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)
297 depends on !$(as-instr, .option arch$(comma) -i)
299 source "arch/riscv/Kconfig.socs"
300 source "arch/riscv/Kconfig.errata"
305 bool "Allow configurations that result in non-portable kernels"
307 RISC-V kernel binaries are compatible between all known systems
308 whenever possible, but there are some use cases that can only be
309 satisfied by configurations that result in kernel binaries that are
310 not portable between systems.
312 Selecting N does not guarantee kernels will be portable to all known
313 systems. Selecting any of the options guarded by NONPORTABLE will
314 result in kernel binaries that are unlikely to be portable between
323 This selects the base ISA that this kernel will target and must match
328 depends on NONPORTABLE
330 select GENERIC_LIB_ASHLDI3
331 select GENERIC_LIB_ASHRDI3
332 select GENERIC_LIB_LSHRDI3
333 select GENERIC_LIB_UCMPDI2
338 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
339 select SWIOTLB if MMU
343 # We must be able to map all physical memory into the kernel, but the compiler
344 # is still a bit more efficient when generating code if it's setup in a manner
345 # such that it can only map 2GiB of memory.
347 prompt "Kernel Code Model"
348 default CMODEL_MEDLOW if 32BIT
349 default CMODEL_MEDANY if 64BIT
352 bool "medium low code model"
354 bool "medium any code model"
357 config MODULE_SECTIONS
359 select HAVE_MOD_ARCH_SPECIFIC
362 bool "Symmetric Multi-Processing"
364 This enables support for systems with more than one CPU. If
365 you say N here, the kernel will run on single and
366 multiprocessor machines, but will use only one CPU of a
367 multiprocessor machine. If you say Y here, the kernel will run
368 on many, but not all, single processor machines. On a single
369 processor machine, the kernel will run faster if you say N
372 If you don't know what to do here, say N.
375 bool "Multi-core scheduler support"
378 Multi-core scheduler support improves the CPU scheduler's decision
379 making when dealing with multi-core CPU chips at a cost of slightly
380 increased overhead in some places. If unsure say N here.
383 int "Maximum number of CPUs (2-512)"
385 range 2 512 if !RISCV_SBI_V01
386 range 2 32 if RISCV_SBI_V01 && 32BIT
387 range 2 64 if RISCV_SBI_V01 && 64BIT
388 default "32" if 32BIT
389 default "64" if 64BIT
392 bool "Support for hot-pluggable CPUs"
394 select GENERIC_IRQ_MIGRATION
397 Say Y here to experiment with turning CPUs off and on. CPUs
398 can be controlled through /sys/devices/system/cpu.
400 Say N if you want to disable CPU hotplug.
411 # Common NUMA Features
413 bool "NUMA Memory Allocation and Scheduler Support"
414 depends on SMP && MMU
415 select ARCH_SUPPORTS_NUMA_BALANCING
416 select GENERIC_ARCH_NUMA
417 select NEED_PER_CPU_EMBED_FIRST_CHUNK
419 select USE_PERCPU_NUMA_NODE_ID
421 Enable NUMA (Non-Uniform Memory Access) support.
423 The kernel will try to allocate memory used by a CPU on the
424 local memory of the CPU and add some more NUMA awareness to the kernel.
427 int "Maximum NUMA Nodes (as a power of 2)"
432 Specify the maximum number of NUMA Nodes available on the target
433 system. Increases memory reserved to accommodate various tables.
435 config RISCV_ALTERNATIVE
437 depends on !XIP_KERNEL
439 This Kconfig allows the kernel to automatically patch the
440 erratum or cpufeature required by the execution platform at run
441 time. The code patching overhead is minimal, as it's only done
442 once at boot and once on each module load.
444 config RISCV_ALTERNATIVE_EARLY
446 depends on RISCV_ALTERNATIVE
448 Allows early patching of the kernel for special errata
451 bool "Emit compressed instructions when building Linux"
454 Adds "C" to the ISA subsets that the toolchain is allowed to emit
455 when building Linux, which results in compressed instructions in the
458 If you don't know what to do here, say Y.
460 config RISCV_ISA_SVNAPOT
461 bool "Svnapot extension support for supervisor mode NAPOT pages"
462 depends on 64BIT && MMU
463 depends on RISCV_ALTERNATIVE
466 Allow kernel to detect the Svnapot ISA-extension dynamically at boot
467 time and enable its usage.
