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+# SPDX-License-Identifier: GPL-2.0
+config XTENSA
+ def_bool y
+ select ARCH_32BIT_OFF_T
+ select ARCH_HAS_BINFMT_FLAT if !MMU
+ select ARCH_HAS_DMA_PREP_COHERENT if MMU
+ select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU
+ select ARCH_HAS_SYNC_DMA_FOR_DEVICE if MMU
+ select ARCH_HAS_DMA_SET_UNCACHED if MMU
+ select ARCH_USE_QUEUED_RWLOCKS
+ select ARCH_USE_QUEUED_SPINLOCKS
+ select ARCH_WANT_FRAME_POINTERS
+ select ARCH_WANT_IPC_PARSE_VERSION
+ select BUILDTIME_TABLE_SORT
+ select CLONE_BACKWARDS
+ select COMMON_CLK
+ select DMA_REMAP if MMU
+ select GENERIC_ATOMIC64
+ select GENERIC_CLOCKEVENTS
+ select GENERIC_IRQ_SHOW
+ select GENERIC_PCI_IOMAP
+ select GENERIC_SCHED_CLOCK
+ select GENERIC_STRNCPY_FROM_USER if KASAN
+ select HAVE_ARCH_AUDITSYSCALL
+ select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
+ select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
+ select HAVE_ARCH_SECCOMP_FILTER
+ select HAVE_ARCH_TRACEHOOK
+ select HAVE_DEBUG_KMEMLEAK
+ select HAVE_DMA_CONTIGUOUS
+ select HAVE_EXIT_THREAD
+ select HAVE_FUNCTION_TRACER
+ select HAVE_FUTEX_CMPXCHG if !MMU && FUTEX
+ select HAVE_HW_BREAKPOINT if PERF_EVENTS
+ select HAVE_IRQ_TIME_ACCOUNTING
+ select HAVE_OPROFILE
+ select HAVE_PCI
+ select HAVE_PERF_EVENTS
+ select HAVE_STACKPROTECTOR
+ select HAVE_SYSCALL_TRACEPOINTS
+ select IRQ_DOMAIN
+ select MODULES_USE_ELF_RELA
+ select PERF_USE_VMALLOC
+ select SET_FS
+ select VIRT_TO_BUS
+ help
+ Xtensa processors are 32-bit RISC machines designed by Tensilica
+ primarily for embedded systems. These processors are both
+ configurable and extensible. The Linux port to the Xtensa
+ architecture supports all processor configurations and extensions,
+ with reasonable minimum requirements. The Xtensa Linux project has
+ a home page at <http://www.linux-xtensa.org/>.
+
+config GENERIC_HWEIGHT
+ def_bool y
+
+config ARCH_HAS_ILOG2_U32
+ def_bool n
+
+config ARCH_HAS_ILOG2_U64
+ def_bool n
+
+config NO_IOPORT_MAP
+ def_bool n
+
+config HZ
+ int
+ default 100
+
+config LOCKDEP_SUPPORT
+ def_bool y
+
+config STACKTRACE_SUPPORT
+ def_bool y
+
+config TRACE_IRQFLAGS_SUPPORT
+ def_bool y
+
+config MMU
+ def_bool n
+
+config HAVE_XTENSA_GPIO32
+ def_bool n
+
+config KASAN_SHADOW_OFFSET
+ hex
+ default 0x6e400000
+
+menu "Processor type and features"
+
+choice
+ prompt "Xtensa Processor Configuration"
+ default XTENSA_VARIANT_FSF
+
+config XTENSA_VARIANT_FSF
+ bool "fsf - default (not generic) configuration"
+ select MMU
+
+config XTENSA_VARIANT_DC232B
+ bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
+ select MMU
+ select HAVE_XTENSA_GPIO32
+ help
+ This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
+
+config XTENSA_VARIANT_DC233C
+ bool "dc233c - Diamond 233L Standard Core Rev.C (LE)"
+ select MMU
+ select HAVE_XTENSA_GPIO32
+ help
+ This variant refers to Tensilica's Diamond 233L Standard core Rev.C (LE).
+
+config XTENSA_VARIANT_CUSTOM
+ bool "Custom Xtensa processor configuration"
+ select HAVE_XTENSA_GPIO32
+ help
+ Select this variant to use a custom Xtensa processor configuration.
