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_SUPPORTS_ATOMIC_RMW
17 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
19 select ARCH_HAS_BINFMT_FLAT
20 select ARCH_HAS_DEBUG_VM_PGTABLE
21 select ARCH_HAS_DEBUG_VIRTUAL if MMU
22 select ARCH_HAS_DEBUG_WX
23 select ARCH_HAS_FORTIFY_SOURCE
24 select ARCH_HAS_GCOV_PROFILE_ALL
25 select ARCH_HAS_GIGANTIC_PAGE
27 select ARCH_HAS_MMIOWB
28 select ARCH_HAS_PTE_SPECIAL
29 select ARCH_HAS_SET_DIRECT_MAP if MMU
30 select ARCH_HAS_SET_MEMORY if MMU
31 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
32 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
33 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
34 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
35 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
36 select ARCH_SUPPORTS_HUGETLBFS if MMU
37 select ARCH_USE_MEMTEST
38 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
39 select ARCH_WANT_FRAME_POINTERS
40 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
41 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
42 select CLONE_BACKWARDS
43 select CLINT_TIMER if !MMU
46 select GENERIC_ARCH_TOPOLOGY if SMP
47 select GENERIC_ATOMIC64 if !64BIT
48 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
49 select GENERIC_EARLY_IOREMAP
50 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
51 select GENERIC_IOREMAP
52 select GENERIC_IRQ_MULTI_HANDLER
53 select GENERIC_IRQ_SHOW
54 select GENERIC_LIB_DEVMEM_IS_ALLOWED
55 select GENERIC_PCI_IOMAP
56 select GENERIC_PTDUMP if MMU
57 select GENERIC_SCHED_CLOCK
58 select GENERIC_SMP_IDLE_THREAD
59 select GENERIC_STRNCPY_FROM_USER if MMU
60 select GENERIC_STRNLEN_USER if MMU
61 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
62 select HANDLE_DOMAIN_IRQ
63 select HAVE_ARCH_AUDITSYSCALL
64 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
65 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
66 select HAVE_ARCH_KASAN if MMU && 64BIT
67 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
68 select HAVE_ARCH_KFENCE if MMU && 64BIT
69 select HAVE_ARCH_KGDB if !XIP_KERNEL
70 select HAVE_ARCH_KGDB_QXFER_PKT
71 select HAVE_ARCH_MMAP_RND_BITS if MMU
72 select HAVE_ARCH_SECCOMP_FILTER
73 select HAVE_ARCH_TRACEHOOK
74 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
75 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
76 select HAVE_ASM_MODVERSIONS
77 select HAVE_CONTEXT_TRACKING
78 select HAVE_DEBUG_KMEMLEAK
79 select HAVE_DMA_CONTIGUOUS if MMU
80 select HAVE_EBPF_JIT if MMU
81 select HAVE_FUNCTION_ERROR_INJECTION
82 select HAVE_FUTEX_CMPXCHG if FUTEX
83 select HAVE_GCC_PLUGINS
84 select HAVE_GENERIC_VDSO if MMU && 64BIT
85 select HAVE_IRQ_TIME_ACCOUNTING
86 select HAVE_KPROBES if !XIP_KERNEL
87 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
88 select HAVE_KRETPROBES if !XIP_KERNEL
92 select HAVE_PERF_EVENTS
94 select HAVE_PERF_USER_STACK_DUMP
95 select HAVE_REGS_AND_STACK_ACCESS_API
96 select HAVE_FUNCTION_ARG_ACCESS_API
97 select HAVE_STACKPROTECTOR
98 select HAVE_SYSCALL_TRACEPOINTS
100 select MODULES_USE_ELF_RELA if MODULES
101 select MODULE_SECTIONS if MODULES
103 select OF_EARLY_FLATTREE
105 select PCI_DOMAINS_GENERIC if PCI
106 select PCI_MSI if PCI
108 select RISCV_TIMER if RISCV_SBI
110 select SYSCTL_EXCEPTION_TRACE
111 select THREAD_INFO_IN_TASK
112 select UACCESS_MEMCPY if !MMU
113 select ZONE_DMA32 if 64BIT
115 config ARCH_MMAP_RND_BITS_MIN
119 # max bits determined by the following formula:
120 # VA_BITS - PAGE_SHIFT - 3
121 config ARCH_MMAP_RND_BITS_MAX
122 default 24 if 64BIT # SV39 based
125 # set if we run in machine mode, cleared if we run in supervisor mode
130 # set if we are running in S-mode and can use SBI calls
133 depends on !RISCV_M_MODE
137 bool "MMU-based Paged Memory Management Support"
140 Select if you want MMU-based virtualised addressing space
141 support by paged memory management. If unsure, say 'Y'.
