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
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.
324 config USE_PERCPU_NUMA_NODE_ID
328 config NEED_PER_CPU_EMBED_FIRST_CHUNK
333 bool "Emit compressed instructions when building Linux"
336 Adds "C" to the ISA subsets that the toolchain is allowed to emit
337 when building Linux, which results in compressed instructions in the
340 If you don't know what to do here, say Y.
342 menu "supported PMU type"
343 depends on PERF_EVENTS
345 config RISCV_BASE_PMU
346 bool "Base Performance Monitoring Unit"
349 A base PMU that serves as a reference implementation and has limited
350 feature of perf. It can run on any RISC-V machines so serves as the
351 fallback, but this option can also be disable to reduce kernel size.
359 Say N here if you want to disable all floating-point related procedure
362 If you don't know what to do here, say Y.
366 menu "Kernel features"
368 source "kernel/Kconfig.hz"
371 bool "SBI v0.1 support"
375 This config allows kernel to use SBI v0.1 APIs. This will be
376 deprecated in future once legacy M-mode software are no longer in use.
379 bool "Kexec system call"
381 select HOTPLUG_CPU if SMP
384 kexec is a system call that implements the ability to shutdown your
385 current kernel, and to start another kernel. It is like a reboot
386 but it is independent of the system firmware. And like a reboot
387 you can start any kernel with it, not just Linux.
389 The name comes from the similarity to the exec system call.
392 bool "Build kdump crash kernel"
394 Generate crash dump after being started by kexec. This should
395 be normally only set in special crash dump kernels which are
396 loaded in the main kernel with kexec-tools into a specially
397 reserved region and then later executed after a crash by
400 For more details see Documentation/admin-guide/kdump/kdump.rst
407 string "Built-in kernel command line"
409 For most platforms, the arguments for the kernel's command line
410 are provided at run-time, during boot. However, there are cases
411 where either no arguments are being provided or the provided
412 arguments are insufficient or even invalid.
414 When that occurs, it is possible to define a built-in command
415 line here and choose how the kernel should use it later on.
418 prompt "Built-in command line usage" if CMDLINE != ""
419 default CMDLINE_FALLBACK
421 Choose how the kernel will handle the provided built-in command
424 config CMDLINE_FALLBACK
425 bool "Use bootloader kernel arguments if available"
427 Use the built-in command line as fallback in case we get nothing
428 during boot. This is the default behaviour.
430 config CMDLINE_EXTEND
431 bool "Extend bootloader kernel arguments"
433 The command-line arguments provided during boot will be
434 appended to the built-in command line. This is useful in
435 cases where the provided arguments are insufficient and
436 you don't want to or cannot modify them.
440 bool "Always use the default kernel command string"
442 Always use the built-in command line, even if we get one during
443 boot. This is useful in case you need to override the provided
444 command line on systems where you don't have or want control
453 bool "UEFI runtime support"
454 depends on OF && !XIP_KERNEL
457 select EFI_PARAMS_FROM_FDT
459 select EFI_GENERIC_STUB
460 select EFI_RUNTIME_WRAPPERS
465 This option provides support for runtime services provided
466 by UEFI firmware (such as non-volatile variables, realtime
467 clock, and platform reset). A UEFI stub is also provided to
468 allow the kernel to be booted as an EFI application. This
469 is only useful on systems that have UEFI firmware.
471 config CC_HAVE_STACKPROTECTOR_TLS
472 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
474 config STACKPROTECTOR_PER_TASK
476 depends on !GCC_PLUGIN_RANDSTRUCT
477 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
479 config PHYS_RAM_BASE_FIXED
480 bool "Explicitly specified physical RAM address"
484 hex "Platform Physical RAM address"
485 depends on PHYS_RAM_BASE_FIXED
488 This is the physical address of RAM in the system. It has to be
489 explicitly specified to run early relocations of read-write data
493 bool "Kernel Execute-In-Place from ROM"
494 depends on MMU && SPARSEMEM
495 # This prevents XIP from being enabled by all{yes,mod}config, which
496 # fail to build since XIP doesn't support large kernels.
497 depends on !COMPILE_TEST
498 select PHYS_RAM_BASE_FIXED
500 Execute-In-Place allows the kernel to run from non-volatile storage
501 directly addressable by the CPU, such as NOR flash. This saves RAM
502 space since the text section of the kernel is not loaded from flash
503 to RAM. Read-write sections, such as the data section and stack,
504 are still copied to RAM. The XIP kernel is not compressed since
505 it has to run directly from flash, so it will take more space to
506 store it. The flash address used to link the kernel object files,
507 and for storing it, is configuration dependent. Therefore, if you
508 say Y here, you must know the proper physical address where to
509 store the kernel image depending on your own flash memory usage.
511 Also note that the make target becomes "make xipImage" rather than
512 "make zImage" or "make Image". The final kernel binary to put in
513 ROM memory will be arch/riscv/boot/xipImage.
515 SPARSEMEM is required because the kernel text and rodata that are
516 flash resident are not backed by memmap, then any attempt to get
517 a struct page on those regions will trigger a fault.
522 hex "XIP Kernel Physical Location"
523 depends on XIP_KERNEL
526 This is the physical address in your flash memory the kernel will
527 be linked for and stored to. This address is dependent on your
535 default y if XIP_KERNEL
537 menu "Power management options"
539 source "kernel/power/Kconfig"
543 source "arch/riscv/kvm/Kconfig"