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_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
107 select ZONE_DMA32 if 64BIT
109 config ARCH_MMAP_RND_BITS_MIN
113 # max bits determined by the following formula:
114 # VA_BITS - PAGE_SHIFT - 3
115 config ARCH_MMAP_RND_BITS_MAX
116 default 24 if 64BIT # SV39 based
119 # set if we run in machine mode, cleared if we run in supervisor mode
124 # set if we are running in S-mode and can use SBI calls
127 depends on !RISCV_M_MODE
131 bool "MMU-based Paged Memory Management Support"
134 Select if you want MMU-based virtualised addressing space
135 support by paged memory management. If unsure, say 'Y'.
149 default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
150 default 0x80000000 if 64BIT && !MMU
151 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
152 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
154 config ARCH_FLATMEM_ENABLE
157 config ARCH_SPARSEMEM_ENABLE
160 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
161 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
163 config ARCH_SELECT_MEMORY_MODEL
164 def_bool ARCH_SPARSEMEM_ENABLE
166 config ARCH_WANT_GENERAL_HUGETLB
169 config ARCH_SUPPORTS_UPROBES
172 config STACKTRACE_SUPPORT
175 config TRACE_IRQFLAGS_SUPPORT
181 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
183 config GENERIC_BUG_RELATIVE_POINTERS
186 config GENERIC_CALIBRATE_DELAY
192 config GENERIC_HWEIGHT
195 config FIX_EARLYCON_MEM
198 config PGTABLE_LEVELS
203 config LOCKDEP_SUPPORT
206 source "arch/riscv/Kconfig.socs"
207 source "arch/riscv/Kconfig.erratas"
215 This selects the base ISA that this kernel will target and must match
221 select GENERIC_LIB_ASHLDI3
222 select GENERIC_LIB_ASHRDI3
223 select GENERIC_LIB_LSHRDI3
224 select GENERIC_LIB_UCMPDI2
230 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
231 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
232 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
233 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
234 select HAVE_FUNCTION_GRAPH_TRACER
235 select HAVE_FUNCTION_TRACER if !XIP_KERNEL
236 select SWIOTLB if MMU
240 # We must be able to map all physical memory into the kernel, but the compiler
241 # is still a bit more efficient when generating code if it's setup in a manner
242 # such that it can only map 2GiB of memory.
244 prompt "Kernel Code Model"
245 default CMODEL_MEDLOW if 32BIT
246 default CMODEL_MEDANY if 64BIT
249 bool "medium low code model"
251 bool "medium any code model"
254 config MODULE_SECTIONS
256 select HAVE_MOD_ARCH_SPECIFIC
259 prompt "Maximum Physical Memory"
260 default MAXPHYSMEM_1GB if 32BIT
261 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
262 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
264 config MAXPHYSMEM_1GB
267 config MAXPHYSMEM_2GB
268 depends on 64BIT && CMODEL_MEDLOW
270 config MAXPHYSMEM_128GB
271 depends on 64BIT && CMODEL_MEDANY
277 bool "Symmetric Multi-Processing"
279 This enables support for systems with more than one CPU. If
280 you say N here, the kernel will run on single and
281 multiprocessor machines, but will use only one CPU of a
282 multiprocessor machine. If you say Y here, the kernel will run
283 on many, but not all, single processor machines. On a single
284 processor machine, the kernel will run faster if you say N
287 If you don't know what to do here, say N.
290 int "Maximum number of CPUs (2-32)"
296 bool "Support for hot-pluggable CPUs"
298 select GENERIC_IRQ_MIGRATION
301 Say Y here to experiment with turning CPUs off and on. CPUs
302 can be controlled through /sys/devices/system/cpu.
304 Say N if you want to disable CPU hotplug.
315 # Common NUMA Features
317 bool "NUMA Memory Allocation and Scheduler Support"
318 depends on SMP && MMU
319 select GENERIC_ARCH_NUMA
321 select ARCH_SUPPORTS_NUMA_BALANCING
323 Enable NUMA (Non-Uniform Memory Access) support.
325 The kernel will try to allocate memory used by a CPU on the
326 local memory of the CPU and add some more NUMA awareness to the kernel.
