}
+__setup("keepinitrd", keepinitrd_setup);
+#endif
+
+static bool __initdata initramfs_async = true;
+static int __init initramfs_async_setup(char *str)
+{
+	return kstrtobool(str, &initramfs_async) == 0;
+}
+__setup("initramfs_async=", initramfs_async_setup);
+
+extern char __initramfs_start[];
+extern unsigned long __initramfs_size;
+#include <linux/initrd.h>
+#include <linux/kexec.h>
+
+void __init reserve_initrd_mem(void)
+{
+	phys_addr_t start;
+	unsigned long size;
+
+	/* Ignore the virtul address computed during device tree parsing */
+	initrd_start = initrd_end = 0;
+
+	if (!phys_initrd_size)
+		return;
+	/*
+	 * Round the memory region to page boundaries as per free_initrd_mem()
+	 * This allows us to detect whether the pages overlapping the initrd
+	 * are in use, but more importantly, reserves the entire set of pages
+	 * as we don't want these pages allocated for other purposes.
+	 */
+	start = round_down(phys_initrd_start, PAGE_SIZE);
+	size = phys_initrd_size + (phys_initrd_start - start);
+	size = round_up(size, PAGE_SIZE);
+
+	if (!memblock_is_region_memory(start, size)) {
+		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
+		       (u64)start, size);
+		goto disable;
+	}
+
+	if (memblock_is_region_reserved(start, size)) {
+		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
+		       (u64)start, size);
+		goto disable;
+	}
+
+	memblock_reserve(start, size);
+	/* Now convert initrd to virtual addresses */
+	initrd_start = (unsigned long)__va(phys_initrd_start);
+	initrd_end = initrd_start + phys_initrd_size;
+	initrd_below_start_ok = 1;
+
+	return;
+disable:
+	pr_cont(" - disabling initrd\n");
+	initrd_start = 0;
+	initrd_end = 0;
+}
+
+void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
+	unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE);
+	unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
+
+	memblock_free((void *)aligned_start, aligned_end - aligned_start);
+#endif
+
+	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
+			"initrd");
+}
+
+#ifdef CONFIG_KEXEC_CORE
+static bool __init kexec_free_initrd(void)
+{
+	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
+	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
+
+	/*
+	 * If the initrd region is overlapped with crashkernel reserved region,
+	 * free only memory that is not part of crashkernel region.
+	 */
+	if (initrd_start >= crashk_end || initrd_end <= crashk_start)
+		return false;
+
+	/*
+	 * Initialize initrd memory region since the kexec boot does not do.
+	 */
+	memset((void *)initrd_start, 0, initrd_end - initrd_start);
+	if (initrd_start < crashk_start)
+		free_initrd_mem(initrd_start, crashk_start);
+	if (initrd_end > crashk_end)
+		free_initrd_mem(crashk_end, initrd_end);
+	return true;
+}
+#else
+static inline bool kexec_free_initrd(void)
+{
+	return false;
+}
+#endif /* CONFIG_KEXEC_CORE */
+
+#ifdef CONFIG_BLK_DEV_RAM
+static void __init populate_initrd_image(char *err)
+{
+	ssize_t written;
+	struct file *file;
+	loff_t pos = 0;
+
+	unpack_to_rootfs(__initramfs_start, __initramfs_size);
+
+	printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
+			err);
+	file = filp_open("/initrd.image", O_WRONLY | O_CREAT, 0700);
+	if (IS_ERR(file))
+		return;
+
+	written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start,
+			&pos);
+	if (written != initrd_end - initrd_start)
+		pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
+		       written, initrd_end - initrd_start);
+	fput(file);
+}
+#endif /* CONFIG_BLK_DEV_RAM */
+
+static void __init do_populate_rootfs(void *unused, async_cookie_t cookie)
+{
+	/* Load the built in initramfs */
+	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
+	if (err)
+		panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */
+
+	if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE))
+		goto done;
+
+	if (IS_ENABLED(CONFIG_BLK_DEV_RAM))
+		printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
+	else
+		printk(KERN_INFO "Unpacking initramfs...\n");
+
+	err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start);
+	if (err) {
+#ifdef CONFIG_BLK_DEV_RAM
+		populate_initrd_image(err);
+#else
+		printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
+#endif
+	}
+
+done:
+	/*
+	 * If the initrd region is overlapped with crashkernel reserved region,
+	 * free only memory that is not part of crashkernel region.
+	 */
+	if (!do_retain_initrd && initrd_start && !kexec_free_initrd())
+		free_initrd_mem(initrd_start, initrd_end);
+	initrd_start = 0;
+	initrd_end = 0;
+
+	flush_delayed_fput();
+	task_work_run();
+}
+
+static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain);
+static async_cookie_t initramfs_cookie;
+
+void wait_for_initramfs(void)
+{
+	if (!initramfs_cookie) {
+		/*
+		 * Something before rootfs_initcall wants to access
+		 * the filesystem/initramfs. Probably a bug. Make a
+		 * note, avoid deadlocking the machine, and let the
+		 * caller's access fail as it used to.
