1 # SPDX-License-Identifier: GPL-2.0-only
3 # For a description of the syntax of this configuration file,
4 # see Documentation/kbuild/kconfig-language.rst.
15 select ARCH_CLOCKSOURCE_INIT
16 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
17 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
18 select ARCH_HAS_BINFMT_FLAT
19 select ARCH_HAS_CURRENT_STACK_POINTER
20 select ARCH_HAS_DEBUG_VM_PGTABLE
21 select ARCH_HAS_DEBUG_VIRTUAL if MMU
22 select ARCH_HAS_DEBUG_WX
23 select ARCH_HAS_FORTIFY_SOURCE
24 select ARCH_HAS_GCOV_PROFILE_ALL
25 select ARCH_HAS_GIGANTIC_PAGE
27 select ARCH_HAS_MMIOWB
28 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
29 select ARCH_HAS_PTE_SPECIAL
30 select ARCH_HAS_SET_DIRECT_MAP if MMU
31 select ARCH_HAS_SET_MEMORY if MMU
32 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
33 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
34 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
35 select ARCH_HAS_UBSAN_SANITIZE_ALL
36 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
37 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
39 select ARCH_SUPPORTS_ATOMIC_RMW
40 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
41 select ARCH_SUPPORTS_HUGETLBFS if MMU
42 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
43 select ARCH_USE_MEMTEST
44 select ARCH_USE_QUEUED_RWLOCKS
45 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
46 select ARCH_WANT_FRAME_POINTERS
47 select ARCH_WANT_GENERAL_HUGETLB
48 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
49 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
50 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
51 select BUILDTIME_TABLE_SORT if MMU
52 select CLONE_BACKWARDS
53 select CLINT_TIMER if !MMU
55 select CPU_PM if CPU_IDLE
57 select GENERIC_ARCH_TOPOLOGY
58 select GENERIC_ATOMIC64 if !64BIT
59 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
60 select GENERIC_EARLY_IOREMAP
61 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
62 select GENERIC_IDLE_POLL_SETUP
63 select GENERIC_IOREMAP if MMU
64 select GENERIC_IRQ_MULTI_HANDLER
65 select GENERIC_IRQ_SHOW
66 select GENERIC_IRQ_SHOW_LEVEL
67 select GENERIC_LIB_DEVMEM_IS_ALLOWED
68 select GENERIC_PCI_IOMAP
69 select GENERIC_PTDUMP if MMU
70 select GENERIC_SCHED_CLOCK
71 select GENERIC_SMP_IDLE_THREAD
72 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
73 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
74 select HARDIRQS_SW_RESEND
75 select HAVE_ARCH_AUDITSYSCALL
76 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
77 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
78 select HAVE_ARCH_KASAN if MMU && 64BIT
79 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
80 select HAVE_ARCH_KFENCE if MMU && 64BIT
81 select HAVE_ARCH_KGDB if !XIP_KERNEL
82 select HAVE_ARCH_KGDB_QXFER_PKT
83 select HAVE_ARCH_MMAP_RND_BITS if MMU
84 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
85 select HAVE_ARCH_SECCOMP_FILTER
86 select HAVE_ARCH_TRACEHOOK
87 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
88 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
89 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
90 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
91 select HAVE_ASM_MODVERSIONS
92 select HAVE_CONTEXT_TRACKING_USER
93 select HAVE_DEBUG_KMEMLEAK
94 select HAVE_DMA_CONTIGUOUS if MMU
95 select HAVE_EBPF_JIT if MMU
96 select HAVE_FUNCTION_ERROR_INJECTION
97 select HAVE_GCC_PLUGINS
98 select HAVE_GENERIC_VDSO if MMU && 64BIT
99 select HAVE_IRQ_TIME_ACCOUNTING
100 select HAVE_KPROBES if !XIP_KERNEL
101 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
102 select HAVE_KRETPROBES if !XIP_KERNEL
106 select HAVE_PERF_EVENTS
107 select HAVE_PERF_REGS
108 select HAVE_PERF_USER_STACK_DUMP