469 The Svnapot extension is used to mark contiguous PTEs as a range
470 of contiguous virtual-to-physical translations for a naturally
471 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
472 size. When HUGETLBFS is also selected this option unconditionally
473 allocates some memory for each NAPOT page size supported by the kernel.
474 When optimizing for low memory consumption and for platforms without
475 the Svnapot extension, it may be better to say N here.
477 If you don't know what to do here, say Y.
479 config RISCV_ISA_SVPBMT
480 bool "Svpbmt extension support for supervisor mode page-based memory types"
481 depends on 64BIT && MMU
482 depends on RISCV_ALTERNATIVE
485 Adds support to dynamically detect the presence of the Svpbmt
486 ISA-extension (Supervisor-mode: page-based memory types) and
489 The memory type for a page contains a combination of attributes
490 that indicate the cacheability, idempotency, and ordering
491 properties for access to that page.
493 The Svpbmt extension is only available on 64-bit cpus.
495 If you don't know what to do here, say Y.
497 config TOOLCHAIN_HAS_V
500 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv)
501 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv)
502 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
503 depends on AS_HAS_OPTION_ARCH
506 bool "VECTOR extension support"
507 depends on TOOLCHAIN_HAS_V
509 select DYNAMIC_SIGFRAME
512 Say N here if you want to disable all vector related procedure
515 If you don't know what to do here, say Y.
517 config RISCV_ISA_V_DEFAULT_ENABLE
518 bool "Enable userspace Vector by default"
519 depends on RISCV_ISA_V
522 Say Y here if you want to enable Vector in userspace by default.
523 Otherwise, userspace has to make explicit prctl() call to enable
524 Vector, or enable it via the sysctl interface.
526 If you don't know what to do here, say Y.
528 config TOOLCHAIN_HAS_ZBB
531 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
532 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
533 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
534 depends on AS_HAS_OPTION_ARCH
537 bool "Zbb extension support for bit manipulation instructions"
538 depends on TOOLCHAIN_HAS_ZBB
540 depends on RISCV_ALTERNATIVE
543 Adds support to dynamically detect the presence of the ZBB
544 extension (basic bit manipulation) and enable its usage.
546 The Zbb extension provides instructions to accelerate a number
547 of bit-specific operations (count bit population, sign extending,
550 If you don't know what to do here, say Y.
552 config RISCV_ISA_ZICBOM
553 bool "Zicbom extension support for non-coherent DMA operation"
555 depends on RISCV_ALTERNATIVE
557 select RISCV_DMA_NONCOHERENT
558 select DMA_DIRECT_REMAP
560 Adds support to dynamically detect the presence of the ZICBOM
561 extension (Cache Block Management Operations) and enable its
564 The Zicbom extension can be used to handle for example
565 non-coherent DMA support on devices that need it.
567 If you don't know what to do here, say Y.
569 config RISCV_ISA_ZICBOZ
570 bool "Zicboz extension support for faster zeroing of memory"
572 depends on RISCV_ALTERNATIVE
575 Enable the use of the Zicboz extension (cbo.zero instruction)
578 The Zicboz extension is used for faster zeroing of memory.
580 If you don't know what to do here, say Y.
582 config TOOLCHAIN_HAS_ZIHINTPAUSE
585 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
586 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
587 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
589 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
591 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
592 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
593 depends on AS_IS_GNU && AS_VERSION >= 23600
595 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
596 20191213 version, which moves some instructions from the I extension to
597 the Zicsr and Zifencei extensions. This requires explicitly specifying
598 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
599 and Zifencei are supported in binutils from version 2.36 onwards.
600 To make life easier, and avoid forcing toolchains that default to a
601 newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
602 For clang < 17 or GCC < 11.3.0, for which this is not possible or need
603 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
605 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
607 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
608 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
609 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
610 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
612 Certain versions of clang and GCC do not support zicsr and zifencei via
613 -march. This option causes an older ISA spec compatible with these older
614 versions of clang and GCC to be passed to GAS, which has the same result
615 as passing zicsr and zifencei to -march.
621 Say N here if you want to disable all floating-point related procedure
624 If you don't know what to do here, say Y.
627 bool "Independent irq & softirq stacks" if EXPERT
629 select HAVE_IRQ_EXIT_ON_IRQ_STACK
630 select HAVE_SOFTIRQ_ON_OWN_STACK
632 Add independent irq & softirq stacks for percpu to prevent kernel stack
633 overflows. We may save some memory footprint by disabling IRQ_STACKS.
