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 ACPI_GENERIC_GSI if ACPI
16 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
17 select ARCH_DMA_DEFAULT_COHERENT
18 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
19 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
20 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
21 select ARCH_HAS_BINFMT_FLAT
22 select ARCH_HAS_CURRENT_STACK_POINTER
23 select ARCH_HAS_DEBUG_VIRTUAL if MMU
24 select ARCH_HAS_DEBUG_VM_PGTABLE
25 select ARCH_HAS_DEBUG_WX
26 select ARCH_HAS_FORTIFY_SOURCE
27 select ARCH_HAS_GCOV_PROFILE_ALL
28 select ARCH_HAS_GIGANTIC_PAGE
30 select ARCH_HAS_MMIOWB
31 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
32 select ARCH_HAS_PMEM_API
33 select ARCH_HAS_PTE_SPECIAL
34 select ARCH_HAS_SET_DIRECT_MAP if MMU
35 select ARCH_HAS_SET_MEMORY if MMU
36 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
37 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
38 select ARCH_HAS_SYSCALL_WRAPPER
39 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
40 select ARCH_HAS_UBSAN_SANITIZE_ALL
41 select ARCH_HAS_VDSO_DATA
42 select ARCH_KEEP_MEMBLOCK if ACPI
43 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
44 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
46 select ARCH_SUPPORTS_ATOMIC_RMW
47 select ARCH_SUPPORTS_CFI_CLANG
48 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
49 select ARCH_SUPPORTS_HUGETLBFS if MMU
50 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
51 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
52 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
53 select ARCH_USE_MEMTEST
54 select ARCH_USE_QUEUED_RWLOCKS
55 select ARCH_USES_CFI_TRAPS if CFI_CLANG
56 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
57 select ARCH_WANT_FRAME_POINTERS
58 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
59 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
60 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
61 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
62 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
63 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
64 select BUILDTIME_TABLE_SORT if MMU
65 select CLINT_TIMER if !MMU
66 select CLONE_BACKWARDS
68 select CPU_PM if CPU_IDLE || HIBERNATION
70 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
71 select GENERIC_ARCH_TOPOLOGY
72 select GENERIC_ATOMIC64 if !64BIT
73 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
74 select GENERIC_EARLY_IOREMAP
76 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
77 select GENERIC_IDLE_POLL_SETUP
78 select GENERIC_IOREMAP if MMU
79 select GENERIC_IRQ_IPI if SMP
80 select GENERIC_IRQ_IPI_MUX if SMP
81 select GENERIC_IRQ_MULTI_HANDLER
82 select GENERIC_IRQ_SHOW
83 select GENERIC_IRQ_SHOW_LEVEL
84 select GENERIC_LIB_DEVMEM_IS_ALLOWED
85 select GENERIC_PCI_IOMAP
86 select GENERIC_PTDUMP if MMU
87 select GENERIC_SCHED_CLOCK
88 select GENERIC_SMP_IDLE_THREAD
89 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
90 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
91 select HARDIRQS_SW_RESEND
92 select HAS_IOPORT if MMU
93 select HAVE_ARCH_AUDITSYSCALL
94 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
95 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
96 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
97 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
98 select HAVE_ARCH_KASAN if MMU && 64BIT
99 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
100 select HAVE_ARCH_KFENCE if MMU && 64BIT
101 select HAVE_ARCH_KGDB if !XIP_KERNEL
102 select HAVE_ARCH_KGDB_QXFER_PKT
103 select HAVE_ARCH_MMAP_RND_BITS if MMU
104 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
105 select HAVE_ARCH_SECCOMP_FILTER
106 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
107 select HAVE_ARCH_TRACEHOOK
108 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
109 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
110 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
111 select HAVE_ASM_MODVERSIONS
112 select HAVE_CONTEXT_TRACKING_USER
113 select HAVE_DEBUG_KMEMLEAK
114 select HAVE_DMA_CONTIGUOUS if MMU
115 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
116 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
117 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
118 select HAVE_FUNCTION_GRAPH_TRACER
119 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
