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_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
16 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
17 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
18 select ARCH_HAS_BINFMT_FLAT
19 select ARCH_HAS_CURRENT_STACK_POINTER
20 select ARCH_HAS_DEBUG_VIRTUAL if MMU
21 select ARCH_HAS_DEBUG_VM_PGTABLE
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_PMEM_API
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_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
49 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
50 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
51 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
52 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
53 select BUILDTIME_TABLE_SORT if MMU
54 select CLINT_TIMER if !MMU
55 select CLONE_BACKWARDS
57 select CPU_PM if CPU_IDLE
59 select GENERIC_ARCH_TOPOLOGY
60 select GENERIC_ATOMIC64 if !64BIT
61 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
62 select GENERIC_EARLY_IOREMAP
63 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
64 select GENERIC_IDLE_POLL_SETUP
65 select GENERIC_IOREMAP if MMU
66 select GENERIC_IRQ_MULTI_HANDLER
67 select GENERIC_IRQ_SHOW
68 select GENERIC_IRQ_SHOW_LEVEL
69 select GENERIC_LIB_DEVMEM_IS_ALLOWED
70 select GENERIC_PCI_IOMAP
71 select GENERIC_PTDUMP if MMU
72 select GENERIC_SCHED_CLOCK
73 select GENERIC_SMP_IDLE_THREAD
74 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
75 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
76 select HARDIRQS_SW_RESEND
77 select HAVE_ARCH_AUDITSYSCALL
78 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
79 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
80 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
81 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
82 select HAVE_ARCH_KASAN if MMU && 64BIT
83 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
84 select HAVE_ARCH_KFENCE if MMU && 64BIT
85 select HAVE_ARCH_KGDB if !XIP_KERNEL
86 select HAVE_ARCH_KGDB_QXFER_PKT
87 select HAVE_ARCH_MMAP_RND_BITS if MMU
88 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
89 select HAVE_ARCH_SECCOMP_FILTER
90 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
91 select HAVE_ARCH_TRACEHOOK
92 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
93 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
94 select HAVE_ASM_MODVERSIONS
95 select HAVE_CONTEXT_TRACKING_USER
96 select HAVE_DEBUG_KMEMLEAK
97 select HAVE_DMA_CONTIGUOUS if MMU
98 select HAVE_EBPF_JIT if MMU
99 select HAVE_FUNCTION_ARG_ACCESS_API
100 select HAVE_FUNCTION_ERROR_INJECTION
101 select HAVE_GCC_PLUGINS
102 select HAVE_GENERIC_VDSO if MMU && 64BIT
103 select HAVE_IRQ_TIME_ACCOUNTING
104 select HAVE_KPROBES if !XIP_KERNEL
105 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
106 select HAVE_KRETPROBES if !XIP_KERNEL
107 select HAVE_RETHOOK if !XIP_KERNEL
111 select HAVE_PERF_EVENTS
112 select HAVE_PERF_REGS
113 select HAVE_PERF_USER_STACK_DUMP
114 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
115 select HAVE_REGS_AND_STACK_ACCESS_API
117 select HAVE_STACKPROTECTOR
118 select HAVE_SYSCALL_TRACEPOINTS
120 select IRQ_FORCED_THREADING
121 select MODULES_USE_ELF_RELA if MODULES
122 select MODULE_SECTIONS if MODULES
124 select OF_DMA_DEFAULT_COHERENT
125 select OF_EARLY_FLATTREE
127 select PCI_DOMAINS_GENERIC if PCI
128 select PCI_MSI if PCI
130 select RISCV_TIMER if RISCV_SBI
133 select SYSCTL_EXCEPTION_TRACE
134 select THREAD_INFO_IN_TASK
135 select TRACE_IRQFLAGS_SUPPORT
136 select UACCESS_MEMCPY if !MMU
137 select ZONE_DMA32 if 64BIT
138 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
139 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
140 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
141 select HAVE_FUNCTION_GRAPH_TRACER
142 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
144 config ARCH_MMAP_RND_BITS_MIN
148 config ARCH_MMAP_RND_COMPAT_BITS_MIN
151 # max bits determined by the following formula:
152 # VA_BITS - PAGE_SHIFT - 3
153 config ARCH_MMAP_RND_BITS_MAX
154 default 24 if 64BIT # SV39 based
157 config ARCH_MMAP_RND_COMPAT_BITS_MAX
160 # set if we run in machine mode, cleared if we run in supervisor mode
165 # set if we are running in S-mode and can use SBI calls
168 depends on !RISCV_M_MODE
172 bool "MMU-based Paged Memory Management Support"
175 Select if you want MMU-based virtualised addressing space
176 support by paged memory management. If unsure, say 'Y'.
