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_HAS_VDSO_DATA
37 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
38 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
40 select ARCH_SUPPORTS_ATOMIC_RMW
41 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
42 select ARCH_SUPPORTS_HUGETLBFS if MMU
43 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
44 select ARCH_USE_MEMTEST
45 select ARCH_USE_QUEUED_RWLOCKS
46 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
47 select ARCH_WANT_FRAME_POINTERS
48 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
49 select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
50 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
51 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
52 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
53 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
54 select BUILDTIME_TABLE_SORT if MMU
55 select CLINT_TIMER if !MMU
56 select CLONE_BACKWARDS
58 select CPU_PM if CPU_IDLE
60 select GENERIC_ARCH_TOPOLOGY
61 select GENERIC_ATOMIC64 if !64BIT
62 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
63 select GENERIC_EARLY_IOREMAP
65 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
66 select GENERIC_IDLE_POLL_SETUP
67 select GENERIC_IOREMAP if MMU
68 select GENERIC_IRQ_MULTI_HANDLER
69 select GENERIC_IRQ_SHOW
70 select GENERIC_IRQ_SHOW_LEVEL
71 select GENERIC_LIB_DEVMEM_IS_ALLOWED
72 select GENERIC_PCI_IOMAP
73 select GENERIC_PTDUMP if MMU
74 select GENERIC_SCHED_CLOCK
75 select GENERIC_SMP_IDLE_THREAD
76 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
77 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
78 select HARDIRQS_SW_RESEND
79 select HAVE_ARCH_AUDITSYSCALL
80 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
81 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
82 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
83 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
84 select HAVE_ARCH_KASAN if MMU && 64BIT
85 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
86 select HAVE_ARCH_KFENCE if MMU && 64BIT
87 select HAVE_ARCH_KGDB if !XIP_KERNEL
88 select HAVE_ARCH_KGDB_QXFER_PKT
89 select HAVE_ARCH_MMAP_RND_BITS if MMU
90 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
91 select HAVE_ARCH_SECCOMP_FILTER
92 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
93 select HAVE_ARCH_TRACEHOOK
94 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
95 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
96 select HAVE_ASM_MODVERSIONS
97 select HAVE_CONTEXT_TRACKING_USER
98 select HAVE_DEBUG_KMEMLEAK
99 select HAVE_DMA_CONTIGUOUS if MMU
100 select HAVE_EBPF_JIT if MMU
101 select HAVE_FUNCTION_ARG_ACCESS_API
102 select HAVE_FUNCTION_ERROR_INJECTION
103 select HAVE_GCC_PLUGINS
104 select HAVE_GENERIC_VDSO if MMU && 64BIT
105 select HAVE_IRQ_TIME_ACCOUNTING
106 select HAVE_KPROBES if !XIP_KERNEL
107 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
108 select HAVE_KRETPROBES if !XIP_KERNEL
109 select HAVE_RETHOOK if !XIP_KERNEL
113 select HAVE_PERF_EVENTS
114 select HAVE_PERF_REGS
115 select HAVE_PERF_USER_STACK_DUMP
116 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
117 select HAVE_REGS_AND_STACK_ACCESS_API
119 select HAVE_STACKPROTECTOR
120 select HAVE_SYSCALL_TRACEPOINTS
122 select IRQ_FORCED_THREADING
123 select KASAN_VMALLOC if KASAN
124 select MODULES_USE_ELF_RELA if MODULES
125 select MODULE_SECTIONS if MODULES
127 select OF_DMA_DEFAULT_COHERENT
128 select OF_EARLY_FLATTREE
130 select PCI_DOMAINS_GENERIC if PCI
131 select PCI_MSI if PCI
132 select RISCV_ALTERNATIVE if !XIP_KERNEL
134 select RISCV_TIMER if RISCV_SBI
137 select SYSCTL_EXCEPTION_TRACE
138 select THREAD_INFO_IN_TASK
139 select TRACE_IRQFLAGS_SUPPORT
140 select UACCESS_MEMCPY if !MMU
141 select ZONE_DMA32 if 64BIT
142 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
143 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
144 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
145 select HAVE_FUNCTION_GRAPH_TRACER
146 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
148 config ARCH_MMAP_RND_BITS_MIN
152 config ARCH_MMAP_RND_COMPAT_BITS_MIN
155 # max bits determined by the following formula:
156 # VA_BITS - PAGE_SHIFT - 3
157 config ARCH_MMAP_RND_BITS_MAX
158 default 24 if 64BIT # SV39 based
161 config ARCH_MMAP_RND_COMPAT_BITS_MAX
164 # set if we run in machine mode, cleared if we run in supervisor mode
169 # set if we are running in S-mode and can use SBI calls
172 depends on !RISCV_M_MODE
176 bool "MMU-based Paged Memory Management Support"
179 Select if you want MMU-based virtualised addressing space
180 support by paged memory management. If unsure, say 'Y'.
