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_PTE_SPECIAL
29 select ARCH_HAS_SET_DIRECT_MAP if MMU
30 select ARCH_HAS_SET_MEMORY if MMU
31 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
32 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
33 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
34 select ARCH_HAS_UBSAN_SANITIZE_ALL
35 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
36 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
38 select ARCH_SUPPORTS_ATOMIC_RMW
39 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
40 select ARCH_SUPPORTS_HUGETLBFS if MMU
41 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
42 select ARCH_USE_MEMTEST
43 select ARCH_USE_QUEUED_RWLOCKS
44 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
45 select ARCH_WANT_FRAME_POINTERS
46 select ARCH_WANT_GENERAL_HUGETLB
47 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
48 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
49 select BUILDTIME_TABLE_SORT if MMU
50 select CLONE_BACKWARDS
51 select CLINT_TIMER if !MMU
53 select CPU_PM if CPU_IDLE
55 select GENERIC_ARCH_TOPOLOGY if SMP
56 select GENERIC_ATOMIC64 if !64BIT
57 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
58 select GENERIC_EARLY_IOREMAP
59 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
60 select GENERIC_IDLE_POLL_SETUP
61 select GENERIC_IOREMAP if MMU
62 select GENERIC_IRQ_MULTI_HANDLER
63 select GENERIC_IRQ_SHOW
64 select GENERIC_IRQ_SHOW_LEVEL
65 select GENERIC_LIB_DEVMEM_IS_ALLOWED
66 select GENERIC_PCI_IOMAP
67 select GENERIC_PTDUMP if MMU
68 select GENERIC_SCHED_CLOCK
69 select GENERIC_SMP_IDLE_THREAD
70 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
71 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
72 select HAVE_ARCH_AUDITSYSCALL
73 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
74 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
75 select HAVE_ARCH_KASAN if MMU && 64BIT
76 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
77 select HAVE_ARCH_KFENCE if MMU && 64BIT
78 select HAVE_ARCH_KGDB if !XIP_KERNEL
79 select HAVE_ARCH_KGDB_QXFER_PKT
80 select HAVE_ARCH_MMAP_RND_BITS if MMU
81 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
82 select HAVE_ARCH_SECCOMP_FILTER
83 select HAVE_ARCH_TRACEHOOK
84 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
85 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
86 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
87 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
88 select HAVE_ASM_MODVERSIONS
89 select HAVE_CONTEXT_TRACKING_USER
90 select HAVE_DEBUG_KMEMLEAK
91 select HAVE_DMA_CONTIGUOUS if MMU
92 select HAVE_EBPF_JIT if MMU
93 select HAVE_FUNCTION_ERROR_INJECTION
94 select HAVE_GCC_PLUGINS
95 select HAVE_GENERIC_VDSO if MMU && 64BIT
96 select HAVE_IRQ_TIME_ACCOUNTING
97 select HAVE_KPROBES if !XIP_KERNEL
98 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
99 select HAVE_KRETPROBES if !XIP_KERNEL
103 select HAVE_PERF_EVENTS
104 select HAVE_PERF_REGS
105 select HAVE_PERF_USER_STACK_DUMP
106 select HAVE_REGS_AND_STACK_ACCESS_API
107 select HAVE_FUNCTION_ARG_ACCESS_API
108 select HAVE_STACKPROTECTOR
109 select HAVE_SYSCALL_TRACEPOINTS
112 select IRQ_FORCED_THREADING
113 select MODULES_USE_ELF_RELA if MODULES
114 select MODULE_SECTIONS if MODULES
116 select OF_EARLY_FLATTREE
118 select PCI_DOMAINS_GENERIC if PCI
119 select PCI_MSI if PCI
121 select RISCV_TIMER if RISCV_SBI
123 select SYSCTL_EXCEPTION_TRACE
124 select THREAD_INFO_IN_TASK
125 select TRACE_IRQFLAGS_SUPPORT
126 select UACCESS_MEMCPY if !MMU
127 select ZONE_DMA32 if 64BIT
129 config ARCH_MMAP_RND_BITS_MIN
133 config ARCH_MMAP_RND_COMPAT_BITS_MIN
136 # max bits determined by the following formula:
137 # VA_BITS - PAGE_SHIFT - 3
138 config ARCH_MMAP_RND_BITS_MAX
139 default 24 if 64BIT # SV39 based
142 config ARCH_MMAP_RND_COMPAT_BITS_MAX
145 # set if we run in machine mode, cleared if we run in supervisor mode
150 # set if we are running in S-mode and can use SBI calls
153 depends on !RISCV_M_MODE
157 bool "MMU-based Paged Memory Management Support"
160 Select if you want MMU-based virtualised addressing space
161 support by paged memory management. If unsure, say 'Y'.
