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_HUGE_PMD_SHARE if 64BIT
44 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
45 select BUILDTIME_TABLE_SORT if MMU
46 select CLONE_BACKWARDS
47 select CLINT_TIMER if !MMU
50 select GENERIC_ARCH_TOPOLOGY if SMP
51 select GENERIC_ATOMIC64 if !64BIT
52 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
53 select GENERIC_EARLY_IOREMAP
54 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
55 select GENERIC_IDLE_POLL_SETUP
56 select GENERIC_IOREMAP if MMU
57 select GENERIC_IRQ_MULTI_HANDLER
58 select GENERIC_IRQ_SHOW
59 select GENERIC_IRQ_SHOW_LEVEL
60 select GENERIC_LIB_DEVMEM_IS_ALLOWED
61 select GENERIC_PCI_IOMAP
62 select GENERIC_PTDUMP if MMU
63 select GENERIC_SCHED_CLOCK
64 select GENERIC_SMP_IDLE_THREAD
65 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
66 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
67 select HAVE_ARCH_AUDITSYSCALL
68 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
69 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
70 select HAVE_ARCH_KASAN if MMU && 64BIT
71 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
72 select HAVE_ARCH_KFENCE if MMU && 64BIT
73 select HAVE_ARCH_KGDB if !XIP_KERNEL
74 select HAVE_ARCH_KGDB_QXFER_PKT
75 select HAVE_ARCH_MMAP_RND_BITS if MMU
76 select HAVE_ARCH_SECCOMP_FILTER
77 select HAVE_ARCH_TRACEHOOK
78 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
79 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
80 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
81 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
82 select HAVE_ASM_MODVERSIONS
83 select HAVE_CONTEXT_TRACKING
84 select HAVE_DEBUG_KMEMLEAK
85 select HAVE_DMA_CONTIGUOUS if MMU
86 select HAVE_EBPF_JIT if MMU
87 select HAVE_FUNCTION_ERROR_INJECTION
88 select HAVE_GCC_PLUGINS
89 select HAVE_GENERIC_VDSO if MMU && 64BIT
90 select HAVE_IRQ_TIME_ACCOUNTING
91 select HAVE_KPROBES if !XIP_KERNEL
92 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
93 select HAVE_KRETPROBES if !XIP_KERNEL
97 select HAVE_PERF_EVENTS
99 select HAVE_PERF_USER_STACK_DUMP
100 select HAVE_REGS_AND_STACK_ACCESS_API
101 select HAVE_FUNCTION_ARG_ACCESS_API
102 select HAVE_STACKPROTECTOR
103 select HAVE_SYSCALL_TRACEPOINTS
105 select IRQ_FORCED_THREADING
106 select MODULES_USE_ELF_RELA if MODULES
107 select MODULE_SECTIONS if MODULES
109 select OF_EARLY_FLATTREE
111 select PCI_DOMAINS_GENERIC if PCI
112 select PCI_MSI if PCI
114 select RISCV_TIMER if RISCV_SBI
116 select SYSCTL_EXCEPTION_TRACE
117 select THREAD_INFO_IN_TASK
118 select TRACE_IRQFLAGS_SUPPORT
119 select UACCESS_MEMCPY if !MMU
120 select ZONE_DMA32 if 64BIT
122 config ARCH_MMAP_RND_BITS_MIN
126 # max bits determined by the following formula:
127 # VA_BITS - PAGE_SHIFT - 3
128 config ARCH_MMAP_RND_BITS_MAX
129 default 24 if 64BIT # SV39 based
132 # set if we run in machine mode, cleared if we run in supervisor mode
137 # set if we are running in S-mode and can use SBI calls
140 depends on !RISCV_M_MODE
144 bool "MMU-based Paged Memory Management Support"
147 Select if you want MMU-based virtualised addressing space
148 support by paged memory management. If unsure, say 'Y'.