120 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
121 select HAVE_EBPF_JIT if MMU
122 select HAVE_FUNCTION_ARG_ACCESS_API
123 select HAVE_FUNCTION_ERROR_INJECTION
124 select HAVE_GCC_PLUGINS
125 select HAVE_GENERIC_VDSO if MMU && 64BIT
126 select HAVE_IRQ_TIME_ACCOUNTING
127 select HAVE_KPROBES if !XIP_KERNEL
128 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
129 select HAVE_KRETPROBES if !XIP_KERNEL
130 # https://github.com/ClangBuiltLinux/linux/issues/1881
131 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
135 select HAVE_PERF_EVENTS
136 select HAVE_PERF_REGS
137 select HAVE_PERF_USER_STACK_DUMP
138 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
139 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
140 select HAVE_REGS_AND_STACK_ACCESS_API
141 select HAVE_RETHOOK if !XIP_KERNEL
143 select HAVE_STACKPROTECTOR
144 select HAVE_SYSCALL_TRACEPOINTS
145 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
147 select IRQ_FORCED_THREADING
148 select KASAN_VMALLOC if KASAN
149 select LOCK_MM_AND_FIND_VMA
150 select MODULES_USE_ELF_RELA if MODULES
151 select MODULE_SECTIONS if MODULES
153 select OF_EARLY_FLATTREE
155 select PCI_DOMAINS_GENERIC if PCI
156 select PCI_MSI if PCI
157 select RISCV_ALTERNATIVE if !XIP_KERNEL
159 select RISCV_TIMER if RISCV_SBI
162 select SYSCTL_EXCEPTION_TRACE
163 select THREAD_INFO_IN_TASK
164 select TRACE_IRQFLAGS_SUPPORT
165 select UACCESS_MEMCPY if !MMU
166 select ZONE_DMA32 if 64BIT
168 config CLANG_SUPPORTS_DYNAMIC_FTRACE
170 # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e
171 depends on CLANG_VERSION >= 130000
172 # https://github.com/ClangBuiltLinux/linux/issues/1817
173 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
175 config GCC_SUPPORTS_DYNAMIC_FTRACE
177 depends on $(cc-option,-fpatchable-function-entry=8)
179 config HAVE_SHADOW_CALL_STACK
180 def_bool $(cc-option,-fsanitize=shadow-call-stack)
181 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
182 depends on $(ld-option,--no-relax-gp)
184 config ARCH_MMAP_RND_BITS_MIN
188 config ARCH_MMAP_RND_COMPAT_BITS_MIN
191 # max bits determined by the following formula:
192 # VA_BITS - PAGE_SHIFT - 3
193 config ARCH_MMAP_RND_BITS_MAX
194 default 24 if 64BIT # SV39 based
197 config ARCH_MMAP_RND_COMPAT_BITS_MAX
200 # set if we run in machine mode, cleared if we run in supervisor mode
205 # set if we are running in S-mode and can use SBI calls
208 depends on !RISCV_M_MODE
212 bool "MMU-based Paged Memory Management Support"
215 Select if you want MMU-based virtualised addressing space
216 support by paged memory management. If unsure, say 'Y'.
220 default 0xC0000000 if 32BIT && MMU
221 default 0x80000000 if !MMU
222 default 0xff60000000000000 if 64BIT
224 config KASAN_SHADOW_OFFSET
226 depends on KASAN_GENERIC
227 default 0xdfffffff00000000 if 64BIT
228 default 0xffffffff if 32BIT
230 config ARCH_FLATMEM_ENABLE
233 config ARCH_SPARSEMEM_ENABLE
236 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
237 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
239 config ARCH_SELECT_MEMORY_MODEL
240 def_bool ARCH_SPARSEMEM_ENABLE
242 config ARCH_SUPPORTS_UPROBES
245 config STACKTRACE_SUPPORT
251 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
253 config GENERIC_BUG_RELATIVE_POINTERS
256 config GENERIC_CALIBRATE_DELAY
262 config GENERIC_HWEIGHT
265 config FIX_EARLYCON_MEM
268 config PGTABLE_LEVELS
273 config LOCKDEP_SUPPORT
276 config RISCV_DMA_NONCOHERENT
278 select ARCH_HAS_DMA_PREP_COHERENT
279 select ARCH_HAS_SETUP_DMA_OPS
280 select ARCH_HAS_SYNC_DMA_FOR_CPU
281 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
282 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
284 config RISCV_NONSTANDARD_CACHE_OPS
287 This enables function pointer support for non-standard noncoherent
288 systems to handle cache management.
291 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
293 config AS_HAS_OPTION_ARCH
294 # https://reviews.llvm.org/D123515
296 depends on $(as-instr, .option arch$(comma) +m)
298 source "arch/riscv/Kconfig.socs"
299 source "arch/riscv/Kconfig.errata"
304 bool "Allow configurations that result in non-portable kernels"
306 RISC-V kernel binaries are compatible between all known systems
307 whenever possible, but there are some use cases that can only be
308 satisfied by configurations that result in kernel binaries that are
309 not portable between systems.
