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+# SPDX-License-Identifier: GPL-2.0-only
+#
+# For a description of the syntax of this configuration file,
+# see Documentation/kbuild/kconfig-language.rst.
+#
+
+config 64BIT
+ bool
+
+config 32BIT
+ bool
+
+config RISCV
+ def_bool y
+ select ACPI_GENERIC_GSI if ACPI
+ select ACPI_REDUCED_HARDWARE_ONLY if ACPI
+ select ARCH_DMA_DEFAULT_COHERENT
+ select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
+ select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
+ select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
+ select ARCH_HAS_BINFMT_FLAT
+ select ARCH_HAS_CURRENT_STACK_POINTER
+ select ARCH_HAS_DEBUG_VIRTUAL if MMU
+ select ARCH_HAS_DEBUG_VM_PGTABLE
+ select ARCH_HAS_DEBUG_WX
+ select ARCH_HAS_FORTIFY_SOURCE
+ select ARCH_HAS_GCOV_PROFILE_ALL
+ select ARCH_HAS_GIGANTIC_PAGE
+ select ARCH_HAS_KCOV
+ select ARCH_HAS_MMIOWB
+ select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+ select ARCH_HAS_PMEM_API
+ select ARCH_HAS_PTE_SPECIAL
+ select ARCH_HAS_SET_DIRECT_MAP if MMU
+ select ARCH_HAS_SET_MEMORY if MMU
+ select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
+ select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
+ select ARCH_HAS_SYSCALL_WRAPPER
+ select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
+ select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARCH_HAS_VDSO_DATA
+ select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
+ select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
+ select ARCH_STACKWALK
+ select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_CFI_CLANG
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
+ select ARCH_SUPPORTS_HUGETLBFS if MMU
+ select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
+ select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
+ select ARCH_USE_MEMTEST
+ select ARCH_USE_QUEUED_RWLOCKS
+ select ARCH_USES_CFI_TRAPS if CFI_CLANG
+ select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
+ select ARCH_WANT_FRAME_POINTERS
+ select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
+ select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
+ select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
+ select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
+ select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
+ select BUILDTIME_TABLE_SORT if MMU
+ select CLINT_TIMER if !MMU
+ select CLONE_BACKWARDS
+ select COMMON_CLK
+ select CPU_PM if CPU_IDLE || HIBERNATION
+ select EDAC_SUPPORT
+ select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
+ select GENERIC_ARCH_TOPOLOGY
+ select GENERIC_ATOMIC64 if !64BIT
+ select GENERIC_CLOCKEVENTS_BROADCAST if SMP
+ select GENERIC_EARLY_IOREMAP
+ select GENERIC_ENTRY
+ select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
+ select GENERIC_IDLE_POLL_SETUP
+ select GENERIC_IOREMAP if MMU
+ select GENERIC_IRQ_IPI if SMP
+ select GENERIC_IRQ_IPI_MUX if SMP
+ select GENERIC_IRQ_MULTI_HANDLER
+ select GENERIC_IRQ_SHOW
+ select GENERIC_IRQ_SHOW_LEVEL
+ select GENERIC_LIB_DEVMEM_IS_ALLOWED
+ select GENERIC_PCI_IOMAP
+ select GENERIC_PTDUMP if MMU
+ select GENERIC_SCHED_CLOCK
+ select GENERIC_SMP_IDLE_THREAD
+ select GENERIC_TIME_VSYSCALL if MMU && 64BIT
+ select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
+ select HARDIRQS_SW_RESEND
+ select HAS_IOPORT if MMU
+ select HAVE_ARCH_AUDITSYSCALL
+ select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
+ select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
+ select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
+ select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
+ select HAVE_ARCH_KASAN if MMU && 64BIT