165 default 0xC0000000 if 32BIT
166 default 0x80000000 if 64BIT && !MMU
167 default 0xff60000000000000 if 64BIT
169 config KASAN_SHADOW_OFFSET
171 depends on KASAN_GENERIC
172 default 0xdfffffff00000000 if 64BIT
173 default 0xffffffff if 32BIT
175 config ARCH_FLATMEM_ENABLE
178 config ARCH_SPARSEMEM_ENABLE
181 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
182 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
184 config ARCH_SELECT_MEMORY_MODEL
185 def_bool ARCH_SPARSEMEM_ENABLE
187 config ARCH_SUPPORTS_UPROBES
190 config STACKTRACE_SUPPORT
196 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
198 config GENERIC_BUG_RELATIVE_POINTERS
201 config GENERIC_CALIBRATE_DELAY
207 config GENERIC_HWEIGHT
210 config FIX_EARLYCON_MEM
213 config PGTABLE_LEVELS
218 config LOCKDEP_SUPPORT
221 source "arch/riscv/Kconfig.socs"
222 source "arch/riscv/Kconfig.erratas"
227 bool "Allow configurations that result in non-portable kernels"
229 RISC-V kernel binaries are compatible between all known systems
230 whenever possible, but there are some use cases that can only be
231 satisfied by configurations that result in kernel binaries that are
232 not portable between systems.
234 Selecting N does not guarantee kernels will be portable to all known
235 systems. Selecting any of the options guarded by NONPORTABLE will
236 result in kernel binaries that are unlikely to be portable between
245 This selects the base ISA that this kernel will target and must match
250 depends on NONPORTABLE
252 select GENERIC_LIB_ASHLDI3
253 select GENERIC_LIB_ASHRDI3
254 select GENERIC_LIB_LSHRDI3
255 select GENERIC_LIB_UCMPDI2
261 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
262 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
263 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
264 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
265 select HAVE_FUNCTION_GRAPH_TRACER
266 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
267 select SWIOTLB if MMU
271 # We must be able to map all physical memory into the kernel, but the compiler
272 # is still a bit more efficient when generating code if it's setup in a manner
273 # such that it can only map 2GiB of memory.
275 prompt "Kernel Code Model"
276 default CMODEL_MEDLOW if 32BIT
277 default CMODEL_MEDANY if 64BIT
280 bool "medium low code model"
282 bool "medium any code model"
285 config MODULE_SECTIONS
287 select HAVE_MOD_ARCH_SPECIFIC
290 bool "Symmetric Multi-Processing"
292 This enables support for systems with more than one CPU. If
293 you say N here, the kernel will run on single and
294 multiprocessor machines, but will use only one CPU of a
295 multiprocessor machine. If you say Y here, the kernel will run
296 on many, but not all, single processor machines. On a single
297 processor machine, the kernel will run faster if you say N
300 If you don't know what to do here, say N.
303 int "Maximum number of CPUs (2-32)"
309 bool "Support for hot-pluggable CPUs"
311 select GENERIC_IRQ_MIGRATION
314 Say Y here to experiment with turning CPUs off and on. CPUs
315 can be controlled through /sys/devices/system/cpu.
317 Say N if you want to disable CPU hotplug.
328 # Common NUMA Features
330 bool "NUMA Memory Allocation and Scheduler Support"
331 depends on SMP && MMU
332 select GENERIC_ARCH_NUMA
334 select ARCH_SUPPORTS_NUMA_BALANCING
335 select USE_PERCPU_NUMA_NODE_ID
336 select NEED_PER_CPU_EMBED_FIRST_CHUNK
338 Enable NUMA (Non-Uniform Memory Access) support.
340 The kernel will try to allocate memory used by a CPU on the
341 local memory of the CPU and add some more NUMA awareness to the kernel.