109 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
110 select HAVE_REGS_AND_STACK_ACCESS_API
111 select HAVE_FUNCTION_ARG_ACCESS_API
112 select HAVE_STACKPROTECTOR
113 select HAVE_SYSCALL_TRACEPOINTS
116 select IRQ_FORCED_THREADING
117 select LOCK_MM_AND_FIND_VMA
118 select MODULES_USE_ELF_RELA if MODULES
119 select MODULE_SECTIONS if MODULES
121 select OF_DMA_DEFAULT_COHERENT
122 select OF_EARLY_FLATTREE
124 select PCI_DOMAINS_GENERIC if PCI
125 select PCI_MSI if PCI
127 select RISCV_TIMER if RISCV_SBI
129 select SYSCTL_EXCEPTION_TRACE
130 select THREAD_INFO_IN_TASK
131 select TRACE_IRQFLAGS_SUPPORT
132 select UACCESS_MEMCPY if !MMU
133 select ZONE_DMA32 if 64BIT
135 config ARCH_MMAP_RND_BITS_MIN
139 config ARCH_MMAP_RND_COMPAT_BITS_MIN
142 # max bits determined by the following formula:
143 # VA_BITS - PAGE_SHIFT - 3
144 config ARCH_MMAP_RND_BITS_MAX
145 default 24 if 64BIT # SV39 based
148 config ARCH_MMAP_RND_COMPAT_BITS_MAX
151 # set if we run in machine mode, cleared if we run in supervisor mode
156 # set if we are running in S-mode and can use SBI calls
159 depends on !RISCV_M_MODE
163 bool "MMU-based Paged Memory Management Support"
166 Select if you want MMU-based virtualised addressing space
167 support by paged memory management. If unsure, say 'Y'.
171 default 0xC0000000 if 32BIT
172 default 0x80000000 if 64BIT && !MMU
173 default 0xff60000000000000 if 64BIT
175 config KASAN_SHADOW_OFFSET
177 depends on KASAN_GENERIC
178 default 0xdfffffff00000000 if 64BIT
179 default 0xffffffff if 32BIT
181 config ARCH_FLATMEM_ENABLE
184 config ARCH_SPARSEMEM_ENABLE
187 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
188 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
190 config ARCH_SELECT_MEMORY_MODEL
191 def_bool ARCH_SPARSEMEM_ENABLE
193 config ARCH_SUPPORTS_UPROBES
196 config STACKTRACE_SUPPORT
202 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
204 config GENERIC_BUG_RELATIVE_POINTERS
207 config GENERIC_CALIBRATE_DELAY
213 config GENERIC_HWEIGHT
216 config FIX_EARLYCON_MEM
219 config PGTABLE_LEVELS
224 config LOCKDEP_SUPPORT
227 config RISCV_DMA_NONCOHERENT
229 select ARCH_HAS_DMA_PREP_COHERENT
230 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
231 select ARCH_HAS_SYNC_DMA_FOR_CPU
232 select ARCH_HAS_SETUP_DMA_OPS
233 select DMA_DIRECT_REMAP
236 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
238 source "arch/riscv/Kconfig.socs"
239 source "arch/riscv/Kconfig.erratas"
244 bool "Allow configurations that result in non-portable kernels"
246 RISC-V kernel binaries are compatible between all known systems
247 whenever possible, but there are some use cases that can only be
248 satisfied by configurations that result in kernel binaries that are
249 not portable between systems.
251 Selecting N does not guarantee kernels will be portable to all known
252 systems. Selecting any of the options guarded by NONPORTABLE will
253 result in kernel binaries that are unlikely to be portable between
262 This selects the base ISA that this kernel will target and must match
267 depends on NONPORTABLE
269 select GENERIC_LIB_ASHLDI3
270 select GENERIC_LIB_ASHRDI3
271 select GENERIC_LIB_LSHRDI3
272 select GENERIC_LIB_UCMPDI2
278 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
279 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
280 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
281 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
282 select HAVE_FUNCTION_GRAPH_TRACER
283 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
284 select SWIOTLB if MMU
288 # We must be able to map all physical memory into the kernel, but the compiler
289 # is still a bit more efficient when generating code if it's setup in a manner
290 # such that it can only map 2GiB of memory.
