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
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 HANDLE_DOMAIN_IRQ
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 UACCESS_MEMCPY if !MMU
118 select ZONE_DMA32 if 64BIT
120 config ARCH_MMAP_RND_BITS_MIN
124 # max bits determined by the following formula:
125 # VA_BITS - PAGE_SHIFT - 3
126 config ARCH_MMAP_RND_BITS_MAX
127 default 24 if 64BIT # SV39 based
130 # set if we run in machine mode, cleared if we run in supervisor mode
135 # set if we are running in S-mode and can use SBI calls
138 depends on !RISCV_M_MODE
142 bool "MMU-based Paged Memory Management Support"
145 Select if you want MMU-based virtualised addressing space
146 support by paged memory management. If unsure, say 'Y'.
160 default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
161 default 0x80000000 if 64BIT && !MMU
162 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
163 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
165 config ARCH_FLATMEM_ENABLE
168 config ARCH_SPARSEMEM_ENABLE
171 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
172 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
174 config ARCH_SELECT_MEMORY_MODEL
175 def_bool ARCH_SPARSEMEM_ENABLE
177 config ARCH_WANT_GENERAL_HUGETLB
180 config ARCH_SUPPORTS_UPROBES
183 config STACKTRACE_SUPPORT
186 config TRACE_IRQFLAGS_SUPPORT
192 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
194 config GENERIC_BUG_RELATIVE_POINTERS
197 config GENERIC_CALIBRATE_DELAY
203 config GENERIC_HWEIGHT
206 config FIX_EARLYCON_MEM
209 config PGTABLE_LEVELS
214 config LOCKDEP_SUPPORT
217 source "arch/riscv/Kconfig.socs"
218 source "arch/riscv/Kconfig.erratas"
226 This selects the base ISA that this kernel will target and must match
232 select GENERIC_LIB_ASHLDI3
233 select GENERIC_LIB_ASHRDI3
234 select GENERIC_LIB_LSHRDI3
235 select GENERIC_LIB_UCMPDI2
241 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
242 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
243 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
244 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
245 select HAVE_FUNCTION_GRAPH_TRACER
246 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
247 select SWIOTLB if MMU
251 # We must be able to map all physical memory into the kernel, but the compiler
252 # is still a bit more efficient when generating code if it's setup in a manner
253 # such that it can only map 2GiB of memory.
255 prompt "Kernel Code Model"
256 default CMODEL_MEDLOW if 32BIT
257 default CMODEL_MEDANY if 64BIT
260 bool "medium low code model"
262 bool "medium any code model"
265 config MODULE_SECTIONS
267 select HAVE_MOD_ARCH_SPECIFIC
270 prompt "Maximum Physical Memory"
271 default MAXPHYSMEM_1GB if 32BIT
272 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
273 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
275 config MAXPHYSMEM_1GB
278 config MAXPHYSMEM_2GB
279 depends on 64BIT && CMODEL_MEDLOW
281 config MAXPHYSMEM_128GB
282 depends on 64BIT && CMODEL_MEDANY
288 bool "Symmetric Multi-Processing"
290 This enables support for systems with more than one CPU. If
291 you say N here, the kernel will run on single and
292 multiprocessor machines, but will use only one CPU of a
293 multiprocessor machine. If you say Y here, the kernel will run
294 on many, but not all, single processor machines. On a single
295 processor machine, the kernel will run faster if you say N
298 If you don't know what to do here, say N.
301 int "Maximum number of CPUs (2-32)"
307 bool "Support for hot-pluggable CPUs"
309 select GENERIC_IRQ_MIGRATION
312 Say Y here to experiment with turning CPUs off and on. CPUs
313 can be controlled through /sys/devices/system/cpu.
315 Say N if you want to disable CPU hotplug.
326 # Common NUMA Features
328 bool "NUMA Memory Allocation and Scheduler Support"
329 depends on SMP && MMU
330 select GENERIC_ARCH_NUMA
332 select ARCH_SUPPORTS_NUMA_BALANCING
334 Enable NUMA (Non-Uniform Memory Access) support.
336 The kernel will try to allocate memory used by a CPU on the
337 local memory of the CPU and add some more NUMA awareness to the kernel.
340 int "Maximum NUMA Nodes (as a power of 2)"
345 Specify the maximum number of NUMA Nodes available on the target
346 system. Increases memory reserved to accommodate various tables.
348 config USE_PERCPU_NUMA_NODE_ID
352 config NEED_PER_CPU_EMBED_FIRST_CHUNK
357 bool "Emit compressed instructions when building Linux"
360 Adds "C" to the ISA subsets that the toolchain is allowed to emit
361 when building Linux, which results in compressed instructions in the
364 If you don't know what to do here, say Y.
366 menu "supported PMU type"
367 depends on PERF_EVENTS
369 config RISCV_BASE_PMU
370 bool "Base Performance Monitoring Unit"
373 A base PMU that serves as a reference implementation and has limited
374 feature of perf. It can run on any RISC-V machines so serves as the
375 fallback, but this option can also be disable to reduce kernel size.