+		 */
+		pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n");
+		return;
+	}
+	async_synchronize_cookie_domain(initramfs_cookie + 1, &initramfs_domain);
+}
+EXPORT_SYMBOL_GPL(wait_for_initramfs);
+
+static int __init populate_rootfs(void)
+{
+	initramfs_cookie = async_schedule_domain(do_populate_rootfs, NULL,
+						 &initramfs_domain);
+	usermodehelper_enable();
+	if (!initramfs_async)
+		wait_for_initramfs();
+	return 0;
+}
+rootfs_initcall(populate_rootfs);
diff --git a/init/main.c b/init/main.c
new file mode 100644
index 0000000000..e24b0780fd
--- /dev/null
+++ b/init/main.c
@@ -0,0 +1,1577 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/init/main.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  GK 2/5/95  -  Changed to support mounting root fs via NFS
+ *  Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
+ *  Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
+ *  Simplified starting of init:  Michael A. Griffith <grif@acm.org>
+ */
+
+#define DEBUG		/* Enable initcall_debug */
+
+#include <linux/types.h>
+#include <linux/extable.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/binfmts.h>
+#include <linux/kernel.h>
+#include <linux/syscalls.h>
+#include <linux/stackprotector.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/initrd.h>
+#include <linux/memblock.h>
+#include <linux/acpi.h>
+#include <linux/bootconfig.h>
+#include <linux/console.h>
+#include <linux/nmi.h>
+#include <linux/percpu.h>
+#include <linux/kmod.h>
+#include <linux/kprobes.h>
+#include <linux/kmsan.h>
+#include <linux/vmalloc.h>
+#include <linux/kernel_stat.h>
+#include <linux/start_kernel.h>
+#include <linux/security.h>
+#include <linux/smp.h>
+#include <linux/profile.h>
+#include <linux/kfence.h>
+#include <linux/rcupdate.h>
+#include <linux/srcu.h>
+#include <linux/moduleparam.h>
+#include <linux/kallsyms.h>
+#include <linux/buildid.h>
+#include <linux/writeback.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/cgroup.h>
+#include <linux/efi.h>
+#include <linux/tick.h>
+#include <linux/sched/isolation.h>
+#include <linux/interrupt.h>
+#include <linux/taskstats_kern.h>
+#include <linux/delayacct.h>
+#include <linux/unistd.h>
+#include <linux/utsname.h>
+#include <linux/rmap.h>
+#include <linux/mempolicy.h>
+#include <linux/key.h>
+#include <linux/debug_locks.h>
+#include <linux/debugobjects.h>
+#include <linux/lockdep.h>
+#include <linux/kmemleak.h>
+#include <linux/padata.h>
+#include <linux/pid_namespace.h>
+#include <linux/device/driver.h>
+#include <linux/kthread.h>
+#include <linux/sched.h>
+#include <linux/sched/init.h>
+#include <linux/signal.h>
+#include <linux/idr.h>
+#include <linux/kgdb.h>
+#include <linux/ftrace.h>
+#include <linux/async.h>
+#include <linux/shmem_fs.h>
+#include <linux/slab.h>
+#include <linux/perf_event.h>
+#include <linux/ptrace.h>
+#include <linux/pti.h>
+#include <linux/blkdev.h>
+#include <linux/sched/clock.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/context_tracking.h>
+#include <linux/random.h>
+#include <linux/list.h>
+#include <linux/integrity.h>
+#include <linux/proc_ns.h>
+#include <linux/io.h>
+#include <linux/cache.h>
+#include <linux/rodata_test.h>
+#include <linux/jump_label.h>
+#include <linux/kcsan.h>
+#include <linux/init_syscalls.h>
+#include <linux/stackdepot.h>
+#include <linux/randomize_kstack.h>
+#include <net/net_namespace.h>
+
+#include <asm/io.h>
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/cacheflush.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/initcall.h>
+
+#include <kunit/test.h>
+
+static int kernel_init(void *);
+
+/*
+ * Debug helper: via this flag we know that we are in 'early bootup code'
+ * where only the boot processor is running with IRQ disabled.  This means
+ * two things - IRQ must not be enabled before the flag is cleared and some
+ * operations which are not allowed with IRQ disabled are allowed while the
+ * flag is set.
+ */
+bool early_boot_irqs_disabled __read_mostly;
+
+enum system_states system_state __read_mostly;
+EXPORT_SYMBOL(system_state);
+
+/*
+ * Boot command-line arguments
+ */
+#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
+#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
+
+/* Default late time init is NULL. archs can override this later. */
+void (*__initdata late_time_init)(void);
+
+/* Untouched command line saved by arch-specific code. */
+char __initdata boot_command_line[COMMAND_LINE_SIZE];
+/* Untouched saved command line (eg. for /proc) */
+char *saved_command_line __ro_after_init;
+unsigned int saved_command_line_len __ro_after_init;
+/* Command line for parameter parsing */
+static char *static_command_line;
+/* Untouched extra command line */
+static char *extra_command_line;
+/* Extra init arguments */
+static char *extra_init_args;
+
+#ifdef CONFIG_BOOT_CONFIG
+/* Is bootconfig on command line? */
+static bool bootconfig_found;
+static size_t initargs_offs;
+#else
+# define bootconfig_found false
+# define initargs_offs 0
+#endif
+
+static char *execute_command;
+static char *ramdisk_execute_command = "/init";
+
+/*
+ * Used to generate warnings if static_key manipulation functions are used
+ * before jump_label_init is called.
+ */
+bool static_key_initialized __read_mostly;
+EXPORT_SYMBOL_GPL(static_key_initialized);
+
+/*
+ * If set, this is an indication to the drivers that reset the underlying
+ * device before going ahead with the initialization otherwise driver might
+ * rely on the BIOS and skip the reset operation.
+ *
+ * This is useful if kernel is booting in an unreliable environment.
+ * For ex. kdump situation where previous kernel has crashed, BIOS has been
+ * skipped and devices will be in unknown state.
+ */
+unsigned int reset_devices;
+EXPORT_SYMBOL(reset_devices);
+
+static int __init set_reset_devices(char *str)
+{
+	reset_devices = 1;
+	return 1;
+}
+
+__setup("reset_devices", set_reset_devices);
+
+static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
+const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
+static const char *panic_later, *panic_param;
+
+static bool __init obsolete_checksetup(char *line)
+{
+	const struct obs_kernel_param *p;
+	bool had_early_param = false;
+
+	p = __setup_start;
+	do {
+		int n = strlen(p->str);
+		if (parameqn(line, p->str, n)) {
+			if (p->early) {
+				/* Already done in parse_early_param?
+				 * (Needs exact match on param part).
+				 * Keep iterating, as we can have early
+				 * params and __setups of same names 8( */
+				if (line[n] == '\0' || line[n] == '=')
+					had_early_param = true;
+			} else if (!p->setup_func) {
+				pr_warn("Parameter %s is obsolete, ignored\n",
+					p->str);
+				return true;
+			} else if (p->setup_func(line + n))
+				return true;
+		}
+		p++;
+	} while (p < __setup_end);
+
+	return had_early_param;
+}
+
+/*
+ * This should be approx 2 Bo*oMips to start (note initial shift), and will
+ * still work even if initially too large, it will just take slightly longer
+ */
+unsigned long loops_per_jiffy = (1<<12);
+EXPORT_SYMBOL(loops_per_jiffy);
+
+static int __init debug_kernel(char *str)
+{
+	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
+	return 0;
+}
+
+static int __init quiet_kernel(char *str)
+{
+	console_loglevel = CONSOLE_LOGLEVEL_QUIET;
+	return 0;
+}
+
+early_param("debug", debug_kernel);
+early_param("quiet", quiet_kernel);
+
+static int __init loglevel(char *str)
+{
+	int newlevel;
+
+	/*
+	 * Only update loglevel value when a correct setting was passed,
+	 * to prevent blind crashes (when loglevel being set to 0) that
+	 * are quite hard to debug
+	 */
+	if (get_option(&str, &newlevel)) {
+		console_loglevel = newlevel;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+early_param("loglevel", loglevel);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+static void * __init get_boot_config_from_initrd(size_t *_size)
+{
+	u32 size, csum;
+	char *data;
+	u32 *hdr;
+	int i;
+
+	if (!initrd_end)
+		return NULL;
+
+	data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
+	/*
+	 * Since Grub may align the size of initrd to 4, we must
+	 * check the preceding 3 bytes as well.