+ select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
+ select HAVE_ARCH_KFENCE if MMU && 64BIT
+ select HAVE_ARCH_KGDB if !XIP_KERNEL
+ select HAVE_ARCH_KGDB_QXFER_PKT
+ select HAVE_ARCH_MMAP_RND_BITS if MMU
+ select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
+ select HAVE_ARCH_SECCOMP_FILTER
+ select HAVE_ARCH_THREAD_STRUCT_WHITELIST
+ select HAVE_ARCH_TRACEHOOK
+ select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
+ select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
+ select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
+ select HAVE_ASM_MODVERSIONS
+ select HAVE_CONTEXT_TRACKING_USER
+ select HAVE_DEBUG_KMEMLEAK
+ select HAVE_DMA_CONTIGUOUS if MMU
+ select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
+ select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
+ select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
+ select HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
+ select HAVE_EBPF_JIT if MMU
+ select HAVE_FUNCTION_ARG_ACCESS_API
+ select HAVE_FUNCTION_ERROR_INJECTION
+ select HAVE_GCC_PLUGINS
+ select HAVE_GENERIC_VDSO if MMU && 64BIT
+ select HAVE_IRQ_TIME_ACCOUNTING
+ select HAVE_KPROBES if !XIP_KERNEL
+ select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
+ select HAVE_KRETPROBES if !XIP_KERNEL
+ # https://github.com/ClangBuiltLinux/linux/issues/1881
+ select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
+ select HAVE_MOVE_PMD
+ select HAVE_MOVE_PUD
+ select HAVE_PCI
+ select HAVE_PERF_EVENTS
+ select HAVE_PERF_REGS
+ select HAVE_PERF_USER_STACK_DUMP
+ select HAVE_POSIX_CPU_TIMERS_TASK_WORK
+ select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
+ select HAVE_REGS_AND_STACK_ACCESS_API
+ select HAVE_RETHOOK if !XIP_KERNEL
+ select HAVE_RSEQ
+ select HAVE_STACKPROTECTOR
+ select HAVE_SYSCALL_TRACEPOINTS
+ select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
+ select IRQ_DOMAIN
+ select IRQ_FORCED_THREADING
+ select KASAN_VMALLOC if KASAN
+ select LOCK_MM_AND_FIND_VMA
+ select MODULES_USE_ELF_RELA if MODULES
+ select MODULE_SECTIONS if MODULES
+ select OF
+ select OF_EARLY_FLATTREE
+ select OF_IRQ
+ select PCI_DOMAINS_GENERIC if PCI
+ select PCI_MSI if PCI
+ select RISCV_ALTERNATIVE if !XIP_KERNEL
+ select RISCV_INTC
+ select RISCV_TIMER if RISCV_SBI
+ select SIFIVE_PLIC
+ select SPARSE_IRQ
+ select SYSCTL_EXCEPTION_TRACE
+ select THREAD_INFO_IN_TASK
+ select TRACE_IRQFLAGS_SUPPORT
+ select UACCESS_MEMCPY if !MMU
+ select ZONE_DMA32 if 64BIT
+
+config CLANG_SUPPORTS_DYNAMIC_FTRACE
+ def_bool CC_IS_CLANG
+ # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e
+ depends on CLANG_VERSION >= 130000
+ # https://github.com/ClangBuiltLinux/linux/issues/1817
+ depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
+
+config GCC_SUPPORTS_DYNAMIC_FTRACE
+ def_bool CC_IS_GCC
+ depends on $(cc-option,-fpatchable-function-entry=8)
+
+config ARCH_MMAP_RND_BITS_MIN
+ default 18 if 64BIT
+ default 8
+
+config ARCH_MMAP_RND_COMPAT_BITS_MIN
+ default 8
+
+# max bits determined by the following formula:
+# VA_BITS - PAGE_SHIFT - 3
+config ARCH_MMAP_RND_BITS_MAX
+ default 24 if 64BIT # SV39 based
+ default 17
+
+config ARCH_MMAP_RND_COMPAT_BITS_MAX
+ default 17
+
+# set if we run in machine mode, cleared if we run in supervisor mode
+config RISCV_M_MODE
+ bool
+ default !MMU
+
+# set if we are running in S-mode and can use SBI calls
+config RISCV_SBI
+ bool
+ depends on !RISCV_M_MODE
+ default y
+
+config MMU
+ bool "MMU-based Paged Memory Management Support"
+ default y
+ help
+ Select if you want MMU-based virtualised addressing space
+ support by paged memory management. If unsure, say 'Y'.