+ You will be prompted for a processor variant CORENAME.
+endchoice
+
+config XTENSA_VARIANT_CUSTOM_NAME
+ string "Xtensa Processor Custom Core Variant Name"
+ depends on XTENSA_VARIANT_CUSTOM
+ help
+ Provide the name of a custom Xtensa processor variant.
+ This CORENAME selects arch/xtensa/variant/CORENAME.
+ Don't forget you have to select MMU if you have one.
+
+config XTENSA_VARIANT_NAME
+ string
+ default "dc232b" if XTENSA_VARIANT_DC232B
+ default "dc233c" if XTENSA_VARIANT_DC233C
+ default "fsf" if XTENSA_VARIANT_FSF
+ default XTENSA_VARIANT_CUSTOM_NAME if XTENSA_VARIANT_CUSTOM
+
+config XTENSA_VARIANT_MMU
+ bool "Core variant has a Full MMU (TLB, Pages, Protection, etc)"
+ depends on XTENSA_VARIANT_CUSTOM
+ default y
+ select MMU
+ help
+ Build a Conventional Kernel with full MMU support,
+ ie: it supports a TLB with auto-loading, page protection.
+
+config XTENSA_VARIANT_HAVE_PERF_EVENTS
+ bool "Core variant has Performance Monitor Module"
+ depends on XTENSA_VARIANT_CUSTOM
+ default n
+ help
+ Enable if core variant has Performance Monitor Module with
+ External Registers Interface.
+
+ If unsure, say N.
+
+config XTENSA_FAKE_NMI
+ bool "Treat PMM IRQ as NMI"
+ depends on XTENSA_VARIANT_HAVE_PERF_EVENTS
+ default n
+ help
+ If PMM IRQ is the only IRQ at EXCM level it is safe to
+ treat it as NMI, which improves accuracy of profiling.
+
+ If there are other interrupts at or above PMM IRQ priority level
+ but not above the EXCM level, PMM IRQ still may be treated as NMI,
+ but only if these IRQs are not used. There will be a build warning
+ saying that this is not safe, and a bugcheck if one of these IRQs
+ actually fire.
+
+ If unsure, say N.
+
+config XTENSA_UNALIGNED_USER
+ bool "Unaligned memory access in user space"
+ help
+ The Xtensa architecture currently does not handle unaligned
+ memory accesses in hardware but through an exception handler.
+ Per default, unaligned memory accesses are disabled in user space.
+
+ Say Y here to enable unaligned memory access in user space.
+
+config HAVE_SMP
+ bool "System Supports SMP (MX)"
+ depends on XTENSA_VARIANT_CUSTOM
+ select XTENSA_MX
+ help
+ This option is used to indicate that the system-on-a-chip (SOC)
+ supports Multiprocessing. Multiprocessor support implemented above
+ the CPU core definition and currently needs to be selected manually.
+
+ Multiprocessor support is implemented with external cache and
+ interrupt controllers.
+
+ The MX interrupt distributer adds Interprocessor Interrupts
+ and causes the IRQ numbers to be increased by 4 for devices
+ like the open cores ethernet driver and the serial interface.
+
+ You still have to select "Enable SMP" to enable SMP on this SOC.
+
+config SMP
+ bool "Enable Symmetric multi-processing support"
+ depends on HAVE_SMP
+ select GENERIC_SMP_IDLE_THREAD
+ help
+ Enabled SMP Software; allows more than one CPU/CORE
+ to be activated during startup.
+
+config NR_CPUS
+ depends on SMP
+ int "Maximum number of CPUs (2-32)"
+ range 2 32
+ default "4"
+
+config HOTPLUG_CPU
+ bool "Enable CPU hotplug support"
+ depends on SMP
+ help
+ Say Y here to allow turning CPUs off and on. CPUs can be
+ controlled through /sys/devices/system/cpu.
+
+ Say N if you want to disable CPU hotplug.
+
+config FAST_SYSCALL_XTENSA
+ bool "Enable fast atomic syscalls"
+ default n
+ help
+ fast_syscall_xtensa is a syscall that can make atomic operations
+ on UP kernel when processor has no s32c1i support.
