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_CLOCKSOURCE_INIT
16 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
17 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
18 select ARCH_HAS_BINFMT_FLAT
19 select ARCH_HAS_CURRENT_STACK_POINTER
20 select ARCH_HAS_DEBUG_VM_PGTABLE
21 select ARCH_HAS_DEBUG_VIRTUAL if MMU
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 if !RISCV_ISA_SVNAPOT
48 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
49 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
50 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
51 select BUILDTIME_TABLE_SORT if MMU
52 select CLONE_BACKWARDS
53 select CLINT_TIMER if !MMU
55 select CPU_PM if CPU_IDLE
57 select GENERIC_ARCH_TOPOLOGY
58 select GENERIC_ATOMIC64 if !64BIT
59 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
60 select GENERIC_EARLY_IOREMAP
61 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
62 select GENERIC_IDLE_POLL_SETUP
63 select GENERIC_IOREMAP if MMU
64 select GENERIC_IRQ_MULTI_HANDLER
65 select GENERIC_IRQ_SHOW
66 select GENERIC_IRQ_SHOW_LEVEL
67 select GENERIC_LIB_DEVMEM_IS_ALLOWED
68 select GENERIC_PCI_IOMAP
69 select GENERIC_PTDUMP if MMU
70 select GENERIC_SCHED_CLOCK
71 select GENERIC_SMP_IDLE_THREAD
72 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
73 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
74 select HARDIRQS_SW_RESEND
75 select HAVE_ARCH_AUDITSYSCALL
76 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
77 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
78 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
79 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
80 select HAVE_ARCH_KASAN if MMU && 64BIT
81 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
82 select HAVE_ARCH_KFENCE if MMU && 64BIT
83 select HAVE_ARCH_KGDB if !XIP_KERNEL
84 select HAVE_ARCH_KGDB_QXFER_PKT
85 select HAVE_ARCH_MMAP_RND_BITS if MMU
86 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
87 select HAVE_ARCH_SECCOMP_FILTER
88 select HAVE_ARCH_TRACEHOOK
89 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
90 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
91 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
92 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
93 select HAVE_ASM_MODVERSIONS
94 select HAVE_CONTEXT_TRACKING_USER
95 select HAVE_DEBUG_KMEMLEAK
96 select HAVE_DMA_CONTIGUOUS if MMU
97 select HAVE_EBPF_JIT if MMU
98 select HAVE_FUNCTION_ERROR_INJECTION
99 select HAVE_GCC_PLUGINS
100 select HAVE_GENERIC_VDSO if MMU && 64BIT
101 select HAVE_IRQ_TIME_ACCOUNTING
102 select HAVE_KPROBES if !XIP_KERNEL
103 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
104 select HAVE_KRETPROBES if !XIP_KERNEL
105 select HAVE_RETHOOK if !XIP_KERNEL
109 select HAVE_PERF_EVENTS
110 select HAVE_PERF_REGS
111 select HAVE_PERF_USER_STACK_DUMP
112 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
113 select HAVE_REGS_AND_STACK_ACCESS_API
114 select HAVE_FUNCTION_ARG_ACCESS_API
115 select HAVE_STACKPROTECTOR
116 select HAVE_SYSCALL_TRACEPOINTS
119 select IRQ_FORCED_THREADING
120 select MODULES_USE_ELF_RELA if MODULES
121 select MODULE_SECTIONS if MODULES
123 select OF_DMA_DEFAULT_COHERENT
124 select OF_EARLY_FLATTREE
126 select PCI_DOMAINS_GENERIC if PCI
127 select PCI_MSI if PCI
129 select RISCV_TIMER if RISCV_SBI
132 select SYSCTL_EXCEPTION_TRACE
133 select THREAD_INFO_IN_TASK
134 select TRACE_IRQFLAGS_SUPPORT
135 select UACCESS_MEMCPY if !MMU
136 select ZONE_DMA32 if 64BIT
137 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
138 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
139 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
140 select HAVE_FUNCTION_GRAPH_TRACER
141 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
143 config ARCH_MMAP_RND_BITS_MIN
147 config ARCH_MMAP_RND_COMPAT_BITS_MIN
150 # max bits determined by the following formula:
151 # VA_BITS - PAGE_SHIFT - 3
152 config ARCH_MMAP_RND_BITS_MAX
153 default 24 if 64BIT # SV39 based
156 config ARCH_MMAP_RND_COMPAT_BITS_MAX
159 # set if we run in machine mode, cleared if we run in supervisor mode
164 # set if we are running in S-mode and can use SBI calls
167 depends on !RISCV_M_MODE
171 bool "MMU-based Paged Memory Management Support"
174 Select if you want MMU-based virtualised addressing space
175 support by paged memory management. If unsure, say 'Y'.