635 config THREAD_SIZE_ORDER
636 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
638 default 1 if 32BIT && !KASAN
639 default 3 if 64BIT && KASAN
642 Specify the Pages of thread stack size (from 4KB to 64KB), which also
643 affects irq stack size, which is equal to thread stack size.
645 endmenu # "Platform type"
647 menu "Kernel features"
649 source "kernel/Kconfig.hz"
652 bool "SBI v0.1 support"
655 This config allows kernel to use SBI v0.1 APIs. This will be
656 deprecated in future once legacy M-mode software are no longer in use.
658 config RISCV_BOOT_SPINWAIT
659 bool "Spinwait booting method"
661 default y if RISCV_SBI_V01 || RISCV_M_MODE
663 This enables support for booting Linux via spinwait method. In the
664 spinwait method, all cores randomly jump to Linux. One of the cores
665 gets chosen via lottery and all other keep spinning on a percpu
666 variable. This method cannot support CPU hotplug and sparse hartid
667 scheme. It should be only enabled for M-mode Linux or platforms relying
668 on older firmware without SBI HSM extension. All other platforms should
669 rely on ordered booting via SBI HSM extension which gets chosen
670 dynamically at runtime if the firmware supports it.
672 Since spinwait is incompatible with sparse hart IDs, it requires
673 NR_CPUS be large enough to contain the physical hart ID of the first
676 If unsure what to do here, say N.
678 config ARCH_SUPPORTS_KEXEC
681 config ARCH_SELECTS_KEXEC
684 select HOTPLUG_CPU if SMP
686 config ARCH_SUPPORTS_KEXEC_FILE
687 def_bool 64BIT && MMU
689 config ARCH_SELECTS_KEXEC_FILE
691 depends on KEXEC_FILE
692 select HAVE_IMA_KEXEC if IMA
695 config ARCH_SUPPORTS_KEXEC_PURGATORY
698 depends on CRYPTO_SHA256=y
700 config ARCH_SUPPORTS_CRASH_DUMP
703 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
707 bool "Kernel support for 32-bit U-mode"
709 depends on 64BIT && MMU
711 This option enables support for a 32-bit U-mode running under a 64-bit
712 kernel at S-mode. riscv32-specific components such as system calls,
713 the user helper functions (vdso), signal rt_frame functions and the
714 ptrace interface are handled appropriately by the kernel.
716 If you want to execute 32-bit userspace applications, say Y.
719 bool "Build a relocatable kernel"
720 depends on MMU && 64BIT && !XIP_KERNEL
722 This builds a kernel as a Position Independent Executable (PIE),
723 which retains all relocation metadata required to relocate the
724 kernel binary at runtime to a different virtual address than the
725 address it was linked at.
726 Since RISCV uses the RELA relocation format, this requires a
727 relocation pass at runtime even if the kernel is loaded at the
728 same address it was linked at.
732 config RANDOMIZE_BASE
733 bool "Randomize the address of the kernel image"
735 depends on MMU && 64BIT && !XIP_KERNEL
737 Randomizes the virtual address at which the kernel image is
738 loaded, as a security feature that deters exploit attempts
739 relying on knowledge of the location of kernel internals.
741 It is the bootloader's job to provide entropy, by passing a
742 random u64 value in /chosen/kaslr-seed at kernel entry.
744 When booting via the UEFI stub, it will invoke the firmware's
745 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
746 to the kernel proper. In addition, it will randomise the physical
747 location of the kernel Image as well.
751 endmenu # "Kernel features"
756 string "Built-in kernel command line"
758 For most platforms, the arguments for the kernel's command line
759 are provided at run-time, during boot. However, there are cases
760 where either no arguments are being provided or the provided
761 arguments are insufficient or even invalid.
763 When that occurs, it is possible to define a built-in command
764 line here and choose how the kernel should use it later on.
767 prompt "Built-in command line usage" if CMDLINE != ""
768 default CMDLINE_FALLBACK
770 Choose how the kernel will handle the provided built-in command
773 config CMDLINE_FALLBACK
774 bool "Use bootloader kernel arguments if available"
776 Use the built-in command line as fallback in case we get nothing
777 during boot. This is the default behaviour.