292 prompt "Kernel Code Model"
293 default CMODEL_MEDLOW if 32BIT
294 default CMODEL_MEDANY if 64BIT
297 bool "medium low code model"
299 bool "medium any code model"
302 config MODULE_SECTIONS
304 select HAVE_MOD_ARCH_SPECIFIC
307 bool "Symmetric Multi-Processing"
309 This enables support for systems with more than one CPU. If
310 you say N here, the kernel will run on single and
311 multiprocessor machines, but will use only one CPU of a
312 multiprocessor machine. If you say Y here, the kernel will run
313 on many, but not all, single processor machines. On a single
314 processor machine, the kernel will run faster if you say N
317 If you don't know what to do here, say N.
320 int "Maximum number of CPUs (2-512)"
322 range 2 512 if !RISCV_SBI_V01
323 range 2 32 if RISCV_SBI_V01 && 32BIT
324 range 2 64 if RISCV_SBI_V01 && 64BIT
325 default "32" if 32BIT
326 default "64" if 64BIT
329 bool "Support for hot-pluggable CPUs"
331 select GENERIC_IRQ_MIGRATION
334 Say Y here to experiment with turning CPUs off and on. CPUs
335 can be controlled through /sys/devices/system/cpu.
337 Say N if you want to disable CPU hotplug.
348 # Common NUMA Features
350 bool "NUMA Memory Allocation and Scheduler Support"
351 depends on SMP && MMU
352 select GENERIC_ARCH_NUMA
354 select ARCH_SUPPORTS_NUMA_BALANCING
355 select USE_PERCPU_NUMA_NODE_ID
356 select NEED_PER_CPU_EMBED_FIRST_CHUNK
358 Enable NUMA (Non-Uniform Memory Access) support.
360 The kernel will try to allocate memory used by a CPU on the
361 local memory of the CPU and add some more NUMA awareness to the kernel.
364 int "Maximum NUMA Nodes (as a power of 2)"
369 Specify the maximum number of NUMA Nodes available on the target
370 system. Increases memory reserved to accommodate various tables.
372 config RISCV_ALTERNATIVE
374 depends on !XIP_KERNEL
376 This Kconfig allows the kernel to automatically patch the
377 errata required by the execution platform at run time. The
378 code patching is performed once in the boot stages. It means
379 that the overhead from this mechanism is just taken once.
381 config RISCV_ALTERNATIVE_EARLY
383 depends on RISCV_ALTERNATIVE
385 Allows early patching of the kernel for special errata
388 bool "Emit compressed instructions when building Linux"
391 Adds "C" to the ISA subsets that the toolchain is allowed to emit
392 when building Linux, which results in compressed instructions in the
395 If you don't know what to do here, say Y.
397 config RISCV_ISA_SVPBMT
398 bool "SVPBMT extension support"
399 depends on 64BIT && MMU
400 depends on !XIP_KERNEL
401 select RISCV_ALTERNATIVE
404 Adds support to dynamically detect the presence of the SVPBMT
405 ISA-extension (Supervisor-mode: page-based memory types) and
408 The memory type for a page contains a combination of attributes
409 that indicate the cacheability, idempotency, and ordering
410 properties for access to that page.
412 The SVPBMT extension is only available on 64Bit cpus.
414 If you don't know what to do here, say Y.
416 config TOOLCHAIN_HAS_ZICBOM
419 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zicbom)
420 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zicbom)
421 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23800
423 config RISCV_ISA_ZICBOM
424 bool "Zicbom extension support for non-coherent DMA operation"
425 depends on TOOLCHAIN_HAS_ZICBOM
426 depends on !XIP_KERNEL && MMU
427 select RISCV_DMA_NONCOHERENT
428 select RISCV_ALTERNATIVE
431 Adds support to dynamically detect the presence of the ZICBOM
432 extension (Cache Block Management Operations) and enable its
435 The Zicbom extension can be used to handle for example
436 non-coherent DMA support on devices that need it.