179 default 0xC0000000 if 32BIT
180 default 0x80000000 if 64BIT && !MMU
181 default 0xff60000000000000 if 64BIT
183 config KASAN_SHADOW_OFFSET
185 depends on KASAN_GENERIC
186 default 0xdfffffff00000000 if 64BIT
187 default 0xffffffff if 32BIT
189 config ARCH_FLATMEM_ENABLE
192 config ARCH_SPARSEMEM_ENABLE
195 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
196 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
198 config ARCH_SELECT_MEMORY_MODEL
199 def_bool ARCH_SPARSEMEM_ENABLE
201 config ARCH_SUPPORTS_UPROBES
204 config STACKTRACE_SUPPORT
210 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
212 config GENERIC_BUG_RELATIVE_POINTERS
215 config GENERIC_CALIBRATE_DELAY
221 config GENERIC_HWEIGHT
224 config FIX_EARLYCON_MEM
227 config PGTABLE_LEVELS
232 config LOCKDEP_SUPPORT
235 config RISCV_DMA_NONCOHERENT
237 select ARCH_HAS_DMA_PREP_COHERENT
238 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
239 select ARCH_HAS_SYNC_DMA_FOR_CPU
240 select ARCH_HAS_SETUP_DMA_OPS
241 select DMA_DIRECT_REMAP
244 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
246 source "arch/riscv/Kconfig.socs"
247 source "arch/riscv/Kconfig.erratas"
252 bool "Allow configurations that result in non-portable kernels"
254 RISC-V kernel binaries are compatible between all known systems
255 whenever possible, but there are some use cases that can only be
256 satisfied by configurations that result in kernel binaries that are
257 not portable between systems.
259 Selecting N does not guarantee kernels will be portable to all known
260 systems. Selecting any of the options guarded by NONPORTABLE will
261 result in kernel binaries that are unlikely to be portable between
270 This selects the base ISA that this kernel will target and must match
275 depends on NONPORTABLE
277 select GENERIC_LIB_ASHLDI3
278 select GENERIC_LIB_ASHRDI3
279 select GENERIC_LIB_LSHRDI3
280 select GENERIC_LIB_UCMPDI2
286 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
287 select SWIOTLB if MMU
291 # We must be able to map all physical memory into the kernel, but the compiler
292 # is still a bit more efficient when generating code if it's setup in a manner
293 # such that it can only map 2GiB of memory.
295 prompt "Kernel Code Model"
296 default CMODEL_MEDLOW if 32BIT
297 default CMODEL_MEDANY if 64BIT
300 bool "medium low code model"
302 bool "medium any code model"
305 config MODULE_SECTIONS
307 select HAVE_MOD_ARCH_SPECIFIC
310 bool "Symmetric Multi-Processing"