+
+config PAGE_OFFSET
+ hex
+ default 0xC0000000 if 32BIT && MMU
+ default 0x80000000 if !MMU
+ default 0xff60000000000000 if 64BIT
+
+config KASAN_SHADOW_OFFSET
+ hex
+ depends on KASAN_GENERIC
+ default 0xdfffffff00000000 if 64BIT
+ default 0xffffffff if 32BIT
+
+config ARCH_FLATMEM_ENABLE
+ def_bool !NUMA
+
+config ARCH_SPARSEMEM_ENABLE
+ def_bool y
+ depends on MMU
+ select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
+ select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
+
+config ARCH_SELECT_MEMORY_MODEL
+ def_bool ARCH_SPARSEMEM_ENABLE
+
+config ARCH_SUPPORTS_UPROBES
+ def_bool y
+
+config STACKTRACE_SUPPORT
+ def_bool y
+
+config GENERIC_BUG
+ def_bool y
+ depends on BUG
+ select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
+
+config GENERIC_BUG_RELATIVE_POINTERS
+ bool
+
+config GENERIC_CALIBRATE_DELAY
+ def_bool y
+
+config GENERIC_CSUM
+ def_bool y
+
+config GENERIC_HWEIGHT
+ def_bool y
+
+config FIX_EARLYCON_MEM
+ def_bool MMU
+
+config PGTABLE_LEVELS
+ int
+ default 5 if 64BIT
+ default 2
+
+config LOCKDEP_SUPPORT
+ def_bool y
+
+config RISCV_DMA_NONCOHERENT
+ bool
+ select ARCH_HAS_DMA_PREP_COHERENT
+ select ARCH_HAS_SETUP_DMA_OPS
+ select ARCH_HAS_SYNC_DMA_FOR_CPU
+ select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+ select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
+
+config RISCV_NONSTANDARD_CACHE_OPS
+ bool
+ help
+ This enables function pointer support for non-standard noncoherent
+ systems to handle cache management.
+
+config AS_HAS_INSN
+ def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
+
+config AS_HAS_OPTION_ARCH
+ # https://reviews.llvm.org/D123515
+ def_bool y
+ depends on $(as-instr, .option arch$(comma) +m)
+ depends on !$(as-instr, .option arch$(comma) -i)
+
+source "arch/riscv/Kconfig.socs"
+source "arch/riscv/Kconfig.errata"
+
+menu "Platform type"
+
+config NONPORTABLE
+ bool "Allow configurations that result in non-portable kernels"
+ help
+ RISC-V kernel binaries are compatible between all known systems
+ whenever possible, but there are some use cases that can only be
+ satisfied by configurations that result in kernel binaries that are
+ not portable between systems.
+
+ Selecting N does not guarantee kernels will be portable to all known
+ systems. Selecting any of the options guarded by NONPORTABLE will
+ result in kernel binaries that are unlikely to be portable between
+ systems.
+
+ If unsure, say N.
+
+choice
+ prompt "Base ISA"
+ default ARCH_RV64I
+ help
+ This selects the base ISA that this kernel will target and must match
+ the target platform.
+
+config ARCH_RV32I
+ bool "RV32I"
+ depends on NONPORTABLE
+ select 32BIT
+ select GENERIC_LIB_ASHLDI3
+ select GENERIC_LIB_ASHRDI3
+ select GENERIC_LIB_LSHRDI3
+ select GENERIC_LIB_UCMPDI2
+
+config ARCH_RV64I
+ bool "RV64I"
+ select 64BIT
+ select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
+ select SWIOTLB if MMU
+
+endchoice
+
+# We must be able to map all physical memory into the kernel, but the compiler
+# is still a bit more efficient when generating code if it's setup in a manner
+# such that it can only map 2GiB of memory.
