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_HAS_BINFMT_FLAT
17 select ARCH_HAS_DEBUG_VIRTUAL if MMU
18 select ARCH_HAS_DEBUG_WX
19 select ARCH_HAS_GCOV_PROFILE_ALL
20 select ARCH_HAS_GIGANTIC_PAGE
21 select ARCH_HAS_MMIOWB
22 select ARCH_HAS_PTE_SPECIAL
23 select ARCH_HAS_SET_DIRECT_MAP
24 select ARCH_HAS_SET_MEMORY
25 select ARCH_HAS_STRICT_KERNEL_RWX if MMU
26 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
27 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
28 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
29 select ARCH_WANT_FRAME_POINTERS
30 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
31 select CLONE_BACKWARDS
34 select GENERIC_ARCH_TOPOLOGY if SMP
35 select GENERIC_ATOMIC64 if !64BIT
36 select GENERIC_CLOCKEVENTS
37 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
38 select GENERIC_IOREMAP
39 select GENERIC_IRQ_MULTI_HANDLER
40 select GENERIC_IRQ_SHOW
41 select GENERIC_PCI_IOMAP
42 select GENERIC_PTDUMP if MMU
43 select GENERIC_SCHED_CLOCK
44 select GENERIC_SMP_IDLE_THREAD
45 select GENERIC_STRNCPY_FROM_USER if MMU
46 select GENERIC_STRNLEN_USER if MMU
47 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
48 select HANDLE_DOMAIN_IRQ
49 select HAVE_ARCH_AUDITSYSCALL
50 select HAVE_ARCH_KASAN if MMU && 64BIT
52 select HAVE_ARCH_KGDB_QXFER_PKT
53 select HAVE_ARCH_MMAP_RND_BITS if MMU
54 select HAVE_ARCH_SECCOMP_FILTER
55 select HAVE_ARCH_TRACEHOOK
56 select HAVE_ASM_MODVERSIONS
57 select HAVE_DMA_CONTIGUOUS if MMU
58 select HAVE_EBPF_JIT if MMU
59 select HAVE_FUTEX_CMPXCHG if FUTEX
60 select HAVE_GENERIC_VDSO if MMU && 64BIT
62 select HAVE_PERF_EVENTS
64 select HAVE_PERF_USER_STACK_DUMP
65 select HAVE_SYSCALL_TRACEPOINTS
67 select MODULES_USE_ELF_RELA if MODULES
68 select MODULE_SECTIONS if MODULES
70 select OF_EARLY_FLATTREE
72 select PCI_DOMAINS_GENERIC if PCI
76 select SPARSEMEM_STATIC if 32BIT
78 select SYSCTL_EXCEPTION_TRACE
79 select THREAD_INFO_IN_TASK
81 config ARCH_MMAP_RND_BITS_MIN
85 # max bits determined by the following formula:
86 # VA_BITS - PAGE_SHIFT - 3
87 config ARCH_MMAP_RND_BITS_MAX
88 default 24 if 64BIT # SV39 based
91 # set if we run in machine mode, cleared if we run in supervisor mode
96 # set if we are running in S-mode and can use SBI calls
99 depends on !RISCV_M_MODE
103 bool "MMU-based Paged Memory Management Support"
106 Select if you want MMU-based virtualised addressing space
107 support by paged memory management. If unsure, say 'Y'.
125 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
126 default 0x80000000 if 64BIT && !MMU
127 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
128 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
130 config ARCH_FLATMEM_ENABLE
133 config ARCH_SPARSEMEM_ENABLE
136 select SPARSEMEM_VMEMMAP_ENABLE
138 config ARCH_SELECT_MEMORY_MODEL
139 def_bool ARCH_SPARSEMEM_ENABLE
141 config ARCH_WANT_GENERAL_HUGETLB
144 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
147 config SYS_SUPPORTS_HUGETLBFS
151 config STACKTRACE_SUPPORT
154 config TRACE_IRQFLAGS_SUPPORT
160 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
162 config GENERIC_BUG_RELATIVE_POINTERS
165 config GENERIC_CALIBRATE_DELAY
171 config GENERIC_HWEIGHT
174 config FIX_EARLYCON_MEM
177 config PGTABLE_LEVELS
182 source "arch/riscv/Kconfig.socs"
190 This selects the base ISA that this kernel will target and must match
196 select GENERIC_LIB_ASHLDI3
197 select GENERIC_LIB_ASHRDI3
198 select GENERIC_LIB_LSHRDI3
199 select GENERIC_LIB_UCMPDI2
205 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
206 select HAVE_DYNAMIC_FTRACE if MMU
207 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
208 select HAVE_FTRACE_MCOUNT_RECORD
209 select HAVE_FUNCTION_GRAPH_TRACER
210 select HAVE_FUNCTION_TRACER
211 select SWIOTLB if MMU
215 # We must be able to map all physical memory into the kernel, but the compiler
216 # is still a bit more efficient when generating code if it's setup in a manner
217 # such that it can only map 2GiB of memory.