438 If you don't know what to do here, say Y.
440 config TOOLCHAIN_HAS_ZIHINTPAUSE
443 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
444 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
445 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
447 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
449 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
450 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
451 depends on AS_IS_GNU && AS_VERSION >= 23600
453 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
454 20191213 version, which moves some instructions from the I extension to
455 the Zicsr and Zifencei extensions. This requires explicitly specifying
456 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
457 and Zifencei are supported in binutils from version 2.36 onwards.
458 To make life easier, and avoid forcing toolchains that default to a
459 newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
460 For clang < 17 or GCC < 11.3.0, for which this is not possible or need
461 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
463 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
465 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
466 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
467 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
468 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
470 Certain versions of clang and GCC do not support zicsr and zifencei via
471 -march. This option causes an older ISA spec compatible with these older
472 versions of clang and GCC to be passed to GAS, which has the same result
473 as passing zicsr and zifencei to -march.
479 Say N here if you want to disable all floating-point related procedure
482 If you don't know what to do here, say Y.
484 endmenu # "Platform type"
486 menu "Kernel features"
488 source "kernel/Kconfig.hz"
491 bool "SBI v0.1 support"
494 This config allows kernel to use SBI v0.1 APIs. This will be
495 deprecated in future once legacy M-mode software are no longer in use.
497 config RISCV_BOOT_SPINWAIT
498 bool "Spinwait booting method"
500 default y if RISCV_SBI_V01 || RISCV_M_MODE
502 This enables support for booting Linux via spinwait method. In the
503 spinwait method, all cores randomly jump to Linux. One of the cores
504 gets chosen via lottery and all other keep spinning on a percpu
505 variable. This method cannot support CPU hotplug and sparse hartid
506 scheme. It should be only enabled for M-mode Linux or platforms relying
507 on older firmware without SBI HSM extension. All other platforms should
508 rely on ordered booting via SBI HSM extension which gets chosen
509 dynamically at runtime if the firmware supports it.
511 Since spinwait is incompatible with sparse hart IDs, it requires
512 NR_CPUS be large enough to contain the physical hart ID of the first
515 If unsure what to do here, say N.
518 bool "Kexec system call"
520 select HOTPLUG_CPU if SMP
523 kexec is a system call that implements the ability to shutdown your
524 current kernel, and to start another kernel. It is like a reboot
525 but it is independent of the system firmware. And like a reboot
526 you can start any kernel with it, not just Linux.
528 The name comes from the similarity to the exec system call.
531 bool "kexec file based systmem call"
534 select HAVE_IMA_KEXEC if IMA
535 depends on 64BIT && MMU
537 This is new version of kexec system call. This system call is
538 file based and takes file descriptors as system call argument
539 for kernel and initramfs as opposed to list of segments as
540 accepted by previous system call.
542 If you don't know what to do here, say Y.
544 config ARCH_HAS_KEXEC_PURGATORY
547 depends on CRYPTO_SHA256=y
550 bool "Build kdump crash kernel"
552 Generate crash dump after being started by kexec. This should
553 be normally only set in special crash dump kernels which are
554 loaded in the main kernel with kexec-tools into a specially
555 reserved region and then later executed after a crash by
558 For more details see Documentation/admin-guide/kdump/kdump.rst
561 bool "Kernel support for 32-bit U-mode"
563 depends on 64BIT && MMU
565 This option enables support for a 32-bit U-mode running under a 64-bit
566 kernel at S-mode. riscv32-specific components such as system calls,
567 the user helper functions (vdso), signal rt_frame functions and the
568 ptrace interface are handled appropriately by the kernel.