+choice
+ prompt "Kernel Code Model"
+ default CMODEL_MEDLOW if 32BIT
+ default CMODEL_MEDANY if 64BIT
+
+ config CMODEL_MEDLOW
+ bool "medium low code model"
+ config CMODEL_MEDANY
+ bool "medium any code model"
+endchoice
+
+config MODULE_SECTIONS
+ bool
+ select HAVE_MOD_ARCH_SPECIFIC
+
+config SMP
+ bool "Symmetric Multi-Processing"
+ help
+ This enables support for systems with more than one CPU. If
+ you say N here, the kernel will run on single and
+ multiprocessor machines, but will use only one CPU of a
+ multiprocessor machine. If you say Y here, the kernel will run
+ on many, but not all, single processor machines. On a single
+ processor machine, the kernel will run faster if you say N
+ here.
+
+ If you don't know what to do here, say N.
+
+config SCHED_MC
+ bool "Multi-core scheduler support"
+ depends on SMP
+ help
+ Multi-core scheduler support improves the CPU scheduler's decision
+ making when dealing with multi-core CPU chips at a cost of slightly
+ increased overhead in some places. If unsure say N here.
+
+config NR_CPUS
+ int "Maximum number of CPUs (2-512)"
+ depends on SMP
+ range 2 512 if !RISCV_SBI_V01
+ range 2 32 if RISCV_SBI_V01 && 32BIT
+ range 2 64 if RISCV_SBI_V01 && 64BIT
+ default "32" if 32BIT
+ default "64" if 64BIT
+
+config HOTPLUG_CPU
+ bool "Support for hot-pluggable CPUs"
+ depends on SMP
+ select GENERIC_IRQ_MIGRATION
+ help
+
+ Say Y here to experiment with turning CPUs off and on. CPUs
+ can be controlled through /sys/devices/system/cpu.
+
+ Say N if you want to disable CPU hotplug.
+
+choice
+ prompt "CPU Tuning"
+ default TUNE_GENERIC
+
+config TUNE_GENERIC
+ bool "generic"
+
+endchoice
+
+# Common NUMA Features
+config NUMA
+ bool "NUMA Memory Allocation and Scheduler Support"
+ depends on SMP && MMU
+ select ARCH_SUPPORTS_NUMA_BALANCING
+ select GENERIC_ARCH_NUMA
+ select NEED_PER_CPU_EMBED_FIRST_CHUNK
+ select OF_NUMA
+ select USE_PERCPU_NUMA_NODE_ID
+ help
+ Enable NUMA (Non-Uniform Memory Access) support.
+
+ The kernel will try to allocate memory used by a CPU on the
+ local memory of the CPU and add some more NUMA awareness to the kernel.
+
+config NODES_SHIFT
+ int "Maximum NUMA Nodes (as a power of 2)"
+ range 1 10
+ default "2"
+ depends on NUMA
+ help
+ Specify the maximum number of NUMA Nodes available on the target
+ system. Increases memory reserved to accommodate various tables.
+
+config RISCV_ALTERNATIVE
+ bool
+ depends on !XIP_KERNEL
+ help
+ This Kconfig allows the kernel to automatically patch the
+ erratum or cpufeature required by the execution platform at run
+ time. The code patching overhead is minimal, as it's only done
+ once at boot and once on each module load.
+
+config RISCV_ALTERNATIVE_EARLY
+ bool
+ depends on RISCV_ALTERNATIVE
+ help
+ Allows early patching of the kernel for special errata
+
+config RISCV_ISA_C
+ bool "Emit compressed instructions when building Linux"
+ default y
+ help
+ Adds "C" to the ISA subsets that the toolchain is allowed to emit
+ when building Linux, which results in compressed instructions in the
+ Linux binary.
+
+ If you don't know what to do here, say Y.
+
+config RISCV_ISA_SVNAPOT
+ bool "Svnapot extension support for supervisor mode NAPOT pages"
+ depends on 64BIT && MMU
+ depends on RISCV_ALTERNATIVE
+ default y
+ help
+ Allow kernel to detect the Svnapot ISA-extension dynamically at boot
+ time and enable its usage.