180 default 0xC0000000 if 32BIT
181 default 0x80000000 if 64BIT && !MMU
182 default 0xff60000000000000 if 64BIT
184 config KASAN_SHADOW_OFFSET
186 depends on KASAN_GENERIC
187 default 0xdfffffff00000000 if 64BIT
188 default 0xffffffff if 32BIT
190 config ARCH_FLATMEM_ENABLE
193 config ARCH_SPARSEMEM_ENABLE
196 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
197 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
199 config ARCH_SELECT_MEMORY_MODEL
200 def_bool ARCH_SPARSEMEM_ENABLE
202 config ARCH_SUPPORTS_UPROBES
205 config STACKTRACE_SUPPORT
211 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
213 config GENERIC_BUG_RELATIVE_POINTERS
216 config GENERIC_CALIBRATE_DELAY
222 config GENERIC_HWEIGHT
225 config FIX_EARLYCON_MEM
228 config PGTABLE_LEVELS
233 config LOCKDEP_SUPPORT
236 config RISCV_DMA_NONCOHERENT
238 select ARCH_HAS_DMA_PREP_COHERENT
239 select ARCH_HAS_SETUP_DMA_OPS
240 select ARCH_HAS_SYNC_DMA_FOR_CPU
241 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
242 select DMA_DIRECT_REMAP
245 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
247 source "arch/riscv/Kconfig.socs"
248 source "arch/riscv/Kconfig.erratas"
253 bool "Allow configurations that result in non-portable kernels"
255 RISC-V kernel binaries are compatible between all known systems
256 whenever possible, but there are some use cases that can only be
257 satisfied by configurations that result in kernel binaries that are
258 not portable between systems.
260 Selecting N does not guarantee kernels will be portable to all known
261 systems. Selecting any of the options guarded by NONPORTABLE will
262 result in kernel binaries that are unlikely to be portable between
271 This selects the base ISA that this kernel will target and must match
276 depends on NONPORTABLE
278 select GENERIC_LIB_ASHLDI3
279 select GENERIC_LIB_ASHRDI3
280 select GENERIC_LIB_LSHRDI3
281 select GENERIC_LIB_UCMPDI2
287 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
288 select SWIOTLB if MMU
292 # We must be able to map all physical memory into the kernel, but the compiler
293 # is still a bit more efficient when generating code if it's setup in a manner
294 # such that it can only map 2GiB of memory.
296 prompt "Kernel Code Model"
297 default CMODEL_MEDLOW if 32BIT
298 default CMODEL_MEDANY if 64BIT
301 bool "medium low code model"
303 bool "medium any code model"
306 config MODULE_SECTIONS
308 select HAVE_MOD_ARCH_SPECIFIC
311 bool "Symmetric Multi-Processing"
313 This enables support for systems with more than one CPU. If
314 you say N here, the kernel will run on single and
315 multiprocessor machines, but will use only one CPU of a
316 multiprocessor machine. If you say Y here, the kernel will run
317 on many, but not all, single processor machines. On a single
318 processor machine, the kernel will run faster if you say N
321 If you don't know what to do here, say N.
324 int "Maximum number of CPUs (2-512)"
326 range 2 512 if !RISCV_SBI_V01
327 range 2 32 if RISCV_SBI_V01 && 32BIT
328 range 2 64 if RISCV_SBI_V01 && 64BIT
329 default "32" if 32BIT
330 default "64" if 64BIT
333 bool "Support for hot-pluggable CPUs"
335 select GENERIC_IRQ_MIGRATION
338 Say Y here to experiment with turning CPUs off and on. CPUs
339 can be controlled through /sys/devices/system/cpu.
341 Say N if you want to disable CPU hotplug.
352 # Common NUMA Features
354 bool "NUMA Memory Allocation and Scheduler Support"
355 depends on SMP && MMU
356 select ARCH_SUPPORTS_NUMA_BALANCING
357 select GENERIC_ARCH_NUMA
358 select NEED_PER_CPU_EMBED_FIRST_CHUNK
360 select USE_PERCPU_NUMA_NODE_ID
362 Enable NUMA (Non-Uniform Memory Access) support.
364 The kernel will try to allocate memory used by a CPU on the
365 local memory of the CPU and add some more NUMA awareness to the kernel.
368 int "Maximum NUMA Nodes (as a power of 2)"
373 Specify the maximum number of NUMA Nodes available on the target
374 system. Increases memory reserved to accommodate various tables.
376 config RISCV_ALTERNATIVE
378 depends on !XIP_KERNEL
380 This Kconfig allows the kernel to automatically patch the
381 errata required by the execution platform at run time. The
382 code patching is performed once in the boot stages. It means
383 that the overhead from this mechanism is just taken once.