312 This enables support for systems with more than one CPU. If
313 you say N here, the kernel will run on single and
314 multiprocessor machines, but will use only one CPU of a
315 multiprocessor machine. If you say Y here, the kernel will run
316 on many, but not all, single processor machines. On a single
317 processor machine, the kernel will run faster if you say N
320 If you don't know what to do here, say N.
323 int "Maximum number of CPUs (2-512)"
325 range 2 512 if !RISCV_SBI_V01
326 range 2 32 if RISCV_SBI_V01 && 32BIT
327 range 2 64 if RISCV_SBI_V01 && 64BIT
328 default "32" if 32BIT
329 default "64" if 64BIT
332 bool "Support for hot-pluggable CPUs"
334 select GENERIC_IRQ_MIGRATION
337 Say Y here to experiment with turning CPUs off and on. CPUs
338 can be controlled through /sys/devices/system/cpu.
340 Say N if you want to disable CPU hotplug.
351 # Common NUMA Features
353 bool "NUMA Memory Allocation and Scheduler Support"
354 depends on SMP && MMU
355 select GENERIC_ARCH_NUMA
357 select ARCH_SUPPORTS_NUMA_BALANCING
358 select USE_PERCPU_NUMA_NODE_ID
359 select NEED_PER_CPU_EMBED_FIRST_CHUNK
361 Enable NUMA (Non-Uniform Memory Access) support.
363 The kernel will try to allocate memory used by a CPU on the
364 local memory of the CPU and add some more NUMA awareness to the kernel.
367 int "Maximum NUMA Nodes (as a power of 2)"
372 Specify the maximum number of NUMA Nodes available on the target
373 system. Increases memory reserved to accommodate various tables.
375 config RISCV_ALTERNATIVE
377 depends on !XIP_KERNEL
379 This Kconfig allows the kernel to automatically patch the
380 errata required by the execution platform at run time. The
381 code patching is performed once in the boot stages. It means
382 that the overhead from this mechanism is just taken once.
384 config RISCV_ALTERNATIVE_EARLY
386 depends on RISCV_ALTERNATIVE
388 Allows early patching of the kernel for special errata
391 bool "Emit compressed instructions when building Linux"
394 Adds "C" to the ISA subsets that the toolchain is allowed to emit
395 when building Linux, which results in compressed instructions in the
398 If you don't know what to do here, say Y.
400 config RISCV_ISA_SVNAPOT
401 bool "SVNAPOT extension support"
402 depends on 64BIT && MMU
404 select RISCV_ALTERNATIVE
406 Allow kernel to detect the SVNAPOT ISA-extension dynamically at boot
407 time and enable its usage.
409 The SVNAPOT extension is used to mark contiguous PTEs as a range
410 of contiguous virtual-to-physical translations for a naturally
411 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
412 size. When HUGETLBFS is also selected this option unconditionally
413 allocates some memory for each NAPOT page size supported by the kernel.
414 When optimizing for low memory consumption and for platforms without
415 the SVNAPOT extension, it may be better to say N here.
417 If you don't know what to do here, say Y.
419 config RISCV_ISA_SVPBMT
420 bool "SVPBMT extension support"
421 depends on 64BIT && MMU
422 depends on !XIP_KERNEL
423 select RISCV_ALTERNATIVE
426 Adds support to dynamically detect the presence of the SVPBMT
427 ISA-extension (Supervisor-mode: page-based memory types) and
430 The memory type for a page contains a combination of attributes
431 that indicate the cacheability, idempotency, and ordering
432 properties for access to that page.
434 The SVPBMT extension is only available on 64Bit cpus.
436 If you don't know what to do here, say Y.
438 config TOOLCHAIN_HAS_ZBB
441 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
442 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
443 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
447 bool "Zbb extension support for bit manipulation instructions"
448 depends on TOOLCHAIN_HAS_ZBB
449 depends on !XIP_KERNEL && MMU
450 select RISCV_ALTERNATIVE
453 Adds support to dynamically detect the presence of the ZBB
454 extension (basic bit manipulation) and enable its usage.