152 default 0xC0000000 if 32BIT
153 default 0x80000000 if 64BIT && !MMU
154 default 0xffffaf8000000000 if 64BIT
156 config KASAN_SHADOW_OFFSET
158 depends on KASAN_GENERIC
159 default 0xdfffffff00000000 if 64BIT
160 default 0xffffffff if 32BIT
162 config ARCH_FLATMEM_ENABLE
165 config ARCH_SPARSEMEM_ENABLE
168 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
169 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
171 config ARCH_SELECT_MEMORY_MODEL
172 def_bool ARCH_SPARSEMEM_ENABLE
174 config ARCH_WANT_GENERAL_HUGETLB
177 config ARCH_SUPPORTS_UPROBES
180 config STACKTRACE_SUPPORT
186 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
188 config GENERIC_BUG_RELATIVE_POINTERS
191 config GENERIC_CALIBRATE_DELAY
197 config GENERIC_HWEIGHT
200 config FIX_EARLYCON_MEM
203 config PGTABLE_LEVELS
208 config LOCKDEP_SUPPORT
211 source "arch/riscv/Kconfig.socs"
212 source "arch/riscv/Kconfig.erratas"
220 This selects the base ISA that this kernel will target and must match
226 select GENERIC_LIB_ASHLDI3
227 select GENERIC_LIB_ASHRDI3
228 select GENERIC_LIB_LSHRDI3
229 select GENERIC_LIB_UCMPDI2
235 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
236 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
237 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
238 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
239 select HAVE_FUNCTION_GRAPH_TRACER
240 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
241 select SWIOTLB if MMU
245 # We must be able to map all physical memory into the kernel, but the compiler
246 # is still a bit more efficient when generating code if it's setup in a manner
247 # such that it can only map 2GiB of memory.
249 prompt "Kernel Code Model"
250 default CMODEL_MEDLOW if 32BIT
251 default CMODEL_MEDANY if 64BIT
254 bool "medium low code model"
256 bool "medium any code model"
259 config MODULE_SECTIONS
261 select HAVE_MOD_ARCH_SPECIFIC
264 bool "Symmetric Multi-Processing"
266 This enables support for systems with more than one CPU. If
267 you say N here, the kernel will run on single and
268 multiprocessor machines, but will use only one CPU of a
269 multiprocessor machine. If you say Y here, the kernel will run
270 on many, but not all, single processor machines. On a single
271 processor machine, the kernel will run faster if you say N
274 If you don't know what to do here, say N.
277 int "Maximum number of CPUs (2-32)"
283 bool "Support for hot-pluggable CPUs"
285 select GENERIC_IRQ_MIGRATION
288 Say Y here to experiment with turning CPUs off and on. CPUs
289 can be controlled through /sys/devices/system/cpu.
291 Say N if you want to disable CPU hotplug.
302 # Common NUMA Features
304 bool "NUMA Memory Allocation and Scheduler Support"
305 depends on SMP && MMU
306 select GENERIC_ARCH_NUMA
308 select ARCH_SUPPORTS_NUMA_BALANCING
309 select USE_PERCPU_NUMA_NODE_ID
310 select NEED_PER_CPU_EMBED_FIRST_CHUNK
312 Enable NUMA (Non-Uniform Memory Access) support.
314 The kernel will try to allocate memory used by a CPU on the
315 local memory of the CPU and add some more NUMA awareness to the kernel.
318 int "Maximum NUMA Nodes (as a power of 2)"
323 Specify the maximum number of NUMA Nodes available on the target
324 system. Increases memory reserved to accommodate various tables.
327 bool "Emit compressed instructions when building Linux"
330 Adds "C" to the ISA subsets that the toolchain is allowed to emit
331 when building Linux, which results in compressed instructions in the
334 If you don't know what to do here, say Y.
336 menu "supported PMU type"
337 depends on PERF_EVENTS
339 config RISCV_BASE_PMU
340 bool "Base Performance Monitoring Unit"
343 A base PMU that serves as a reference implementation and has limited
344 feature of perf. It can run on any RISC-V machines so serves as the
345 fallback, but this option can also be disable to reduce kernel size.
353 Say N here if you want to disable all floating-point related procedure
356 If you don't know what to do here, say Y.
360 menu "Kernel features"
362 source "kernel/Kconfig.hz"
365 bool "SBI v0.1 support"
368 This config allows kernel to use SBI v0.1 APIs. This will be
369 deprecated in future once legacy M-mode software are no longer in use.
371 config RISCV_BOOT_SPINWAIT
372 bool "Spinwait booting method"
376 This enables support for booting Linux via spinwait method. In the
377 spinwait method, all cores randomly jump to Linux. One of the cores
378 gets chosen via lottery and all other keep spinning on a percpu
379 variable. This method cannot support CPU hotplug and sparse hartid
380 scheme. It should be only enabled for M-mode Linux or platforms relying
381 on older firmware without SBI HSM extension. All other platforms should
382 rely on ordered booting via SBI HSM extension which gets chosen
383 dynamically at runtime if the firmware supports it.