344 int "Maximum NUMA Nodes (as a power of 2)"
349 Specify the maximum number of NUMA Nodes available on the target
350 system. Increases memory reserved to accommodate various tables.
352 config RISCV_ALTERNATIVE
354 depends on !XIP_KERNEL
356 This Kconfig allows the kernel to automatically patch the
357 errata required by the execution platform at run time. The
358 code patching is performed once in the boot stages. It means
359 that the overhead from this mechanism is just taken once.
361 config RISCV_ALTERNATIVE_EARLY
363 depends on RISCV_ALTERNATIVE
365 Allows early patching of the kernel for special errata
368 bool "Emit compressed instructions when building Linux"
371 Adds "C" to the ISA subsets that the toolchain is allowed to emit
372 when building Linux, which results in compressed instructions in the
375 If you don't know what to do here, say Y.
377 config RISCV_ISA_SVPBMT
378 bool "SVPBMT extension support"
379 depends on 64BIT && MMU
380 select RISCV_ALTERNATIVE
383 Adds support to dynamically detect the presence of the SVPBMT
384 ISA-extension (Supervisor-mode: page-based memory types) and
387 The memory type for a page contains a combination of attributes
388 that indicate the cacheability, idempotency, and ordering
389 properties for access to that page.
391 The SVPBMT extension is only available on 64Bit cpus.
393 If you don't know what to do here, say Y.
399 Say N here if you want to disable all floating-point related procedure
402 If you don't know what to do here, say Y.
404 endmenu # "Platform type"
406 menu "Kernel features"
408 source "kernel/Kconfig.hz"
411 bool "SBI v0.1 support"
414 This config allows kernel to use SBI v0.1 APIs. This will be
415 deprecated in future once legacy M-mode software are no longer in use.
417 config RISCV_BOOT_SPINWAIT
418 bool "Spinwait booting method"
420 default y if RISCV_SBI_V01 || RISCV_M_MODE
422 This enables support for booting Linux via spinwait method. In the
423 spinwait method, all cores randomly jump to Linux. One of the cores
424 gets chosen via lottery and all other keep spinning on a percpu
425 variable. This method cannot support CPU hotplug and sparse hartid
426 scheme. It should be only enabled for M-mode Linux or platforms relying
427 on older firmware without SBI HSM extension. All other platforms should
428 rely on ordered booting via SBI HSM extension which gets chosen
429 dynamically at runtime if the firmware supports it.
431 Since spinwait is incompatible with sparse hart IDs, it requires
432 NR_CPUS be large enough to contain the physical hart ID of the first
435 If unsure what to do here, say N.
438 bool "Kexec system call"
440 select HOTPLUG_CPU if SMP
443 kexec is a system call that implements the ability to shutdown your
444 current kernel, and to start another kernel. It is like a reboot
445 but it is independent of the system firmware. And like a reboot
446 you can start any kernel with it, not just Linux.
448 The name comes from the similarity to the exec system call.
451 bool "kexec file based systmem call"
454 select HAVE_IMA_KEXEC if IMA
457 This is new version of kexec system call. This system call is
458 file based and takes file descriptors as system call argument
459 for kernel and initramfs as opposed to list of segments as
460 accepted by previous system call.
462 If you don't know what to do here, say Y.
464 config ARCH_HAS_KEXEC_PURGATORY
468 depends on CRYPTO_SHA256=y
471 bool "Build kdump crash kernel"
473 Generate crash dump after being started by kexec. This should
474 be normally only set in special crash dump kernels which are
475 loaded in the main kernel with kexec-tools into a specially
476 reserved region and then later executed after a crash by
479 For more details see Documentation/admin-guide/kdump/kdump.rst
482 bool "Kernel support for 32-bit U-mode"
484 depends on 64BIT && MMU
486 This option enables support for a 32-bit U-mode running under a 64-bit
487 kernel at S-mode. riscv32-specific components such as system calls,
488 the user helper functions (vdso), signal rt_frame functions and the
489 ptrace interface are handled appropriately by the kernel.