311 Selecting N does not guarantee kernels will be portable to all known
312 systems. Selecting any of the options guarded by NONPORTABLE will
313 result in kernel binaries that are unlikely to be portable between
322 This selects the base ISA that this kernel will target and must match
327 depends on NONPORTABLE
329 select GENERIC_LIB_ASHLDI3
330 select GENERIC_LIB_ASHRDI3
331 select GENERIC_LIB_LSHRDI3
332 select GENERIC_LIB_UCMPDI2
337 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
338 select SWIOTLB if MMU
342 # We must be able to map all physical memory into the kernel, but the compiler
343 # is still a bit more efficient when generating code if it's setup in a manner
344 # such that it can only map 2GiB of memory.
346 prompt "Kernel Code Model"
347 default CMODEL_MEDLOW if 32BIT
348 default CMODEL_MEDANY if 64BIT
351 bool "medium low code model"
353 bool "medium any code model"
356 config MODULE_SECTIONS
358 select HAVE_MOD_ARCH_SPECIFIC
361 bool "Symmetric Multi-Processing"
363 This enables support for systems with more than one CPU. If
364 you say N here, the kernel will run on single and
365 multiprocessor machines, but will use only one CPU of a
366 multiprocessor machine. If you say Y here, the kernel will run
367 on many, but not all, single processor machines. On a single
368 processor machine, the kernel will run faster if you say N
371 If you don't know what to do here, say N.
374 bool "Multi-core scheduler support"
377 Multi-core scheduler support improves the CPU scheduler's decision
378 making when dealing with multi-core CPU chips at a cost of slightly
379 increased overhead in some places. If unsure say N here.
382 int "Maximum number of CPUs (2-512)"
384 range 2 512 if !RISCV_SBI_V01
385 range 2 32 if RISCV_SBI_V01 && 32BIT
386 range 2 64 if RISCV_SBI_V01 && 64BIT
387 default "32" if 32BIT
388 default "64" if 64BIT
391 bool "Support for hot-pluggable CPUs"
393 select GENERIC_IRQ_MIGRATION
396 Say Y here to experiment with turning CPUs off and on. CPUs
397 can be controlled through /sys/devices/system/cpu.
399 Say N if you want to disable CPU hotplug.
410 # Common NUMA Features
412 bool "NUMA Memory Allocation and Scheduler Support"
413 depends on SMP && MMU
414 select ARCH_SUPPORTS_NUMA_BALANCING
415 select GENERIC_ARCH_NUMA
416 select NEED_PER_CPU_EMBED_FIRST_CHUNK
418 select USE_PERCPU_NUMA_NODE_ID
420 Enable NUMA (Non-Uniform Memory Access) support.
422 The kernel will try to allocate memory used by a CPU on the
423 local memory of the CPU and add some more NUMA awareness to the kernel.
426 int "Maximum NUMA Nodes (as a power of 2)"
431 Specify the maximum number of NUMA Nodes available on the target
432 system. Increases memory reserved to accommodate various tables.
434 config RISCV_ALTERNATIVE
436 depends on !XIP_KERNEL
438 This Kconfig allows the kernel to automatically patch the
439 erratum or cpufeature required by the execution platform at run
440 time. The code patching overhead is minimal, as it's only done
441 once at boot and once on each module load.
443 config RISCV_ALTERNATIVE_EARLY
445 depends on RISCV_ALTERNATIVE
447 Allows early patching of the kernel for special errata
450 bool "Emit compressed instructions when building Linux"
453 Adds "C" to the ISA subsets that the toolchain is allowed to emit
454 when building Linux, which results in compressed instructions in the
457 If you don't know what to do here, say Y.
459 config RISCV_ISA_SVNAPOT
460 bool "Svnapot extension support for supervisor mode NAPOT pages"
461 depends on 64BIT && MMU
462 depends on RISCV_ALTERNATIVE
465 Allow kernel to detect the Svnapot ISA-extension dynamically at boot
466 time and enable its usage.
468 The Svnapot extension is used to mark contiguous PTEs as a range
469 of contiguous virtual-to-physical translations for a naturally
470 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
471 size. When HUGETLBFS is also selected this option unconditionally
472 allocates some memory for each NAPOT page size supported by the kernel.