+	 */
+	for (i = 0; i < 4; i++) {
+		if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
+			goto found;
+		data--;
+	}
+	return NULL;
+
+found:
+	hdr = (u32 *)(data - 8);
+	size = le32_to_cpu(hdr[0]);
+	csum = le32_to_cpu(hdr[1]);
+
+	data = ((void *)hdr) - size;
+	if ((unsigned long)data < initrd_start) {
+		pr_err("bootconfig size %d is greater than initrd size %ld\n",
+			size, initrd_end - initrd_start);
+		return NULL;
+	}
+
+	if (xbc_calc_checksum(data, size) != csum) {
+		pr_err("bootconfig checksum failed\n");
+		return NULL;
+	}
+
+	/* Remove bootconfig from initramfs/initrd */
+	initrd_end = (unsigned long)data;
+	if (_size)
+		*_size = size;
+
+	return data;
+}
+#else
+static void * __init get_boot_config_from_initrd(size_t *_size)
+{
+	return NULL;
+}
+#endif
+
+#ifdef CONFIG_BOOT_CONFIG
+
+static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
+
+#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
+
+static int __init xbc_snprint_cmdline(char *buf, size_t size,
+				      struct xbc_node *root)
+{
+	struct xbc_node *knode, *vnode;
+	char *end = buf + size;
+	const char *val;
+	int ret;
+
+	xbc_node_for_each_key_value(root, knode, val) {
+		ret = xbc_node_compose_key_after(root, knode,
+					xbc_namebuf, XBC_KEYLEN_MAX);
+		if (ret < 0)
+			return ret;
+
+		vnode = xbc_node_get_child(knode);
+		if (!vnode) {
+			ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
+			if (ret < 0)
+				return ret;
+			buf += ret;
+			continue;
+		}
+		xbc_array_for_each_value(vnode, val) {
+			ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
+				       xbc_namebuf, val);
+			if (ret < 0)
+				return ret;
+			buf += ret;
+		}
+	}
+
+	return buf - (end - size);
+}
+#undef rest
+
+/* Make an extra command line under given key word */
+static char * __init xbc_make_cmdline(const char *key)
+{
+	struct xbc_node *root;
+	char *new_cmdline;
+	int ret, len = 0;
+
+	root = xbc_find_node(key);
+	if (!root)
+		return NULL;
+
+	/* Count required buffer size */
+	len = xbc_snprint_cmdline(NULL, 0, root);
+	if (len <= 0)
+		return NULL;
+
+	new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
+	if (!new_cmdline) {
+		pr_err("Failed to allocate memory for extra kernel cmdline.\n");
+		return NULL;
+	}
+
+	ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
+	if (ret < 0 || ret > len) {
+		pr_err("Failed to print extra kernel cmdline.\n");
+		memblock_free(new_cmdline, len + 1);
+		return NULL;
+	}
+
+	return new_cmdline;
+}
+
+static int __init bootconfig_params(char *param, char *val,
+				    const char *unused, void *arg)
+{
+	if (strcmp(param, "bootconfig") == 0) {
+		bootconfig_found = true;
+	}
+	return 0;
+}
+
+static int __init warn_bootconfig(char *str)
+{
+	/* The 'bootconfig' has been handled by bootconfig_params(). */
+	return 0;
+}
+
+static void __init setup_boot_config(void)
+{
+	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
+	const char *msg, *data;
+	int pos, ret;
+	size_t size;
+	char *err;
+
+	/* Cut out the bootconfig data even if we have no bootconfig option */
+	data = get_boot_config_from_initrd(&size);
+	/* If there is no bootconfig in initrd, try embedded one. */
+	if (!data)
+		data = xbc_get_embedded_bootconfig(&size);
+
+	strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+	err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
+			 bootconfig_params);
+
+	if (IS_ERR(err) || !(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE)))
+		return;
+
+	/* parse_args() stops at the next param of '--' and returns an address */
+	if (err)
+		initargs_offs = err - tmp_cmdline;
+
+	if (!data) {
+		/* If user intended to use bootconfig, show an error level message */
+		if (bootconfig_found)
+			pr_err("'bootconfig' found on command line, but no bootconfig found\n");
+		else
+			pr_info("No bootconfig data provided, so skipping bootconfig");
+		return;
+	}
+
+	if (size >= XBC_DATA_MAX) {
+		pr_err("bootconfig size %ld greater than max size %d\n",
+			(long)size, XBC_DATA_MAX);
+		return;
+	}
+
+	ret = xbc_init(data, size, &msg, &pos);
+	if (ret < 0) {
+		if (pos < 0)
+			pr_err("Failed to init bootconfig: %s.\n", msg);
+		else
+			pr_err("Failed to parse bootconfig: %s at %d.\n",
+				msg, pos);
+	} else {
+		xbc_get_info(&ret, NULL);
+		pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
+		/* keys starting with "kernel." are passed via cmdline */
+		extra_command_line = xbc_make_cmdline("kernel");
+		/* Also, "init." keys are init arguments */
+		extra_init_args = xbc_make_cmdline("init");
+	}
+	return;
+}
+
+static void __init exit_boot_config(void)
+{
+	xbc_exit();
+}
+
+#else	/* !CONFIG_BOOT_CONFIG */
+
+static void __init setup_boot_config(void)
+{
+	/* Remove bootconfig data from initrd */
+	get_boot_config_from_initrd(NULL);
+}
+
+static int __init warn_bootconfig(char *str)
+{
+	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
+	return 0;
+}
+
+#define exit_boot_config()	do {} while (0)
+
+#endif	/* CONFIG_BOOT_CONFIG */
+
+early_param("bootconfig", warn_bootconfig);
+
+/* Change NUL term back to "=", to make "param" the whole string. */
+static void __init repair_env_string(char *param, char *val)
+{
+	if (val) {
+		/* param=val or param="val"? */
+		if (val == param+strlen(param)+1)
+			val[-1] = '=';
+		else if (val == param+strlen(param)+2) {
+			val[-2] = '=';
+			memmove(val-1, val, strlen(val)+1);
+		} else
+			BUG();
+	}
+}
+
+/* Anything after -- gets handed straight to init. */
+static int __init set_init_arg(char *param, char *val,
+			       const char *unused, void *arg)
+{
+	unsigned int i;
+
+	if (panic_later)
+		return 0;
+
+	repair_env_string(param, val);
+
+	for (i = 0; argv_init[i]; i++) {
+		if (i == MAX_INIT_ARGS) {
+			panic_later = "init";
+			panic_param = param;
+			return 0;
+		}
+	}
+	argv_init[i] = param;
+	return 0;
+}
+
+/*
+ * Unknown boot options get handed to init, unless they look like
+ * unused parameters (modprobe will find them in /proc/cmdline).