385 config RISCV_ALTERNATIVE_EARLY
387 depends on RISCV_ALTERNATIVE
389 Allows early patching of the kernel for special errata
392 bool "Emit compressed instructions when building Linux"
395 Adds "C" to the ISA subsets that the toolchain is allowed to emit
396 when building Linux, which results in compressed instructions in the
399 If you don't know what to do here, say Y.
401 config RISCV_ISA_SVPBMT
402 bool "SVPBMT extension support"
403 depends on 64BIT && MMU
404 depends on !XIP_KERNEL
406 select RISCV_ALTERNATIVE
408 Adds support to dynamically detect the presence of the SVPBMT
409 ISA-extension (Supervisor-mode: page-based memory types) and
412 The memory type for a page contains a combination of attributes
413 that indicate the cacheability, idempotency, and ordering
414 properties for access to that page.
416 The SVPBMT extension is only available on 64Bit cpus.
418 If you don't know what to do here, say Y.
420 config TOOLCHAIN_HAS_ZBB
423 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
424 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
425 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
429 bool "Zbb extension support for bit manipulation instructions"
430 depends on TOOLCHAIN_HAS_ZBB
431 depends on !XIP_KERNEL && MMU
432 select RISCV_ALTERNATIVE
435 Adds support to dynamically detect the presence of the ZBB
436 extension (basic bit manipulation) and enable its usage.
438 The Zbb extension provides instructions to accelerate a number
439 of bit-specific operations (count bit population, sign extending,
442 If you don't know what to do here, say Y.
444 config RISCV_ISA_ZICBOM
445 bool "Zicbom extension support for non-coherent DMA operation"
446 depends on !XIP_KERNEL && MMU
448 select RISCV_ALTERNATIVE
449 select RISCV_DMA_NONCOHERENT
451 Adds support to dynamically detect the presence of the ZICBOM
452 extension (Cache Block Management Operations) and enable its
455 The Zicbom extension can be used to handle for example
456 non-coherent DMA support on devices that need it.
458 If you don't know what to do here, say Y.
460 config TOOLCHAIN_HAS_ZIHINTPAUSE
463 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
464 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
465 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
467 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
469 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
470 depends on AS_IS_GNU && AS_VERSION >= 23800
472 Newer binutils versions default to ISA spec version 20191213 which
473 moves some instructions from the I extension to the Zicsr and Zifencei
476 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
478 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
479 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
480 depends on CC_IS_CLANG && CLANG_VERSION < 170000
482 Certain versions of clang do not support zicsr and zifencei via -march
483 but newer versions of binutils require it for the reasons noted in the
484 help text of CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. This
485 option causes an older ISA spec compatible with these older versions
486 of clang to be passed to GAS, which has the same result as passing zicsr
487 and zifencei to -march.
493 Say N here if you want to disable all floating-point related procedure
496 If you don't know what to do here, say Y.
498 endmenu # "Platform type"
500 menu "Kernel features"
502 source "kernel/Kconfig.hz"
505 bool "SBI v0.1 support"
508 This config allows kernel to use SBI v0.1 APIs. This will be
509 deprecated in future once legacy M-mode software are no longer in use.
511 config RISCV_BOOT_SPINWAIT
512 bool "Spinwait booting method"
514 default y if RISCV_SBI_V01 || RISCV_M_MODE
516 This enables support for booting Linux via spinwait method. In the
517 spinwait method, all cores randomly jump to Linux. One of the cores
518 gets chosen via lottery and all other keep spinning on a percpu
519 variable. This method cannot support CPU hotplug and sparse hartid
520 scheme. It should be only enabled for M-mode Linux or platforms relying
521 on older firmware without SBI HSM extension. All other platforms should
522 rely on ordered booting via SBI HSM extension which gets chosen
523 dynamically at runtime if the firmware supports it.
525 Since spinwait is incompatible with sparse hart IDs, it requires
526 NR_CPUS be large enough to contain the physical hart ID of the first
529 If unsure what to do here, say N.
532 bool "Kexec system call"
534 select HOTPLUG_CPU if SMP
537 kexec is a system call that implements the ability to shutdown your
538 current kernel, and to start another kernel. It is like a reboot
539 but it is independent of the system firmware. And like a reboot
540 you can start any kernel with it, not just Linux.
542 The name comes from the similarity to the exec system call.
545 bool "kexec file based systmem call"
546 depends on 64BIT && MMU
547 select HAVE_IMA_KEXEC if IMA
551 This is new version of kexec system call. This system call is
552 file based and takes file descriptors as system call argument
553 for kernel and initramfs as opposed to list of segments as
554 accepted by previous system call.
