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_DEBUG_VM_PGTABLE
20 select ARCH_HAS_DEBUG_VIRTUAL if MMU
21 select ARCH_HAS_DEBUG_WX
22 select ARCH_HAS_FORTIFY_SOURCE
23 select ARCH_HAS_GCOV_PROFILE_ALL
24 select ARCH_HAS_GIGANTIC_PAGE
26 select ARCH_HAS_MMIOWB
27 select ARCH_HAS_PTE_SPECIAL
28 select ARCH_HAS_SET_DIRECT_MAP if MMU
29 select ARCH_HAS_SET_MEMORY if MMU
30 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
31 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
32 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
33 select ARCH_HAS_UBSAN_SANITIZE_ALL
34 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
35 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
37 select ARCH_SUPPORTS_ATOMIC_RMW
38 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
39 select ARCH_SUPPORTS_HUGETLBFS if MMU
40 select ARCH_USE_MEMTEST
41 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
42 select ARCH_WANT_FRAME_POINTERS
43 select ARCH_WANT_GENERAL_HUGETLB
44 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
45 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
46 select BUILDTIME_TABLE_SORT if MMU
47 select CLONE_BACKWARDS
48 select CLINT_TIMER if !MMU
51 select GENERIC_ARCH_TOPOLOGY if SMP
52 select GENERIC_ATOMIC64 if !64BIT
53 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
54 select GENERIC_EARLY_IOREMAP
55 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
56 select GENERIC_IDLE_POLL_SETUP
57 select GENERIC_IOREMAP if MMU
58 select GENERIC_IRQ_MULTI_HANDLER
59 select GENERIC_IRQ_SHOW
60 select GENERIC_IRQ_SHOW_LEVEL
61 select GENERIC_LIB_DEVMEM_IS_ALLOWED
62 select GENERIC_PCI_IOMAP
63 select GENERIC_PTDUMP if MMU
64 select GENERIC_SCHED_CLOCK
65 select GENERIC_SMP_IDLE_THREAD
66 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
67 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
68 select HAVE_ARCH_AUDITSYSCALL
69 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
70 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
71 select HAVE_ARCH_KASAN if MMU && 64BIT
72 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
73 select HAVE_ARCH_KFENCE if MMU && 64BIT
74 select HAVE_ARCH_KGDB if !XIP_KERNEL
75 select HAVE_ARCH_KGDB_QXFER_PKT
76 select HAVE_ARCH_MMAP_RND_BITS if MMU
77 select HAVE_ARCH_SECCOMP_FILTER
78 select HAVE_ARCH_TRACEHOOK
79 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
80 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
81 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
82 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
83 select HAVE_ASM_MODVERSIONS
84 select HAVE_CONTEXT_TRACKING
85 select HAVE_DEBUG_KMEMLEAK
86 select HAVE_DMA_CONTIGUOUS if MMU
87 select HAVE_EBPF_JIT if MMU
88 select HAVE_FUNCTION_ERROR_INJECTION
89 select HAVE_GCC_PLUGINS
90 select HAVE_GENERIC_VDSO if MMU && 64BIT
91 select HAVE_IRQ_TIME_ACCOUNTING
92 select HAVE_KPROBES if !XIP_KERNEL
93 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
94 select HAVE_KRETPROBES if !XIP_KERNEL
98 select HAVE_PERF_EVENTS
100 select HAVE_PERF_USER_STACK_DUMP
101 select HAVE_REGS_AND_STACK_ACCESS_API
102 select HAVE_FUNCTION_ARG_ACCESS_API
103 select HAVE_STACKPROTECTOR
104 select HAVE_SYSCALL_TRACEPOINTS
106 select IRQ_FORCED_THREADING
107 select MODULES_USE_ELF_RELA if MODULES
108 select MODULE_SECTIONS if MODULES
110 select OF_EARLY_FLATTREE
112 select PCI_DOMAINS_GENERIC if PCI
113 select PCI_MSI if PCI
115 select RISCV_TIMER if RISCV_SBI
117 select SYSCTL_EXCEPTION_TRACE
118 select THREAD_INFO_IN_TASK
119 select TRACE_IRQFLAGS_SUPPORT
120 select UACCESS_MEMCPY if !MMU
121 select ZONE_DMA32 if 64BIT
123 config ARCH_MMAP_RND_BITS_MIN
127 # max bits determined by the following formula:
128 # VA_BITS - PAGE_SHIFT - 3
129 config ARCH_MMAP_RND_BITS_MAX
130 default 24 if 64BIT # SV39 based
133 # set if we run in machine mode, cleared if we run in supervisor mode
138 # set if we are running in S-mode and can use SBI calls
141 depends on !RISCV_M_MODE
145 bool "MMU-based Paged Memory Management Support"
148 Select if you want MMU-based virtualised addressing space
149 support by paged memory management. If unsure, say 'Y'.
