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_IPI if SMP
67 select GENERIC_IRQ_IPI_MUX if SMP
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 HAS_IOPORT if MMU
80 select HAVE_ARCH_AUDITSYSCALL
81 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
82 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
83 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
84 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
85 select HAVE_ARCH_KASAN if MMU && 64BIT
86 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
87 select HAVE_ARCH_KFENCE if MMU && 64BIT
88 select HAVE_ARCH_KGDB if !XIP_KERNEL
89 select HAVE_ARCH_KGDB_QXFER_PKT
90 select HAVE_ARCH_MMAP_RND_BITS if MMU
91 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
92 select HAVE_ARCH_SECCOMP_FILTER
93 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
94 select HAVE_ARCH_TRACEHOOK
95 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
96 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
97 select HAVE_ASM_MODVERSIONS
98 select HAVE_CONTEXT_TRACKING_USER
99 select HAVE_DEBUG_KMEMLEAK
100 select HAVE_DMA_CONTIGUOUS if MMU
101 select HAVE_EBPF_JIT if MMU
102 select HAVE_FUNCTION_ARG_ACCESS_API
103 select HAVE_FUNCTION_ERROR_INJECTION
104 select HAVE_GCC_PLUGINS
105 select HAVE_GENERIC_VDSO if MMU && 64BIT
106 select HAVE_IRQ_TIME_ACCOUNTING
107 select HAVE_KPROBES if !XIP_KERNEL
108 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
109 select HAVE_KRETPROBES if !XIP_KERNEL
110 select HAVE_RETHOOK if !XIP_KERNEL
114 select HAVE_PERF_EVENTS
115 select HAVE_PERF_REGS
116 select HAVE_PERF_USER_STACK_DUMP
117 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
118 select HAVE_REGS_AND_STACK_ACCESS_API
120 select HAVE_STACKPROTECTOR
121 select HAVE_SYSCALL_TRACEPOINTS
123 select IRQ_FORCED_THREADING
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
185 default 0x80000000 if 64BIT && !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.erratas"
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
291 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
292 select SWIOTLB if MMU
296 # We must be able to map all physical memory into the kernel, but the compiler
297 # is still a bit more efficient when generating code if it's setup in a manner
298 # such that it can only map 2GiB of memory.
300 prompt "Kernel Code Model"
301 default CMODEL_MEDLOW if 32BIT
302 default CMODEL_MEDANY if 64BIT
305 bool "medium low code model"
307 bool "medium any code model"
310 config MODULE_SECTIONS
312 select HAVE_MOD_ARCH_SPECIFIC
315 bool "Symmetric Multi-Processing"
317 This enables support for systems with more than one CPU. If
318 you say N here, the kernel will run on single and
319 multiprocessor machines, but will use only one CPU of a
320 multiprocessor machine. If you say Y here, the kernel will run
321 on many, but not all, single processor machines. On a single
322 processor machine, the kernel will run faster if you say N
325 If you don't know what to do here, say N.
328 int "Maximum number of CPUs (2-512)"
330 range 2 512 if !RISCV_SBI_V01
331 range 2 32 if RISCV_SBI_V01 && 32BIT
332 range 2 64 if RISCV_SBI_V01 && 64BIT
333 default "32" if 32BIT
334 default "64" if 64BIT
337 bool "Support for hot-pluggable CPUs"
339 select GENERIC_IRQ_MIGRATION
342 Say Y here to experiment with turning CPUs off and on. CPUs
343 can be controlled through /sys/devices/system/cpu.
345 Say N if you want to disable CPU hotplug.
356 # Common NUMA Features
358 bool "NUMA Memory Allocation and Scheduler Support"
359 depends on SMP && MMU
360 select ARCH_SUPPORTS_NUMA_BALANCING
361 select GENERIC_ARCH_NUMA
362 select NEED_PER_CPU_EMBED_FIRST_CHUNK
364 select USE_PERCPU_NUMA_NODE_ID
366 Enable NUMA (Non-Uniform Memory Access) support.
368 The kernel will try to allocate memory used by a CPU on the
369 local memory of the CPU and add some more NUMA awareness to the kernel.
372 int "Maximum NUMA Nodes (as a power of 2)"
377 Specify the maximum number of NUMA Nodes available on the target
378 system. Increases memory reserved to accommodate various tables.
380 config RISCV_ALTERNATIVE
382 depends on !XIP_KERNEL
384 This Kconfig allows the kernel to automatically patch the
385 errata required by the execution platform at run time. The
386 code patching is performed once in the boot stages. It means
387 that the overhead from this mechanism is just taken once.