+ */
+static int __init unknown_bootoption(char *param, char *val,
+				     const char *unused, void *arg)
+{
+	size_t len = strlen(param);
+
+	/* Handle params aliased to sysctls */
+	if (sysctl_is_alias(param))
+		return 0;
+
+	repair_env_string(param, val);
+
+	/* Handle obsolete-style parameters */
+	if (obsolete_checksetup(param))
+		return 0;
+
+	/* Unused module parameter. */
+	if (strnchr(param, len, '.'))
+		return 0;
+
+	if (panic_later)
+		return 0;
+
+	if (val) {
+		/* Environment option */
+		unsigned int i;
+		for (i = 0; envp_init[i]; i++) {
+			if (i == MAX_INIT_ENVS) {
+				panic_later = "env";
+				panic_param = param;
+			}
+			if (!strncmp(param, envp_init[i], len+1))
+				break;
+		}
+		envp_init[i] = param;
+	} else {
+		/* Command line option */
+		unsigned int i;
+		for (i = 0; argv_init[i]; i++) {
+			if (i == MAX_INIT_ARGS) {
+				panic_later = "init";
+				panic_param = param;
+			}
+		}
+		argv_init[i] = param;
+	}
+	return 0;
+}
+
+static int __init init_setup(char *str)
+{
+	unsigned int i;
+
+	execute_command = str;
+	/*
+	 * In case LILO is going to boot us with default command line,
+	 * it prepends "auto" before the whole cmdline which makes
+	 * the shell think it should execute a script with such name.
+	 * So we ignore all arguments entered _before_ init=... [MJ]
+	 */
+	for (i = 1; i < MAX_INIT_ARGS; i++)
+		argv_init[i] = NULL;
+	return 1;
+}
+__setup("init=", init_setup);
+
+static int __init rdinit_setup(char *str)
+{
+	unsigned int i;
+
+	ramdisk_execute_command = str;
+	/* See "auto" comment in init_setup */
+	for (i = 1; i < MAX_INIT_ARGS; i++)
+		argv_init[i] = NULL;
+	return 1;
+}
+__setup("rdinit=", rdinit_setup);
+
+#ifndef CONFIG_SMP
+static const unsigned int setup_max_cpus = NR_CPUS;
+static inline void setup_nr_cpu_ids(void) { }
+static inline void smp_prepare_cpus(unsigned int maxcpus) { }
+#endif
+
+/*
+ * We need to store the untouched command line for future reference.
+ * We also need to store the touched command line since the parameter
+ * parsing is performed in place, and we should allow a component to
+ * store reference of name/value for future reference.
+ */
+static void __init setup_command_line(char *command_line)
+{
+	size_t len, xlen = 0, ilen = 0;
+
+	if (extra_command_line)
+		xlen = strlen(extra_command_line);
+	if (extra_init_args)
+		ilen = strlen(extra_init_args) + 4; /* for " -- " */
+
+	len = xlen + strlen(boot_command_line) + 1;
+
+	saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
+	if (!saved_command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
+
+	static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
+	if (!static_command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+
+	if (xlen) {
+		/*
+		 * We have to put extra_command_line before boot command
+		 * lines because there could be dashes (separator of init
+		 * command line) in the command lines.
+		 */
+		strcpy(saved_command_line, extra_command_line);
+		strcpy(static_command_line, extra_command_line);
+	}
+	strcpy(saved_command_line + xlen, boot_command_line);
+	strcpy(static_command_line + xlen, command_line);
+
+	if (ilen) {
+		/*
+		 * Append supplemental init boot args to saved_command_line
+		 * so that user can check what command line options passed
+		 * to init.
+		 * The order should always be
+		 * " -- "[bootconfig init-param][cmdline init-param]
+		 */
+		if (initargs_offs) {
+			len = xlen + initargs_offs;
+			strcpy(saved_command_line + len, extra_init_args);
+			len += ilen - 4;	/* strlen(extra_init_args) */
+			strcpy(saved_command_line + len,
+				boot_command_line + initargs_offs - 1);
+		} else {
+			len = strlen(saved_command_line);
+			strcpy(saved_command_line + len, " -- ");
+			len += 4;
+			strcpy(saved_command_line + len, extra_init_args);
+		}
+	}
+
+	saved_command_line_len = strlen(saved_command_line);
+}
+
+/*
+ * We need to finalize in a non-__init function or else race conditions
+ * between the root thread and the init thread may cause start_kernel to
+ * be reaped by free_initmem before the root thread has proceeded to
+ * cpu_idle.
+ *
+ * gcc-3.4 accidentally inlines this function, so use noinline.
+ */
+
+static __initdata DECLARE_COMPLETION(kthreadd_done);
+
+noinline void __ref __noreturn rest_init(void)
+{
+	struct task_struct *tsk;
+	int pid;
+
+	rcu_scheduler_starting();
+	/*
+	 * We need to spawn init first so that it obtains pid 1, however
+	 * the init task will end up wanting to create kthreads, which, if
+	 * we schedule it before we create kthreadd, will OOPS.
+	 */
+	pid = user_mode_thread(kernel_init, NULL, CLONE_FS);
+	/*
+	 * Pin init on the boot CPU. Task migration is not properly working
+	 * until sched_init_smp() has been run. It will set the allowed
+	 * CPUs for init to the non isolated CPUs.
+	 */
+	rcu_read_lock();
+	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
+	tsk->flags |= PF_NO_SETAFFINITY;
+	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
+	rcu_read_unlock();
+
+	numa_default_policy();
+	pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES);
+	rcu_read_lock();
+	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
+	rcu_read_unlock();
+
+	/*
+	 * Enable might_sleep() and smp_processor_id() checks.
+	 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
+	 * kernel_thread() would trigger might_sleep() splats. With
+	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
+	 * already, but it's stuck on the kthreadd_done completion.