+
+ The Svnapot extension is used to mark contiguous PTEs as a range
+ of contiguous virtual-to-physical translations for a naturally
+ aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
+ size. When HUGETLBFS is also selected this option unconditionally
+ allocates some memory for each NAPOT page size supported by the kernel.
+ When optimizing for low memory consumption and for platforms without
+ the Svnapot extension, it may be better to say N here.
+
+ If you don't know what to do here, say Y.
+
+config RISCV_ISA_SVPBMT
+ bool "Svpbmt extension support for supervisor mode page-based memory types"
+ depends on 64BIT && MMU
+ depends on RISCV_ALTERNATIVE
+ default y
+ help
+ Adds support to dynamically detect the presence of the Svpbmt
+ ISA-extension (Supervisor-mode: page-based memory types) and
+ enable its usage.
+
+ The memory type for a page contains a combination of attributes
+ that indicate the cacheability, idempotency, and ordering
+ properties for access to that page.
+
+ The Svpbmt extension is only available on 64-bit cpus.
+
+ If you don't know what to do here, say Y.
+
+config TOOLCHAIN_HAS_V
+ bool
+ default y
+ depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv)
+ depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv)
+ depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
+ depends on AS_HAS_OPTION_ARCH
+
+config RISCV_ISA_V
+ bool "VECTOR extension support"
+ depends on TOOLCHAIN_HAS_V
+ depends on FPU
+ select DYNAMIC_SIGFRAME
+ default y
+ help
+ Say N here if you want to disable all vector related procedure
+ in the kernel.
+
+ If you don't know what to do here, say Y.
+
+config RISCV_ISA_V_DEFAULT_ENABLE
+ bool "Enable userspace Vector by default"
+ depends on RISCV_ISA_V
+ default y
+ help
+ Say Y here if you want to enable Vector in userspace by default.
+ Otherwise, userspace has to make explicit prctl() call to enable
+ Vector, or enable it via the sysctl interface.
+
+ If you don't know what to do here, say Y.
+
+config TOOLCHAIN_HAS_ZBB
+ bool
+ default y
+ depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
+ depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
+ depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
+ depends on AS_HAS_OPTION_ARCH
+
+config RISCV_ISA_ZBB
+ bool "Zbb extension support for bit manipulation instructions"
+ depends on TOOLCHAIN_HAS_ZBB
+ depends on MMU
+ depends on RISCV_ALTERNATIVE
+ default y
+ help
+ Adds support to dynamically detect the presence of the ZBB
+ extension (basic bit manipulation) and enable its usage.
+
+ The Zbb extension provides instructions to accelerate a number
+ of bit-specific operations (count bit population, sign extending,
+ bitrotation, etc).
+
+ If you don't know what to do here, say Y.
+
+config RISCV_ISA_ZICBOM
+ bool "Zicbom extension support for non-coherent DMA operation"
+ depends on MMU
+ depends on RISCV_ALTERNATIVE
+ default y
+ select RISCV_DMA_NONCOHERENT
+ select DMA_DIRECT_REMAP
+ help
+ Adds support to dynamically detect the presence of the ZICBOM
+ extension (Cache Block Management Operations) and enable its
+ usage.
+
+ The Zicbom extension can be used to handle for example
+ non-coherent DMA support on devices that need it.
+
+ If you don't know what to do here, say Y.
+
+config RISCV_ISA_ZICBOZ
+ bool "Zicboz extension support for faster zeroing of memory"
+ depends on MMU
+ depends on RISCV_ALTERNATIVE
+ default y
+ help
+ Enable the use of the Zicboz extension (cbo.zero instruction)
+ when available.
+
+ The Zicboz extension is used for faster zeroing of memory.
+
+ If you don't know what to do here, say Y.