+
+ This syscall is deprecated. It may have issues when called with
+ invalid arguments. It is provided only for backwards compatibility.
+ Only enable it if your userspace software requires it.
+
+ If unsure, say N.
+
+config FAST_SYSCALL_SPILL_REGISTERS
+ bool "Enable spill registers syscall"
+ default n
+ help
+ fast_syscall_spill_registers is a syscall that spills all active
+ register windows of a calling userspace task onto its stack.
+
+ This syscall is deprecated. It may have issues when called with
+ invalid arguments. It is provided only for backwards compatibility.
+ Only enable it if your userspace software requires it.
+
+ If unsure, say N.
+
+config USER_ABI_CALL0
+ bool
+
+choice
+ prompt "Userspace ABI"
+ default USER_ABI_DEFAULT
+ help
+ Select supported userspace ABI.
+
+ If unsure, choose the default ABI.
+
+config USER_ABI_DEFAULT
+ bool "Default ABI only"
+ help
+ Assume default userspace ABI. For XEA2 cores it is windowed ABI.
+ call0 ABI binaries may be run on such kernel, but signal delivery
+ will not work correctly for them.
+
+config USER_ABI_CALL0_ONLY
+ bool "Call0 ABI only"
+ select USER_ABI_CALL0
+ help
+ Select this option to support only call0 ABI in userspace.
+ Windowed ABI binaries will crash with a segfault caused by
+ an illegal instruction exception on the first 'entry' opcode.
+
+ Choose this option if you're planning to run only user code
+ built with call0 ABI.
+
+config USER_ABI_CALL0_PROBE
+ bool "Support both windowed and call0 ABI by probing"
+ select USER_ABI_CALL0
+ help
+ Select this option to support both windowed and call0 userspace
+ ABIs. When enabled all processes are started with PS.WOE disabled
+ and a fast user exception handler for an illegal instruction is
+ used to turn on PS.WOE bit on the first 'entry' opcode executed by
+ the userspace.
+
+ This option should be enabled for the kernel that must support
+ both call0 and windowed ABIs in userspace at the same time.
+
+ Note that Xtensa ISA does not guarantee that entry opcode will
+ raise an illegal instruction exception on cores with XEA2 when
+ PS.WOE is disabled, check whether the target core supports it.
+
+endchoice
+
+endmenu
+
+config XTENSA_CALIBRATE_CCOUNT
+ def_bool n
+ help
+ On some platforms (XT2000, for example), the CPU clock rate can
+ vary. The frequency can be determined, however, by measuring
+ against a well known, fixed frequency, such as an UART oscillator.
+
+config SERIAL_CONSOLE
+ def_bool n
+
+config PLATFORM_HAVE_XIP
+ def_bool n
+
+menu "Platform options"
+
+choice
+ prompt "Xtensa System Type"
+ default XTENSA_PLATFORM_ISS
+
+config XTENSA_PLATFORM_ISS
+ bool "ISS"
+ select XTENSA_CALIBRATE_CCOUNT
+ select SERIAL_CONSOLE
+ help
+ ISS is an acronym for Tensilica's Instruction Set Simulator.
+
+config XTENSA_PLATFORM_XT2000
+ bool "XT2000"
+ select HAVE_IDE
+ help
+ XT2000 is the name of Tensilica's feature-rich emulation platform.
+ This hardware is capable of running a full Linux distribution.
+
+config XTENSA_PLATFORM_XTFPGA
+ bool "XTFPGA"
+ select ETHOC if ETHERNET
+ select PLATFORM_WANT_DEFAULT_MEM if !MMU
+ select SERIAL_CONSOLE
+ select XTENSA_CALIBRATE_CCOUNT
+ select PLATFORM_HAVE_XIP
+ help
+ XTFPGA is the name of Tensilica board family (LX60, LX110, LX200, ML605).
+ This hardware is capable of running a full Linux distribution.
+
+endchoice
+
+config PLATFORM_NR_IRQS
+ int
+ default 3 if XTENSA_PLATFORM_XT2000
+ default 0
+
+config XTENSA_CPU_CLOCK
+ int "CPU clock rate [MHz]"
+ depends on !XTENSA_CALIBRATE_CCOUNT
+ default 16
+
+config GENERIC_CALIBRATE_DELAY
+ bool "Auto calibration of the BogoMIPS value"
+ help
+ The BogoMIPS value can easily be derived from the CPU frequency.
