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
30 select ARCH_HAS_SET_MEMORY
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_KGDB if !XIP_KERNEL
69 select HAVE_ARCH_KGDB_QXFER_PKT
70 select HAVE_ARCH_MMAP_RND_BITS if MMU
71 select HAVE_ARCH_SECCOMP_FILTER
72 select HAVE_ARCH_TRACEHOOK
73 select HAVE_ASM_MODVERSIONS
74 select HAVE_CONTEXT_TRACKING
75 select HAVE_DEBUG_KMEMLEAK
76 select HAVE_DMA_CONTIGUOUS if MMU
77 select HAVE_EBPF_JIT if MMU
78 select HAVE_FUNCTION_ERROR_INJECTION
79 select HAVE_FUTEX_CMPXCHG if FUTEX
80 select HAVE_GCC_PLUGINS
81 select HAVE_GENERIC_VDSO if MMU && 64BIT
82 select HAVE_IRQ_TIME_ACCOUNTING
83 select HAVE_KPROBES if !XIP_KERNEL
84 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
85 select HAVE_KRETPROBES if !XIP_KERNEL
87 select HAVE_PERF_EVENTS
89 select HAVE_PERF_USER_STACK_DUMP
90 select HAVE_REGS_AND_STACK_ACCESS_API
91 select HAVE_STACKPROTECTOR
92 select HAVE_SYSCALL_TRACEPOINTS
94 select MODULES_USE_ELF_RELA if MODULES
95 select MODULE_SECTIONS if MODULES
97 select OF_EARLY_FLATTREE
99 select PCI_DOMAINS_GENERIC if PCI
100 select PCI_MSI if PCI
102 select RISCV_TIMER if RISCV_SBI
104 select SYSCTL_EXCEPTION_TRACE
105 select THREAD_INFO_IN_TASK
106 select UACCESS_MEMCPY if !MMU
108 config ARCH_MMAP_RND_BITS_MIN
112 # max bits determined by the following formula:
113 # VA_BITS - PAGE_SHIFT - 3
114 config ARCH_MMAP_RND_BITS_MAX
115 default 24 if 64BIT # SV39 based
118 # set if we run in machine mode, cleared if we run in supervisor mode
123 # set if we are running in S-mode and can use SBI calls
126 depends on !RISCV_M_MODE
130 bool "MMU-based Paged Memory Management Support"
133 Select if you want MMU-based virtualised addressing space
134 support by paged memory management. If unsure, say 'Y'.
152 default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
153 default 0x80000000 if 64BIT && !MMU
154 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
155 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
157 config ARCH_FLATMEM_ENABLE
160 config ARCH_SPARSEMEM_ENABLE
163 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
164 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
166 config ARCH_SELECT_MEMORY_MODEL
167 def_bool ARCH_SPARSEMEM_ENABLE
169 config ARCH_WANT_GENERAL_HUGETLB
172 config ARCH_SUPPORTS_UPROBES
175 config STACKTRACE_SUPPORT
178 config TRACE_IRQFLAGS_SUPPORT
184 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
186 config GENERIC_BUG_RELATIVE_POINTERS
189 config GENERIC_CALIBRATE_DELAY
195 config GENERIC_HWEIGHT
198 config FIX_EARLYCON_MEM
201 config PGTABLE_LEVELS
206 config LOCKDEP_SUPPORT
209 source "arch/riscv/Kconfig.socs"
210 source "arch/riscv/Kconfig.erratas"
218 This selects the base ISA that this kernel will target and must match
224 select GENERIC_LIB_ASHLDI3
225 select GENERIC_LIB_ASHRDI3
226 select GENERIC_LIB_LSHRDI3
227 select GENERIC_LIB_UCMPDI2
233 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
234 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
235 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
236 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
237 select HAVE_FUNCTION_GRAPH_TRACER
238 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
239 select SWIOTLB if MMU
243 # We must be able to map all physical memory into the kernel, but the compiler
244 # is still a bit more efficient when generating code if it's setup in a manner
245 # such that it can only map 2GiB of memory.
247 prompt "Kernel Code Model"
248 default CMODEL_MEDLOW if 32BIT
249 default CMODEL_MEDANY if 64BIT
252 bool "medium low code model"
254 bool "medium any code model"
257 config MODULE_SECTIONS
259 select HAVE_MOD_ARCH_SPECIFIC
262 prompt "Maximum Physical Memory"
263 default MAXPHYSMEM_1GB if 32BIT
264 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
265 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
267 config MAXPHYSMEM_1GB
270 config MAXPHYSMEM_2GB
271 depends on 64BIT && CMODEL_MEDLOW
273 config MAXPHYSMEM_128GB
274 depends on 64BIT && CMODEL_MEDANY
280 bool "Symmetric Multi-Processing"
282 This enables support for systems with more than one CPU. If
283 you say N here, the kernel will run on single and
284 multiprocessor machines, but will use only one CPU of a
285 multiprocessor machine. If you say Y here, the kernel will run
286 on many, but not all, single processor machines. On a single
287 processor machine, the kernel will run faster if you say N
290 If you don't know what to do here, say N.
293 int "Maximum number of CPUs (2-32)"
299 bool "Support for hot-pluggable CPUs"
301 select GENERIC_IRQ_MIGRATION
304 Say Y here to experiment with turning CPUs off and on. CPUs
305 can be controlled through /sys/devices/system/cpu.
307 Say N if you want to disable CPU hotplug.
318 # Common NUMA Features
320 bool "NUMA Memory Allocation and Scheduler Support"
321 depends on SMP && MMU
322 select GENERIC_ARCH_NUMA
324 select ARCH_SUPPORTS_NUMA_BALANCING
326 Enable NUMA (Non-Uniform Memory Access) support.
328 The kernel will try to allocate memory used by a CPU on the
329 local memory of the CPU and add some more NUMA awareness to the kernel.