329 int "Maximum NUMA Nodes (as a power of 2)"
334 Specify the maximum number of NUMA Nodes available on the target
335 system. Increases memory reserved to accommodate various tables.
337 config USE_PERCPU_NUMA_NODE_ID
341 config NEED_PER_CPU_EMBED_FIRST_CHUNK
346 bool "Emit compressed instructions when building Linux"
349 Adds "C" to the ISA subsets that the toolchain is allowed to emit
350 when building Linux, which results in compressed instructions in the
353 If you don't know what to do here, say Y.
355 menu "supported PMU type"
356 depends on PERF_EVENTS
358 config RISCV_BASE_PMU
359 bool "Base Performance Monitoring Unit"
362 A base PMU that serves as a reference implementation and has limited
363 feature of perf. It can run on any RISC-V machines so serves as the
364 fallback, but this option can also be disable to reduce kernel size.
372 Say N here if you want to disable all floating-point related procedure
375 If you don't know what to do here, say Y.
379 menu "Kernel features"
381 source "kernel/Kconfig.hz"
384 bool "SBI v0.1 support"
388 This config allows kernel to use SBI v0.1 APIs. This will be
389 deprecated in future once legacy M-mode software are no longer in use.
392 bool "Kexec system call"
394 select HOTPLUG_CPU if SMP
397 kexec is a system call that implements the ability to shutdown your
398 current kernel, and to start another kernel. It is like a reboot
399 but it is independent of the system firmware. And like a reboot
400 you can start any kernel with it, not just Linux.
402 The name comes from the similarity to the exec system call.
405 bool "Build kdump crash kernel"
407 Generate crash dump after being started by kexec. This should
408 be normally only set in special crash dump kernels which are
409 loaded in the main kernel with kexec-tools into a specially
410 reserved region and then later executed after a crash by
413 For more details see Documentation/admin-guide/kdump/kdump.rst
420 string "Built-in kernel command line"
422 For most platforms, the arguments for the kernel's command line
423 are provided at run-time, during boot. However, there are cases
424 where either no arguments are being provided or the provided
425 arguments are insufficient or even invalid.
427 When that occurs, it is possible to define a built-in command
428 line here and choose how the kernel should use it later on.
431 prompt "Built-in command line usage" if CMDLINE != ""
432 default CMDLINE_FALLBACK
434 Choose how the kernel will handle the provided built-in command
437 config CMDLINE_FALLBACK
438 bool "Use bootloader kernel arguments if available"
440 Use the built-in command line as fallback in case we get nothing
441 during boot. This is the default behaviour.
443 config CMDLINE_EXTEND
444 bool "Extend bootloader kernel arguments"
446 The command-line arguments provided during boot will be
447 appended to the built-in command line. This is useful in
448 cases where the provided arguments are insufficient and
449 you don't want to or cannot modify them.
453 bool "Always use the default kernel command string"
455 Always use the built-in command line, even if we get one during
456 boot. This is useful in case you need to override the provided
457 command line on systems where you don't have or want control
466 bool "UEFI runtime support"
467 depends on OF && !XIP_KERNEL
470 select EFI_PARAMS_FROM_FDT
472 select EFI_GENERIC_STUB
473 select EFI_RUNTIME_WRAPPERS
478 This option provides support for runtime services provided
479 by UEFI firmware (such as non-volatile variables, realtime
480 clock, and platform reset). A UEFI stub is also provided to
481 allow the kernel to be booted as an EFI application. This
482 is only useful on systems that have UEFI firmware.
484 config CC_HAVE_STACKPROTECTOR_TLS
485 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
487 config STACKPROTECTOR_PER_TASK
489 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
491 config PHYS_RAM_BASE_FIXED
492 bool "Explicitly specified physical RAM address"
496 hex "Platform Physical RAM address"
497 depends on PHYS_RAM_BASE_FIXED
500 This is the physical address of RAM in the system. It has to be
501 explicitly specified to run early relocations of read-write data
505 bool "Kernel Execute-In-Place from ROM"
506 depends on MMU && SPARSEMEM
507 # This prevents XIP from being enabled by all{yes,mod}config, which
508 # fail to build since XIP doesn't support large kernels.
509 depends on !COMPILE_TEST
510 select PHYS_RAM_BASE_FIXED
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"