473 When optimizing for low memory consumption and for platforms without
474 the Svnapot extension, it may be better to say N here.
476 If you don't know what to do here, say Y.
478 config RISCV_ISA_SVPBMT
479 bool "Svpbmt extension support for supervisor mode page-based memory types"
480 depends on 64BIT && MMU
481 depends on RISCV_ALTERNATIVE
484 Adds support to dynamically detect the presence of the Svpbmt
485 ISA-extension (Supervisor-mode: page-based memory types) and
488 The memory type for a page contains a combination of attributes
489 that indicate the cacheability, idempotency, and ordering
490 properties for access to that page.
492 The Svpbmt extension is only available on 64-bit cpus.
494 If you don't know what to do here, say Y.
496 config TOOLCHAIN_HAS_V
499 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv)
500 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv)
501 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
502 depends on AS_HAS_OPTION_ARCH
505 bool "VECTOR extension support"
506 depends on TOOLCHAIN_HAS_V
508 select DYNAMIC_SIGFRAME
511 Say N here if you want to disable all vector related procedure
514 If you don't know what to do here, say Y.
516 config RISCV_ISA_V_DEFAULT_ENABLE
517 bool "Enable userspace Vector by default"
518 depends on RISCV_ISA_V
521 Say Y here if you want to enable Vector in userspace by default.
522 Otherwise, userspace has to make explicit prctl() call to enable
523 Vector, or enable it via the sysctl interface.
525 If you don't know what to do here, say Y.
527 config TOOLCHAIN_HAS_ZBB
530 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
531 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
532 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
533 depends on AS_HAS_OPTION_ARCH
536 bool "Zbb extension support for bit manipulation instructions"
537 depends on TOOLCHAIN_HAS_ZBB
539 depends on RISCV_ALTERNATIVE
542 Adds support to dynamically detect the presence of the ZBB
543 extension (basic bit manipulation) and enable its usage.
545 The Zbb extension provides instructions to accelerate a number
546 of bit-specific operations (count bit population, sign extending,
549 If you don't know what to do here, say Y.
551 config RISCV_ISA_ZICBOM
552 bool "Zicbom extension support for non-coherent DMA operation"
554 depends on RISCV_ALTERNATIVE
556 select RISCV_DMA_NONCOHERENT
557 select DMA_DIRECT_REMAP
559 Adds support to dynamically detect the presence of the ZICBOM
560 extension (Cache Block Management Operations) and enable its
563 The Zicbom extension can be used to handle for example
564 non-coherent DMA support on devices that need it.
566 If you don't know what to do here, say Y.
568 config RISCV_ISA_ZICBOZ
569 bool "Zicboz extension support for faster zeroing of memory"
571 depends on RISCV_ALTERNATIVE
574 Enable the use of the Zicboz extension (cbo.zero instruction)
577 The Zicboz extension is used for faster zeroing of memory.
579 If you don't know what to do here, say Y.
581 config TOOLCHAIN_HAS_ZIHINTPAUSE
584 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
585 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
586 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
588 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
590 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
591 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
592 depends on AS_IS_GNU && AS_VERSION >= 23600
594 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
595 20191213 version, which moves some instructions from the I extension to
596 the Zicsr and Zifencei extensions. This requires explicitly specifying
597 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
598 and Zifencei are supported in binutils from version 2.36 onwards.
599 To make life easier, and avoid forcing toolchains that default to a
600 newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
601 For clang < 17 or GCC < 11.3.0, for which this is not possible or need
602 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
604 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
606 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
607 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
608 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
609 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
611 Certain versions of clang and GCC do not support zicsr and zifencei via
612 -march. This option causes an older ISA spec compatible with these older
613 versions of clang and GCC to be passed to GAS, which has the same result
614 as passing zicsr and zifencei to -march.
620 Say N here if you want to disable all floating-point related procedure
623 If you don't know what to do here, say Y.
626 bool "Independent irq & softirq stacks" if EXPERT
628 select HAVE_IRQ_EXIT_ON_IRQ_STACK
629 select HAVE_SOFTIRQ_ON_OWN_STACK
631 Add independent irq & softirq stacks for percpu to prevent kernel stack
632 overflows. We may save some memory footprint by disabling IRQ_STACKS.
634 config THREAD_SIZE_ORDER
635 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
637 default 1 if 32BIT && !KASAN
638 default 3 if 64BIT && KASAN
641 Specify the Pages of thread stack size (from 4KB to 64KB), which also
642 affects irq stack size, which is equal to thread stack size.
