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_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
27 select ARCH_WANT_FRAME_POINTERS
28 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
29 select CLONE_BACKWARDS
32 select GENERIC_ARCH_TOPOLOGY if SMP
33 select GENERIC_ATOMIC64 if !64BIT
34 select GENERIC_CLOCKEVENTS
35 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
36 select GENERIC_IOREMAP
37 select GENERIC_IRQ_MULTI_HANDLER
38 select GENERIC_IRQ_SHOW
39 select GENERIC_PCI_IOMAP
40 select GENERIC_PTDUMP if MMU
41 select GENERIC_SCHED_CLOCK
42 select GENERIC_SMP_IDLE_THREAD
43 select GENERIC_STRNCPY_FROM_USER if MMU
44 select GENERIC_STRNLEN_USER if MMU
45 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
46 select HANDLE_DOMAIN_IRQ
47 select HAVE_ARCH_AUDITSYSCALL
48 select HAVE_ARCH_KASAN if MMU && 64BIT
50 select HAVE_ARCH_KGDB_QXFER_PKT
51 select HAVE_ARCH_MMAP_RND_BITS if MMU
52 select HAVE_ARCH_SECCOMP_FILTER
53 select HAVE_ARCH_TRACEHOOK
54 select HAVE_ASM_MODVERSIONS
55 select HAVE_COPY_THREAD_TLS
56 select HAVE_DMA_CONTIGUOUS if MMU
57 select HAVE_EBPF_JIT if MMU
58 select HAVE_FUTEX_CMPXCHG if FUTEX
59 select HAVE_GENERIC_VDSO if MMU && 64BIT
61 select HAVE_PERF_EVENTS
63 select HAVE_PERF_USER_STACK_DUMP
64 select HAVE_SYSCALL_TRACEPOINTS
66 select MODULES_USE_ELF_RELA if MODULES
67 select MODULE_SECTIONS if MODULES
69 select OF_EARLY_FLATTREE
71 select PCI_DOMAINS_GENERIC if PCI
75 select SPARSEMEM_STATIC if 32BIT
77 select SYSCTL_EXCEPTION_TRACE
78 select THREAD_INFO_IN_TASK
80 config ARCH_MMAP_RND_BITS_MIN
84 # max bits determined by the following formula:
85 # VA_BITS - PAGE_SHIFT - 3
86 config ARCH_MMAP_RND_BITS_MAX
87 default 24 if 64BIT # SV39 based
90 # set if we run in machine mode, cleared if we run in supervisor mode
95 # set if we are running in S-mode and can use SBI calls
98 depends on !RISCV_M_MODE
102 bool "MMU-based Paged Memory Management Support"
105 Select if you want MMU-based virtualised addressing space
106 support by paged memory management. If unsure, say 'Y'.
124 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
125 default 0x80000000 if 64BIT && !MMU
126 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
127 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
129 config ARCH_FLATMEM_ENABLE
132 config ARCH_SPARSEMEM_ENABLE
135 select SPARSEMEM_VMEMMAP_ENABLE
137 config ARCH_SELECT_MEMORY_MODEL
138 def_bool ARCH_SPARSEMEM_ENABLE
140 config ARCH_WANT_GENERAL_HUGETLB
143 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
146 config SYS_SUPPORTS_HUGETLBFS
150 config STACKTRACE_SUPPORT
153 config TRACE_IRQFLAGS_SUPPORT
159 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
161 config GENERIC_BUG_RELATIVE_POINTERS
164 config GENERIC_CALIBRATE_DELAY
170 config GENERIC_HWEIGHT
173 config FIX_EARLYCON_MEM
176 config PGTABLE_LEVELS
181 source "arch/riscv/Kconfig.socs"
189 This selects the base ISA that this kernel will target and must match
195 select GENERIC_LIB_ASHLDI3
196 select GENERIC_LIB_ASHRDI3
197 select GENERIC_LIB_LSHRDI3
198 select GENERIC_LIB_UCMPDI2
204 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
205 select HAVE_DYNAMIC_FTRACE if MMU
206 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
207 select HAVE_FTRACE_MCOUNT_RECORD
208 select HAVE_FUNCTION_GRAPH_TRACER
209 select HAVE_FUNCTION_TRACER
210 select SWIOTLB if MMU
214 # We must be able to map all physical memory into the kernel, but the compiler
215 # is still a bit more efficient when generating code if it's setup in a manner
216 # such that it can only map 2GiB of memory.