+	 */
+	system_state = SYSTEM_SCHEDULING;
+
+	complete(&kthreadd_done);
+
+	/*
+	 * The boot idle thread must execute schedule()
+	 * at least once to get things moving:
+	 */
+	schedule_preempt_disabled();
+	/* Call into cpu_idle with preempt disabled */
+	cpu_startup_entry(CPUHP_ONLINE);
+}
+
+/* Check for early params. */
+static int __init do_early_param(char *param, char *val,
+				 const char *unused, void *arg)
+{
+	const struct obs_kernel_param *p;
+
+	for (p = __setup_start; p < __setup_end; p++) {
+		if ((p->early && parameq(param, p->str)) ||
+		    (strcmp(param, "console") == 0 &&
+		     strcmp(p->str, "earlycon") == 0)
+		) {
+			if (p->setup_func(val) != 0)
+				pr_warn("Malformed early option '%s'\n", param);
+		}
+	}
+	/* We accept everything at this stage. */
+	return 0;
+}
+
+void __init parse_early_options(char *cmdline)
+{
+	parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
+		   do_early_param);
+}
+
+/* Arch code calls this early on, or if not, just before other parsing. */
+void __init parse_early_param(void)
+{
+	static int done __initdata;
+	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
+
+	if (done)
+		return;
+
+	/* All fall through to do_early_param. */
+	strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+	parse_early_options(tmp_cmdline);
+	done = 1;
+}
+
+void __init __weak arch_post_acpi_subsys_init(void) { }
+
+void __init __weak smp_setup_processor_id(void)
+{
+}
+
+# if THREAD_SIZE >= PAGE_SIZE
+void __init __weak thread_stack_cache_init(void)
+{
+}
+#endif
+
+void __init __weak poking_init(void) { }
+
+void __init __weak pgtable_cache_init(void) { }
+
+void __init __weak trap_init(void) { }
+
+bool initcall_debug;
+core_param(initcall_debug, initcall_debug, bool, 0644);
+
+#ifdef TRACEPOINTS_ENABLED
+static void __init initcall_debug_enable(void);
+#else
+static inline void initcall_debug_enable(void)
+{
+}
+#endif
+
+#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
+DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
+			   randomize_kstack_offset);
+DEFINE_PER_CPU(u32, kstack_offset);
+
+static int __init early_randomize_kstack_offset(char *buf)
+{
+	int ret;
+	bool bool_result;
+
+	ret = kstrtobool(buf, &bool_result);
+	if (ret)
+		return ret;
+
+	if (bool_result)
+		static_branch_enable(&randomize_kstack_offset);
+	else
+		static_branch_disable(&randomize_kstack_offset);
+	return 0;
+}
+early_param("randomize_kstack_offset", early_randomize_kstack_offset);
+#endif
+
+void __init __weak __noreturn arch_call_rest_init(void)
+{
+	rest_init();
+}
+
+static void __init print_unknown_bootoptions(void)
+{
+	char *unknown_options;
+	char *end;
+	const char *const *p;
+	size_t len;
+
+	if (panic_later || (!argv_init[1] && !envp_init[2]))
+		return;
+
+	/*
+	 * Determine how many options we have to print out, plus a space
+	 * before each
+	 */
+	len = 1; /* null terminator */
+	for (p = &argv_init[1]; *p; p++) {
+		len++;
+		len += strlen(*p);
+	}
+	for (p = &envp_init[2]; *p; p++) {
+		len++;
+		len += strlen(*p);
+	}
+
+	unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
+	if (!unknown_options) {
+		pr_err("%s: Failed to allocate %zu bytes\n",
+			__func__, len);
+		return;
+	}
+	end = unknown_options;
+
+	for (p = &argv_init[1]; *p; p++)
+		end += sprintf(end, " %s", *p);
+	for (p = &envp_init[2]; *p; p++)
+		end += sprintf(end, " %s", *p);
+
+	/* Start at unknown_options[1] to skip the initial space */
+	pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
+		&unknown_options[1]);
+	memblock_free(unknown_options, len);
+}
+
+asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector
+void start_kernel(void)
+{
+	char *command_line;
+	char *after_dashes;
+
+	set_task_stack_end_magic(&init_task);
+	smp_setup_processor_id();
+	debug_objects_early_init();
+	init_vmlinux_build_id();
+
+	cgroup_init_early();
+
+	local_irq_disable();
+	early_boot_irqs_disabled = true;
+
+	/*
+	 * Interrupts are still disabled. Do necessary setups, then
+	 * enable them.
+	 */
+	boot_cpu_init();
+	page_address_init();
+	pr_notice("%s", linux_banner);
+	early_security_init();
+	setup_arch(&command_line);
+	setup_boot_config();
+	setup_command_line(command_line);
+	setup_nr_cpu_ids();
+	setup_per_cpu_areas();
+	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
+	boot_cpu_hotplug_init();
+
+	pr_notice("Kernel command line: %s\n", saved_command_line);
+	/* parameters may set static keys */
+	jump_label_init();
+	parse_early_param();
+	after_dashes = parse_args("Booting kernel",
+				  static_command_line, __start___param,
+				  __stop___param - __start___param,
+				  -1, -1, NULL, &unknown_bootoption);
+	print_unknown_bootoptions();
+	if (!IS_ERR_OR_NULL(after_dashes))
+		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
+			   NULL, set_init_arg);
+	if (extra_init_args)
+		parse_args("Setting extra init args", extra_init_args,
+			   NULL, 0, -1, -1, NULL, set_init_arg);
+
+	/* Architectural and non-timekeeping rng init, before allocator init */
+	random_init_early(command_line);
+
+	/*
+	 * These use large bootmem allocations and must precede
+	 * initalization of page allocator
+	 */
+	setup_log_buf(0);
+	vfs_caches_init_early();
+	sort_main_extable();
+	trap_init();
+	mm_core_init();
+	poking_init();
+	ftrace_init();
+
+	/* trace_printk can be enabled here */
+	early_trace_init();
+
+	/*
+	 * Set up the scheduler prior starting any interrupts (such as the
+	 * timer interrupt). Full topology setup happens at smp_init()
+	 * time - but meanwhile we still have a functioning scheduler.
+	 */
+	sched_init();
+
+	if (WARN(!irqs_disabled(),
+		 "Interrupts were enabled *very* early, fixing it\n"))
+		local_irq_disable();
+	radix_tree_init();
+	maple_tree_init();
+
+	/*
+	 * Set up housekeeping before setting up workqueues to allow the unbound
+	 * workqueue to take non-housekeeping into account.
+	 */
+	housekeeping_init();
+
+	/*
+	 * Allow workqueue creation and work item queueing/cancelling
+	 * early.  Work item execution depends on kthreads and starts after
+	 * workqueue_init().
+	 */
+	workqueue_init_early();
+
+	rcu_init();
+
+	/* Trace events are available after this */
+	trace_init();
+
+	if (initcall_debug)
+		initcall_debug_enable();
+
+	context_tracking_init();
+	/* init some links before init_ISA_irqs() */
+	early_irq_init();
+	init_IRQ();
+	tick_init();
+	rcu_init_nohz();
+	init_timers();
+	srcu_init();
+	hrtimers_init();
+	softirq_init();
+	timekeeping_init();
+	time_init();
+
+	/* This must be after timekeeping is initialized */
+	random_init();
+
+	/* These make use of the fully initialized rng */
+	kfence_init();
+	boot_init_stack_canary();
+
+	perf_event_init();
+	profile_init();
+	call_function_init();
+	WARN(!irqs_disabled(), "Interrupts were enabled early\n");
+
+	early_boot_irqs_disabled = false;
+	local_irq_enable();
+
+	kmem_cache_init_late();
+
+	/*
+	 * HACK ALERT! This is early. We're enabling the console before
+	 * we've done PCI setups etc, and console_init() must be aware of
+	 * this. But we do want output early, in case something goes wrong.