184 default 0xC0000000 if 32BIT && MMU
185 default 0x80000000 if !MMU
186 default 0xff60000000000000 if 64BIT
188 config KASAN_SHADOW_OFFSET
190 depends on KASAN_GENERIC
191 default 0xdfffffff00000000 if 64BIT
192 default 0xffffffff if 32BIT
194 config ARCH_FLATMEM_ENABLE
197 config ARCH_SPARSEMEM_ENABLE
200 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
201 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
203 config ARCH_SELECT_MEMORY_MODEL
204 def_bool ARCH_SPARSEMEM_ENABLE
206 config ARCH_SUPPORTS_UPROBES
209 config STACKTRACE_SUPPORT
215 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
217 config GENERIC_BUG_RELATIVE_POINTERS
220 config GENERIC_CALIBRATE_DELAY
226 config GENERIC_HWEIGHT
229 config FIX_EARLYCON_MEM
232 config PGTABLE_LEVELS
237 config LOCKDEP_SUPPORT
240 config RISCV_DMA_NONCOHERENT
242 select ARCH_HAS_DMA_PREP_COHERENT
243 select ARCH_HAS_SETUP_DMA_OPS
244 select ARCH_HAS_SYNC_DMA_FOR_CPU
245 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
246 select DMA_DIRECT_REMAP
249 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
251 source "arch/riscv/Kconfig.socs"
252 source "arch/riscv/Kconfig.errata"
257 bool "Allow configurations that result in non-portable kernels"
259 RISC-V kernel binaries are compatible between all known systems
260 whenever possible, but there are some use cases that can only be
261 satisfied by configurations that result in kernel binaries that are
262 not portable between systems.
264 Selecting N does not guarantee kernels will be portable to all known
265 systems. Selecting any of the options guarded by NONPORTABLE will
266 result in kernel binaries that are unlikely to be portable between
275 This selects the base ISA that this kernel will target and must match
280 depends on NONPORTABLE
282 select GENERIC_LIB_ASHLDI3
283 select GENERIC_LIB_ASHRDI3
284 select GENERIC_LIB_LSHRDI3
285 select GENERIC_LIB_UCMPDI2
290 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
291 select SWIOTLB if MMU
295 # We must be able to map all physical memory into the kernel, but the compiler
296 # is still a bit more efficient when generating code if it's setup in a manner
297 # such that it can only map 2GiB of memory.
299 prompt "Kernel Code Model"
300 default CMODEL_MEDLOW if 32BIT
301 default CMODEL_MEDANY if 64BIT
304 bool "medium low code model"
306 bool "medium any code model"
309 config MODULE_SECTIONS
311 select HAVE_MOD_ARCH_SPECIFIC
314 bool "Symmetric Multi-Processing"
316 This enables support for systems with more than one CPU. If
317 you say N here, the kernel will run on single and
318 multiprocessor machines, but will use only one CPU of a
319 multiprocessor machine. If you say Y here, the kernel will run
320 on many, but not all, single processor machines. On a single
321 processor machine, the kernel will run faster if you say N
324 If you don't know what to do here, say N.
327 bool "Multi-core scheduler support"
330 Multi-core scheduler support improves the CPU scheduler's decision
331 making when dealing with multi-core CPU chips at a cost of slightly
332 increased overhead in some places. If unsure say N here.
