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_HAS_BINFMT_FLAT
18 select ARCH_HAS_DEBUG_VM_PGTABLE
19 select ARCH_HAS_DEBUG_VIRTUAL if MMU
20 select ARCH_HAS_DEBUG_WX
21 select ARCH_HAS_FORTIFY_SOURCE
22 select ARCH_HAS_GCOV_PROFILE_ALL
23 select ARCH_HAS_GIGANTIC_PAGE
25 select ARCH_HAS_MMIOWB
26 select ARCH_HAS_PTE_SPECIAL
27 select ARCH_HAS_SET_DIRECT_MAP if MMU
28 select ARCH_HAS_SET_MEMORY if MMU
29 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
30 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
31 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
32 select ARCH_HAS_UBSAN_SANITIZE_ALL
33 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
34 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
36 select ARCH_SUPPORTS_ATOMIC_RMW
37 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
38 select ARCH_SUPPORTS_HUGETLBFS if MMU
39 select ARCH_USE_MEMTEST
40 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
41 select ARCH_WANT_FRAME_POINTERS
42 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
43 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
44 select BUILDTIME_TABLE_SORT if MMU
45 select CLONE_BACKWARDS
46 select CLINT_TIMER if !MMU
49 select GENERIC_ARCH_TOPOLOGY if SMP
50 select GENERIC_ATOMIC64 if !64BIT
51 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
52 select GENERIC_EARLY_IOREMAP
53 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
54 select GENERIC_IDLE_POLL_SETUP
55 select GENERIC_IOREMAP if MMU
56 select GENERIC_IRQ_MULTI_HANDLER
57 select GENERIC_IRQ_SHOW
58 select GENERIC_IRQ_SHOW_LEVEL
59 select GENERIC_LIB_DEVMEM_IS_ALLOWED
60 select GENERIC_PCI_IOMAP
61 select GENERIC_PTDUMP if MMU
62 select GENERIC_SCHED_CLOCK
63 select GENERIC_SMP_IDLE_THREAD
64 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
65 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
66 select HAVE_ARCH_AUDITSYSCALL
67 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
68 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
69 select HAVE_ARCH_KASAN if MMU && 64BIT
70 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
71 select HAVE_ARCH_KFENCE if MMU && 64BIT
72 select HAVE_ARCH_KGDB if !XIP_KERNEL
73 select HAVE_ARCH_KGDB_QXFER_PKT
74 select HAVE_ARCH_MMAP_RND_BITS if MMU
75 select HAVE_ARCH_SECCOMP_FILTER
76 select HAVE_ARCH_TRACEHOOK
77 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
78 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
79 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
80 select HAVE_ASM_MODVERSIONS
81 select HAVE_CONTEXT_TRACKING
82 select HAVE_DEBUG_KMEMLEAK
83 select HAVE_DMA_CONTIGUOUS if MMU
84 select HAVE_EBPF_JIT if MMU
85 select HAVE_FUNCTION_ERROR_INJECTION
86 select HAVE_FUTEX_CMPXCHG if FUTEX
87 select HAVE_GCC_PLUGINS
88 select HAVE_GENERIC_VDSO if MMU && 64BIT
89 select HAVE_IRQ_TIME_ACCOUNTING
90 select HAVE_KPROBES if !XIP_KERNEL
91 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
92 select HAVE_KRETPROBES if !XIP_KERNEL
96 select HAVE_PERF_EVENTS
98 select HAVE_PERF_USER_STACK_DUMP
99 select HAVE_REGS_AND_STACK_ACCESS_API
100 select HAVE_FUNCTION_ARG_ACCESS_API
101 select HAVE_STACKPROTECTOR
102 select HAVE_SYSCALL_TRACEPOINTS
104 select IRQ_FORCED_THREADING
105 select MODULES_USE_ELF_RELA if MODULES
106 select MODULE_SECTIONS if MODULES
108 select OF_EARLY_FLATTREE
110 select PCI_DOMAINS_GENERIC if PCI
111 select PCI_MSI if PCI
113 select RISCV_TIMER if RISCV_SBI
115 select SYSCTL_EXCEPTION_TRACE
116 select THREAD_INFO_IN_TASK
117 select TRACE_IRQFLAGS_SUPPORT
118 select UACCESS_MEMCPY if !MMU
119 select ZONE_DMA32 if 64BIT
121 config ARCH_MMAP_RND_BITS_MIN
125 # max bits determined by the following formula:
126 # VA_BITS - PAGE_SHIFT - 3
127 config ARCH_MMAP_RND_BITS_MAX
128 default 24 if 64BIT # SV39 based
131 # set if we run in machine mode, cleared if we run in supervisor mode
136 # set if we are running in S-mode and can use SBI calls
139 depends on !RISCV_M_MODE
143 bool "MMU-based Paged Memory Management Support"
146 Select if you want MMU-based virtualised addressing space
147 support by paged memory management. If unsure, say 'Y'.