332 int "Maximum NUMA Nodes (as a power of 2)"
335 depends on NEED_MULTIPLE_NODES
337 Specify the maximum number of NUMA Nodes available on the target
338 system. Increases memory reserved to accommodate various tables.
340 config USE_PERCPU_NUMA_NODE_ID
344 config NEED_PER_CPU_EMBED_FIRST_CHUNK
349 bool "Emit compressed instructions when building Linux"
352 Adds "C" to the ISA subsets that the toolchain is allowed to emit
353 when building Linux, which results in compressed instructions in the
356 If you don't know what to do here, say Y.
358 menu "supported PMU type"
359 depends on PERF_EVENTS
361 config RISCV_BASE_PMU
362 bool "Base Performance Monitoring Unit"
365 A base PMU that serves as a reference implementation and has limited
366 feature of perf. It can run on any RISC-V machines so serves as the
367 fallback, but this option can also be disable to reduce kernel size.
375 Say N here if you want to disable all floating-point related procedure
378 If you don't know what to do here, say Y.
382 menu "Kernel features"
384 source "kernel/Kconfig.hz"
387 bool "SBI v0.1 support"
391 This config allows kernel to use SBI v0.1 APIs. This will be
392 deprecated in future once legacy M-mode software are no longer in use.
395 bool "Kexec system call"
397 select HOTPLUG_CPU if SMP
400 kexec is a system call that implements the ability to shutdown your
401 current kernel, and to start another kernel. It is like a reboot
402 but it is independent of the system firmware. And like a reboot
403 you can start any kernel with it, not just Linux.
405 The name comes from the similarity to the exec system call.
408 bool "Build kdump crash kernel"
410 Generate crash dump after being started by kexec. This should
411 be normally only set in special crash dump kernels which are
412 loaded in the main kernel with kexec-tools into a specially
413 reserved region and then later executed after a crash by
416 For more details see Documentation/admin-guide/kdump/kdump.rst
423 string "Built-in kernel command line"
425 For most platforms, the arguments for the kernel's command line
426 are provided at run-time, during boot. However, there are cases
427 where either no arguments are being provided or the provided
428 arguments are insufficient or even invalid.
430 When that occurs, it is possible to define a built-in command
431 line here and choose how the kernel should use it later on.
434 prompt "Built-in command line usage" if CMDLINE != ""
435 default CMDLINE_FALLBACK
437 Choose how the kernel will handle the provided built-in command
440 config CMDLINE_FALLBACK
441 bool "Use bootloader kernel arguments if available"
443 Use the built-in command line as fallback in case we get nothing
444 during boot. This is the default behaviour.
446 config CMDLINE_EXTEND
447 bool "Extend bootloader kernel arguments"
449 The command-line arguments provided during boot will be
450 appended to the built-in command line. This is useful in
451 cases where the provided arguments are insufficient and
452 you don't want to or cannot modify them.
456 bool "Always use the default kernel command string"
458 Always use the built-in command line, even if we get one during
459 boot. This is useful in case you need to override the provided
460 command line on systems where you don't have or want control
469 bool "UEFI runtime support"
470 depends on OF && !XIP_KERNEL
473 select EFI_PARAMS_FROM_FDT
475 select EFI_GENERIC_STUB
476 select EFI_RUNTIME_WRAPPERS
481 This option provides support for runtime services provided
482 by UEFI firmware (such as non-volatile variables, realtime
483 clock, and platform reset). A UEFI stub is also provided to
484 allow the kernel to be booted as an EFI application. This
485 is only useful on systems that have UEFI firmware.
487 config CC_HAVE_STACKPROTECTOR_TLS
488 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
490 config STACKPROTECTOR_PER_TASK
492 depends on !GCC_PLUGIN_RANDSTRUCT
493 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
495 config PHYS_RAM_BASE_FIXED
496 bool "Explicitly specified physical RAM address"
500 hex "Platform Physical RAM address"
501 depends on PHYS_RAM_BASE_FIXED
504 This is the physical address of RAM in the system. It has to be
505 explicitly specified to run early relocations of read-write data
509 bool "Kernel Execute-In-Place from ROM"
510 depends on MMU && SPARSEMEM
511 # This prevents XIP from being enabled by all{yes,mod}config, which
512 # fail to build since XIP doesn't support large kernels.
513 depends on !COMPILE_TEST
514 select PHYS_RAM_BASE_FIXED
516 Execute-In-Place allows the kernel to run from non-volatile storage
517 directly addressable by the CPU, such as NOR flash. This saves RAM
518 space since the text section of the kernel is not loaded from flash
519 to RAM. Read-write sections, such as the data section and stack,
520 are still copied to RAM. The XIP kernel is not compressed since
521 it has to run directly from flash, so it will take more space to
522 store it. The flash address used to link the kernel object files,
523 and for storing it, is configuration dependent. Therefore, if you
524 say Y here, you must know the proper physical address where to
525 store the kernel image depending on your own flash memory usage.
527 Also note that the make target becomes "make xipImage" rather than
528 "make zImage" or "make Image". The final kernel binary to put in
529 ROM memory will be arch/riscv/boot/xipImage.
531 SPARSEMEM is required because the kernel text and rodata that are
532 flash resident are not backed by memmap, then any attempt to get
533 a struct page on those regions will trigger a fault.
538 hex "XIP Kernel Physical Location"
539 depends on XIP_KERNEL
542 This is the physical address in your flash memory the kernel will
543 be linked for and stored to. This address is dependent on your
551 default y if XIP_KERNEL
553 menu "Power management options"
555 source "kernel/power/Kconfig"
559 source "drivers/firmware/Kconfig"