491 If you want to execute 32-bit userspace applications, say Y.
493 endmenu # "Kernel features"
498 string "Built-in kernel command line"
500 For most platforms, the arguments for the kernel's command line
501 are provided at run-time, during boot. However, there are cases
502 where either no arguments are being provided or the provided
503 arguments are insufficient or even invalid.
505 When that occurs, it is possible to define a built-in command
506 line here and choose how the kernel should use it later on.
509 prompt "Built-in command line usage" if CMDLINE != ""
510 default CMDLINE_FALLBACK
512 Choose how the kernel will handle the provided built-in command
515 config CMDLINE_FALLBACK
516 bool "Use bootloader kernel arguments if available"
518 Use the built-in command line as fallback in case we get nothing
519 during boot. This is the default behaviour.
521 config CMDLINE_EXTEND
522 bool "Extend bootloader kernel arguments"
524 The command-line arguments provided during boot will be
525 appended to the built-in command line. This is useful in
526 cases where the provided arguments are insufficient and
527 you don't want to or cannot modify them.
530 bool "Always use the default kernel command string"
532 Always use the built-in command line, even if we get one during
533 boot. This is useful in case you need to override the provided
534 command line on systems where you don't have or want control
543 bool "UEFI runtime support"
544 depends on OF && !XIP_KERNEL
547 select EFI_PARAMS_FROM_FDT
549 select EFI_GENERIC_STUB
550 select EFI_RUNTIME_WRAPPERS
555 This option provides support for runtime services provided
556 by UEFI firmware (such as non-volatile variables, realtime
557 clock, and platform reset). A UEFI stub is also provided to
558 allow the kernel to be booted as an EFI application. This
559 is only useful on systems that have UEFI firmware.
561 config CC_HAVE_STACKPROTECTOR_TLS
562 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
564 config STACKPROTECTOR_PER_TASK
566 depends on !RANDSTRUCT
567 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
569 config PHYS_RAM_BASE_FIXED
570 bool "Explicitly specified physical RAM address"
571 depends on NONPORTABLE
575 hex "Platform Physical RAM address"
576 depends on PHYS_RAM_BASE_FIXED
579 This is the physical address of RAM in the system. It has to be
580 explicitly specified to run early relocations of read-write data
584 bool "Kernel Execute-In-Place from ROM"
585 depends on MMU && SPARSEMEM && NONPORTABLE
586 # This prevents XIP from being enabled by all{yes,mod}config, which
587 # fail to build since XIP doesn't support large kernels.
588 depends on !COMPILE_TEST
589 select PHYS_RAM_BASE_FIXED
591 Execute-In-Place allows the kernel to run from non-volatile storage
592 directly addressable by the CPU, such as NOR flash. This saves RAM
593 space since the text section of the kernel is not loaded from flash
594 to RAM. Read-write sections, such as the data section and stack,
595 are still copied to RAM. The XIP kernel is not compressed since
596 it has to run directly from flash, so it will take more space to
597 store it. The flash address used to link the kernel object files,
598 and for storing it, is configuration dependent. Therefore, if you
599 say Y here, you must know the proper physical address where to
600 store the kernel image depending on your own flash memory usage.
602 Also note that the make target becomes "make xipImage" rather than
603 "make zImage" or "make Image". The final kernel binary to put in
604 ROM memory will be arch/riscv/boot/xipImage.
606 SPARSEMEM is required because the kernel text and rodata that are
607 flash resident are not backed by memmap, then any attempt to get
608 a struct page on those regions will trigger a fault.
613 hex "XIP Kernel Physical Location"
614 depends on XIP_KERNEL
617 This is the physical address in your flash memory the kernel will
618 be linked for and stored to. This address is dependent on your
621 endmenu # "Boot options"
625 depends on OF && NONPORTABLE
626 default y if XIP_KERNEL
635 menu "Power management options"
637 source "kernel/power/Kconfig"
639 endmenu # "Power management options"
641 menu "CPU Power Management"
643 source "drivers/cpuidle/Kconfig"
645 endmenu # "CPU Power Management"
647 source "arch/riscv/kvm/Kconfig"