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 CLONE_BACKWARDS
45 select CLINT_TIMER if !MMU
48 select GENERIC_ARCH_TOPOLOGY if SMP
49 select GENERIC_ATOMIC64 if !64BIT
50 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
51 select GENERIC_EARLY_IOREMAP
52 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
53 select GENERIC_IDLE_POLL_SETUP
54 select GENERIC_IOREMAP
55 select GENERIC_IRQ_MULTI_HANDLER
56 select GENERIC_IRQ_SHOW
57 select GENERIC_IRQ_SHOW_LEVEL
58 select GENERIC_LIB_DEVMEM_IS_ALLOWED
59 select GENERIC_PCI_IOMAP
60 select GENERIC_PTDUMP if MMU
61 select GENERIC_SCHED_CLOCK
62 select GENERIC_SMP_IDLE_THREAD
63 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
64 select HANDLE_DOMAIN_IRQ
65 select HAVE_ARCH_AUDITSYSCALL
66 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
67 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
68 select HAVE_ARCH_KASAN if MMU && 64BIT
69 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
70 select HAVE_ARCH_KFENCE if MMU && 64BIT
71 select HAVE_ARCH_KGDB if !XIP_KERNEL
72 select HAVE_ARCH_KGDB_QXFER_PKT
73 select HAVE_ARCH_MMAP_RND_BITS if MMU
74 select HAVE_ARCH_SECCOMP_FILTER
75 select HAVE_ARCH_TRACEHOOK
76 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
77 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
78 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
79 select HAVE_ASM_MODVERSIONS
80 select HAVE_CONTEXT_TRACKING
81 select HAVE_DEBUG_KMEMLEAK
82 select HAVE_DMA_CONTIGUOUS if MMU
83 select HAVE_EBPF_JIT if MMU
84 select HAVE_FUNCTION_ERROR_INJECTION
85 select HAVE_FUTEX_CMPXCHG if FUTEX
86 select HAVE_GCC_PLUGINS
87 select HAVE_GENERIC_VDSO if MMU && 64BIT
88 select HAVE_IRQ_TIME_ACCOUNTING
89 select HAVE_KPROBES if !XIP_KERNEL
90 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
91 select HAVE_KRETPROBES if !XIP_KERNEL
95 select HAVE_PERF_EVENTS
97 select HAVE_PERF_USER_STACK_DUMP
98 select HAVE_REGS_AND_STACK_ACCESS_API
99 select HAVE_FUNCTION_ARG_ACCESS_API
100 select HAVE_STACKPROTECTOR
101 select HAVE_SYSCALL_TRACEPOINTS
103 select IRQ_FORCED_THREADING
104 select MODULES_USE_ELF_RELA if MODULES
105 select MODULE_SECTIONS if MODULES
107 select OF_EARLY_FLATTREE
109 select PCI_DOMAINS_GENERIC if PCI
110 select PCI_MSI if PCI
112 select RISCV_TIMER if RISCV_SBI
114 select SYSCTL_EXCEPTION_TRACE
115 select THREAD_INFO_IN_TASK
116 select UACCESS_MEMCPY if !MMU
117 select ZONE_DMA32 if 64BIT
119 config ARCH_MMAP_RND_BITS_MIN
123 # max bits determined by the following formula:
124 # VA_BITS - PAGE_SHIFT - 3
125 config ARCH_MMAP_RND_BITS_MAX
126 default 24 if 64BIT # SV39 based
129 # set if we run in machine mode, cleared if we run in supervisor mode
134 # set if we are running in S-mode and can use SBI calls
137 depends on !RISCV_M_MODE
141 bool "MMU-based Paged Memory Management Support"
144 Select if you want MMU-based virtualised addressing space
145 support by paged memory management. If unsure, say 'Y'.