+
+config CMDLINE_BOOL
+ bool "Default bootloader kernel arguments"
+
+config CMDLINE
+ string "Initial kernel command string"
+ depends on CMDLINE_BOOL
+ default "console=ttyS0,38400 root=/dev/ram"
+ help
+ On some architectures (EBSA110 and CATS), there is currently no way
+ for the boot loader to pass arguments to the kernel. For these
+ architectures, you should supply some command-line options at build
+ time by entering them here. As a minimum, you should specify the
+ memory size and the root device (e.g., mem=64M root=/dev/nfs).
+
+config USE_OF
+ bool "Flattened Device Tree support"
+ select OF
+ select OF_EARLY_FLATTREE
+ help
+ Include support for flattened device tree machine descriptions.
+
+config BUILTIN_DTB_SOURCE
+ string "DTB to build into the kernel image"
+ depends on OF
+
+config PARSE_BOOTPARAM
+ bool "Parse bootparam block"
+ default y
+ help
+ Parse parameters passed to the kernel from the bootloader. It may
+ be disabled if the kernel is known to run without the bootloader.
+
+ If unsure, say Y.
+
+config BLK_DEV_SIMDISK
+ tristate "Host file-based simulated block device support"
+ default n
+ depends on XTENSA_PLATFORM_ISS && BLOCK
+ help
+ Create block devices that map to files in the host file system.
+ Device binding to host file may be changed at runtime via proc
+ interface provided the device is not in use.
+
+config BLK_DEV_SIMDISK_COUNT
+ int "Number of host file-based simulated block devices"
+ range 1 10
+ depends on BLK_DEV_SIMDISK
+ default 2
+ help
+ This is the default minimal number of created block devices.
+ Kernel/module parameter 'simdisk_count' may be used to change this
+ value at runtime. More file names (but no more than 10) may be
+ specified as parameters, simdisk_count grows accordingly.
+
+config SIMDISK0_FILENAME
+ string "Host filename for the first simulated device"
+ depends on BLK_DEV_SIMDISK = y
+ default ""
+ help
+ Attach a first simdisk to a host file. Conventionally, this file
+ contains a root file system.
+
+config SIMDISK1_FILENAME
+ string "Host filename for the second simulated device"
+ depends on BLK_DEV_SIMDISK = y && BLK_DEV_SIMDISK_COUNT != 1
+ default ""
+ help
+ Another simulated disk in a host file for a buildroot-independent
+ storage.
+
+config XTFPGA_LCD
+ bool "Enable XTFPGA LCD driver"
+ depends on XTENSA_PLATFORM_XTFPGA
+ default n
+ help
+ There's a 2x16 LCD on most of XTFPGA boards, kernel may output
+ progress messages there during bootup/shutdown. It may be useful
+ during board bringup.
+
+ If unsure, say N.
+
+config XTFPGA_LCD_BASE_ADDR
+ hex "XTFPGA LCD base address"
+ depends on XTFPGA_LCD
+ default "0x0d0c0000"
+ help
+ Base address of the LCD controller inside KIO region.
+ Different boards from XTFPGA family have LCD controller at different
+ addresses. Please consult prototyping user guide for your board for
+ the correct address. Wrong address here may lead to hardware lockup.
+
+config XTFPGA_LCD_8BIT_ACCESS
+ bool "Use 8-bit access to XTFPGA LCD"
+ depends on XTFPGA_LCD
+ default n
+ help
+ LCD may be connected with 4- or 8-bit interface, 8-bit access may
+ only be used with 8-bit interface. Please consult prototyping user
+ guide for your board for the correct interface width.
+
+comment "Kernel memory layout"
+
+config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+ bool "Initialize Xtensa MMU inside the Linux kernel code"
+ depends on !XTENSA_VARIANT_FSF && !XTENSA_VARIANT_DC232B
+ default y if XTENSA_VARIANT_DC233C || XTENSA_VARIANT_CUSTOM
+ help
+ Earlier version initialized the MMU in the exception vector
+ before jumping to _startup in head.S and had an advantage that
+ it was possible to place a software breakpoint at 'reset' and
+ then enter your normal kernel breakpoints once the MMU was mapped
+ to the kernel mappings (0XC0000000).
