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
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
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"
230 This selects the base ISA that this kernel will target and must match
236 select GENERIC_LIB_ASHLDI3
237 select GENERIC_LIB_ASHRDI3
238 select GENERIC_LIB_LSHRDI3
239 select GENERIC_LIB_UCMPDI2
245 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
246 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
247 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
248 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
249 select HAVE_FUNCTION_GRAPH_TRACER
250 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
251 select SWIOTLB if MMU
255 # We must be able to map all physical memory into the kernel, but the compiler
256 # is still a bit more efficient when generating code if it's setup in a manner
257 # such that it can only map 2GiB of memory.
259 prompt "Kernel Code Model"
260 default CMODEL_MEDLOW if 32BIT
261 default CMODEL_MEDANY if 64BIT
264 bool "medium low code model"
266 bool "medium any code model"
269 config MODULE_SECTIONS
271 select HAVE_MOD_ARCH_SPECIFIC
274 bool "Symmetric Multi-Processing"
276 This enables support for systems with more than one CPU. If
277 you say N here, the kernel will run on single and
278 multiprocessor machines, but will use only one CPU of a
279 multiprocessor machine. If you say Y here, the kernel will run
280 on many, but not all, single processor machines. On a single
281 processor machine, the kernel will run faster if you say N
284 If you don't know what to do here, say N.
287 int "Maximum number of CPUs (2-32)"
293 bool "Support for hot-pluggable CPUs"
295 select GENERIC_IRQ_MIGRATION
298 Say Y here to experiment with turning CPUs off and on. CPUs
299 can be controlled through /sys/devices/system/cpu.
301 Say N if you want to disable CPU hotplug.
312 # Common NUMA Features
314 bool "NUMA Memory Allocation and Scheduler Support"
315 depends on SMP && MMU
316 select GENERIC_ARCH_NUMA
318 select ARCH_SUPPORTS_NUMA_BALANCING
319 select USE_PERCPU_NUMA_NODE_ID
320 select NEED_PER_CPU_EMBED_FIRST_CHUNK
322 Enable NUMA (Non-Uniform Memory Access) support.
324 The kernel will try to allocate memory used by a CPU on the
325 local memory of the CPU and add some more NUMA awareness to the kernel.
328 int "Maximum NUMA Nodes (as a power of 2)"
333 Specify the maximum number of NUMA Nodes available on the target
334 system. Increases memory reserved to accommodate various tables.
336 config RISCV_ALTERNATIVE
338 depends on !XIP_KERNEL
340 This Kconfig allows the kernel to automatically patch the
341 errata required by the execution platform at run time. The
342 code patching is performed once in the boot stages. It means
343 that the overhead from this mechanism is just taken once.
345 config RISCV_ALTERNATIVE_EARLY
347 depends on RISCV_ALTERNATIVE
349 Allows early patching of the kernel for special errata
352 bool "Emit compressed instructions when building Linux"
355 Adds "C" to the ISA subsets that the toolchain is allowed to emit
356 when building Linux, which results in compressed instructions in the
359 If you don't know what to do here, say Y.
361 config RISCV_ISA_SVPBMT
362 bool "SVPBMT extension support"
363 depends on 64BIT && MMU
364 select RISCV_ALTERNATIVE
367 Adds support to dynamically detect the presence of the SVPBMT extension
368 (Supervisor-mode: page-based memory types) and enable its usage.
370 The SVPBMT extension is only available on 64Bit cpus.
372 If you don't know what to do here, say Y.
378 Say N here if you want to disable all floating-point related procedure
381 If you don't know what to do here, say Y.
385 menu "Kernel features"
387 source "kernel/Kconfig.hz"
390 bool "SBI v0.1 support"
393 This config allows kernel to use SBI v0.1 APIs. This will be
394 deprecated in future once legacy M-mode software are no longer in use.
396 config RISCV_BOOT_SPINWAIT
397 bool "Spinwait booting method"
399 default y if RISCV_SBI_V01 || RISCV_M_MODE
401 This enables support for booting Linux via spinwait method. In the
402 spinwait method, all cores randomly jump to Linux. One of the cores
403 gets chosen via lottery and all other keep spinning on a percpu
404 variable. This method cannot support CPU hotplug and sparse hartid
405 scheme. It should be only enabled for M-mode Linux or platforms relying
406 on older firmware without SBI HSM extension. All other platforms should
407 rely on ordered booting via SBI HSM extension which gets chosen
408 dynamically at runtime if the firmware supports it.
410 Since spinwait is incompatible with sparse hart IDs, it requires
411 NR_CPUS be large enough to contain the physical hart ID of the first
414 If unsure what to do here, say N.
417 bool "Kexec system call"
419 select HOTPLUG_CPU if SMP
422 kexec is a system call that implements the ability to shutdown your
423 current kernel, and to start another kernel. It is like a reboot
424 but it is independent of the system firmware. And like a reboot
425 you can start any kernel with it, not just Linux.
