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 MODULES_USE_ELF_RELA if MODULES
124 select MODULE_SECTIONS if MODULES
126 select OF_DMA_DEFAULT_COHERENT
127 select OF_EARLY_FLATTREE
129 select PCI_DOMAINS_GENERIC if PCI
130 select PCI_MSI if PCI
131 select RISCV_ALTERNATIVE if !XIP_KERNEL
133 select RISCV_TIMER if RISCV_SBI
136 select SYSCTL_EXCEPTION_TRACE
137 select THREAD_INFO_IN_TASK
138 select TRACE_IRQFLAGS_SUPPORT
139 select UACCESS_MEMCPY if !MMU
140 select ZONE_DMA32 if 64BIT
141 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
142 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
143 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
144 select HAVE_FUNCTION_GRAPH_TRACER
145 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
147 config ARCH_MMAP_RND_BITS_MIN
151 config ARCH_MMAP_RND_COMPAT_BITS_MIN
154 # max bits determined by the following formula:
155 # VA_BITS - PAGE_SHIFT - 3
156 config ARCH_MMAP_RND_BITS_MAX
157 default 24 if 64BIT # SV39 based
160 config ARCH_MMAP_RND_COMPAT_BITS_MAX
163 # set if we run in machine mode, cleared if we run in supervisor mode
168 # set if we are running in S-mode and can use SBI calls
171 depends on !RISCV_M_MODE
175 bool "MMU-based Paged Memory Management Support"
178 Select if you want MMU-based virtualised addressing space
179 support by paged memory management. If unsure, say 'Y'.
183 default 0xC0000000 if 32BIT && MMU
184 default 0x80000000 if !MMU
185 default 0xff60000000000000 if 64BIT
187 config KASAN_SHADOW_OFFSET
189 depends on KASAN_GENERIC
190 default 0xdfffffff00000000 if 64BIT
191 default 0xffffffff if 32BIT
193 config ARCH_FLATMEM_ENABLE
196 config ARCH_SPARSEMEM_ENABLE
199 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
200 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
202 config ARCH_SELECT_MEMORY_MODEL
203 def_bool ARCH_SPARSEMEM_ENABLE
205 config ARCH_SUPPORTS_UPROBES
208 config STACKTRACE_SUPPORT
214 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
216 config GENERIC_BUG_RELATIVE_POINTERS
219 config GENERIC_CALIBRATE_DELAY
225 config GENERIC_HWEIGHT
228 config FIX_EARLYCON_MEM
231 config PGTABLE_LEVELS
236 config LOCKDEP_SUPPORT
239 config RISCV_DMA_NONCOHERENT
241 select ARCH_HAS_DMA_PREP_COHERENT
242 select ARCH_HAS_SETUP_DMA_OPS
243 select ARCH_HAS_SYNC_DMA_FOR_CPU
244 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
245 select DMA_DIRECT_REMAP
248 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
250 source "arch/riscv/Kconfig.socs"
251 source "arch/riscv/Kconfig.errata"
256 bool "Allow configurations that result in non-portable kernels"
258 RISC-V kernel binaries are compatible between all known systems
259 whenever possible, but there are some use cases that can only be
260 satisfied by configurations that result in kernel binaries that are
261 not portable between systems.
263 Selecting N does not guarantee kernels will be portable to all known
264 systems. Selecting any of the options guarded by NONPORTABLE will
265 result in kernel binaries that are unlikely to be portable between
274 This selects the base ISA that this kernel will target and must match
279 depends on NONPORTABLE
281 select GENERIC_LIB_ASHLDI3
282 select GENERIC_LIB_ASHRDI3
283 select GENERIC_LIB_LSHRDI3
284 select GENERIC_LIB_UCMPDI2
289 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
290 select SWIOTLB if MMU
294 # We must be able to map all physical memory into the kernel, but the compiler
295 # is still a bit more efficient when generating code if it's setup in a manner
296 # such that it can only map 2GiB of memory.