386 bool "Kexec system call"
388 select HOTPLUG_CPU if SMP
391 kexec is a system call that implements the ability to shutdown your
392 current kernel, and to start another kernel. It is like a reboot
393 but it is independent of the system firmware. And like a reboot
394 you can start any kernel with it, not just Linux.
396 The name comes from the similarity to the exec system call.
399 bool "Build kdump crash kernel"
401 Generate crash dump after being started by kexec. This should
402 be normally only set in special crash dump kernels which are
403 loaded in the main kernel with kexec-tools into a specially
404 reserved region and then later executed after a crash by
407 For more details see Documentation/admin-guide/kdump/kdump.rst
414 string "Built-in kernel command line"
416 For most platforms, the arguments for the kernel's command line
417 are provided at run-time, during boot. However, there are cases
418 where either no arguments are being provided or the provided
419 arguments are insufficient or even invalid.
421 When that occurs, it is possible to define a built-in command
422 line here and choose how the kernel should use it later on.
425 prompt "Built-in command line usage" if CMDLINE != ""
426 default CMDLINE_FALLBACK
428 Choose how the kernel will handle the provided built-in command
431 config CMDLINE_FALLBACK
432 bool "Use bootloader kernel arguments if available"
434 Use the built-in command line as fallback in case we get nothing
435 during boot. This is the default behaviour.
437 config CMDLINE_EXTEND
438 bool "Extend bootloader kernel arguments"
440 The command-line arguments provided during boot will be
441 appended to the built-in command line. This is useful in
442 cases where the provided arguments are insufficient and
443 you don't want to or cannot modify them.
447 bool "Always use the default kernel command string"
449 Always use the built-in command line, even if we get one during
450 boot. This is useful in case you need to override the provided
451 command line on systems where you don't have or want control
460 bool "UEFI runtime support"
461 depends on OF && !XIP_KERNEL
464 select EFI_PARAMS_FROM_FDT
466 select EFI_GENERIC_STUB
467 select EFI_RUNTIME_WRAPPERS
472 This option provides support for runtime services provided
473 by UEFI firmware (such as non-volatile variables, realtime
474 clock, and platform reset). A UEFI stub is also provided to
475 allow the kernel to be booted as an EFI application. This
476 is only useful on systems that have UEFI firmware.
478 config CC_HAVE_STACKPROTECTOR_TLS
479 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
481 config STACKPROTECTOR_PER_TASK
483 depends on !GCC_PLUGIN_RANDSTRUCT
484 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
486 config PHYS_RAM_BASE_FIXED
487 bool "Explicitly specified physical RAM address"
491 hex "Platform Physical RAM address"
492 depends on PHYS_RAM_BASE_FIXED
495 This is the physical address of RAM in the system. It has to be
496 explicitly specified to run early relocations of read-write data
500 bool "Kernel Execute-In-Place from ROM"
501 depends on MMU && SPARSEMEM
502 # This prevents XIP from being enabled by all{yes,mod}config, which
503 # fail to build since XIP doesn't support large kernels.
504 depends on !COMPILE_TEST
505 select PHYS_RAM_BASE_FIXED
507 Execute-In-Place allows the kernel to run from non-volatile storage
508 directly addressable by the CPU, such as NOR flash. This saves RAM
509 space since the text section of the kernel is not loaded from flash
510 to RAM. Read-write sections, such as the data section and stack,
511 are still copied to RAM. The XIP kernel is not compressed since
512 it has to run directly from flash, so it will take more space to
513 store it. The flash address used to link the kernel object files,
514 and for storing it, is configuration dependent. Therefore, if you
515 say Y here, you must know the proper physical address where to
516 store the kernel image depending on your own flash memory usage.
518 Also note that the make target becomes "make xipImage" rather than
519 "make zImage" or "make Image". The final kernel binary to put in
520 ROM memory will be arch/riscv/boot/xipImage.
522 SPARSEMEM is required because the kernel text and rodata that are
523 flash resident are not backed by memmap, then any attempt to get
524 a struct page on those regions will trigger a fault.
529 hex "XIP Kernel Physical Location"
530 depends on XIP_KERNEL
533 This is the physical address in your flash memory the kernel will
534 be linked for and stored to. This address is dependent on your
542 default y if XIP_KERNEL
544 menu "Power management options"
546 source "kernel/power/Kconfig"
550 source "arch/riscv/kvm/Kconfig"