427 The name comes from the similarity to the exec system call.
430 bool "kexec file based systmem call"
433 select HAVE_IMA_KEXEC if IMA
436 This is new version of kexec system call. This system call is
437 file based and takes file descriptors as system call argument
438 for kernel and initramfs as opposed to list of segments as
439 accepted by previous system call.
441 If you don't know what to do here, say Y.
443 config ARCH_HAS_KEXEC_PURGATORY
447 depends on CRYPTO_SHA256=y
450 bool "Build kdump crash kernel"
452 Generate crash dump after being started by kexec. This should
453 be normally only set in special crash dump kernels which are
454 loaded in the main kernel with kexec-tools into a specially
455 reserved region and then later executed after a crash by
458 For more details see Documentation/admin-guide/kdump/kdump.rst
461 bool "Kernel support for 32-bit U-mode"
463 depends on 64BIT && MMU
465 This option enables support for a 32-bit U-mode running under a 64-bit
466 kernel at S-mode. riscv32-specific components such as system calls,
467 the user helper functions (vdso), signal rt_frame functions and the
468 ptrace interface are handled appropriately by the kernel.
470 If you want to execute 32-bit userspace applications, say Y.
477 string "Built-in kernel command line"
479 For most platforms, the arguments for the kernel's command line
480 are provided at run-time, during boot. However, there are cases
481 where either no arguments are being provided or the provided
482 arguments are insufficient or even invalid.
484 When that occurs, it is possible to define a built-in command
485 line here and choose how the kernel should use it later on.
488 prompt "Built-in command line usage" if CMDLINE != ""
489 default CMDLINE_FALLBACK
491 Choose how the kernel will handle the provided built-in command
494 config CMDLINE_FALLBACK
495 bool "Use bootloader kernel arguments if available"
497 Use the built-in command line as fallback in case we get nothing
498 during boot. This is the default behaviour.
500 config CMDLINE_EXTEND
501 bool "Extend bootloader kernel arguments"
503 The command-line arguments provided during boot will be
504 appended to the built-in command line. This is useful in
505 cases where the provided arguments are insufficient and
506 you don't want to or cannot modify them.
510 bool "Always use the default kernel command string"
512 Always use the built-in command line, even if we get one during
513 boot. This is useful in case you need to override the provided
514 command line on systems where you don't have or want control
523 bool "UEFI runtime support"
524 depends on OF && !XIP_KERNEL
527 select EFI_PARAMS_FROM_FDT
529 select EFI_GENERIC_STUB
530 select EFI_RUNTIME_WRAPPERS
535 This option provides support for runtime services provided
536 by UEFI firmware (such as non-volatile variables, realtime
537 clock, and platform reset). A UEFI stub is also provided to
538 allow the kernel to be booted as an EFI application. This
539 is only useful on systems that have UEFI firmware.
541 config CC_HAVE_STACKPROTECTOR_TLS
542 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
544 config STACKPROTECTOR_PER_TASK
546 depends on !RANDSTRUCT
547 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
549 config PHYS_RAM_BASE_FIXED
550 bool "Explicitly specified physical RAM address"
554 hex "Platform Physical RAM address"
555 depends on PHYS_RAM_BASE_FIXED
558 This is the physical address of RAM in the system. It has to be
559 explicitly specified to run early relocations of read-write data
563 bool "Kernel Execute-In-Place from ROM"
564 depends on MMU && SPARSEMEM
565 # This prevents XIP from being enabled by all{yes,mod}config, which
566 # fail to build since XIP doesn't support large kernels.
567 depends on !COMPILE_TEST
568 select PHYS_RAM_BASE_FIXED
570 Execute-In-Place allows the kernel to run from non-volatile storage
571 directly addressable by the CPU, such as NOR flash. This saves RAM
572 space since the text section of the kernel is not loaded from flash
573 to RAM. Read-write sections, such as the data section and stack,
574 are still copied to RAM. The XIP kernel is not compressed since
575 it has to run directly from flash, so it will take more space to
576 store it. The flash address used to link the kernel object files,
577 and for storing it, is configuration dependent. Therefore, if you
578 say Y here, you must know the proper physical address where to
579 store the kernel image depending on your own flash memory usage.
581 Also note that the make target becomes "make xipImage" rather than
582 "make zImage" or "make Image". The final kernel binary to put in
583 ROM memory will be arch/riscv/boot/xipImage.
585 SPARSEMEM is required because the kernel text and rodata that are
586 flash resident are not backed by memmap, then any attempt to get
587 a struct page on those regions will trigger a fault.
592 hex "XIP Kernel Physical Location"
593 depends on XIP_KERNEL
596 This is the physical address in your flash memory the kernel will
597 be linked for and stored to. This address is dependent on your
605 default y if XIP_KERNEL
607 menu "Power management options"
609 source "kernel/power/Kconfig"
613 menu "CPU Power Management"
615 source "drivers/cpuidle/Kconfig"
619 source "arch/riscv/kvm/Kconfig"