arch/riscv/Kconfig - linux - Git at Google

 # 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 ARCH_CLOCKSOURCE_INIT
 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
 	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	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_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_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	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_DEBUG_PAGEALLOC if MMU
 	select ARCH_SUPPORTS_HUGETLBFS if MMU
 	select ARCH_USE_MEMTEST
 	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
 	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
 	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
 	select BUILDTIME_TABLE_SORT if MMU
 	select CLONE_BACKWARDS
 	select CLINT_TIMER if !MMU
 	select COMMON_CLK
 	select EDAC_SUPPORT
 	select GENERIC_ARCH_TOPOLOGY if SMP
 	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
 	select GENERIC_IDLE_POLL_SETUP
 	select GENERIC_IOREMAP if MMU
 	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 HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_AUDITSYSCALL
 	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_SECCOMP_FILTER
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
 	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
 	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
 	select HAVE_ASM_MODVERSIONS
 	select HAVE_CONTEXT_TRACKING
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DMA_CONTIGUOUS if MMU
 	select HAVE_EBPF_JIT if MMU
 	select HAVE_FUNCTION_ERROR_INJECTION
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	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
 	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_REGS_AND_STACK_ACCESS_API
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select HAVE_STACKPROTECTOR
 	select HAVE_SYSCALL_TRACEPOINTS
 	select IRQ_DOMAIN
 	select IRQ_FORCED_THREADING
 	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_INTC
 	select RISCV_TIMER if RISCV_SBI
 	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 ARCH_MMAP_RND_BITS_MIN
 	default 18 if 64BIT
 	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

 # 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 VA_BITS
 	int
 	default 32 if 32BIT
 	default 39 if 64BIT

 config PA_BITS
 	int
 	default 34 if 32BIT
 	default 56 if 64BIT

 config PAGE_OFFSET
 	hex
 	default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
 	default 0x80000000 if 64BIT && !MMU
 	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
 	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB

 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_WANT_GENERAL_HUGETLB
 	def_bool y

 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 3 if 64BIT
 	default 2

 config LOCKDEP_SUPPORT
 	def_bool y

 source "arch/riscv/Kconfig.socs"
 source "arch/riscv/Kconfig.erratas"

 menu "Platform type"

 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"
 	select 32BIT
 	select GENERIC_LIB_ASHLDI3
 	select GENERIC_LIB_ASHRDI3
 	select GENERIC_LIB_LSHRDI3
 	select GENERIC_LIB_UCMPDI2
 	select MMU

 config ARCH_RV64I
 	bool "RV64I"
 	select 64BIT
 	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
 	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
 	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_TRACER if !XIP_KERNEL
 	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

 choice
 	prompt "Maximum Physical Memory"
 	default MAXPHYSMEM_1GB if 32BIT
 	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
 	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY

 	config MAXPHYSMEM_1GB
 		depends on 32BIT
 		bool "1GiB"
 	config MAXPHYSMEM_2GB
 		depends on 64BIT && CMODEL_MEDLOW
 		bool "2GiB"
 	config MAXPHYSMEM_128GB
 		depends on 64BIT && CMODEL_MEDANY
 		bool "128GiB"
 endchoice


 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 NR_CPUS
 	int "Maximum number of CPUs (2-32)"
 	range 2 32
 	depends on SMP
 	default "8"

 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 GENERIC_ARCH_NUMA
 	select OF_NUMA
 	select ARCH_SUPPORTS_NUMA_BALANCING
 	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 USE_PERCPU_NUMA_NODE_ID
 	def_bool y
 	depends on NUMA

 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 	def_bool y
 	depends on NUMA

 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.

 menu "supported PMU type"
 	depends on PERF_EVENTS

 config RISCV_BASE_PMU
 	bool "Base Performance Monitoring Unit"
 	def_bool y
 	help
 	  A base PMU that serves as a reference implementation and has limited
 	  feature of perf.  It can run on any RISC-V machines so serves as the
 	  fallback, but this option can also be disable to reduce kernel size.

 endmenu

 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.

 endmenu

 menu "Kernel features"

 source "kernel/Kconfig.hz"

 config RISCV_SBI_V01
 	bool "SBI v0.1 support"
 	default y
 	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 KEXEC
 	bool "Kexec system call"
 	select KEXEC_CORE
 	select HOTPLUG_CPU if SMP
 	depends on MMU
 	help
 	  kexec is a system call that implements the ability to shutdown your
 	  current kernel, and to start another kernel. It is like a reboot
 	  but it is independent of the system firmware. And like a reboot
 	  you can start any kernel with it, not just Linux.