+	 */
+	console_init();
+	if (panic_later)
+		panic("Too many boot %s vars at `%s'", panic_later,
+		      panic_param);
+
+	lockdep_init();
+
+	/*
+	 * Need to run this when irqs are enabled, because it wants
+	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
+	 * too:
+	 */
+	locking_selftest();
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (initrd_start && !initrd_below_start_ok &&
+	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
+		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
+		    page_to_pfn(virt_to_page((void *)initrd_start)),
+		    min_low_pfn);
+		initrd_start = 0;
+	}
+#endif
+	setup_per_cpu_pageset();
+	numa_policy_init();
+	acpi_early_init();
+	if (late_time_init)
+		late_time_init();
+	sched_clock_init();
+	calibrate_delay();
+
+	arch_cpu_finalize_init();
+
+	pid_idr_init();
+	anon_vma_init();
+#ifdef CONFIG_X86
+	if (efi_enabled(EFI_RUNTIME_SERVICES))
+		efi_enter_virtual_mode();
+#endif
+	thread_stack_cache_init();
+	cred_init();
+	fork_init();
+	proc_caches_init();
+	uts_ns_init();
+	key_init();
+	security_init();
+	dbg_late_init();
+	net_ns_init();
+	vfs_caches_init();
+	pagecache_init();
+	signals_init();
+	seq_file_init();
+	proc_root_init();
+	nsfs_init();
+	cpuset_init();
+	cgroup_init();
+	taskstats_init_early();
+	delayacct_init();
+
+	acpi_subsystem_init();
+	arch_post_acpi_subsys_init();
+	kcsan_init();
+
+	/* Do the rest non-__init'ed, we're now alive */
+	arch_call_rest_init();
+
+	/*
+	 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10
+	 * and older.
+	 */
+#if !__has_attribute(__no_stack_protector__)
+	prevent_tail_call_optimization();
+#endif
+}
+
+/* Call all constructor functions linked into the kernel. */
+static void __init do_ctors(void)
+{
+/*
+ * For UML, the constructors have already been called by the
+ * normal setup code as it's just a normal ELF binary, so we
+ * cannot do it again - but we do need CONFIG_CONSTRUCTORS
+ * even on UML for modules.
+ */
+#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
+	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
+
+	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
+		(*fn)();
+#endif
+}
+
+#ifdef CONFIG_KALLSYMS
+struct blacklist_entry {
+	struct list_head next;
+	char *buf;
+};
+
+static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
+
+static int __init initcall_blacklist(char *str)
+{
+	char *str_entry;
+	struct blacklist_entry *entry;
+
+	/* str argument is a comma-separated list of functions */
+	do {
+		str_entry = strsep(&str, ",");
+		if (str_entry) {
+			pr_debug("blacklisting initcall %s\n", str_entry);
+			entry = memblock_alloc(sizeof(*entry),
+					       SMP_CACHE_BYTES);
+			if (!entry)
+				panic("%s: Failed to allocate %zu bytes\n",
+				      __func__, sizeof(*entry));
+			entry->buf = memblock_alloc(strlen(str_entry) + 1,
+						    SMP_CACHE_BYTES);
+			if (!entry->buf)
+				panic("%s: Failed to allocate %zu bytes\n",
+				      __func__, strlen(str_entry) + 1);
+			strcpy(entry->buf, str_entry);
+			list_add(&entry->next, &blacklisted_initcalls);
+		}
+	} while (str_entry);
+
+	return 1;
+}
+
+static bool __init_or_module initcall_blacklisted(initcall_t fn)
+{
+	struct blacklist_entry *entry;
+	char fn_name[KSYM_SYMBOL_LEN];
+	unsigned long addr;
+
+	if (list_empty(&blacklisted_initcalls))
+		return false;
+
+	addr = (unsigned long) dereference_function_descriptor(fn);
+	sprint_symbol_no_offset(fn_name, addr);
+
+	/*
+	 * fn will be "function_name [module_name]" where [module_name] is not
+	 * displayed for built-in init functions.  Strip off the [module_name].
+	 */
+	strreplace(fn_name, ' ', '\0');
+
+	list_for_each_entry(entry, &blacklisted_initcalls, next) {
+		if (!strcmp(fn_name, entry->buf)) {
+			pr_debug("initcall %s blacklisted\n", fn_name);
+			return true;
+		}
+	}
+
+	return false;
+}
+#else
+static int __init initcall_blacklist(char *str)
+{
+	pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
+	return 0;
+}
+
+static bool __init_or_module initcall_blacklisted(initcall_t fn)
+{
+	return false;
+}
+#endif
+__setup("initcall_blacklist=", initcall_blacklist);
+
+static __init_or_module void
+trace_initcall_start_cb(void *data, initcall_t fn)
+{
+	ktime_t *calltime = data;
+
+	printk(KERN_DEBUG "calling  %pS @ %i\n", fn, task_pid_nr(current));
+	*calltime = ktime_get();
+}
+
+static __init_or_module void
+trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
+{
+	ktime_t rettime, *calltime = data;
+
+	rettime = ktime_get();
+	printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
+		 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
+}
+
+static ktime_t initcall_calltime;
+
+#ifdef TRACEPOINTS_ENABLED
+static void __init initcall_debug_enable(void)
+{
+	int ret;
+
+	ret = register_trace_initcall_start(trace_initcall_start_cb,
+					    &initcall_calltime);
+	ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
+					      &initcall_calltime);
+	WARN(ret, "Failed to register initcall tracepoints\n");
+}
+# define do_trace_initcall_start	trace_initcall_start
+# define do_trace_initcall_finish	trace_initcall_finish
+#else
+static inline void do_trace_initcall_start(initcall_t fn)
+{
+	if (!initcall_debug)
+		return;
+	trace_initcall_start_cb(&initcall_calltime, fn);
+}
+static inline void do_trace_initcall_finish(initcall_t fn, int ret)
+{
+	if (!initcall_debug)
+		return;
+	trace_initcall_finish_cb(&initcall_calltime, fn, ret);
+}
+#endif /* !TRACEPOINTS_ENABLED */
+
+int __init_or_module do_one_initcall(initcall_t fn)
+{
+	int count = preempt_count();
+	char msgbuf[64];
+	int ret;
+
+	if (initcall_blacklisted(fn))
+		return -EPERM;
+
+	do_trace_initcall_start(fn);
+	ret = fn();
+	do_trace_initcall_finish(fn, ret);