+
+config TOOLCHAIN_HAS_ZIHINTPAUSE
+ bool
+ default y
+ depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
+ depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
+ depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
+
+config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
+ def_bool y
+ # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
+ # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
+ depends on AS_IS_GNU && AS_VERSION >= 23600
+ help
+ Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
+ 20191213 version, which moves some instructions from the I extension to
+ the Zicsr and Zifencei extensions. This requires explicitly specifying
+ Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
+ and Zifencei are supported in binutils from version 2.36 onwards.
+ To make life easier, and avoid forcing toolchains that default to a
+ newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
+ For clang < 17 or GCC < 11.3.0, for which this is not possible or need
+ special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
+
+config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
+ def_bool y
+ depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
+ # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
+ # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
+ depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
+ help
+ Certain versions of clang and GCC do not support zicsr and zifencei via
+ -march. This option causes an older ISA spec compatible with these older
+ versions of clang and GCC to be passed to GAS, which has the same result
+ as passing zicsr and zifencei to -march.
+
+config FPU
+ bool "FPU support"
+ default y
+ help
+ Say N here if you want to disable all floating-point related procedure
+ in the kernel.
+
+ If you don't know what to do here, say Y.
+
+config IRQ_STACKS
+ bool "Independent irq & softirq stacks" if EXPERT
+ default y
+ select HAVE_IRQ_EXIT_ON_IRQ_STACK
+ select HAVE_SOFTIRQ_ON_OWN_STACK
+ help
+ Add independent irq & softirq stacks for percpu to prevent kernel stack
+ overflows. We may save some memory footprint by disabling IRQ_STACKS.
+
+config THREAD_SIZE_ORDER
+ int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
+ range 0 4
+ default 1 if 32BIT && !KASAN
+ default 3 if 64BIT && KASAN
+ default 2
+ help
+ Specify the Pages of thread stack size (from 4KB to 64KB), which also
+ affects irq stack size, which is equal to thread stack size.
+
+endmenu # "Platform type"
+
+menu "Kernel features"
+
+source "kernel/Kconfig.hz"
+
+config RISCV_SBI_V01
+ bool "SBI v0.1 support"
+ depends on RISCV_SBI
+ help
+ This config allows kernel to use SBI v0.1 APIs. This will be
+ deprecated in future once legacy M-mode software are no longer in use.
+
+config RISCV_BOOT_SPINWAIT
+ bool "Spinwait booting method"
+ depends on SMP
+ default y if RISCV_SBI_V01 || RISCV_M_MODE
+ help
+ This enables support for booting Linux via spinwait method. In the
+ spinwait method, all cores randomly jump to Linux. One of the cores
+ gets chosen via lottery and all other keep spinning on a percpu
+ variable. This method cannot support CPU hotplug and sparse hartid
+ scheme. It should be only enabled for M-mode Linux or platforms relying
+ on older firmware without SBI HSM extension. All other platforms should
+ rely on ordered booting via SBI HSM extension which gets chosen
+ dynamically at runtime if the firmware supports it.
+
+ Since spinwait is incompatible with sparse hart IDs, it requires
+ NR_CPUS be large enough to contain the physical hart ID of the first
+ hart to enter Linux.
+
+ If unsure what to do here, say N.
+
+config ARCH_SUPPORTS_KEXEC
+ def_bool y
+
+config ARCH_SELECTS_KEXEC
+ def_bool y
+ depends on KEXEC
+ select HOTPLUG_CPU if SMP
+
+config ARCH_SUPPORTS_KEXEC_FILE
+ def_bool 64BIT
+
+config ARCH_SELECTS_KEXEC_FILE
+ def_bool y
+ depends on KEXEC_FILE
+ select HAVE_IMA_KEXEC if IMA
+ select KEXEC_ELF
+
+config ARCH_SUPPORTS_KEXEC_PURGATORY
+ def_bool ARCH_SUPPORTS_KEXEC_FILE
+
+config ARCH_SUPPORTS_CRASH_DUMP
+ def_bool y
+
+config COMPAT
+ bool "Kernel support for 32-bit U-mode"
+ default 64BIT
+ depends on 64BIT && MMU
+ help
+ This option enables support for a 32-bit U-mode running under a 64-bit
+ kernel at S-mode. riscv32-specific components such as system calls,
+ the user helper functions (vdso), signal rt_frame functions and the
+ ptrace interface are handled appropriately by the kernel.