298 prompt "Kernel Code Model"
299 default CMODEL_MEDLOW if 32BIT
300 default CMODEL_MEDANY if 64BIT
303 bool "medium low code model"
305 bool "medium any code model"
308 config MODULE_SECTIONS
310 select HAVE_MOD_ARCH_SPECIFIC
313 bool "Symmetric Multi-Processing"
315 This enables support for systems with more than one CPU. If
316 you say N here, the kernel will run on single and
317 multiprocessor machines, but will use only one CPU of a
318 multiprocessor machine. If you say Y here, the kernel will run
319 on many, but not all, single processor machines. On a single
320 processor machine, the kernel will run faster if you say N
323 If you don't know what to do here, say N.
326 bool "Multi-core scheduler support"
329 Multi-core scheduler support improves the CPU scheduler's decision
330 making when dealing with multi-core CPU chips at a cost of slightly
331 increased overhead in some places. If unsure say N here.
334 int "Maximum number of CPUs (2-512)"
336 range 2 512 if !RISCV_SBI_V01
337 range 2 32 if RISCV_SBI_V01 && 32BIT
338 range 2 64 if RISCV_SBI_V01 && 64BIT
339 default "32" if 32BIT
340 default "64" if 64BIT
343 bool "Support for hot-pluggable CPUs"
345 select GENERIC_IRQ_MIGRATION
348 Say Y here to experiment with turning CPUs off and on. CPUs
349 can be controlled through /sys/devices/system/cpu.
351 Say N if you want to disable CPU hotplug.
362 # Common NUMA Features
364 bool "NUMA Memory Allocation and Scheduler Support"
365 depends on SMP && MMU
366 select ARCH_SUPPORTS_NUMA_BALANCING
367 select GENERIC_ARCH_NUMA
368 select NEED_PER_CPU_EMBED_FIRST_CHUNK
370 select USE_PERCPU_NUMA_NODE_ID
372 Enable NUMA (Non-Uniform Memory Access) support.
374 The kernel will try to allocate memory used by a CPU on the
375 local memory of the CPU and add some more NUMA awareness to the kernel.
378 int "Maximum NUMA Nodes (as a power of 2)"
383 Specify the maximum number of NUMA Nodes available on the target
384 system. Increases memory reserved to accommodate various tables.
386 config RISCV_ALTERNATIVE
388 depends on !XIP_KERNEL
390 This Kconfig allows the kernel to automatically patch the
391 erratum or cpufeature required by the execution platform at run
392 time. The code patching overhead is minimal, as it's only done
393 once at boot and once on each module load.
395 config RISCV_ALTERNATIVE_EARLY
397 depends on RISCV_ALTERNATIVE
399 Allows early patching of the kernel for special errata
402 bool "Emit compressed instructions when building Linux"
405 Adds "C" to the ISA subsets that the toolchain is allowed to emit
406 when building Linux, which results in compressed instructions in the
409 If you don't know what to do here, say Y.
411 config RISCV_ISA_SVNAPOT
412 bool "Svnapot extension support for supervisor mode NAPOT pages"
413 depends on 64BIT && MMU
414 depends on RISCV_ALTERNATIVE
417 Allow kernel to detect the Svnapot ISA-extension dynamically at boot
418 time and enable its usage.
420 The Svnapot extension is used to mark contiguous PTEs as a range
421 of contiguous virtual-to-physical translations for a naturally
422 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
423 size. When HUGETLBFS is also selected this option unconditionally
424 allocates some memory for each NAPOT page size supported by the kernel.
425 When optimizing for low memory consumption and for platforms without
426 the Svnapot extension, it may be better to say N here.
428 If you don't know what to do here, say Y.
430 config RISCV_ISA_SVPBMT
431 bool "Svpbmt extension support for supervisor mode page-based memory types"
432 depends on 64BIT && MMU
433 depends on RISCV_ALTERNATIVE
436 Adds support to dynamically detect the presence of the Svpbmt
437 ISA-extension (Supervisor-mode: page-based memory types) and
440 The memory type for a page contains a combination of attributes
441 that indicate the cacheability, idempotency, and ordering
442 properties for access to that page.