+
+ This unfortunately won't work for U-Boot and likely also wont
+ work for using KEXEC to have a hot kernel ready for doing a
+ KDUMP.
+
+ So now the MMU is initialized in head.S but it's necessary to
+ use hardware breakpoints (gdb 'hbreak' cmd) to break at _startup.
+ xt-gdb can't place a Software Breakpoint in the 0XD region prior
+ to mapping the MMU and after mapping even if the area of low memory
+ was mapped gdb wouldn't remove the breakpoint on hitting it as the
+ PC wouldn't match. Since Hardware Breakpoints are recommended for
+ Linux configurations it seems reasonable to just assume they exist
+ and leave this older mechanism for unfortunate souls that choose
+ not to follow Tensilica's recommendation.
+
+ Selecting this will cause U-Boot to set the KERNEL Load and Entry
+ address at 0x00003000 instead of the mapped std of 0xD0003000.
+
+ If in doubt, say Y.
+
+config XIP_KERNEL
+ bool "Kernel Execute-In-Place from ROM"
+ depends on PLATFORM_HAVE_XIP
+ 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 Image" or "make uImage". The final kernel binary to put in
+ ROM memory will be arch/xtensa/boot/xipImage.
+
+ If unsure, say N.
+
+config MEMMAP_CACHEATTR
+ hex "Cache attributes for the memory address space"
+ depends on !MMU
+ default 0x22222222
+ help
+ These cache attributes are set up for noMMU systems. Each hex digit
+ specifies cache attributes for the corresponding 512MB memory
+ region: bits 0..3 -- for addresses 0x00000000..0x1fffffff,
+ bits 4..7 -- for addresses 0x20000000..0x3fffffff, and so on.
+
+ Cache attribute values are specific for the MMU type.
+ For region protection MMUs:
+ 1: WT cached,
+ 2: cache bypass,
+ 4: WB cached,
+ f: illegal.
+ For full MMU:
+ bit 0: executable,
+ bit 1: writable,
+ bits 2..3:
+ 0: cache bypass,
+ 1: WB cache,
+ 2: WT cache,
+ 3: special (c and e are illegal, f is reserved).
+ For MPU:
+ 0: illegal,
+ 1: WB cache,
+ 2: WB, no-write-allocate cache,
+ 3: WT cache,
+ 4: cache bypass.
+
+config KSEG_PADDR
+ hex "Physical address of the KSEG mapping"
+ depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX && MMU
+ default 0x00000000
+ help
+ This is the physical address where KSEG is mapped. Please refer to
+ the chosen KSEG layout help for the required address alignment.
+ Unpacked kernel image (including vectors) must be located completely
+ within KSEG.
+ Physical memory below this address is not available to linux.
+
+ If unsure, leave the default value here.
+
+config KERNEL_VIRTUAL_ADDRESS
+ hex "Kernel virtual address"
+ depends on MMU && XIP_KERNEL
+ default 0xd0003000
+ help
+ This is the virtual address where the XIP kernel is mapped.
+ XIP kernel may be mapped into KSEG or KIO region, virtual address
+ provided here must match kernel load address provided in
+ KERNEL_LOAD_ADDRESS.
+
+config KERNEL_LOAD_ADDRESS
+ hex "Kernel load address"
+ default 0x60003000 if !MMU
+ default 0x00003000 if MMU && INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+ default 0xd0003000 if MMU && !INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+ help
+ This is the address where the kernel is loaded.
+ It is virtual address for MMUv2 configurations and physical address
+ for all other configurations.
+
+ If unsure, leave the default value here.
+
+choice
+ prompt "Relocatable vectors location"
+ default XTENSA_VECTORS_IN_TEXT
+ help
+ Choose whether relocatable vectors are merged into the kernel .text
+ or placed separately at runtime. This option does not affect
+ configurations without VECBASE register where vectors are always
+ placed at their hardware-defined locations.