155 default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
156 default 0x80000000 if 64BIT && !MMU
157 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
158 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
160 config ARCH_FLATMEM_ENABLE
163 config ARCH_SPARSEMEM_ENABLE
166 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
167 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
169 config ARCH_SELECT_MEMORY_MODEL
170 def_bool ARCH_SPARSEMEM_ENABLE
172 config ARCH_WANT_GENERAL_HUGETLB
175 config ARCH_SUPPORTS_UPROBES
178 config STACKTRACE_SUPPORT
181 config TRACE_IRQFLAGS_SUPPORT
187 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
189 config GENERIC_BUG_RELATIVE_POINTERS
192 config GENERIC_CALIBRATE_DELAY
198 config GENERIC_HWEIGHT
201 config FIX_EARLYCON_MEM
204 config PGTABLE_LEVELS
209 config LOCKDEP_SUPPORT
212 source "arch/riscv/Kconfig.socs"
213 source "arch/riscv/Kconfig.erratas"
221 This selects the base ISA that this kernel will target and must match
227 select GENERIC_LIB_ASHLDI3
228 select GENERIC_LIB_ASHRDI3
229 select GENERIC_LIB_LSHRDI3
230 select GENERIC_LIB_UCMPDI2
236 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
237 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
238 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
239 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
240 select HAVE_FUNCTION_GRAPH_TRACER
241 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
242 select SWIOTLB if MMU
246 # We must be able to map all physical memory into the kernel, but the compiler
247 # is still a bit more efficient when generating code if it's setup in a manner
248 # such that it can only map 2GiB of memory.
250 prompt "Kernel Code Model"
251 default CMODEL_MEDLOW if 32BIT
252 default CMODEL_MEDANY if 64BIT
255 bool "medium low code model"
257 bool "medium any code model"
260 config MODULE_SECTIONS
262 select HAVE_MOD_ARCH_SPECIFIC
265 prompt "Maximum Physical Memory"
266 default MAXPHYSMEM_1GB if 32BIT
267 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
268 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
270 config MAXPHYSMEM_1GB
273 config MAXPHYSMEM_2GB
274 depends on 64BIT && CMODEL_MEDLOW
276 config MAXPHYSMEM_128GB
277 depends on 64BIT && CMODEL_MEDANY
283 bool "Symmetric Multi-Processing"
285 This enables support for systems with more than one CPU. If
286 you say N here, the kernel will run on single and
287 multiprocessor machines, but will use only one CPU of a
288 multiprocessor machine. If you say Y here, the kernel will run
289 on many, but not all, single processor machines. On a single
290 processor machine, the kernel will run faster if you say N
293 If you don't know what to do here, say N.
296 int "Maximum number of CPUs (2-32)"
302 bool "Support for hot-pluggable CPUs"
304 select GENERIC_IRQ_MIGRATION
307 Say Y here to experiment with turning CPUs off and on. CPUs
308 can be controlled through /sys/devices/system/cpu.
310 Say N if you want to disable CPU hotplug.
321 # Common NUMA Features
323 bool "NUMA Memory Allocation and Scheduler Support"
324 depends on SMP && MMU
325 select GENERIC_ARCH_NUMA
327 select ARCH_SUPPORTS_NUMA_BALANCING
329 Enable NUMA (Non-Uniform Memory Access) support.
331 The kernel will try to allocate memory used by a CPU on the
332 local memory of the CPU and add some more NUMA awareness to the kernel.
335 int "Maximum NUMA Nodes (as a power of 2)"
340 Specify the maximum number of NUMA Nodes available on the target
341 system. Increases memory reserved to accommodate various tables.
343 config USE_PERCPU_NUMA_NODE_ID
347 config NEED_PER_CPU_EMBED_FIRST_CHUNK
352 bool "Emit compressed instructions when building Linux"
355 Adds "C" to the ISA subsets that the toolchain is allowed to emit
356 when building Linux, which results in compressed instructions in the
359 If you don't know what to do here, say Y.
361 menu "supported PMU type"
362 depends on PERF_EVENTS
364 config RISCV_BASE_PMU
365 bool "Base Performance Monitoring Unit"
368 A base PMU that serves as a reference implementation and has limited
369 feature of perf. It can run on any RISC-V machines so serves as the
370 fallback, but this option can also be disable to reduce kernel size.