335 int "Maximum number of CPUs (2-512)"
337 range 2 512 if !RISCV_SBI_V01
338 range 2 32 if RISCV_SBI_V01 && 32BIT
339 range 2 64 if RISCV_SBI_V01 && 64BIT
340 default "32" if 32BIT
341 default "64" if 64BIT
344 bool "Support for hot-pluggable CPUs"
346 select GENERIC_IRQ_MIGRATION
349 Say Y here to experiment with turning CPUs off and on. CPUs
350 can be controlled through /sys/devices/system/cpu.
352 Say N if you want to disable CPU hotplug.
363 # Common NUMA Features
365 bool "NUMA Memory Allocation and Scheduler Support"
366 depends on SMP && MMU
367 select ARCH_SUPPORTS_NUMA_BALANCING
368 select GENERIC_ARCH_NUMA
369 select NEED_PER_CPU_EMBED_FIRST_CHUNK
371 select USE_PERCPU_NUMA_NODE_ID
373 Enable NUMA (Non-Uniform Memory Access) support.
375 The kernel will try to allocate memory used by a CPU on the
376 local memory of the CPU and add some more NUMA awareness to the kernel.
379 int "Maximum NUMA Nodes (as a power of 2)"
384 Specify the maximum number of NUMA Nodes available on the target
385 system. Increases memory reserved to accommodate various tables.
387 config RISCV_ALTERNATIVE
389 depends on !XIP_KERNEL
391 This Kconfig allows the kernel to automatically patch the
392 erratum or cpufeature required by the execution platform at run
393 time. The code patching overhead is minimal, as it's only done
394 once at boot and once on each module load.
396 config RISCV_ALTERNATIVE_EARLY
398 depends on RISCV_ALTERNATIVE
400 Allows early patching of the kernel for special errata
403 bool "Emit compressed instructions when building Linux"
406 Adds "C" to the ISA subsets that the toolchain is allowed to emit
407 when building Linux, which results in compressed instructions in the
410 If you don't know what to do here, say Y.
412 config RISCV_ISA_SVNAPOT
413 bool "Svnapot extension support for supervisor mode NAPOT pages"
414 depends on 64BIT && MMU
415 depends on RISCV_ALTERNATIVE
418 Allow kernel to detect the Svnapot ISA-extension dynamically at boot
419 time and enable its usage.
421 The Svnapot extension is used to mark contiguous PTEs as a range
422 of contiguous virtual-to-physical translations for a naturally
423 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
424 size. When HUGETLBFS is also selected this option unconditionally
425 allocates some memory for each NAPOT page size supported by the kernel.
426 When optimizing for low memory consumption and for platforms without
427 the Svnapot extension, it may be better to say N here.
429 If you don't know what to do here, say Y.
431 config RISCV_ISA_SVPBMT
432 bool "Svpbmt extension support for supervisor mode page-based memory types"
433 depends on 64BIT && MMU
434 depends on RISCV_ALTERNATIVE
437 Adds support to dynamically detect the presence of the Svpbmt
438 ISA-extension (Supervisor-mode: page-based memory types) and
441 The memory type for a page contains a combination of attributes
442 that indicate the cacheability, idempotency, and ordering
443 properties for access to that page.
445 The Svpbmt extension is only available on 64-bit cpus.
447 If you don't know what to do here, say Y.
449 config TOOLCHAIN_HAS_ZBB
452 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
453 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
454 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
458 bool "Zbb extension support for bit manipulation instructions"
459 depends on TOOLCHAIN_HAS_ZBB
461 depends on RISCV_ALTERNATIVE
464 Adds support to dynamically detect the presence of the ZBB
465 extension (basic bit manipulation) and enable its usage.