+
+	msgbuf[0] = 0;
+
+	if (preempt_count() != count) {
+		sprintf(msgbuf, "preemption imbalance ");
+		preempt_count_set(count);
+	}
+	if (irqs_disabled()) {
+		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
+		local_irq_enable();
+	}
+	WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
+
+	add_latent_entropy();
+	return ret;
+}
+
+
+static initcall_entry_t *initcall_levels[] __initdata = {
+	__initcall0_start,
+	__initcall1_start,
+	__initcall2_start,
+	__initcall3_start,
+	__initcall4_start,
+	__initcall5_start,
+	__initcall6_start,
+	__initcall7_start,
+	__initcall_end,
+};
+
+/* Keep these in sync with initcalls in include/linux/init.h */
+static const char *initcall_level_names[] __initdata = {
+	"pure",
+	"core",
+	"postcore",
+	"arch",
+	"subsys",
+	"fs",
+	"device",
+	"late",
+};
+
+static int __init ignore_unknown_bootoption(char *param, char *val,
+			       const char *unused, void *arg)
+{
+	return 0;
+}
+
+static void __init do_initcall_level(int level, char *command_line)
+{
+	initcall_entry_t *fn;
+
+	parse_args(initcall_level_names[level],
+		   command_line, __start___param,
+		   __stop___param - __start___param,
+		   level, level,
+		   NULL, ignore_unknown_bootoption);
+
+	trace_initcall_level(initcall_level_names[level]);
+	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
+		do_one_initcall(initcall_from_entry(fn));
+}
+
+static void __init do_initcalls(void)
+{
+	int level;
+	size_t len = saved_command_line_len + 1;
+	char *command_line;
+
+	command_line = kzalloc(len, GFP_KERNEL);
+	if (!command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+
+	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
+		/* Parser modifies command_line, restore it each time */
+		strcpy(command_line, saved_command_line);
+		do_initcall_level(level, command_line);
+	}
+
+	kfree(command_line);
+}
+
+/*
+ * Ok, the machine is now initialized. None of the devices
+ * have been touched yet, but the CPU subsystem is up and
+ * running, and memory and process management works.
+ *
+ * Now we can finally start doing some real work..
+ */
+static void __init do_basic_setup(void)
+{
+	cpuset_init_smp();
+	driver_init();
+	init_irq_proc();
+	do_ctors();
+	do_initcalls();
+}
+
+static void __init do_pre_smp_initcalls(void)
+{
+	initcall_entry_t *fn;
+
+	trace_initcall_level("early");
+	for (fn = __initcall_start; fn < __initcall0_start; fn++)
+		do_one_initcall(initcall_from_entry(fn));
+}
+
+static int run_init_process(const char *init_filename)
+{
+	const char *const *p;
+
+	argv_init[0] = init_filename;
+	pr_info("Run %s as init process\n", init_filename);
+	pr_debug("  with arguments:\n");
+	for (p = argv_init; *p; p++)
+		pr_debug("    %s\n", *p);
+	pr_debug("  with environment:\n");
+	for (p = envp_init; *p; p++)
+		pr_debug("    %s\n", *p);
+	return kernel_execve(init_filename, argv_init, envp_init);
+}
+
+static int try_to_run_init_process(const char *init_filename)
+{
+	int ret;
+
+	ret = run_init_process(init_filename);
+
+	if (ret && ret != -ENOENT) {
+		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
+		       init_filename, ret);
+	}
+
+	return ret;
+}
+
+static noinline void __init kernel_init_freeable(void);
+
+#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
+bool rodata_enabled __ro_after_init = true;
+
+#ifndef arch_parse_debug_rodata
+static inline bool arch_parse_debug_rodata(char *str) { return false; }
+#endif
+
+static int __init set_debug_rodata(char *str)
+{
+	if (arch_parse_debug_rodata(str))
+		return 0;
+
+	if (str && !strcmp(str, "on"))
+		rodata_enabled = true;
+	else if (str && !strcmp(str, "off"))
+		rodata_enabled = false;
+	else
+		pr_warn("Invalid option string for rodata: '%s'\n", str);
+	return 0;
+}
+early_param("rodata", set_debug_rodata);
+#endif
+
+#ifdef CONFIG_STRICT_KERNEL_RWX
+static void mark_readonly(void)
+{
+	if (rodata_enabled) {
+		/*
+		 * load_module() results in W+X mappings, which are cleaned
+		 * up with call_rcu().  Let's make sure that queued work is
+		 * flushed so that we don't hit false positives looking for
+		 * insecure pages which are W+X.
+		 */
+		rcu_barrier();
+		mark_rodata_ro();
+		rodata_test();
+	} else
+		pr_info("Kernel memory protection disabled.\n");
+}
+#elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
+static inline void mark_readonly(void)
+{
+	pr_warn("Kernel memory protection not selected by kernel config.\n");
+}
+#else
+static inline void mark_readonly(void)
+{
+	pr_warn("This architecture does not have kernel memory protection.\n");
+}
+#endif
+
+void __weak free_initmem(void)
+{
+	free_initmem_default(POISON_FREE_INITMEM);
+}
+
+static int __ref kernel_init(void *unused)
+{
+	int ret;
+
+	/*
+	 * Wait until kthreadd is all set-up.
+	 */
+	wait_for_completion(&kthreadd_done);
+
+	kernel_init_freeable();
+	/* need to finish all async __init code before freeing the memory */
+	async_synchronize_full();
+
+	system_state = SYSTEM_FREEING_INITMEM;
+	kprobe_free_init_mem();
+	ftrace_free_init_mem();
+	kgdb_free_init_mem();
+	exit_boot_config();
+	free_initmem();
+	mark_readonly();
+
+	/*
+	 * Kernel mappings are now finalized - update the userspace page-table
+	 * to finalize PTI.
+	 */
+	pti_finalize();
+
+	system_state = SYSTEM_RUNNING;
+	numa_default_policy();
+
+	rcu_end_inkernel_boot();
+
+	do_sysctl_args();
+
+	if (ramdisk_execute_command) {
+		ret = run_init_process(ramdisk_execute_command);
+		if (!ret)
+			return 0;
+		pr_err("Failed to execute %s (error %d)\n",
+		       ramdisk_execute_command, ret);
+	}
+
+	/*
+	 * We try each of these until one succeeds.
+	 *
+	 * The Bourne shell can be used instead of init if we are
+	 * trying to recover a really broken machine.