151 default 0xC0000000 if 32BIT
152 default 0x80000000 if 64BIT && !MMU
153 default 0xffffffd800000000 if 64BIT
155 config KASAN_SHADOW_OFFSET
157 depends on KASAN_GENERIC
158 default 0xdfffffff00000000 if 64BIT
159 default 0xffffffff if 32BIT
161 config ARCH_FLATMEM_ENABLE
164 config ARCH_SPARSEMEM_ENABLE
167 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
168 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
170 config ARCH_SELECT_MEMORY_MODEL
171 def_bool ARCH_SPARSEMEM_ENABLE
173 config ARCH_WANT_GENERAL_HUGETLB
176 config ARCH_SUPPORTS_UPROBES
179 config STACKTRACE_SUPPORT
185 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
187 config GENERIC_BUG_RELATIVE_POINTERS
190 config GENERIC_CALIBRATE_DELAY
196 config GENERIC_HWEIGHT
199 config FIX_EARLYCON_MEM
202 config PGTABLE_LEVELS
207 config LOCKDEP_SUPPORT
210 source "arch/riscv/Kconfig.socs"
211 source "arch/riscv/Kconfig.erratas"
219 This selects the base ISA that this kernel will target and must match
225 select GENERIC_LIB_ASHLDI3
226 select GENERIC_LIB_ASHRDI3
227 select GENERIC_LIB_LSHRDI3
228 select GENERIC_LIB_UCMPDI2
234 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
235 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
236 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
237 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
238 select HAVE_FUNCTION_GRAPH_TRACER
239 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
240 select SWIOTLB if MMU
244 # We must be able to map all physical memory into the kernel, but the compiler
245 # is still a bit more efficient when generating code if it's setup in a manner
246 # such that it can only map 2GiB of memory.
248 prompt "Kernel Code Model"
249 default CMODEL_MEDLOW if 32BIT
250 default CMODEL_MEDANY if 64BIT
253 bool "medium low code model"
255 bool "medium any code model"
258 config MODULE_SECTIONS
260 select HAVE_MOD_ARCH_SPECIFIC
263 bool "Symmetric Multi-Processing"
265 This enables support for systems with more than one CPU. If
266 you say N here, the kernel will run on single and
267 multiprocessor machines, but will use only one CPU of a
268 multiprocessor machine. If you say Y here, the kernel will run
269 on many, but not all, single processor machines. On a single
270 processor machine, the kernel will run faster if you say N
273 If you don't know what to do here, say N.
276 int "Maximum number of CPUs (2-32)"
282 bool "Support for hot-pluggable CPUs"
284 select GENERIC_IRQ_MIGRATION
287 Say Y here to experiment with turning CPUs off and on. CPUs
288 can be controlled through /sys/devices/system/cpu.
290 Say N if you want to disable CPU hotplug.
301 # Common NUMA Features
303 bool "NUMA Memory Allocation and Scheduler Support"
304 depends on SMP && MMU
305 select GENERIC_ARCH_NUMA
307 select ARCH_SUPPORTS_NUMA_BALANCING
309 Enable NUMA (Non-Uniform Memory Access) support.
311 The kernel will try to allocate memory used by a CPU on the
312 local memory of the CPU and add some more NUMA awareness to the kernel.
315 int "Maximum NUMA Nodes (as a power of 2)"
320 Specify the maximum number of NUMA Nodes available on the target
321 system. Increases memory reserved to accommodate various tables.
323 config USE_PERCPU_NUMA_NODE_ID
327 config NEED_PER_CPU_EMBED_FIRST_CHUNK
332 bool "Emit compressed instructions when building Linux"
335 Adds "C" to the ISA subsets that the toolchain is allowed to emit
336 when building Linux, which results in compressed instructions in the
339 If you don't know what to do here, say Y.
341 menu "supported PMU type"
342 depends on PERF_EVENTS
344 config RISCV_BASE_PMU
345 bool "Base Performance Monitoring Unit"
348 A base PMU that serves as a reference implementation and has limited
349 feature of perf. It can run on any RISC-V machines so serves as the
350 fallback, but this option can also be disable to reduce kernel size.