456 The Zbb extension provides instructions to accelerate a number
457 of bit-specific operations (count bit population, sign extending,
460 If you don't know what to do here, say Y.
462 config TOOLCHAIN_HAS_ZICBOM
465 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zicbom)
466 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zicbom)
467 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23800
469 config RISCV_ISA_ZICBOM
470 bool "Zicbom extension support for non-coherent DMA operation"
471 depends on TOOLCHAIN_HAS_ZICBOM
472 depends on !XIP_KERNEL && MMU
473 select RISCV_DMA_NONCOHERENT
474 select RISCV_ALTERNATIVE
477 Adds support to dynamically detect the presence of the ZICBOM
478 extension (Cache Block Management Operations) and enable its
481 The Zicbom extension can be used to handle for example
482 non-coherent DMA support on devices that need it.
484 If you don't know what to do here, say Y.
486 config TOOLCHAIN_HAS_ZIHINTPAUSE
489 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
490 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
491 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
497 Say N here if you want to disable all floating-point related procedure
500 If you don't know what to do here, say Y.
502 endmenu # "Platform type"
504 menu "Kernel features"
506 source "kernel/Kconfig.hz"
509 bool "SBI v0.1 support"
512 This config allows kernel to use SBI v0.1 APIs. This will be
513 deprecated in future once legacy M-mode software are no longer in use.
515 config RISCV_BOOT_SPINWAIT
516 bool "Spinwait booting method"
518 default y if RISCV_SBI_V01 || RISCV_M_MODE
520 This enables support for booting Linux via spinwait method. In the
521 spinwait method, all cores randomly jump to Linux. One of the cores
522 gets chosen via lottery and all other keep spinning on a percpu
523 variable. This method cannot support CPU hotplug and sparse hartid
524 scheme. It should be only enabled for M-mode Linux or platforms relying
525 on older firmware without SBI HSM extension. All other platforms should
526 rely on ordered booting via SBI HSM extension which gets chosen
527 dynamically at runtime if the firmware supports it.
529 Since spinwait is incompatible with sparse hart IDs, it requires
530 NR_CPUS be large enough to contain the physical hart ID of the first
533 If unsure what to do here, say N.
536 bool "Kexec system call"
538 select HOTPLUG_CPU if SMP
541 kexec is a system call that implements the ability to shutdown your
542 current kernel, and to start another kernel. It is like a reboot
543 but it is independent of the system firmware. And like a reboot
544 you can start any kernel with it, not just Linux.
546 The name comes from the similarity to the exec system call.
549 bool "kexec file based systmem call"
552 select HAVE_IMA_KEXEC if IMA
553 depends on 64BIT && MMU
555 This is new version of kexec system call. This system call is
556 file based and takes file descriptors as system call argument
557 for kernel and initramfs as opposed to list of segments as
558 accepted by previous system call.
560 If you don't know what to do here, say Y.
562 config ARCH_HAS_KEXEC_PURGATORY
565 depends on CRYPTO_SHA256=y
568 bool "Build kdump crash kernel"
570 Generate crash dump after being started by kexec. This should
571 be normally only set in special crash dump kernels which are
572 loaded in the main kernel with kexec-tools into a specially
573 reserved region and then later executed after a crash by
576 For more details see Documentation/admin-guide/kdump/kdump.rst
579 bool "Kernel support for 32-bit U-mode"
581 depends on 64BIT && MMU
583 This option enables support for a 32-bit U-mode running under a 64-bit
584 kernel at S-mode. riscv32-specific components such as system calls,
585 the user helper functions (vdso), signal rt_frame functions and the
586 ptrace interface are handled appropriately by the kernel.
588 If you want to execute 32-bit userspace applications, say Y.
590 endmenu # "Kernel features"
595 string "Built-in kernel command line"
597 For most platforms, the arguments for the kernel's command line
598 are provided at run-time, during boot. However, there are cases
599 where either no arguments are being provided or the provided
600 arguments are insufficient or even invalid.