 	  The name comes from the similarity to the exec system call.

 config CRASH_DUMP
 	bool "Build kdump crash kernel"
 	help
 	  Generate crash dump after being started by kexec. This should
 	  be normally only set in special crash dump kernels which are
 	  loaded in the main kernel with kexec-tools into a specially
 	  reserved region and then later executed after a crash by
 	  kdump/kexec.

 	  For more details see Documentation/admin-guide/kdump/kdump.rst

 endmenu

 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
 	select LIBFDT
 	select UCS2_STRING
 	select EFI_PARAMS_FROM_FDT
 	select EFI_STUB
 	select EFI_GENERIC_STUB
 	select EFI_RUNTIME_WRAPPERS
 	select RISCV_ISA_C
 	depends on MMU
 	default y
 	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 !GCC_PLUGIN_RANDSTRUCT
 	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS

 config PHYS_RAM_BASE_FIXED
 	bool "Explicitly specified physical RAM address"
 	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
 	# 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.

 endmenu

 config BUILTIN_DTB
 	bool
 	depends on OF
 	default y if XIP_KERNEL

 menu "Power management options"

 source "kernel/power/Kconfig"

 endmenu

 source "drivers/firmware/Kconfig"
	# 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 ARCH_CLOCKSOURCE_INIT
	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
	select ARCH_HAS_BINFMT_FLAT
	select ARCH_HAS_DEBUG_VM_PGTABLE
	select ARCH_HAS_DEBUG_VIRTUAL if MMU
	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_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_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
	select ARCH_HAS_UBSAN_SANITIZE_ALL
	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_DEBUG_PAGEALLOC if MMU
	select ARCH_SUPPORTS_HUGETLBFS if MMU
	select ARCH_USE_MEMTEST
	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
	select ARCH_WANT_FRAME_POINTERS
	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
	select BUILDTIME_TABLE_SORT if MMU
	select CLONE_BACKWARDS
	select CLINT_TIMER if !MMU
	select COMMON_CLK
	select EDAC_SUPPORT
	select GENERIC_ARCH_TOPOLOGY if SMP
	select GENERIC_ATOMIC64 if !64BIT
	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
	select GENERIC_EARLY_IOREMAP
	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
	select GENERIC_IDLE_POLL_SETUP
	select GENERIC_IOREMAP if MMU
	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 HANDLE_DOMAIN_IRQ
	select HAVE_ARCH_AUDITSYSCALL
	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_SECCOMP_FILTER
	select HAVE_ARCH_TRACEHOOK
	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
	select HAVE_ASM_MODVERSIONS
	select HAVE_CONTEXT_TRACKING
	select HAVE_DEBUG_KMEMLEAK
	select HAVE_DMA_CONTIGUOUS if MMU
	select HAVE_EBPF_JIT if MMU
	select HAVE_FUNCTION_ERROR_INJECTION
	select HAVE_FUTEX_CMPXCHG if FUTEX
	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
	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_REGS_AND_STACK_ACCESS_API
	select HAVE_FUNCTION_ARG_ACCESS_API
	select HAVE_STACKPROTECTOR
	select HAVE_SYSCALL_TRACEPOINTS
	select IRQ_DOMAIN
	select IRQ_FORCED_THREADING
	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_INTC
	select RISCV_TIMER if RISCV_SBI
	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 ARCH_MMAP_RND_BITS_MIN
	default 18 if 64BIT
	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