358 Say N here if you want to disable all floating-point related procedure
361 If you don't know what to do here, say Y.
365 menu "Kernel features"
367 source "kernel/Kconfig.hz"
370 bool "SBI v0.1 support"
374 This config allows kernel to use SBI v0.1 APIs. This will be
375 deprecated in future once legacy M-mode software are no longer in use.
378 bool "Kexec system call"
380 select HOTPLUG_CPU if SMP
383 kexec is a system call that implements the ability to shutdown your
384 current kernel, and to start another kernel. It is like a reboot
385 but it is independent of the system firmware. And like a reboot
386 you can start any kernel with it, not just Linux.
388 The name comes from the similarity to the exec system call.
391 bool "Build kdump crash kernel"
393 Generate crash dump after being started by kexec. This should
394 be normally only set in special crash dump kernels which are
395 loaded in the main kernel with kexec-tools into a specially
396 reserved region and then later executed after a crash by
399 For more details see Documentation/admin-guide/kdump/kdump.rst
406 string "Built-in kernel command line"
408 For most platforms, the arguments for the kernel's command line
409 are provided at run-time, during boot. However, there are cases
410 where either no arguments are being provided or the provided
411 arguments are insufficient or even invalid.
413 When that occurs, it is possible to define a built-in command
414 line here and choose how the kernel should use it later on.
417 prompt "Built-in command line usage" if CMDLINE != ""
418 default CMDLINE_FALLBACK
420 Choose how the kernel will handle the provided built-in command
423 config CMDLINE_FALLBACK
424 bool "Use bootloader kernel arguments if available"
426 Use the built-in command line as fallback in case we get nothing
427 during boot. This is the default behaviour.
429 config CMDLINE_EXTEND
430 bool "Extend bootloader kernel arguments"
432 The command-line arguments provided during boot will be
433 appended to the built-in command line. This is useful in
434 cases where the provided arguments are insufficient and
435 you don't want to or cannot modify them.
439 bool "Always use the default kernel command string"
441 Always use the built-in command line, even if we get one during
442 boot. This is useful in case you need to override the provided
443 command line on systems where you don't have or want control
452 bool "UEFI runtime support"
453 depends on OF && !XIP_KERNEL
456 select EFI_PARAMS_FROM_FDT
458 select EFI_GENERIC_STUB
459 select EFI_RUNTIME_WRAPPERS
464 This option provides support for runtime services provided
465 by UEFI firmware (such as non-volatile variables, realtime
466 clock, and platform reset). A UEFI stub is also provided to
467 allow the kernel to be booted as an EFI application. This
468 is only useful on systems that have UEFI firmware.
470 config CC_HAVE_STACKPROTECTOR_TLS
471 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
473 config STACKPROTECTOR_PER_TASK
475 depends on !GCC_PLUGIN_RANDSTRUCT
476 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
478 config PHYS_RAM_BASE_FIXED
479 bool "Explicitly specified physical RAM address"
483 hex "Platform Physical RAM address"
484 depends on PHYS_RAM_BASE_FIXED
487 This is the physical address of RAM in the system. It has to be
488 explicitly specified to run early relocations of read-write data
492 bool "Kernel Execute-In-Place from ROM"
493 depends on MMU && SPARSEMEM
494 # This prevents XIP from being enabled by all{yes,mod}config, which
495 # fail to build since XIP doesn't support large kernels.
496 depends on !COMPILE_TEST
497 select PHYS_RAM_BASE_FIXED
499 Execute-In-Place allows the kernel to run from non-volatile storage
500 directly addressable by the CPU, such as NOR flash. This saves RAM
501 space since the text section of the kernel is not loaded from flash
502 to RAM. Read-write sections, such as the data section and stack,
503 are still copied to RAM. The XIP kernel is not compressed since
504 it has to run directly from flash, so it will take more space to
505 store it. The flash address used to link the kernel object files,
506 and for storing it, is configuration dependent. Therefore, if you
507 say Y here, you must know the proper physical address where to
508 store the kernel image depending on your own flash memory usage.
510 Also note that the make target becomes "make xipImage" rather than
511 "make zImage" or "make Image". The final kernel binary to put in
512 ROM memory will be arch/riscv/boot/xipImage.
514 SPARSEMEM is required because the kernel text and rodata that are
515 flash resident are not backed by memmap, then any attempt to get
516 a struct page on those regions will trigger a fault.
521 hex "XIP Kernel Physical Location"
522 depends on XIP_KERNEL
525 This is the physical address in your flash memory the kernel will
526 be linked for and stored to. This address is dependent on your
534 default y if XIP_KERNEL
536 menu "Power management options"
538 source "kernel/power/Kconfig"
542 source "arch/riscv/kvm/Kconfig"