153 default 0xC0000000 if 32BIT
154 default 0x80000000 if 64BIT && !MMU
155 default 0xffffaf8000000000 if 64BIT
157 config KASAN_SHADOW_OFFSET
159 depends on KASAN_GENERIC
160 default 0xdfffffff00000000 if 64BIT
161 default 0xffffffff if 32BIT
163 config ARCH_FLATMEM_ENABLE
166 config ARCH_SPARSEMEM_ENABLE
169 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
170 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
172 config ARCH_SELECT_MEMORY_MODEL
173 def_bool ARCH_SPARSEMEM_ENABLE
175 config ARCH_SUPPORTS_UPROBES
178 config STACKTRACE_SUPPORT
184 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
186 config GENERIC_BUG_RELATIVE_POINTERS
189 config GENERIC_CALIBRATE_DELAY
195 config GENERIC_HWEIGHT
198 config FIX_EARLYCON_MEM
201 config PGTABLE_LEVELS
206 config LOCKDEP_SUPPORT
209 source "arch/riscv/Kconfig.socs"
210 source "arch/riscv/Kconfig.erratas"
218 This selects the base ISA that this kernel will target and must match
224 select GENERIC_LIB_ASHLDI3
225 select GENERIC_LIB_ASHRDI3
226 select GENERIC_LIB_LSHRDI3
227 select GENERIC_LIB_UCMPDI2
233 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
234 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
235 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
236 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
237 select HAVE_FUNCTION_GRAPH_TRACER
238 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
239 select SWIOTLB if MMU
243 # We must be able to map all physical memory into the kernel, but the compiler
244 # is still a bit more efficient when generating code if it's setup in a manner
245 # such that it can only map 2GiB of memory.
247 prompt "Kernel Code Model"
248 default CMODEL_MEDLOW if 32BIT
249 default CMODEL_MEDANY if 64BIT
252 bool "medium low code model"
254 bool "medium any code model"
257 config MODULE_SECTIONS
259 select HAVE_MOD_ARCH_SPECIFIC
262 bool "Symmetric Multi-Processing"
264 This enables support for systems with more than one CPU. If
265 you say N here, the kernel will run on single and
266 multiprocessor machines, but will use only one CPU of a
267 multiprocessor machine. If you say Y here, the kernel will run
268 on many, but not all, single processor machines. On a single
269 processor machine, the kernel will run faster if you say N
272 If you don't know what to do here, say N.
275 int "Maximum number of CPUs (2-32)"
281 bool "Support for hot-pluggable CPUs"
283 select GENERIC_IRQ_MIGRATION
286 Say Y here to experiment with turning CPUs off and on. CPUs
287 can be controlled through /sys/devices/system/cpu.
289 Say N if you want to disable CPU hotplug.
300 # Common NUMA Features
302 bool "NUMA Memory Allocation and Scheduler Support"
303 depends on SMP && MMU
304 select GENERIC_ARCH_NUMA
306 select ARCH_SUPPORTS_NUMA_BALANCING
307 select USE_PERCPU_NUMA_NODE_ID
308 select NEED_PER_CPU_EMBED_FIRST_CHUNK
310 Enable NUMA (Non-Uniform Memory Access) support.
312 The kernel will try to allocate memory used by a CPU on the
313 local memory of the CPU and add some more NUMA awareness to the kernel.
316 int "Maximum NUMA Nodes (as a power of 2)"
321 Specify the maximum number of NUMA Nodes available on the target
322 system. Increases memory reserved to accommodate various tables.
325 bool "Emit compressed instructions when building Linux"
328 Adds "C" to the ISA subsets that the toolchain is allowed to emit
329 when building Linux, which results in compressed instructions in the
332 If you don't know what to do here, say Y.
334 menu "supported PMU type"
335 depends on PERF_EVENTS
337 config RISCV_BASE_PMU
338 bool "Base Performance Monitoring Unit"
341 A base PMU that serves as a reference implementation and has limited
342 feature of perf. It can run on any RISC-V machines so serves as the
343 fallback, but this option can also be disable to reduce kernel size.
351 Say N here if you want to disable all floating-point related procedure
354 If you don't know what to do here, say Y.
358 menu "Kernel features"
360 source "kernel/Kconfig.hz"
363 bool "SBI v0.1 support"
366 This config allows kernel to use SBI v0.1 APIs. This will be
367 deprecated in future once legacy M-mode software are no longer in use.