378 Say N here if you want to disable all floating-point related procedure
381 If you don't know what to do here, say Y.
385 menu "Kernel features"
387 source "kernel/Kconfig.hz"
390 bool "SBI v0.1 support"
394 This config allows kernel to use SBI v0.1 APIs. This will be
395 deprecated in future once legacy M-mode software are no longer in use.
398 bool "Kexec system call"
400 select HOTPLUG_CPU if SMP
403 kexec is a system call that implements the ability to shutdown your
404 current kernel, and to start another kernel. It is like a reboot
405 but it is independent of the system firmware. And like a reboot
406 you can start any kernel with it, not just Linux.
408 The name comes from the similarity to the exec system call.
411 bool "Build kdump crash kernel"
413 Generate crash dump after being started by kexec. This should
414 be normally only set in special crash dump kernels which are
415 loaded in the main kernel with kexec-tools into a specially
416 reserved region and then later executed after a crash by
419 For more details see Documentation/admin-guide/kdump/kdump.rst
426 string "Built-in kernel command line"
428 For most platforms, the arguments for the kernel's command line
429 are provided at run-time, during boot. However, there are cases
430 where either no arguments are being provided or the provided
431 arguments are insufficient or even invalid.
433 When that occurs, it is possible to define a built-in command
434 line here and choose how the kernel should use it later on.
437 prompt "Built-in command line usage" if CMDLINE != ""
438 default CMDLINE_FALLBACK
440 Choose how the kernel will handle the provided built-in command
443 config CMDLINE_FALLBACK
444 bool "Use bootloader kernel arguments if available"
446 Use the built-in command line as fallback in case we get nothing
447 during boot. This is the default behaviour.
449 config CMDLINE_EXTEND
450 bool "Extend bootloader kernel arguments"
452 The command-line arguments provided during boot will be
453 appended to the built-in command line. This is useful in
454 cases where the provided arguments are insufficient and
455 you don't want to or cannot modify them.
459 bool "Always use the default kernel command string"
461 Always use the built-in command line, even if we get one during
462 boot. This is useful in case you need to override the provided
463 command line on systems where you don't have or want control
472 bool "UEFI runtime support"
473 depends on OF && !XIP_KERNEL
476 select EFI_PARAMS_FROM_FDT
478 select EFI_GENERIC_STUB
479 select EFI_RUNTIME_WRAPPERS
484 This option provides support for runtime services provided
485 by UEFI firmware (such as non-volatile variables, realtime
486 clock, and platform reset). A UEFI stub is also provided to
487 allow the kernel to be booted as an EFI application. This
488 is only useful on systems that have UEFI firmware.
490 config CC_HAVE_STACKPROTECTOR_TLS
491 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
493 config STACKPROTECTOR_PER_TASK
495 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
498 hex "Platform Physical RAM address"
501 This is the physical address of RAM in the system. It has to be
502 explicitly specified to run early relocations of read-write data
506 bool "Kernel Execute-In-Place from ROM"
507 depends on MMU && SPARSEMEM
508 # This prevents XIP from being enabled by all{yes,mod}config, which
509 # fail to build since XIP doesn't support large kernels.
510 depends on !COMPILE_TEST
512 Execute-In-Place allows the kernel to run from non-volatile storage
513 directly addressable by the CPU, such as NOR flash. This saves RAM
514 space since the text section of the kernel is not loaded from flash
515 to RAM. Read-write sections, such as the data section and stack,
516 are still copied to RAM. The XIP kernel is not compressed since
517 it has to run directly from flash, so it will take more space to
518 store it. The flash address used to link the kernel object files,
519 and for storing it, is configuration dependent. Therefore, if you
520 say Y here, you must know the proper physical address where to
521 store the kernel image depending on your own flash memory usage.
523 Also note that the make target becomes "make xipImage" rather than
524 "make zImage" or "make Image". The final kernel binary to put in
525 ROM memory will be arch/riscv/boot/xipImage.
527 SPARSEMEM is required because the kernel text and rodata that are
528 flash resident are not backed by memmap, then any attempt to get
529 a struct page on those regions will trigger a fault.
534 hex "XIP Kernel Physical Location"
535 depends on XIP_KERNEL
538 This is the physical address in your flash memory the kernel will
539 be linked for and stored to. This address is dependent on your
547 default y if XIP_KERNEL
549 menu "Power management options"
551 source "kernel/power/Kconfig"
555 source "drivers/firmware/Kconfig"