779 config CMDLINE_EXTEND
780 bool "Extend bootloader kernel arguments"
782 The command-line arguments provided during boot will be
783 appended to the built-in command line. This is useful in
784 cases where the provided arguments are insufficient and
785 you don't want to or cannot modify them.
788 bool "Always use the default kernel command string"
790 Always use the built-in command line, even if we get one during
791 boot. This is useful in case you need to override the provided
792 command line on systems where you don't have or want control
801 bool "UEFI runtime support"
802 depends on OF && !XIP_KERNEL
805 select ARCH_SUPPORTS_ACPI if 64BIT
806 select EFI_GENERIC_STUB
807 select EFI_PARAMS_FROM_FDT
808 select EFI_RUNTIME_WRAPPERS
814 This option provides support for runtime services provided
815 by UEFI firmware (such as non-volatile variables, realtime
816 clock, and platform reset). A UEFI stub is also provided to
817 allow the kernel to be booted as an EFI application. This
818 is only useful on systems that have UEFI firmware.
820 config CC_HAVE_STACKPROTECTOR_TLS
821 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
823 config STACKPROTECTOR_PER_TASK
825 depends on !RANDSTRUCT
826 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
828 config PHYS_RAM_BASE_FIXED
829 bool "Explicitly specified physical RAM address"
830 depends on NONPORTABLE
834 hex "Platform Physical RAM address"
835 depends on PHYS_RAM_BASE_FIXED
838 This is the physical address of RAM in the system. It has to be
839 explicitly specified to run early relocations of read-write data
843 bool "Kernel Execute-In-Place from ROM"
844 depends on MMU && SPARSEMEM && NONPORTABLE
845 # This prevents XIP from being enabled by all{yes,mod}config, which
846 # fail to build since XIP doesn't support large kernels.
847 depends on !COMPILE_TEST
848 select PHYS_RAM_BASE_FIXED
850 Execute-In-Place allows the kernel to run from non-volatile storage
851 directly addressable by the CPU, such as NOR flash. This saves RAM
852 space since the text section of the kernel is not loaded from flash
853 to RAM. Read-write sections, such as the data section and stack,
854 are still copied to RAM. The XIP kernel is not compressed since
855 it has to run directly from flash, so it will take more space to
856 store it. The flash address used to link the kernel object files,
857 and for storing it, is configuration dependent. Therefore, if you
858 say Y here, you must know the proper physical address where to
859 store the kernel image depending on your own flash memory usage.
861 Also note that the make target becomes "make xipImage" rather than
862 "make zImage" or "make Image". The final kernel binary to put in
863 ROM memory will be arch/riscv/boot/xipImage.
865 SPARSEMEM is required because the kernel text and rodata that are
866 flash resident are not backed by memmap, then any attempt to get
867 a struct page on those regions will trigger a fault.
872 hex "XIP Kernel Physical Location"
873 depends on XIP_KERNEL
876 This is the physical address in your flash memory the kernel will
877 be linked for and stored to. This address is dependent on your
880 config RISCV_ISA_FALLBACK
881 bool "Permit falling back to parsing riscv,isa for extension support by default"
884 Parsing the "riscv,isa" devicetree property has been deprecated and
885 replaced by a list of explicitly defined strings. For compatibility
886 with existing platforms, the kernel will fall back to parsing the
887 "riscv,isa" property if the replacements are not found.
889 Selecting N here will result in a kernel that does not use the
890 fallback, unless the commandline "riscv_isa_fallback" parameter is
893 Please see the dt-binding, located at
894 Documentation/devicetree/bindings/riscv/extensions.yaml for details
895 on the replacement properties, "riscv,isa-base" and
896 "riscv,isa-extensions".
898 endmenu # "Boot options"
902 depends on OF && NONPORTABLE
903 default y if XIP_KERNEL
912 menu "Power management options"
914 source "kernel/power/Kconfig"
916 # Hibernation is only possible on systems where the SBI implementation has
917 # marked its reserved memory as not accessible from, or does not run
918 # from the same memory as, Linux
919 config ARCH_HIBERNATION_POSSIBLE
922 config ARCH_HIBERNATION_HEADER
925 config ARCH_SUSPEND_POSSIBLE
928 endmenu # "Power management options"
930 menu "CPU Power Management"
932 source "drivers/cpuidle/Kconfig"
934 source "drivers/cpufreq/Kconfig"
936 endmenu # "CPU Power Management"
938 source "arch/riscv/kvm/Kconfig"
940 source "drivers/acpi/Kconfig"