369 config RISCV_BOOT_SPINWAIT
370 bool "Spinwait booting method"
374 This enables support for booting Linux via spinwait method. In the
375 spinwait method, all cores randomly jump to Linux. One of the cores
376 gets chosen via lottery and all other keep spinning on a percpu
377 variable. This method cannot support CPU hotplug and sparse hartid
378 scheme. It should be only enabled for M-mode Linux or platforms relying
379 on older firmware without SBI HSM extension. All other platforms should
380 rely on ordered booting via SBI HSM extension which gets chosen
381 dynamically at runtime if the firmware supports it.
384 bool "Kexec system call"
386 select HOTPLUG_CPU if SMP
389 kexec is a system call that implements the ability to shutdown your
390 current kernel, and to start another kernel. It is like a reboot
391 but it is independent of the system firmware. And like a reboot
392 you can start any kernel with it, not just Linux.
394 The name comes from the similarity to the exec system call.
397 bool "Build kdump crash kernel"
399 Generate crash dump after being started by kexec. This should
400 be normally only set in special crash dump kernels which are
401 loaded in the main kernel with kexec-tools into a specially
402 reserved region and then later executed after a crash by
405 For more details see Documentation/admin-guide/kdump/kdump.rst
412 string "Built-in kernel command line"
414 For most platforms, the arguments for the kernel's command line
415 are provided at run-time, during boot. However, there are cases
416 where either no arguments are being provided or the provided
417 arguments are insufficient or even invalid.
419 When that occurs, it is possible to define a built-in command
420 line here and choose how the kernel should use it later on.
423 prompt "Built-in command line usage" if CMDLINE != ""
424 default CMDLINE_FALLBACK
426 Choose how the kernel will handle the provided built-in command
429 config CMDLINE_FALLBACK
430 bool "Use bootloader kernel arguments if available"
432 Use the built-in command line as fallback in case we get nothing
433 during boot. This is the default behaviour.
435 config CMDLINE_EXTEND
436 bool "Extend bootloader kernel arguments"
438 The command-line arguments provided during boot will be
439 appended to the built-in command line. This is useful in
440 cases where the provided arguments are insufficient and
441 you don't want to or cannot modify them.
445 bool "Always use the default kernel command string"
447 Always use the built-in command line, even if we get one during
448 boot. This is useful in case you need to override the provided
449 command line on systems where you don't have or want control
458 bool "UEFI runtime support"
459 depends on OF && !XIP_KERNEL
462 select EFI_PARAMS_FROM_FDT
464 select EFI_GENERIC_STUB
465 select EFI_RUNTIME_WRAPPERS
470 This option provides support for runtime services provided
471 by UEFI firmware (such as non-volatile variables, realtime
472 clock, and platform reset). A UEFI stub is also provided to
473 allow the kernel to be booted as an EFI application. This
474 is only useful on systems that have UEFI firmware.
476 config CC_HAVE_STACKPROTECTOR_TLS
477 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
479 config STACKPROTECTOR_PER_TASK
481 depends on !GCC_PLUGIN_RANDSTRUCT
482 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
484 config PHYS_RAM_BASE_FIXED
485 bool "Explicitly specified physical RAM address"
489 hex "Platform Physical RAM address"
490 depends on PHYS_RAM_BASE_FIXED
493 This is the physical address of RAM in the system. It has to be
494 explicitly specified to run early relocations of read-write data
498 bool "Kernel Execute-In-Place from ROM"
499 depends on MMU && SPARSEMEM
500 # This prevents XIP from being enabled by all{yes,mod}config, which
501 # fail to build since XIP doesn't support large kernels.
502 depends on !COMPILE_TEST
503 select PHYS_RAM_BASE_FIXED
505 Execute-In-Place allows the kernel to run from non-volatile storage
506 directly addressable by the CPU, such as NOR flash. This saves RAM
507 space since the text section of the kernel is not loaded from flash
508 to RAM. Read-write sections, such as the data section and stack,
509 are still copied to RAM. The XIP kernel is not compressed since
510 it has to run directly from flash, so it will take more space to
511 store it. The flash address used to link the kernel object files,
512 and for storing it, is configuration dependent. Therefore, if you
513 say Y here, you must know the proper physical address where to
514 store the kernel image depending on your own flash memory usage.
516 Also note that the make target becomes "make xipImage" rather than
517 "make zImage" or "make Image". The final kernel binary to put in
518 ROM memory will be arch/riscv/boot/xipImage.
520 SPARSEMEM is required because the kernel text and rodata that are
521 flash resident are not backed by memmap, then any attempt to get
522 a struct page on those regions will trigger a fault.
527 hex "XIP Kernel Physical Location"
528 depends on XIP_KERNEL
531 This is the physical address in your flash memory the kernel will
532 be linked for and stored to. This address is dependent on your
540 default y if XIP_KERNEL
542 menu "Power management options"
544 source "kernel/power/Kconfig"
548 source "arch/riscv/kvm/Kconfig"