644 config RISCV_MISALIGNED
645 bool "Support misaligned load/store traps for kernel and userspace"
646 select SYSCTL_ARCH_UNALIGN_ALLOW
649 Say Y here if you want the kernel to embed support for misaligned
650 load/store for both kernel and userspace. When disable, misaligned
651 accesses will generate SIGBUS in userspace and panic in kernel.
653 endmenu # "Platform type"
655 menu "Kernel features"
657 source "kernel/Kconfig.hz"
660 bool "SBI v0.1 support"
663 This config allows kernel to use SBI v0.1 APIs. This will be
664 deprecated in future once legacy M-mode software are no longer in use.
666 config RISCV_BOOT_SPINWAIT
667 bool "Spinwait booting method"
669 default y if RISCV_SBI_V01 || RISCV_M_MODE
671 This enables support for booting Linux via spinwait method. In the
672 spinwait method, all cores randomly jump to Linux. One of the cores
673 gets chosen via lottery and all other keep spinning on a percpu
674 variable. This method cannot support CPU hotplug and sparse hartid
675 scheme. It should be only enabled for M-mode Linux or platforms relying
676 on older firmware without SBI HSM extension. All other platforms should
677 rely on ordered booting via SBI HSM extension which gets chosen
678 dynamically at runtime if the firmware supports it.
680 Since spinwait is incompatible with sparse hart IDs, it requires
681 NR_CPUS be large enough to contain the physical hart ID of the first
684 If unsure what to do here, say N.
686 config ARCH_SUPPORTS_KEXEC
689 config ARCH_SELECTS_KEXEC
692 select HOTPLUG_CPU if SMP
694 config ARCH_SUPPORTS_KEXEC_FILE
697 config ARCH_SELECTS_KEXEC_FILE
699 depends on KEXEC_FILE
700 select HAVE_IMA_KEXEC if IMA
703 config ARCH_SUPPORTS_KEXEC_PURGATORY
704 def_bool ARCH_SUPPORTS_KEXEC_FILE
706 config ARCH_SUPPORTS_CRASH_DUMP
709 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
713 bool "Kernel support for 32-bit U-mode"
715 depends on 64BIT && MMU
717 This option enables support for a 32-bit U-mode running under a 64-bit
718 kernel at S-mode. riscv32-specific components such as system calls,
719 the user helper functions (vdso), signal rt_frame functions and the
720 ptrace interface are handled appropriately by the kernel.
722 If you want to execute 32-bit userspace applications, say Y.
725 bool "Build a relocatable kernel"
726 depends on MMU && 64BIT && !XIP_KERNEL
728 This builds a kernel as a Position Independent Executable (PIE),
729 which retains all relocation metadata required to relocate the
730 kernel binary at runtime to a different virtual address than the
731 address it was linked at.
732 Since RISCV uses the RELA relocation format, this requires a
733 relocation pass at runtime even if the kernel is loaded at the
734 same address it was linked at.
738 config RANDOMIZE_BASE
739 bool "Randomize the address of the kernel image"
741 depends on MMU && 64BIT && !XIP_KERNEL
743 Randomizes the virtual address at which the kernel image is
744 loaded, as a security feature that deters exploit attempts
745 relying on knowledge of the location of kernel internals.
747 It is the bootloader's job to provide entropy, by passing a
748 random u64 value in /chosen/kaslr-seed at kernel entry.
750 When booting via the UEFI stub, it will invoke the firmware's
751 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
752 to the kernel proper. In addition, it will randomise the physical
753 location of the kernel Image as well.
757 endmenu # "Kernel features"
762 string "Built-in kernel command line"
764 For most platforms, the arguments for the kernel's command line
765 are provided at run-time, during boot. However, there are cases
766 where either no arguments are being provided or the provided
767 arguments are insufficient or even invalid.
769 When that occurs, it is possible to define a built-in command
770 line here and choose how the kernel should use it later on.
773 prompt "Built-in command line usage" if CMDLINE != ""
774 default CMDLINE_FALLBACK
776 Choose how the kernel will handle the provided built-in command
779 config CMDLINE_FALLBACK
780 bool "Use bootloader kernel arguments if available"
782 Use the built-in command line as fallback in case we get nothing
783 during boot. This is the default behaviour.