570 If you want to execute 32-bit userspace applications, say Y.
572 endmenu # "Kernel features"
577 string "Built-in kernel command line"
579 For most platforms, the arguments for the kernel's command line
580 are provided at run-time, during boot. However, there are cases
581 where either no arguments are being provided or the provided
582 arguments are insufficient or even invalid.
584 When that occurs, it is possible to define a built-in command
585 line here and choose how the kernel should use it later on.
588 prompt "Built-in command line usage" if CMDLINE != ""
589 default CMDLINE_FALLBACK
591 Choose how the kernel will handle the provided built-in command
594 config CMDLINE_FALLBACK
595 bool "Use bootloader kernel arguments if available"
597 Use the built-in command line as fallback in case we get nothing
598 during boot. This is the default behaviour.
600 config CMDLINE_EXTEND
601 bool "Extend bootloader kernel arguments"
603 The command-line arguments provided during boot will be
604 appended to the built-in command line. This is useful in
605 cases where the provided arguments are insufficient and
606 you don't want to or cannot modify them.
609 bool "Always use the default kernel command string"
611 Always use the built-in command line, even if we get one during
612 boot. This is useful in case you need to override the provided
613 command line on systems where you don't have or want control
622 bool "UEFI runtime support"
623 depends on OF && !XIP_KERNEL
626 select EFI_PARAMS_FROM_FDT
628 select EFI_GENERIC_STUB
629 select EFI_RUNTIME_WRAPPERS
634 This option provides support for runtime services provided
635 by UEFI firmware (such as non-volatile variables, realtime
636 clock, and platform reset). A UEFI stub is also provided to
637 allow the kernel to be booted as an EFI application. This
638 is only useful on systems that have UEFI firmware.
640 config CC_HAVE_STACKPROTECTOR_TLS
641 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
643 config STACKPROTECTOR_PER_TASK
645 depends on !RANDSTRUCT
646 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
648 config PHYS_RAM_BASE_FIXED
649 bool "Explicitly specified physical RAM address"
650 depends on NONPORTABLE
654 hex "Platform Physical RAM address"
655 depends on PHYS_RAM_BASE_FIXED
658 This is the physical address of RAM in the system. It has to be
659 explicitly specified to run early relocations of read-write data
663 bool "Kernel Execute-In-Place from ROM"
664 depends on MMU && SPARSEMEM && NONPORTABLE
665 # This prevents XIP from being enabled by all{yes,mod}config, which
666 # fail to build since XIP doesn't support large kernels.
667 depends on !COMPILE_TEST
668 select PHYS_RAM_BASE_FIXED
670 Execute-In-Place allows the kernel to run from non-volatile storage
671 directly addressable by the CPU, such as NOR flash. This saves RAM
672 space since the text section of the kernel is not loaded from flash
673 to RAM. Read-write sections, such as the data section and stack,
674 are still copied to RAM. The XIP kernel is not compressed since
675 it has to run directly from flash, so it will take more space to
676 store it. The flash address used to link the kernel object files,
677 and for storing it, is configuration dependent. Therefore, if you
678 say Y here, you must know the proper physical address where to
679 store the kernel image depending on your own flash memory usage.
681 Also note that the make target becomes "make xipImage" rather than
682 "make zImage" or "make Image". The final kernel binary to put in
683 ROM memory will be arch/riscv/boot/xipImage.
685 SPARSEMEM is required because the kernel text and rodata that are
686 flash resident are not backed by memmap, then any attempt to get
687 a struct page on those regions will trigger a fault.
692 hex "XIP Kernel Physical Location"
693 depends on XIP_KERNEL
696 This is the physical address in your flash memory the kernel will
697 be linked for and stored to. This address is dependent on your
700 endmenu # "Boot options"
704 depends on OF && NONPORTABLE
705 default y if XIP_KERNEL
714 menu "Power management options"
716 source "kernel/power/Kconfig"
718 endmenu # "Power management options"
720 menu "CPU Power Management"
722 source "drivers/cpuidle/Kconfig"
724 endmenu # "CPU Power Management"
726 source "arch/riscv/kvm/Kconfig"