+
+ If you want to execute 32-bit userspace applications, say Y.
+
+config RELOCATABLE
+ bool "Build a relocatable kernel"
+ depends on MMU && 64BIT && !XIP_KERNEL
+ help
+ This builds a kernel as a Position Independent Executable (PIE),
+ which retains all relocation metadata required to relocate the
+ kernel binary at runtime to a different virtual address than the
+ address it was linked at.
+ Since RISCV uses the RELA relocation format, this requires a
+ relocation pass at runtime even if the kernel is loaded at the
+ same address it was linked at.
+
+ If unsure, say N.
+
+config RANDOMIZE_BASE
+ bool "Randomize the address of the kernel image"
+ select RELOCATABLE
+ depends on MMU && 64BIT && !XIP_KERNEL
+ help
+ Randomizes the virtual address at which the kernel image is
+ loaded, as a security feature that deters exploit attempts
+ relying on knowledge of the location of kernel internals.
+
+ It is the bootloader's job to provide entropy, by passing a
+ random u64 value in /chosen/kaslr-seed at kernel entry.
+
+ When booting via the UEFI stub, it will invoke the firmware's
+ EFI_RNG_PROTOCOL implementation (if available) to supply entropy
+ to the kernel proper. In addition, it will randomise the physical
+ location of the kernel Image as well.
+
+ If unsure, say N.
+
+endmenu # "Kernel features"
+
+menu "Boot options"
+
+config CMDLINE
+ string "Built-in kernel command line"
+ help
+ For most platforms, the arguments for the kernel's command line
+ are provided at run-time, during boot. However, there are cases
+ where either no arguments are being provided or the provided
+ arguments are insufficient or even invalid.
+
+ When that occurs, it is possible to define a built-in command
+ line here and choose how the kernel should use it later on.
+
+choice
+ prompt "Built-in command line usage" if CMDLINE != ""
+ default CMDLINE_FALLBACK
+ help
+ Choose how the kernel will handle the provided built-in command
+ line.
+
+config CMDLINE_FALLBACK
+ bool "Use bootloader kernel arguments if available"
+ help
+ Use the built-in command line as fallback in case we get nothing
+ during boot. This is the default behaviour.
+
+config CMDLINE_EXTEND
+ bool "Extend bootloader kernel arguments"
+ help
+ The command-line arguments provided during boot will be
+ appended to the built-in command line. This is useful in
+ cases where the provided arguments are insufficient and
+ you don't want to or cannot modify them.
+
+config CMDLINE_FORCE
+ bool "Always use the default kernel command string"
+ help
+ Always use the built-in command line, even if we get one during
+ boot. This is useful in case you need to override the provided
+ command line on systems where you don't have or want control
+ over it.
+
+endchoice
+
+config EFI_STUB
+ bool
+
+config EFI
+ bool "UEFI runtime support"
+ depends on OF && !XIP_KERNEL
+ depends on MMU
+ default y
+ select ARCH_SUPPORTS_ACPI if 64BIT
+ select EFI_GENERIC_STUB
+ select EFI_PARAMS_FROM_FDT
+ select EFI_RUNTIME_WRAPPERS
+ select EFI_STUB
+ select LIBFDT
+ select RISCV_ISA_C
+ select UCS2_STRING
+ help
+ This option provides support for runtime services provided
+ by UEFI firmware (such as non-volatile variables, realtime
+ clock, and platform reset). A UEFI stub is also provided to
+ allow the kernel to be booted as an EFI application. This
+ is only useful on systems that have UEFI firmware.