785 config CMDLINE_EXTEND
786 bool "Extend bootloader kernel arguments"
788 The command-line arguments provided during boot will be
789 appended to the built-in command line. This is useful in
790 cases where the provided arguments are insufficient and
791 you don't want to or cannot modify them.
794 bool "Always use the default kernel command string"
796 Always use the built-in command line, even if we get one during
797 boot. This is useful in case you need to override the provided
798 command line on systems where you don't have or want control
807 bool "UEFI runtime support"
808 depends on OF && !XIP_KERNEL
811 select ARCH_SUPPORTS_ACPI if 64BIT
812 select EFI_GENERIC_STUB
813 select EFI_PARAMS_FROM_FDT
814 select EFI_RUNTIME_WRAPPERS
820 This option provides support for runtime services provided
821 by UEFI firmware (such as non-volatile variables, realtime
822 clock, and platform reset). A UEFI stub is also provided to
823 allow the kernel to be booted as an EFI application. This
824 is only useful on systems that have UEFI firmware.
826 config CC_HAVE_STACKPROTECTOR_TLS
827 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
829 config STACKPROTECTOR_PER_TASK
831 depends on !RANDSTRUCT
832 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
834 config PHYS_RAM_BASE_FIXED
835 bool "Explicitly specified physical RAM address"
836 depends on NONPORTABLE
840 hex "Platform Physical RAM address"
841 depends on PHYS_RAM_BASE_FIXED
844 This is the physical address of RAM in the system. It has to be
845 explicitly specified to run early relocations of read-write data
849 bool "Kernel Execute-In-Place from ROM"
850 depends on MMU && SPARSEMEM && NONPORTABLE
851 # This prevents XIP from being enabled by all{yes,mod}config, which
852 # fail to build since XIP doesn't support large kernels.
853 depends on !COMPILE_TEST
854 select PHYS_RAM_BASE_FIXED
856 Execute-In-Place allows the kernel to run from non-volatile storage
857 directly addressable by the CPU, such as NOR flash. This saves RAM
858 space since the text section of the kernel is not loaded from flash
859 to RAM. Read-write sections, such as the data section and stack,
860 are still copied to RAM. The XIP kernel is not compressed since
861 it has to run directly from flash, so it will take more space to
862 store it. The flash address used to link the kernel object files,
863 and for storing it, is configuration dependent. Therefore, if you
864 say Y here, you must know the proper physical address where to
865 store the kernel image depending on your own flash memory usage.
867 Also note that the make target becomes "make xipImage" rather than
868 "make zImage" or "make Image". The final kernel binary to put in
869 ROM memory will be arch/riscv/boot/xipImage.
871 SPARSEMEM is required because the kernel text and rodata that are
872 flash resident are not backed by memmap, then any attempt to get
873 a struct page on those regions will trigger a fault.
878 hex "XIP Kernel Physical Location"
879 depends on XIP_KERNEL
882 This is the physical address in your flash memory the kernel will
883 be linked for and stored to. This address is dependent on your
886 config RISCV_ISA_FALLBACK
887 bool "Permit falling back to parsing riscv,isa for extension support by default"
890 Parsing the "riscv,isa" devicetree property has been deprecated and
891 replaced by a list of explicitly defined strings. For compatibility
892 with existing platforms, the kernel will fall back to parsing the
893 "riscv,isa" property if the replacements are not found.
895 Selecting N here will result in a kernel that does not use the
896 fallback, unless the commandline "riscv_isa_fallback" parameter is
899 Please see the dt-binding, located at
900 Documentation/devicetree/bindings/riscv/extensions.yaml for details
901 on the replacement properties, "riscv,isa-base" and
902 "riscv,isa-extensions".
904 endmenu # "Boot options"
908 depends on OF && NONPORTABLE
909 default y if XIP_KERNEL
918 config ARCH_PROC_KCORE_TEXT
921 menu "Power management options"
923 source "kernel/power/Kconfig"
925 # Hibernation is only possible on systems where the SBI implementation has
926 # marked its reserved memory as not accessible from, or does not run
927 # from the same memory as, Linux
928 config ARCH_HIBERNATION_POSSIBLE
931 config ARCH_HIBERNATION_HEADER
934 config ARCH_SUSPEND_POSSIBLE
937 endmenu # "Power management options"
939 menu "CPU Power Management"
941 source "drivers/cpuidle/Kconfig"
943 source "drivers/cpufreq/Kconfig"
945 endmenu # "CPU Power Management"
947 source "arch/riscv/kvm/Kconfig"
949 source "drivers/acpi/Kconfig"