+
+config XTENSA_VECTORS_IN_TEXT
+ bool "Merge relocatable vectors into kernel text"
+ depends on !MTD_XIP
+ help
+ This option puts relocatable vectors into the kernel .text section
+ with proper alignment.
+ This is a safe choice for most configurations.
+
+config XTENSA_VECTORS_SEPARATE
+ bool "Put relocatable vectors at fixed address"
+ help
+ This option puts relocatable vectors at specific virtual address.
+ Vectors are merged with the .init data in the kernel image and
+ are copied into their designated location during kernel startup.
+ Use it to put vectors into IRAM or out of FLASH on kernels with
+ XIP-aware MTD support.
+
+endchoice
+
+config VECTORS_ADDR
+ hex "Kernel vectors virtual address"
+ default 0x00000000
+ depends on XTENSA_VECTORS_SEPARATE
+ help
+ This is the virtual address of the (relocatable) vectors base.
+ It must be within KSEG if MMU is used.
+
+config XIP_DATA_ADDR
+ hex "XIP kernel data virtual address"
+ depends on XIP_KERNEL
+ default 0x00000000
+ help
+ This is the virtual address where XIP kernel data is copied.
+ It must be within KSEG if MMU is used.
+
+config PLATFORM_WANT_DEFAULT_MEM
+ def_bool n
+
+config DEFAULT_MEM_START
+ hex
+ prompt "PAGE_OFFSET/PHYS_OFFSET" if !MMU && PLATFORM_WANT_DEFAULT_MEM
+ default 0x60000000 if PLATFORM_WANT_DEFAULT_MEM
+ default 0x00000000
+ help
+ This is the base address used for both PAGE_OFFSET and PHYS_OFFSET
+ in noMMU configurations.
+
+ If unsure, leave the default value here.
+
+choice
+ prompt "KSEG layout"
+ depends on MMU
+ default XTENSA_KSEG_MMU_V2
+
+config XTENSA_KSEG_MMU_V2
+ bool "MMUv2: 128MB cached + 128MB uncached"
+ help
+ MMUv2 compatible kernel memory map: TLB way 5 maps 128MB starting
+ at KSEG_PADDR to 0xd0000000 with cache and to 0xd8000000
+ without cache.
+ KSEG_PADDR must be aligned to 128MB.
+
+config XTENSA_KSEG_256M
+ bool "256MB cached + 256MB uncached"
+ depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+ help
+ TLB way 6 maps 256MB starting at KSEG_PADDR to 0xb0000000
+ with cache and to 0xc0000000 without cache.
+ KSEG_PADDR must be aligned to 256MB.
+
+config XTENSA_KSEG_512M
+ bool "512MB cached + 512MB uncached"
+ depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+ help
+ TLB way 6 maps 512MB starting at KSEG_PADDR to 0xa0000000
+ with cache and to 0xc0000000 without cache.
+ KSEG_PADDR must be aligned to 256MB.
+
+endchoice
+
+config HIGHMEM
+ bool "High Memory Support"
+ depends on MMU
+ help
+ Linux can use the full amount of RAM in the system by
+ default. However, the default MMUv2 setup only maps the
+ lowermost 128 MB of memory linearly to the areas starting
+ at 0xd0000000 (cached) and 0xd8000000 (uncached).
+ When there are more than 128 MB memory in the system not
+ all of it can be "permanently mapped" by the kernel.
+ The physical memory that's not permanently mapped is called
+ "high memory".
+
+ If you are compiling a kernel which will never run on a
+ machine with more than 128 MB total physical RAM, answer
+ N here.
+
+ If unsure, say Y.
+
+config FORCE_MAX_ZONEORDER
+ int "Maximum zone order"
+ default "11"
+ help
+ The kernel memory allocator divides physically contiguous memory
+ blocks into "zones", where each zone is a power of two number of
+ pages. This option selects the largest power of two that the kernel
+ keeps in the memory allocator. If you need to allocate very large
+ blocks of physically contiguous memory, then you may need to
+ increase this value.
+
+ This config option is actually maximum order plus one. For example,
+ a value of 11 means that the largest free memory block is 2^10 pages.
+
+endmenu
+
+menu "Power management options"
+
+source "kernel/power/Kconfig"
+
+endmenu