219 prompt "Kernel Code Model"
220 default CMODEL_MEDLOW if 32BIT
221 default CMODEL_MEDANY if 64BIT
224 bool "medium low code model"
226 bool "medium any code model"
229 config MODULE_SECTIONS
231 select HAVE_MOD_ARCH_SPECIFIC
234 prompt "Maximum Physical Memory"
235 default MAXPHYSMEM_2GB if 32BIT
236 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
237 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
239 config MAXPHYSMEM_2GB
241 config MAXPHYSMEM_128GB
242 depends on 64BIT && CMODEL_MEDANY
248 bool "Symmetric Multi-Processing"
250 This enables support for systems with more than one CPU. If
251 you say N here, the kernel will run on single and
252 multiprocessor machines, but will use only one CPU of a
253 multiprocessor machine. If you say Y here, the kernel will run
254 on many, but not all, single processor machines. On a single
255 processor machine, the kernel will run faster if you say N
258 If you don't know what to do here, say N.
261 int "Maximum number of CPUs (2-32)"
267 bool "Support for hot-pluggable CPUs"
269 select GENERIC_IRQ_MIGRATION
272 Say Y here to experiment with turning CPUs off and on. CPUs
273 can be controlled through /sys/devices/system/cpu.
275 Say N if you want to disable CPU hotplug.
287 bool "Emit compressed instructions when building Linux"
290 Adds "C" to the ISA subsets that the toolchain is allowed to emit
291 when building Linux, which results in compressed instructions in the
294 If you don't know what to do here, say Y.
296 menu "supported PMU type"
297 depends on PERF_EVENTS
299 config RISCV_BASE_PMU
300 bool "Base Performance Monitoring Unit"
303 A base PMU that serves as a reference implementation and has limited
304 feature of perf. It can run on any RISC-V machines so serves as the
305 fallback, but this option can also be disable to reduce kernel size.
313 Say N here if you want to disable all floating-point related procedure
316 If you don't know what to do here, say Y.
320 menu "Kernel features"
322 source "kernel/Kconfig.hz"
325 bool "Enable seccomp to safely compute untrusted bytecode"
327 This kernel feature is useful for number crunching applications
328 that may need to compute untrusted bytecode during their
329 execution. By using pipes or other transports made available to
330 the process as file descriptors supporting the read/write
331 syscalls, it's possible to isolate those applications in
332 their own address space using seccomp. Once seccomp is
333 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
334 and the task is only allowed to execute a few safe syscalls
335 defined by each seccomp mode.
338 bool "SBI v0.1 support"
342 This config allows kernel to use SBI v0.1 APIs. This will be
343 deprecated in future once legacy M-mode software are no longer in use.
349 string "Built-in kernel command line"
351 For most platforms, the arguments for the kernel's command line
352 are provided at run-time, during boot. However, there are cases
353 where either no arguments are being provided or the provided
354 arguments are insufficient or even invalid.
356 When that occurs, it is possible to define a built-in command
357 line here and choose how the kernel should use it later on.
360 prompt "Built-in command line usage" if CMDLINE != ""
361 default CMDLINE_FALLBACK
363 Choose how the kernel will handle the provided built-in command
366 config CMDLINE_FALLBACK
367 bool "Use bootloader kernel arguments if available"
369 Use the built-in command line as fallback in case we get nothing
370 during boot. This is the default behaviour.
372 config CMDLINE_EXTEND
373 bool "Extend bootloader kernel arguments"
375 The command-line arguments provided during boot will be
376 appended to the built-in command line. This is useful in
377 cases where the provided arguments are insufficient and
378 you don't want to or cannot modify them.
382 bool "Always use the default kernel command string"
384 Always use the built-in command line, even if we get one during
385 boot. This is useful in case you need to override the provided
386 command line on systems where you don't have or want control
395 depends on RISCV_M_MODE
398 menu "Power management options"
400 source "kernel/power/Kconfig"