389 config RISCV_ALTERNATIVE_EARLY
391 depends on RISCV_ALTERNATIVE
393 Allows early patching of the kernel for special errata
396 bool "Emit compressed instructions when building Linux"
399 Adds "C" to the ISA subsets that the toolchain is allowed to emit
400 when building Linux, which results in compressed instructions in the
403 If you don't know what to do here, say Y.
405 config RISCV_ISA_SVPBMT
406 bool "SVPBMT extension support"
407 depends on 64BIT && MMU
408 depends on RISCV_ALTERNATIVE
411 Adds support to dynamically detect the presence of the SVPBMT
412 ISA-extension (Supervisor-mode: page-based memory types) and
415 The memory type for a page contains a combination of attributes
416 that indicate the cacheability, idempotency, and ordering
417 properties for access to that page.
419 The SVPBMT extension is only available on 64Bit cpus.
421 If you don't know what to do here, say Y.
423 config TOOLCHAIN_HAS_ZBB
426 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
427 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
428 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
432 bool "Zbb extension support for bit manipulation instructions"
433 depends on TOOLCHAIN_HAS_ZBB
435 depends on RISCV_ALTERNATIVE
438 Adds support to dynamically detect the presence of the ZBB
439 extension (basic bit manipulation) and enable its usage.
441 The Zbb extension provides instructions to accelerate a number
442 of bit-specific operations (count bit population, sign extending,
445 If you don't know what to do here, say Y.
447 config RISCV_ISA_ZICBOM
448 bool "Zicbom extension support for non-coherent DMA operation"
450 depends on RISCV_ALTERNATIVE
452 select RISCV_DMA_NONCOHERENT
454 Adds support to dynamically detect the presence of the ZICBOM
455 extension (Cache Block Management Operations) and enable its
458 The Zicbom extension can be used to handle for example
459 non-coherent DMA support on devices that need it.
461 If you don't know what to do here, say Y.
463 config TOOLCHAIN_HAS_ZIHINTPAUSE
466 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
467 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
468 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
470 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
472 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
473 depends on AS_IS_GNU && AS_VERSION >= 23800
475 Newer binutils versions default to ISA spec version 20191213 which
476 moves some instructions from the I extension to the Zicsr and Zifencei
479 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
481 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
482 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
483 depends on CC_IS_CLANG && CLANG_VERSION < 170000
485 Certain versions of clang do not support zicsr and zifencei via -march
486 but newer versions of binutils require it for the reasons noted in the
487 help text of CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. This
488 option causes an older ISA spec compatible with these older versions
489 of clang to be passed to GAS, which has the same result as passing zicsr
490 and zifencei to -march.
496 Say N here if you want to disable all floating-point related procedure
499 If you don't know what to do here, say Y.
501 endmenu # "Platform type"
503 menu "Kernel features"
505 source "kernel/Kconfig.hz"
508 bool "SBI v0.1 support"
511 This config allows kernel to use SBI v0.1 APIs. This will be
512 deprecated in future once legacy M-mode software are no longer in use.
514 config RISCV_BOOT_SPINWAIT
515 bool "Spinwait booting method"
517 default y if RISCV_SBI_V01 || RISCV_M_MODE
519 This enables support for booting Linux via spinwait method. In the
520 spinwait method, all cores randomly jump to Linux. One of the cores
521 gets chosen via lottery and all other keep spinning on a percpu
522 variable. This method cannot support CPU hotplug and sparse hartid
523 scheme. It should be only enabled for M-mode Linux or platforms relying
524 on older firmware without SBI HSM extension. All other platforms should
525 rely on ordered booting via SBI HSM extension which gets chosen
526 dynamically at runtime if the firmware supports it.
528 Since spinwait is incompatible with sparse hart IDs, it requires
529 NR_CPUS be large enough to contain the physical hart ID of the first
532 If unsure what to do here, say N.
535 bool "Kexec system call"
537 select HOTPLUG_CPU if SMP
540 kexec is a system call that implements the ability to shutdown your
541 current kernel, and to start another kernel. It is like a reboot
542 but it is independent of the system firmware. And like a reboot
543 you can start any kernel with it, not just Linux.
545 The name comes from the similarity to the exec system call.
548 bool "kexec file based systmem call"
549 depends on 64BIT && MMU
550 select HAVE_IMA_KEXEC if IMA
554 This is new version of kexec system call. This system call is
555 file based and takes file descriptors as system call argument
556 for kernel and initramfs as opposed to list of segments as
557 accepted by previous system call.