383 Say N here if you want to disable all floating-point related procedure
386 If you don't know what to do here, say Y.
390 menu "Kernel features"
392 source "kernel/Kconfig.hz"
395 bool "SBI v0.1 support"
399 This config allows kernel to use SBI v0.1 APIs. This will be
400 deprecated in future once legacy M-mode software are no longer in use.
403 bool "Kexec system call"
405 select HOTPLUG_CPU if SMP
408 kexec is a system call that implements the ability to shutdown your
409 current kernel, and to start another kernel. It is like a reboot
410 but it is independent of the system firmware. And like a reboot
411 you can start any kernel with it, not just Linux.
413 The name comes from the similarity to the exec system call.
416 bool "Build kdump crash kernel"
418 Generate crash dump after being started by kexec. This should
419 be normally only set in special crash dump kernels which are
420 loaded in the main kernel with kexec-tools into a specially
421 reserved region and then later executed after a crash by
424 For more details see Documentation/admin-guide/kdump/kdump.rst
431 string "Built-in kernel command line"
433 For most platforms, the arguments for the kernel's command line
434 are provided at run-time, during boot. However, there are cases
435 where either no arguments are being provided or the provided
436 arguments are insufficient or even invalid.
438 When that occurs, it is possible to define a built-in command
439 line here and choose how the kernel should use it later on.
442 prompt "Built-in command line usage" if CMDLINE != ""
443 default CMDLINE_FALLBACK
445 Choose how the kernel will handle the provided built-in command
448 config CMDLINE_FALLBACK
449 bool "Use bootloader kernel arguments if available"
451 Use the built-in command line as fallback in case we get nothing
452 during boot. This is the default behaviour.
454 config CMDLINE_EXTEND
455 bool "Extend bootloader kernel arguments"
457 The command-line arguments provided during boot will be
458 appended to the built-in command line. This is useful in
459 cases where the provided arguments are insufficient and
460 you don't want to or cannot modify them.
464 bool "Always use the default kernel command string"
466 Always use the built-in command line, even if we get one during
467 boot. This is useful in case you need to override the provided
468 command line on systems where you don't have or want control
477 bool "UEFI runtime support"
478 depends on OF && !XIP_KERNEL
481 select EFI_PARAMS_FROM_FDT
483 select EFI_GENERIC_STUB
484 select EFI_RUNTIME_WRAPPERS
489 This option provides support for runtime services provided
490 by UEFI firmware (such as non-volatile variables, realtime
491 clock, and platform reset). A UEFI stub is also provided to
492 allow the kernel to be booted as an EFI application. This
493 is only useful on systems that have UEFI firmware.
495 config CC_HAVE_STACKPROTECTOR_TLS
496 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
498 config STACKPROTECTOR_PER_TASK
500 depends on !GCC_PLUGIN_RANDSTRUCT
501 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
503 config PHYS_RAM_BASE_FIXED
504 bool "Explicitly specified physical RAM address"
508 hex "Platform Physical RAM address"
509 depends on PHYS_RAM_BASE_FIXED
512 This is the physical address of RAM in the system. It has to be
513 explicitly specified to run early relocations of read-write data
517 bool "Kernel Execute-In-Place from ROM"
518 depends on MMU && SPARSEMEM
519 # This prevents XIP from being enabled by all{yes,mod}config, which
520 # fail to build since XIP doesn't support large kernels.
521 depends on !COMPILE_TEST
522 select PHYS_RAM_BASE_FIXED
524 Execute-In-Place allows the kernel to run from non-volatile storage
525 directly addressable by the CPU, such as NOR flash. This saves RAM
526 space since the text section of the kernel is not loaded from flash
527 to RAM. Read-write sections, such as the data section and stack,
528 are still copied to RAM. The XIP kernel is not compressed since
529 it has to run directly from flash, so it will take more space to
530 store it. The flash address used to link the kernel object files,
531 and for storing it, is configuration dependent. Therefore, if you
532 say Y here, you must know the proper physical address where to
533 store the kernel image depending on your own flash memory usage.
535 Also note that the make target becomes "make xipImage" rather than
536 "make zImage" or "make Image". The final kernel binary to put in
537 ROM memory will be arch/riscv/boot/xipImage.
539 SPARSEMEM is required because the kernel text and rodata that are
540 flash resident are not backed by memmap, then any attempt to get
541 a struct page on those regions will trigger a fault.
546 hex "XIP Kernel Physical Location"
547 depends on XIP_KERNEL
550 This is the physical address in your flash memory the kernel will
551 be linked for and stored to. This address is dependent on your
559 default y if XIP_KERNEL
561 menu "Power management options"
563 source "kernel/power/Kconfig"
567 source "drivers/firmware/Kconfig"