467 The Zbb extension provides instructions to accelerate a number
468 of bit-specific operations (count bit population, sign extending,
471 If you don't know what to do here, say Y.
473 config RISCV_ISA_ZICBOM
474 bool "Zicbom extension support for non-coherent DMA operation"
476 depends on RISCV_ALTERNATIVE
478 select RISCV_DMA_NONCOHERENT
480 Adds support to dynamically detect the presence of the ZICBOM
481 extension (Cache Block Management Operations) and enable its
484 The Zicbom extension can be used to handle for example
485 non-coherent DMA support on devices that need it.
487 If you don't know what to do here, say Y.
489 config RISCV_ISA_ZICBOZ
490 bool "Zicboz extension support for faster zeroing of memory"
492 depends on RISCV_ALTERNATIVE
495 Enable the use of the Zicboz extension (cbo.zero instruction)
498 The Zicboz extension is used for faster zeroing of memory.
500 If you don't know what to do here, say Y.
502 config TOOLCHAIN_HAS_ZIHINTPAUSE
505 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
506 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
507 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
513 Say N here if you want to disable all floating-point related procedure
516 If you don't know what to do here, say Y.
518 endmenu # "Platform type"
520 menu "Kernel features"
522 source "kernel/Kconfig.hz"
525 bool "SBI v0.1 support"
528 This config allows kernel to use SBI v0.1 APIs. This will be
529 deprecated in future once legacy M-mode software are no longer in use.
531 config RISCV_BOOT_SPINWAIT
532 bool "Spinwait booting method"
534 default y if RISCV_SBI_V01 || RISCV_M_MODE
536 This enables support for booting Linux via spinwait method. In the
537 spinwait method, all cores randomly jump to Linux. One of the cores
538 gets chosen via lottery and all other keep spinning on a percpu
539 variable. This method cannot support CPU hotplug and sparse hartid
540 scheme. It should be only enabled for M-mode Linux or platforms relying
541 on older firmware without SBI HSM extension. All other platforms should
542 rely on ordered booting via SBI HSM extension which gets chosen
543 dynamically at runtime if the firmware supports it.
545 Since spinwait is incompatible with sparse hart IDs, it requires
546 NR_CPUS be large enough to contain the physical hart ID of the first
549 If unsure what to do here, say N.
552 bool "Kexec system call"
554 select HOTPLUG_CPU if SMP
557 kexec is a system call that implements the ability to shutdown your
558 current kernel, and to start another kernel. It is like a reboot
559 but it is independent of the system firmware. And like a reboot
560 you can start any kernel with it, not just Linux.
562 The name comes from the similarity to the exec system call.
565 bool "kexec file based systmem call"
566 depends on 64BIT && MMU
567 select HAVE_IMA_KEXEC if IMA
571 This is new version of kexec system call. This system call is
572 file based and takes file descriptors as system call argument
573 for kernel and initramfs as opposed to list of segments as
574 accepted by previous system call.
576 If you don't know what to do here, say Y.
578 config ARCH_HAS_KEXEC_PURGATORY
581 depends on CRYPTO_SHA256=y
584 bool "Build kdump crash kernel"
586 Generate crash dump after being started by kexec. This should
587 be normally only set in special crash dump kernels which are
588 loaded in the main kernel with kexec-tools into a specially
589 reserved region and then later executed after a crash by
592 For more details see Documentation/admin-guide/kdump/kdump.rst
595 bool "Kernel support for 32-bit U-mode"
597 depends on 64BIT && MMU
599 This option enables support for a 32-bit U-mode running under a 64-bit
600 kernel at S-mode. riscv32-specific components such as system calls,
601 the user helper functions (vdso), signal rt_frame functions and the
602 ptrace interface are handled appropriately by the kernel.
604 If you want to execute 32-bit userspace applications, say Y.
606 endmenu # "Kernel features"
611 string "Built-in kernel command line"
613 For most platforms, the arguments for the kernel's command line
614 are provided at run-time, during boot. However, there are cases
615 where either no arguments are being provided or the provided
616 arguments are insufficient or even invalid.