+
+config CC_HAVE_STACKPROTECTOR_TLS
+ def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
+
+config STACKPROTECTOR_PER_TASK
+ def_bool y
+ depends on !RANDSTRUCT
+ depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
+
+config PHYS_RAM_BASE_FIXED
+ bool "Explicitly specified physical RAM address"
+ depends on NONPORTABLE
+ default n
+
+config PHYS_RAM_BASE
+ hex "Platform Physical RAM address"
+ depends on PHYS_RAM_BASE_FIXED
+ default "0x80000000"
+ help
+ This is the physical address of RAM in the system. It has to be
+ explicitly specified to run early relocations of read-write data
+ from flash to RAM.
+
+config XIP_KERNEL
+ bool "Kernel Execute-In-Place from ROM"
+ depends on MMU && SPARSEMEM && NONPORTABLE
+ # This prevents XIP from being enabled by all{yes,mod}config, which
+ # fail to build since XIP doesn't support large kernels.
+ depends on !COMPILE_TEST
+ select PHYS_RAM_BASE_FIXED
+ help
+ Execute-In-Place allows the kernel to run from non-volatile storage
+ directly addressable by the CPU, such as NOR flash. This saves RAM
+ space since the text section of the kernel is not loaded from flash
+ to RAM. Read-write sections, such as the data section and stack,
+ are still copied to RAM. The XIP kernel is not compressed since
+ it has to run directly from flash, so it will take more space to
+ store it. The flash address used to link the kernel object files,
+ and for storing it, is configuration dependent. Therefore, if you
+ say Y here, you must know the proper physical address where to
+ store the kernel image depending on your own flash memory usage.
+
+ Also note that the make target becomes "make xipImage" rather than
+ "make zImage" or "make Image". The final kernel binary to put in
+ ROM memory will be arch/riscv/boot/xipImage.
+
+ SPARSEMEM is required because the kernel text and rodata that are
+ flash resident are not backed by memmap, then any attempt to get
+ a struct page on those regions will trigger a fault.
+
+ If unsure, say N.
+
+config XIP_PHYS_ADDR
+ hex "XIP Kernel Physical Location"
+ depends on XIP_KERNEL
+ default "0x21000000"
+ help
+ This is the physical address in your flash memory the kernel will
+ be linked for and stored to. This address is dependent on your
+ own flash usage.
+
+config RISCV_ISA_FALLBACK
+ bool "Permit falling back to parsing riscv,isa for extension support by default"
+ default y
+ help
+ Parsing the "riscv,isa" devicetree property has been deprecated and
+ replaced by a list of explicitly defined strings. For compatibility
+ with existing platforms, the kernel will fall back to parsing the
+ "riscv,isa" property if the replacements are not found.
+
+ Selecting N here will result in a kernel that does not use the
+ fallback, unless the commandline "riscv_isa_fallback" parameter is
+ present.
+
+ Please see the dt-binding, located at
+ Documentation/devicetree/bindings/riscv/extensions.yaml for details
+ on the replacement properties, "riscv,isa-base" and
+ "riscv,isa-extensions".
+
+endmenu # "Boot options"
+
+config BUILTIN_DTB
+ bool
+ depends on OF && NONPORTABLE
+ default y if XIP_KERNEL
+
+config PORTABLE
+ bool
+ default !NONPORTABLE
+ select EFI
+ select MMU
+ select OF
+
+menu "Power management options"
+
+source "kernel/power/Kconfig"
+
+# Hibernation is only possible on systems where the SBI implementation has
+# marked its reserved memory as not accessible from, or does not run
+# from the same memory as, Linux
+config ARCH_HIBERNATION_POSSIBLE
+ def_bool NONPORTABLE
+
+config ARCH_HIBERNATION_HEADER
+ def_bool HIBERNATION
+
+config ARCH_SUSPEND_POSSIBLE
+ def_bool y
+
+endmenu # "Power management options"
+
+menu "CPU Power Management"
+
+source "drivers/cpuidle/Kconfig"
+
+source "drivers/cpufreq/Kconfig"
+
+endmenu # "CPU Power Management"
+
+source "arch/riscv/kvm/Kconfig"
+
+source "drivers/acpi/Kconfig"