159 default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
160 default 0x80000000 if 64BIT && !MMU
161 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
162 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
164 config ARCH_FLATMEM_ENABLE
167 config ARCH_SPARSEMEM_ENABLE
170 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
171 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
173 config ARCH_SELECT_MEMORY_MODEL
174 def_bool ARCH_SPARSEMEM_ENABLE
176 config ARCH_WANT_GENERAL_HUGETLB
179 config ARCH_SUPPORTS_UPROBES
182 config STACKTRACE_SUPPORT
185 config TRACE_IRQFLAGS_SUPPORT
191 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
193 config GENERIC_BUG_RELATIVE_POINTERS
196 config GENERIC_CALIBRATE_DELAY
202 config GENERIC_HWEIGHT
205 config FIX_EARLYCON_MEM
208 config PGTABLE_LEVELS
213 config LOCKDEP_SUPPORT
216 source "arch/riscv/Kconfig.socs"
217 source "arch/riscv/Kconfig.erratas"
225 This selects the base ISA that this kernel will target and must match
231 select GENERIC_LIB_ASHLDI3
232 select GENERIC_LIB_ASHRDI3
233 select GENERIC_LIB_LSHRDI3
234 select GENERIC_LIB_UCMPDI2
240 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
241 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
242 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
243 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
244 select HAVE_FUNCTION_GRAPH_TRACER
245 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
246 select SWIOTLB if MMU
250 # We must be able to map all physical memory into the kernel, but the compiler
251 # is still a bit more efficient when generating code if it's setup in a manner
252 # such that it can only map 2GiB of memory.
254 prompt "Kernel Code Model"
255 default CMODEL_MEDLOW if 32BIT
256 default CMODEL_MEDANY if 64BIT
259 bool "medium low code model"
261 bool "medium any code model"
264 config MODULE_SECTIONS
266 select HAVE_MOD_ARCH_SPECIFIC
269 prompt "Maximum Physical Memory"
270 default MAXPHYSMEM_1GB if 32BIT
271 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
272 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
274 config MAXPHYSMEM_1GB
277 config MAXPHYSMEM_2GB
278 depends on 64BIT && CMODEL_MEDLOW
280 config MAXPHYSMEM_128GB
281 depends on 64BIT && CMODEL_MEDANY
287 bool "Symmetric Multi-Processing"
289 This enables support for systems with more than one CPU. If
290 you say N here, the kernel will run on single and
291 multiprocessor machines, but will use only one CPU of a
292 multiprocessor machine. If you say Y here, the kernel will run
293 on many, but not all, single processor machines. On a single
294 processor machine, the kernel will run faster if you say N
297 If you don't know what to do here, say N.
300 int "Maximum number of CPUs (2-32)"
306 bool "Support for hot-pluggable CPUs"
308 select GENERIC_IRQ_MIGRATION
311 Say Y here to experiment with turning CPUs off and on. CPUs
312 can be controlled through /sys/devices/system/cpu.
314 Say N if you want to disable CPU hotplug.
325 # Common NUMA Features
327 bool "NUMA Memory Allocation and Scheduler Support"
328 depends on SMP && MMU
329 select GENERIC_ARCH_NUMA
331 select ARCH_SUPPORTS_NUMA_BALANCING
333 Enable NUMA (Non-Uniform Memory Access) support.
335 The kernel will try to allocate memory used by a CPU on the
336 local memory of the CPU and add some more NUMA awareness to the kernel.
339 int "Maximum NUMA Nodes (as a power of 2)"
344 Specify the maximum number of NUMA Nodes available on the target
345 system. Increases memory reserved to accommodate various tables.
347 config USE_PERCPU_NUMA_NODE_ID
351 config NEED_PER_CPU_EMBED_FIRST_CHUNK
356 bool "Emit compressed instructions when building Linux"
359 Adds "C" to the ISA subsets that the toolchain is allowed to emit
360 when building Linux, which results in compressed instructions in the
363 If you don't know what to do here, say Y.
365 menu "supported PMU type"
366 depends on PERF_EVENTS
368 config RISCV_BASE_PMU
369 bool "Base Performance Monitoring Unit"
372 A base PMU that serves as a reference implementation and has limited
373 feature of perf. It can run on any RISC-V machines so serves as the
374 fallback, but this option can also be disable to reduce kernel size.
382 Say N here if you want to disable all floating-point related procedure
385 If you don't know what to do here, say Y.
389 menu "Kernel features"
391 source "kernel/Kconfig.hz"
394 bool "SBI v0.1 support"
398 This config allows kernel to use SBI v0.1 APIs. This will be
399 deprecated in future once legacy M-mode software are no longer in use.