556 If you don't know what to do here, say Y.
558 config ARCH_HAS_KEXEC_PURGATORY
561 depends on CRYPTO_SHA256=y
564 bool "Build kdump crash kernel"
566 Generate crash dump after being started by kexec. This should
567 be normally only set in special crash dump kernels which are
568 loaded in the main kernel with kexec-tools into a specially
569 reserved region and then later executed after a crash by
572 For more details see Documentation/admin-guide/kdump/kdump.rst
575 bool "Kernel support for 32-bit U-mode"
577 depends on 64BIT && MMU
579 This option enables support for a 32-bit U-mode running under a 64-bit
580 kernel at S-mode. riscv32-specific components such as system calls,
581 the user helper functions (vdso), signal rt_frame functions and the
582 ptrace interface are handled appropriately by the kernel.
584 If you want to execute 32-bit userspace applications, say Y.
586 endmenu # "Kernel features"
591 string "Built-in kernel command line"
593 For most platforms, the arguments for the kernel's command line
594 are provided at run-time, during boot. However, there are cases
595 where either no arguments are being provided or the provided
596 arguments are insufficient or even invalid.
598 When that occurs, it is possible to define a built-in command
599 line here and choose how the kernel should use it later on.
602 prompt "Built-in command line usage" if CMDLINE != ""
603 default CMDLINE_FALLBACK
605 Choose how the kernel will handle the provided built-in command
608 config CMDLINE_FALLBACK
609 bool "Use bootloader kernel arguments if available"
611 Use the built-in command line as fallback in case we get nothing
612 during boot. This is the default behaviour.
614 config CMDLINE_EXTEND
615 bool "Extend bootloader kernel arguments"
617 The command-line arguments provided during boot will be
618 appended to the built-in command line. This is useful in
619 cases where the provided arguments are insufficient and
620 you don't want to or cannot modify them.
623 bool "Always use the default kernel command string"
625 Always use the built-in command line, even if we get one during
626 boot. This is useful in case you need to override the provided
627 command line on systems where you don't have or want control
636 bool "UEFI runtime support"
637 depends on OF && !XIP_KERNEL
640 select EFI_GENERIC_STUB
641 select EFI_PARAMS_FROM_FDT
642 select EFI_RUNTIME_WRAPPERS
648 This option provides support for runtime services provided
649 by UEFI firmware (such as non-volatile variables, realtime
650 clock, and platform reset). A UEFI stub is also provided to
651 allow the kernel to be booted as an EFI application. This
652 is only useful on systems that have UEFI firmware.
654 config CC_HAVE_STACKPROTECTOR_TLS
655 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
657 config STACKPROTECTOR_PER_TASK
659 depends on !RANDSTRUCT
660 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
662 config PHYS_RAM_BASE_FIXED
663 bool "Explicitly specified physical RAM address"
664 depends on NONPORTABLE
668 hex "Platform Physical RAM address"
669 depends on PHYS_RAM_BASE_FIXED
672 This is the physical address of RAM in the system. It has to be
673 explicitly specified to run early relocations of read-write data
677 bool "Kernel Execute-In-Place from ROM"
678 depends on MMU && SPARSEMEM && NONPORTABLE
679 # This prevents XIP from being enabled by all{yes,mod}config, which
680 # fail to build since XIP doesn't support large kernels.
681 depends on !COMPILE_TEST
682 select PHYS_RAM_BASE_FIXED
684 Execute-In-Place allows the kernel to run from non-volatile storage
685 directly addressable by the CPU, such as NOR flash. This saves RAM
686 space since the text section of the kernel is not loaded from flash
687 to RAM. Read-write sections, such as the data section and stack,
688 are still copied to RAM. The XIP kernel is not compressed since
689 it has to run directly from flash, so it will take more space to
690 store it. The flash address used to link the kernel object files,
691 and for storing it, is configuration dependent. Therefore, if you
692 say Y here, you must know the proper physical address where to
693 store the kernel image depending on your own flash memory usage.
695 Also note that the make target becomes "make xipImage" rather than
696 "make zImage" or "make Image". The final kernel binary to put in
697 ROM memory will be arch/riscv/boot/xipImage.
699 SPARSEMEM is required because the kernel text and rodata that are
700 flash resident are not backed by memmap, then any attempt to get
701 a struct page on those regions will trigger a fault.
706 hex "XIP Kernel Physical Location"
707 depends on XIP_KERNEL
710 This is the physical address in your flash memory the kernel will
711 be linked for and stored to. This address is dependent on your
714 endmenu # "Boot options"
718 depends on OF && NONPORTABLE
719 default y if XIP_KERNEL
728 menu "Power management options"
730 source "kernel/power/Kconfig"
732 endmenu # "Power management options"
734 menu "CPU Power Management"
736 source "drivers/cpuidle/Kconfig"
738 source "drivers/cpufreq/Kconfig"
740 endmenu # "CPU Power Management"
742 source "arch/riscv/kvm/Kconfig"