	# 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 VA_BITS
	int
	default 32 if 32BIT
	default 39 if 64BIT

	config PA_BITS
	int
	default 34 if 32BIT
	default 56 if 64BIT

	config PAGE_OFFSET
	hex
	default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
	default 0x80000000 if 64BIT && !MMU
	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB

	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_WANT_GENERAL_HUGETLB
	def_bool y

	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 3 if 64BIT
	default 2

	config LOCKDEP_SUPPORT
	def_bool y

	source "arch/riscv/Kconfig.socs"
	source "arch/riscv/Kconfig.erratas"

	menu "Platform type"

	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"
	select 32BIT
	select GENERIC_LIB_ASHLDI3
	select GENERIC_LIB_ASHRDI3
	select GENERIC_LIB_LSHRDI3
	select GENERIC_LIB_UCMPDI2
	select MMU

	config ARCH_RV64I
	bool "RV64I"
	select 64BIT
	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
	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_TRACER if !XIP_KERNEL
	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

	choice
	prompt "Maximum Physical Memory"
	default MAXPHYSMEM_1GB if 32BIT
	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY

	config MAXPHYSMEM_1GB
	depends on 32BIT
	bool "1GiB"
	config MAXPHYSMEM_2GB
	depends on 64BIT && CMODEL_MEDLOW
	bool "2GiB"
	config MAXPHYSMEM_128GB
	depends on 64BIT && CMODEL_MEDANY
	bool "128GiB"
	endchoice


	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 NR_CPUS
	int "Maximum number of CPUs (2-32)"
	range 2 32
	depends on SMP
	default "8"

	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 GENERIC_ARCH_NUMA
	select OF_NUMA
	select ARCH_SUPPORTS_NUMA_BALANCING
	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 USE_PERCPU_NUMA_NODE_ID
	def_bool y
	depends on NUMA

	config NEED_PER_CPU_EMBED_FIRST_CHUNK
	def_bool y
	depends on NUMA

	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.

	menu "supported PMU type"
	depends on PERF_EVENTS

	config RISCV_BASE_PMU
	bool "Base Performance Monitoring Unit"
	def_bool y
	help
	A base PMU that serves as a reference implementation and has limited
	feature of perf. It can run on any RISC-V machines so serves as the
	fallback, but this option can also be disable to reduce kernel size.

	endmenu

	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.

	endmenu

	menu "Kernel features"

	source "kernel/Kconfig.hz"

	config RISCV_SBI_V01
	bool "SBI v0.1 support"
	default y
	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 KEXEC
	bool "Kexec system call"
	select KEXEC_CORE
	select HOTPLUG_CPU if SMP
	depends on MMU
	help
	kexec is a system call that implements the ability to shutdown your
	current kernel, and to start another kernel. It is like a reboot
	but it is independent of the system firmware. And like a reboot
	you can start any kernel with it, not just Linux.

	The name comes from the similarity to the exec system call.

	config CRASH_DUMP
	bool "Build kdump crash kernel"
	help
	Generate crash dump after being started by kexec. This should
	be normally only set in special crash dump kernels which are
	loaded in the main kernel with kexec-tools into a specially
	reserved region and then later executed after a crash by
	kdump/kexec.

	For more details see Documentation/admin-guide/kdump/kdump.rst

	endmenu

	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
	select LIBFDT
	select UCS2_STRING
	select EFI_PARAMS_FROM_FDT
	select EFI_STUB
	select EFI_GENERIC_STUB
	select EFI_RUNTIME_WRAPPERS
	select RISCV_ISA_C
	depends on MMU
	default y
	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 !GCC_PLUGIN_RANDSTRUCT
	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS

	config PHYS_RAM_BASE_FIXED
	bool "Explicitly specified physical RAM address"
	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
	# 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.

	endmenu

	config BUILTIN_DTB
	bool
	depends on OF
	default y if XIP_KERNEL

	menu "Power management options"

	source "kernel/power/Kconfig"

	endmenu

	source "drivers/firmware/Kconfig"