402 bool "Kexec system call"
404 select HOTPLUG_CPU if SMP
407 kexec is a system call that implements the ability to shutdown your
408 current kernel, and to start another kernel. It is like a reboot
409 but it is independent of the system firmware. And like a reboot
410 you can start any kernel with it, not just Linux.
412 The name comes from the similarity to the exec system call.
415 bool "Build kdump crash kernel"
417 Generate crash dump after being started by kexec. This should
418 be normally only set in special crash dump kernels which are
419 loaded in the main kernel with kexec-tools into a specially
420 reserved region and then later executed after a crash by
423 For more details see Documentation/admin-guide/kdump/kdump.rst
430 string "Built-in kernel command line"
432 For most platforms, the arguments for the kernel's command line
433 are provided at run-time, during boot. However, there are cases
434 where either no arguments are being provided or the provided
435 arguments are insufficient or even invalid.
437 When that occurs, it is possible to define a built-in command
438 line here and choose how the kernel should use it later on.
441 prompt "Built-in command line usage" if CMDLINE != ""
442 default CMDLINE_FALLBACK
444 Choose how the kernel will handle the provided built-in command
447 config CMDLINE_FALLBACK
448 bool "Use bootloader kernel arguments if available"
450 Use the built-in command line as fallback in case we get nothing
451 during boot. This is the default behaviour.
453 config CMDLINE_EXTEND
454 bool "Extend bootloader kernel arguments"
456 The command-line arguments provided during boot will be
457 appended to the built-in command line. This is useful in
458 cases where the provided arguments are insufficient and
459 you don't want to or cannot modify them.
463 bool "Always use the default kernel command string"
465 Always use the built-in command line, even if we get one during
466 boot. This is useful in case you need to override the provided
467 command line on systems where you don't have or want control
476 bool "UEFI runtime support"
477 depends on OF && !XIP_KERNEL
480 select EFI_PARAMS_FROM_FDT
482 select EFI_GENERIC_STUB
483 select EFI_RUNTIME_WRAPPERS
488 This option provides support for runtime services provided
489 by UEFI firmware (such as non-volatile variables, realtime
490 clock, and platform reset). A UEFI stub is also provided to
491 allow the kernel to be booted as an EFI application. This
492 is only useful on systems that have UEFI firmware.
494 config CC_HAVE_STACKPROTECTOR_TLS
495 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
497 config STACKPROTECTOR_PER_TASK
499 depends on !GCC_PLUGIN_RANDSTRUCT
500 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
502 config PHYS_RAM_BASE_FIXED
503 bool "Explicitly specified physical RAM address"
507 hex "Platform Physical RAM address"
508 depends on PHYS_RAM_BASE_FIXED
511 This is the physical address of RAM in the system. It has to be
512 explicitly specified to run early relocations of read-write data
516 bool "Kernel Execute-In-Place from ROM"
517 depends on MMU && SPARSEMEM
518 # This prevents XIP from being enabled by all{yes,mod}config, which
519 # fail to build since XIP doesn't support large kernels.
520 depends on !COMPILE_TEST
521 select PHYS_RAM_BASE_FIXED
523 Execute-In-Place allows the kernel to run from non-volatile storage
524 directly addressable by the CPU, such as NOR flash. This saves RAM
525 space since the text section of the kernel is not loaded from flash
526 to RAM. Read-write sections, such as the data section and stack,
527 are still copied to RAM. The XIP kernel is not compressed since
528 it has to run directly from flash, so it will take more space to
529 store it. The flash address used to link the kernel object files,
530 and for storing it, is configuration dependent. Therefore, if you
531 say Y here, you must know the proper physical address where to
532 store the kernel image depending on your own flash memory usage.
534 Also note that the make target becomes "make xipImage" rather than
535 "make zImage" or "make Image". The final kernel binary to put in
536 ROM memory will be arch/riscv/boot/xipImage.
538 SPARSEMEM is required because the kernel text and rodata that are
539 flash resident are not backed by memmap, then any attempt to get
540 a struct page on those regions will trigger a fault.
545 hex "XIP Kernel Physical Location"
546 depends on XIP_KERNEL
549 This is the physical address in your flash memory the kernel will
550 be linked for and stored to. This address is dependent on your
558 default y if XIP_KERNEL
560 menu "Power management options"
562 source "kernel/power/Kconfig"
566 source "drivers/firmware/Kconfig"