444 The Svpbmt extension is only available on 64-bit cpus.
446 If you don't know what to do here, say Y.
448 config TOOLCHAIN_HAS_ZBB
451 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
452 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
453 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
457 bool "Zbb extension support for bit manipulation instructions"
458 depends on TOOLCHAIN_HAS_ZBB
460 depends on RISCV_ALTERNATIVE
463 Adds support to dynamically detect the presence of the ZBB
464 extension (basic bit manipulation) and enable its usage.
466 The Zbb extension provides instructions to accelerate a number
467 of bit-specific operations (count bit population, sign extending,
470 If you don't know what to do here, say Y.
472 config RISCV_ISA_ZICBOM
473 bool "Zicbom extension support for non-coherent DMA operation"
475 depends on RISCV_ALTERNATIVE
477 select RISCV_DMA_NONCOHERENT
479 Adds support to dynamically detect the presence of the ZICBOM
480 extension (Cache Block Management Operations) and enable its
483 The Zicbom extension can be used to handle for example
484 non-coherent DMA support on devices that need it.
486 If you don't know what to do here, say Y.
488 config RISCV_ISA_ZICBOZ
489 bool "Zicboz extension support for faster zeroing of memory"
491 depends on RISCV_ALTERNATIVE
494 Enable the use of the Zicboz extension (cbo.zero instruction)
497 The Zicboz extension is used for faster zeroing of memory.
499 If you don't know what to do here, say Y.
501 config TOOLCHAIN_HAS_ZIHINTPAUSE
504 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
505 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
506 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
512 Say N here if you want to disable all floating-point related procedure
515 If you don't know what to do here, say Y.
517 endmenu # "Platform type"
519 menu "Kernel features"
521 source "kernel/Kconfig.hz"
524 bool "SBI v0.1 support"
527 This config allows kernel to use SBI v0.1 APIs. This will be
528 deprecated in future once legacy M-mode software are no longer in use.
530 config RISCV_BOOT_SPINWAIT
531 bool "Spinwait booting method"
533 default y if RISCV_SBI_V01 || RISCV_M_MODE
535 This enables support for booting Linux via spinwait method. In the
536 spinwait method, all cores randomly jump to Linux. One of the cores
537 gets chosen via lottery and all other keep spinning on a percpu
538 variable. This method cannot support CPU hotplug and sparse hartid
539 scheme. It should be only enabled for M-mode Linux or platforms relying
540 on older firmware without SBI HSM extension. All other platforms should
541 rely on ordered booting via SBI HSM extension which gets chosen
542 dynamically at runtime if the firmware supports it.
544 Since spinwait is incompatible with sparse hart IDs, it requires
545 NR_CPUS be large enough to contain the physical hart ID of the first
548 If unsure what to do here, say N.
551 bool "Kexec system call"
553 select HOTPLUG_CPU if SMP
556 kexec is a system call that implements the ability to shutdown your
557 current kernel, and to start another kernel. It is like a reboot
558 but it is independent of the system firmware. And like a reboot
559 you can start any kernel with it, not just Linux.
561 The name comes from the similarity to the exec system call.
564 bool "kexec file based systmem call"
565 depends on 64BIT && MMU
566 select HAVE_IMA_KEXEC if IMA
570 This is new version of kexec system call. This system call is
571 file based and takes file descriptors as system call argument
572 for kernel and initramfs as opposed to list of segments as
573 accepted by previous system call.
575 If you don't know what to do here, say Y.
577 config ARCH_HAS_KEXEC_PURGATORY
580 depends on CRYPTO_SHA256=y
583 bool "Build kdump crash kernel"
585 Generate crash dump after being started by kexec. This should
586 be normally only set in special crash dump kernels which are
587 loaded in the main kernel with kexec-tools into a specially
588 reserved region and then later executed after a crash by
591 For more details see Documentation/admin-guide/kdump/kdump.rst
594 bool "Kernel support for 32-bit U-mode"
596 depends on 64BIT && MMU
598 This option enables support for a 32-bit U-mode running under a 64-bit
599 kernel at S-mode. riscv32-specific components such as system calls,
600 the user helper functions (vdso), signal rt_frame functions and the
601 ptrace interface are handled appropriately by the kernel.