618 When that occurs, it is possible to define a built-in command
619 line here and choose how the kernel should use it later on.
622 prompt "Built-in command line usage" if CMDLINE != ""
623 default CMDLINE_FALLBACK
625 Choose how the kernel will handle the provided built-in command
628 config CMDLINE_FALLBACK
629 bool "Use bootloader kernel arguments if available"
631 Use the built-in command line as fallback in case we get nothing
632 during boot. This is the default behaviour.
634 config CMDLINE_EXTEND
635 bool "Extend bootloader kernel arguments"
637 The command-line arguments provided during boot will be
638 appended to the built-in command line. This is useful in
639 cases where the provided arguments are insufficient and
640 you don't want to or cannot modify them.
643 bool "Always use the default kernel command string"
645 Always use the built-in command line, even if we get one during
646 boot. This is useful in case you need to override the provided
647 command line on systems where you don't have or want control
656 bool "UEFI runtime support"
657 depends on OF && !XIP_KERNEL
660 select EFI_GENERIC_STUB
661 select EFI_PARAMS_FROM_FDT
662 select EFI_RUNTIME_WRAPPERS
668 This option provides support for runtime services provided
669 by UEFI firmware (such as non-volatile variables, realtime
670 clock, and platform reset). A UEFI stub is also provided to
671 allow the kernel to be booted as an EFI application. This
672 is only useful on systems that have UEFI firmware.
674 config CC_HAVE_STACKPROTECTOR_TLS
675 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
677 config STACKPROTECTOR_PER_TASK
679 depends on !RANDSTRUCT
680 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
682 config PHYS_RAM_BASE_FIXED
683 bool "Explicitly specified physical RAM address"
684 depends on NONPORTABLE
688 hex "Platform Physical RAM address"
689 depends on PHYS_RAM_BASE_FIXED
692 This is the physical address of RAM in the system. It has to be
693 explicitly specified to run early relocations of read-write data
697 bool "Kernel Execute-In-Place from ROM"
698 depends on MMU && SPARSEMEM && NONPORTABLE
699 # This prevents XIP from being enabled by all{yes,mod}config, which
700 # fail to build since XIP doesn't support large kernels.
701 depends on !COMPILE_TEST
702 select PHYS_RAM_BASE_FIXED
704 Execute-In-Place allows the kernel to run from non-volatile storage
705 directly addressable by the CPU, such as NOR flash. This saves RAM
706 space since the text section of the kernel is not loaded from flash
707 to RAM. Read-write sections, such as the data section and stack,
708 are still copied to RAM. The XIP kernel is not compressed since
709 it has to run directly from flash, so it will take more space to
710 store it. The flash address used to link the kernel object files,
711 and for storing it, is configuration dependent. Therefore, if you
712 say Y here, you must know the proper physical address where to
713 store the kernel image depending on your own flash memory usage.
715 Also note that the make target becomes "make xipImage" rather than
716 "make zImage" or "make Image". The final kernel binary to put in
717 ROM memory will be arch/riscv/boot/xipImage.
719 SPARSEMEM is required because the kernel text and rodata that are
720 flash resident are not backed by memmap, then any attempt to get
721 a struct page on those regions will trigger a fault.
726 hex "XIP Kernel Physical Location"
727 depends on XIP_KERNEL
730 This is the physical address in your flash memory the kernel will
731 be linked for and stored to. This address is dependent on your
734 endmenu # "Boot options"
738 depends on OF && NONPORTABLE
739 default y if XIP_KERNEL
748 menu "Power management options"
750 source "kernel/power/Kconfig"
752 endmenu # "Power management options"
754 menu "CPU Power Management"
756 source "drivers/cpuidle/Kconfig"
758 source "drivers/cpufreq/Kconfig"
760 endmenu # "CPU Power Management"
762 source "arch/riscv/kvm/Kconfig"