602 When that occurs, it is possible to define a built-in command
603 line here and choose how the kernel should use it later on.
606 prompt "Built-in command line usage" if CMDLINE != ""
607 default CMDLINE_FALLBACK
609 Choose how the kernel will handle the provided built-in command
612 config CMDLINE_FALLBACK
613 bool "Use bootloader kernel arguments if available"
615 Use the built-in command line as fallback in case we get nothing
616 during boot. This is the default behaviour.
618 config CMDLINE_EXTEND
619 bool "Extend bootloader kernel arguments"
621 The command-line arguments provided during boot will be
622 appended to the built-in command line. This is useful in
623 cases where the provided arguments are insufficient and
624 you don't want to or cannot modify them.
627 bool "Always use the default kernel command string"
629 Always use the built-in command line, even if we get one during
630 boot. This is useful in case you need to override the provided
631 command line on systems where you don't have or want control
640 bool "UEFI runtime support"
641 depends on OF && !XIP_KERNEL
644 select EFI_PARAMS_FROM_FDT
646 select EFI_GENERIC_STUB
647 select EFI_RUNTIME_WRAPPERS
652 This option provides support for runtime services provided
653 by UEFI firmware (such as non-volatile variables, realtime
654 clock, and platform reset). A UEFI stub is also provided to
655 allow the kernel to be booted as an EFI application. This
656 is only useful on systems that have UEFI firmware.
658 config CC_HAVE_STACKPROTECTOR_TLS
659 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
661 config STACKPROTECTOR_PER_TASK
663 depends on !RANDSTRUCT
664 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
666 config PHYS_RAM_BASE_FIXED
667 bool "Explicitly specified physical RAM address"
668 depends on NONPORTABLE
672 hex "Platform Physical RAM address"
673 depends on PHYS_RAM_BASE_FIXED
676 This is the physical address of RAM in the system. It has to be
677 explicitly specified to run early relocations of read-write data
681 bool "Kernel Execute-In-Place from ROM"
682 depends on MMU && SPARSEMEM && NONPORTABLE
683 # This prevents XIP from being enabled by all{yes,mod}config, which
684 # fail to build since XIP doesn't support large kernels.
685 depends on !COMPILE_TEST
686 select PHYS_RAM_BASE_FIXED
688 Execute-In-Place allows the kernel to run from non-volatile storage
689 directly addressable by the CPU, such as NOR flash. This saves RAM
690 space since the text section of the kernel is not loaded from flash
691 to RAM. Read-write sections, such as the data section and stack,
692 are still copied to RAM. The XIP kernel is not compressed since
693 it has to run directly from flash, so it will take more space to
694 store it. The flash address used to link the kernel object files,
695 and for storing it, is configuration dependent. Therefore, if you
696 say Y here, you must know the proper physical address where to
697 store the kernel image depending on your own flash memory usage.
699 Also note that the make target becomes "make xipImage" rather than
700 "make zImage" or "make Image". The final kernel binary to put in
701 ROM memory will be arch/riscv/boot/xipImage.
703 SPARSEMEM is required because the kernel text and rodata that are
704 flash resident are not backed by memmap, then any attempt to get
705 a struct page on those regions will trigger a fault.
710 hex "XIP Kernel Physical Location"
711 depends on XIP_KERNEL
714 This is the physical address in your flash memory the kernel will
715 be linked for and stored to. This address is dependent on your
718 endmenu # "Boot options"
722 depends on OF && NONPORTABLE
723 default y if XIP_KERNEL
732 menu "Power management options"
734 source "kernel/power/Kconfig"
736 endmenu # "Power management options"
738 menu "CPU Power Management"
740 source "drivers/cpuidle/Kconfig"
742 source "drivers/cpufreq/Kconfig"
744 endmenu # "CPU Power Management"
746 source "arch/riscv/kvm/Kconfig"