603 If you want to execute 32-bit userspace applications, say Y.
605 endmenu # "Kernel features"
610 string "Built-in kernel command line"
612 For most platforms, the arguments for the kernel's command line
613 are provided at run-time, during boot. However, there are cases
614 where either no arguments are being provided or the provided
615 arguments are insufficient or even invalid.
617 When that occurs, it is possible to define a built-in command
618 line here and choose how the kernel should use it later on.
621 prompt "Built-in command line usage" if CMDLINE != ""
622 default CMDLINE_FALLBACK
624 Choose how the kernel will handle the provided built-in command
627 config CMDLINE_FALLBACK
628 bool "Use bootloader kernel arguments if available"
630 Use the built-in command line as fallback in case we get nothing
631 during boot. This is the default behaviour.
633 config CMDLINE_EXTEND
634 bool "Extend bootloader kernel arguments"
636 The command-line arguments provided during boot will be
637 appended to the built-in command line. This is useful in
638 cases where the provided arguments are insufficient and
639 you don't want to or cannot modify them.
642 bool "Always use the default kernel command string"
644 Always use the built-in command line, even if we get one during
645 boot. This is useful in case you need to override the provided
646 command line on systems where you don't have or want control
655 bool "UEFI runtime support"
656 depends on OF && !XIP_KERNEL
659 select EFI_GENERIC_STUB
660 select EFI_PARAMS_FROM_FDT
661 select EFI_RUNTIME_WRAPPERS
667 This option provides support for runtime services provided
668 by UEFI firmware (such as non-volatile variables, realtime
669 clock, and platform reset). A UEFI stub is also provided to
670 allow the kernel to be booted as an EFI application. This
671 is only useful on systems that have UEFI firmware.
673 config CC_HAVE_STACKPROTECTOR_TLS
674 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
676 config STACKPROTECTOR_PER_TASK
678 depends on !RANDSTRUCT
679 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
681 config PHYS_RAM_BASE_FIXED
682 bool "Explicitly specified physical RAM address"
683 depends on NONPORTABLE
687 hex "Platform Physical RAM address"
688 depends on PHYS_RAM_BASE_FIXED
691 This is the physical address of RAM in the system. It has to be
692 explicitly specified to run early relocations of read-write data
696 bool "Kernel Execute-In-Place from ROM"
697 depends on MMU && SPARSEMEM && NONPORTABLE
698 # This prevents XIP from being enabled by all{yes,mod}config, which
699 # fail to build since XIP doesn't support large kernels.
700 depends on !COMPILE_TEST
701 select PHYS_RAM_BASE_FIXED
703 Execute-In-Place allows the kernel to run from non-volatile storage
704 directly addressable by the CPU, such as NOR flash. This saves RAM
705 space since the text section of the kernel is not loaded from flash
706 to RAM. Read-write sections, such as the data section and stack,
707 are still copied to RAM. The XIP kernel is not compressed since
708 it has to run directly from flash, so it will take more space to
709 store it. The flash address used to link the kernel object files,
710 and for storing it, is configuration dependent. Therefore, if you
711 say Y here, you must know the proper physical address where to
712 store the kernel image depending on your own flash memory usage.
714 Also note that the make target becomes "make xipImage" rather than
715 "make zImage" or "make Image". The final kernel binary to put in
716 ROM memory will be arch/riscv/boot/xipImage.
718 SPARSEMEM is required because the kernel text and rodata that are
719 flash resident are not backed by memmap, then any attempt to get
720 a struct page on those regions will trigger a fault.
725 hex "XIP Kernel Physical Location"
726 depends on XIP_KERNEL
729 This is the physical address in your flash memory the kernel will
730 be linked for and stored to. This address is dependent on your
733 endmenu # "Boot options"
737 depends on OF && NONPORTABLE
738 default y if XIP_KERNEL
747 menu "Power management options"
749 source "kernel/power/Kconfig"
751 endmenu # "Power management options"
753 menu "CPU Power Management"
755 source "drivers/cpuidle/Kconfig"
757 source "drivers/cpufreq/Kconfig"
759 endmenu # "CPU Power Management"
761 source "arch/riscv/kvm/Kconfig"