+	 */
+	if (execute_command) {
+		ret = run_init_process(execute_command);
+		if (!ret)
+			return 0;
+		panic("Requested init %s failed (error %d).",
+		      execute_command, ret);
+	}
+
+	if (CONFIG_DEFAULT_INIT[0] != '\0') {
+		ret = run_init_process(CONFIG_DEFAULT_INIT);
+		if (ret)
+			pr_err("Default init %s failed (error %d)\n",
+			       CONFIG_DEFAULT_INIT, ret);
+		else
+			return 0;
+	}
+
+	if (!try_to_run_init_process("/sbin/init") ||
+	    !try_to_run_init_process("/etc/init") ||
+	    !try_to_run_init_process("/bin/init") ||
+	    !try_to_run_init_process("/bin/sh"))
+		return 0;
+
+	panic("No working init found.  Try passing init= option to kernel. "
+	      "See Linux Documentation/admin-guide/init.rst for guidance.");
+}
+
+/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
+void __init console_on_rootfs(void)
+{
+	struct file *file = filp_open("/dev/console", O_RDWR, 0);
+
+	if (IS_ERR(file)) {
+		pr_err("Warning: unable to open an initial console.\n");
+		return;
+	}
+	init_dup(file);
+	init_dup(file);
+	init_dup(file);
+	fput(file);
+}
+
+static noinline void __init kernel_init_freeable(void)
+{
+	/* Now the scheduler is fully set up and can do blocking allocations */
+	gfp_allowed_mask = __GFP_BITS_MASK;
+
+	/*
+	 * init can allocate pages on any node
+	 */
+	set_mems_allowed(node_states[N_MEMORY]);
+
+	cad_pid = get_pid(task_pid(current));
+
+	smp_prepare_cpus(setup_max_cpus);
+
+	workqueue_init();
+
+	init_mm_internals();
+
+	rcu_init_tasks_generic();
+	do_pre_smp_initcalls();
+	lockup_detector_init();
+
+	smp_init();
+	sched_init_smp();
+
+	workqueue_init_topology();
+	padata_init();
+	page_alloc_init_late();
+
+	do_basic_setup();
+
+	kunit_run_all_tests();
+
+	wait_for_initramfs();
+	console_on_rootfs();
+
+	/*
+	 * check if there is an early userspace init.  If yes, let it do all
+	 * the work
+	 */
+	if (init_eaccess(ramdisk_execute_command) != 0) {
+		ramdisk_execute_command = NULL;
+		prepare_namespace();
+	}
+
+	/*
+	 * Ok, we have completed the initial bootup, and
+	 * we're essentially up and running. Get rid of the
+	 * initmem segments and start the user-mode stuff..
+	 *
+	 * rootfs is available now, try loading the public keys
+	 * and default modules
+	 */
+
+	integrity_load_keys();
+}
diff --git a/init/noinitramfs.c b/init/noinitramfs.c
new file mode 100644
index 0000000000..d1d26b93d2
--- /dev/null
+++ b/init/noinitramfs.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * init/noinitramfs.c
+ *
+ * Copyright (C) 2006, NXP Semiconductors, All Rights Reserved
+ * Author: Jean-Paul Saman <jean-paul.saman@nxp.com>
+ */
+#include <linux/init.h>
+#include <linux/stat.h>
+#include <linux/kdev_t.h>
+#include <linux/syscalls.h>
+#include <linux/init_syscalls.h>
+#include <linux/umh.h>
+
+/*
+ * Create a simple rootfs that is similar to the default initramfs
+ */
+static int __init default_rootfs(void)
+{
+	int err;
+
+	usermodehelper_enable();
+	err = init_mkdir("/dev", 0755);
+	if (err < 0)
+		goto out;
+
+	err = init_mknod("/dev/console", S_IFCHR | S_IRUSR | S_IWUSR,
+			new_encode_dev(MKDEV(5, 1)));
+	if (err < 0)
+		goto out;
+
+	err = init_mkdir("/root", 0700);
+	if (err < 0)
+		goto out;
+
+	return 0;
+
+out:
+	printk(KERN_WARNING "Failed to create a rootfs\n");
+	return err;
+}
+rootfs_initcall(default_rootfs);
diff --git a/init/version-timestamp.c b/init/version-timestamp.c
new file mode 100644
index 0000000000..043cbf80a7
--- /dev/null
+++ b/init/version-timestamp.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <generated/compile.h>
+#include <generated/utsrelease.h>
+#include <linux/proc_ns.h>
+#include <linux/refcount.h>
+#include <linux/uts.h>
+#include <linux/utsname.h>
+
+struct uts_namespace init_uts_ns = {
+	.ns.count = REFCOUNT_INIT(2),
+	.name = {
+		.sysname	= UTS_SYSNAME,
+		.nodename	= UTS_NODENAME,
+		.release	= UTS_RELEASE,
+		.version	= UTS_VERSION,
+		.machine	= UTS_MACHINE,
+		.domainname	= UTS_DOMAINNAME,
+	},
+	.user_ns = &init_user_ns,
+	.ns.inum = PROC_UTS_INIT_INO,
+#ifdef CONFIG_UTS_NS
+	.ns.ops = &utsns_operations,
+#endif
+};
+
+/* FIXED STRINGS! Don't touch! */
+const char linux_banner[] =
+	"Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@"
+	LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n";
diff --git a/init/version.c b/init/version.c
new file mode 100644
index 0000000000..f117921811
--- /dev/null
+++ b/init/version.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/init/version.c
+ *
+ *  Copyright (C) 1992  Theodore Ts'o
+ *
+ *  May be freely distributed as part of Linux.
+ */
+
+#include <generated/compile.h>
+#include <linux/build-salt.h>
+#include <linux/elfnote-lto.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/printk.h>
+#include <linux/uts.h>
+#include <linux/utsname.h>
+#include <linux/proc_ns.h>
+
+static int __init early_hostname(char *arg)
+{
+	size_t bufsize = sizeof(init_uts_ns.name.nodename);
+	size_t maxlen  = bufsize - 1;
+	size_t arglen;
+
+	arglen = strlcpy(init_uts_ns.name.nodename, arg, bufsize);
+	if (arglen > maxlen) {
+		pr_warn("hostname parameter exceeds %zd characters and will be truncated",
+			maxlen);
+	}
+	return 0;
+}
+early_param("hostname", early_hostname);
+
+const char linux_proc_banner[] =
+	"%s version %s"
+	" (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ")"
+	" (" LINUX_COMPILER ") %s\n";
+
+BUILD_SALT;
+BUILD_LTO_INFO;
+
+/*
+ * init_uts_ns and linux_banner contain the build version and timestamp,
+ * which are really fixed at the very last step of build process.
+ * They are compiled with __weak first, and without __weak later.
+ */
+
+struct uts_namespace init_uts_ns __weak;
+const char linux_banner[] __weak;
+
+#include "version-timestamp.c"
+
+EXPORT_SYMBOL_GPL(init_uts_ns);