218 prompt "Kernel Code Model"
219 default CMODEL_MEDLOW if 32BIT
220 default CMODEL_MEDANY if 64BIT
223 bool "medium low code model"
225 bool "medium any code model"
228 config MODULE_SECTIONS
230 select HAVE_MOD_ARCH_SPECIFIC
233 prompt "Maximum Physical Memory"
234 default MAXPHYSMEM_2GB if 32BIT
235 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
236 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
238 config MAXPHYSMEM_2GB
240 config MAXPHYSMEM_128GB
241 depends on 64BIT && CMODEL_MEDANY
247 bool "Symmetric Multi-Processing"
249 This enables support for systems with more than one CPU. If
250 you say N here, the kernel will run on single and
251 multiprocessor machines, but will use only one CPU of a
252 multiprocessor machine. If you say Y here, the kernel will run
253 on many, but not all, single processor machines. On a single
254 processor machine, the kernel will run faster if you say N
257 If you don't know what to do here, say N.
260 int "Maximum number of CPUs (2-32)"
266 bool "Support for hot-pluggable CPUs"
268 select GENERIC_IRQ_MIGRATION
271 Say Y here to experiment with turning CPUs off and on. CPUs
272 can be controlled through /sys/devices/system/cpu.
274 Say N if you want to disable CPU hotplug.
286 bool "Emit compressed instructions when building Linux"
289 Adds "C" to the ISA subsets that the toolchain is allowed to emit
290 when building Linux, which results in compressed instructions in the
293 If you don't know what to do here, say Y.
295 menu "supported PMU type"
296 depends on PERF_EVENTS
298 config RISCV_BASE_PMU
299 bool "Base Performance Monitoring Unit"
302 A base PMU that serves as a reference implementation and has limited
303 feature of perf. It can run on any RISC-V machines so serves as the
304 fallback, but this option can also be disable to reduce kernel size.
312 Say N here if you want to disable all floating-point related procedure
315 If you don't know what to do here, say Y.
319 menu "Kernel features"
321 source "kernel/Kconfig.hz"
324 bool "Enable seccomp to safely compute untrusted bytecode"
326 This kernel feature is useful for number crunching applications
327 that may need to compute untrusted bytecode during their
328 execution. By using pipes or other transports made available to
329 the process as file descriptors supporting the read/write
330 syscalls, it's possible to isolate those applications in
331 their own address space using seccomp. Once seccomp is
332 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
333 and the task is only allowed to execute a few safe syscalls
334 defined by each seccomp mode.
337 bool "SBI v0.1 support"
341 This config allows kernel to use SBI v0.1 APIs. This will be
342 deprecated in future once legacy M-mode software are no longer in use.
348 string "Built-in kernel command line"
350 For most platforms, the arguments for the kernel's command line
351 are provided at run-time, during boot. However, there are cases
352 where either no arguments are being provided or the provided
353 arguments are insufficient or even invalid.
355 When that occurs, it is possible to define a built-in command
356 line here and choose how the kernel should use it later on.
359 prompt "Built-in command line usage" if CMDLINE != ""
360 default CMDLINE_FALLBACK
362 Choose how the kernel will handle the provided built-in command
365 config CMDLINE_FALLBACK
366 bool "Use bootloader kernel arguments if available"
368 Use the built-in command line as fallback in case we get nothing
369 during boot. This is the default behaviour.
371 config CMDLINE_EXTEND
372 bool "Extend bootloader kernel arguments"
374 The command-line arguments provided during boot will be
375 appended to the built-in command line. This is useful in
376 cases where the provided arguments are insufficient and
377 you don't want to or cannot modify them.
381 bool "Always use the default kernel command string"
383 Always use the built-in command line, even if we get one during
384 boot. This is useful in case you need to override the provided
385 command line on systems where you don't have or want control
394 depends on RISCV_M_MODE
397 menu "Power management options"
399 source "kernel/power/Kconfig"