559 If you don't know what to do here, say Y.
561 config ARCH_HAS_KEXEC_PURGATORY
564 depends on CRYPTO_SHA256=y
567 bool "Build kdump crash kernel"
569 Generate crash dump after being started by kexec. This should
570 be normally only set in special crash dump kernels which are
571 loaded in the main kernel with kexec-tools into a specially
572 reserved region and then later executed after a crash by
575 For more details see Documentation/admin-guide/kdump/kdump.rst
578 bool "Kernel support for 32-bit U-mode"
580 depends on 64BIT && MMU
582 This option enables support for a 32-bit U-mode running under a 64-bit
583 kernel at S-mode. riscv32-specific components such as system calls,
584 the user helper functions (vdso), signal rt_frame functions and the
585 ptrace interface are handled appropriately by the kernel.
587 If you want to execute 32-bit userspace applications, say Y.
589 endmenu # "Kernel features"
594 string "Built-in kernel command line"
596 For most platforms, the arguments for the kernel's command line
597 are provided at run-time, during boot. However, there are cases
598 where either no arguments are being provided or the provided
599 arguments are insufficient or even invalid.
601 When that occurs, it is possible to define a built-in command
602 line here and choose how the kernel should use it later on.
605 prompt "Built-in command line usage" if CMDLINE != ""
606 default CMDLINE_FALLBACK
608 Choose how the kernel will handle the provided built-in command
611 config CMDLINE_FALLBACK
612 bool "Use bootloader kernel arguments if available"
614 Use the built-in command line as fallback in case we get nothing
615 during boot. This is the default behaviour.
617 config CMDLINE_EXTEND
618 bool "Extend bootloader kernel arguments"
620 The command-line arguments provided during boot will be
621 appended to the built-in command line. This is useful in
622 cases where the provided arguments are insufficient and
623 you don't want to or cannot modify them.
626 bool "Always use the default kernel command string"
628 Always use the built-in command line, even if we get one during
629 boot. This is useful in case you need to override the provided
630 command line on systems where you don't have or want control
639 bool "UEFI runtime support"
640 depends on OF && !XIP_KERNEL
643 select EFI_GENERIC_STUB
644 select EFI_PARAMS_FROM_FDT
645 select EFI_RUNTIME_WRAPPERS
651 This option provides support for runtime services provided
652 by UEFI firmware (such as non-volatile variables, realtime
653 clock, and platform reset). A UEFI stub is also provided to
654 allow the kernel to be booted as an EFI application. This
655 is only useful on systems that have UEFI firmware.
657 config CC_HAVE_STACKPROTECTOR_TLS
658 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
660 config STACKPROTECTOR_PER_TASK
662 depends on !RANDSTRUCT
663 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
665 config PHYS_RAM_BASE_FIXED
666 bool "Explicitly specified physical RAM address"
667 depends on NONPORTABLE
671 hex "Platform Physical RAM address"
672 depends on PHYS_RAM_BASE_FIXED
675 This is the physical address of RAM in the system. It has to be
676 explicitly specified to run early relocations of read-write data
680 bool "Kernel Execute-In-Place from ROM"
681 depends on MMU && SPARSEMEM && NONPORTABLE
682 # This prevents XIP from being enabled by all{yes,mod}config, which
683 # fail to build since XIP doesn't support large kernels.
684 depends on !COMPILE_TEST
685 select PHYS_RAM_BASE_FIXED
687 Execute-In-Place allows the kernel to run from non-volatile storage
688 directly addressable by the CPU, such as NOR flash. This saves RAM
689 space since the text section of the kernel is not loaded from flash
690 to RAM. Read-write sections, such as the data section and stack,
691 are still copied to RAM. The XIP kernel is not compressed since
692 it has to run directly from flash, so it will take more space to
693 store it. The flash address used to link the kernel object files,
694 and for storing it, is configuration dependent. Therefore, if you
695 say Y here, you must know the proper physical address where to
696 store the kernel image depending on your own flash memory usage.
698 Also note that the make target becomes "make xipImage" rather than
699 "make zImage" or "make Image". The final kernel binary to put in
700 ROM memory will be arch/riscv/boot/xipImage.
702 SPARSEMEM is required because the kernel text and rodata that are
703 flash resident are not backed by memmap, then any attempt to get
704 a struct page on those regions will trigger a fault.
709 hex "XIP Kernel Physical Location"
710 depends on XIP_KERNEL
713 This is the physical address in your flash memory the kernel will
714 be linked for and stored to. This address is dependent on your
717 endmenu # "Boot options"
721 depends on OF && NONPORTABLE
722 default y if XIP_KERNEL
731 menu "Power management options"
733 source "kernel/power/Kconfig"
735 endmenu # "Power management options"
737 menu "CPU Power Management"
739 source "drivers/cpuidle/Kconfig"
741 source "drivers/cpufreq/Kconfig"
743 endmenu # "CPU Power Management"
745 source "arch/riscv/kvm/Kconfig"