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.
16 select OF_EARLY_FLATTREE
18 select ARCH_HAS_BINFMT_FLAT
19 select ARCH_HAS_DEBUG_WX
20 select ARCH_WANT_FRAME_POINTERS
21 select CLONE_BACKWARDS
23 select GENERIC_CLOCKEVENTS
24 select GENERIC_IRQ_SHOW
25 select GENERIC_PCI_IOMAP
26 select GENERIC_SCHED_CLOCK
27 select GENERIC_STRNCPY_FROM_USER if MMU
28 select GENERIC_STRNLEN_USER if MMU
29 select GENERIC_SMP_IDLE_THREAD
30 select GENERIC_ATOMIC64 if !64BIT
31 select GENERIC_IOREMAP
32 select GENERIC_PTDUMP if MMU
33 select HAVE_ARCH_AUDITSYSCALL
34 select HAVE_ARCH_SECCOMP_FILTER
35 select HAVE_ASM_MODVERSIONS
36 select HAVE_DMA_CONTIGUOUS if MMU
37 select HAVE_FUTEX_CMPXCHG if FUTEX
38 select HAVE_PERF_EVENTS
40 select HAVE_PERF_USER_STACK_DUMP
41 select HAVE_SYSCALL_TRACEPOINTS
44 select SYSCTL_EXCEPTION_TRACE
45 select HAVE_ARCH_TRACEHOOK
47 select MODULES_USE_ELF_RELA if MODULES
48 select MODULE_SECTIONS if MODULES
49 select THREAD_INFO_IN_TASK
50 select PCI_DOMAINS_GENERIC if PCI
53 select GENERIC_IRQ_MULTI_HANDLER
54 select GENERIC_ARCH_TOPOLOGY if SMP
55 select ARCH_HAS_PTE_SPECIAL
56 select ARCH_HAS_MMIOWB
57 select ARCH_HAS_DEBUG_VIRTUAL if MMU
58 select HAVE_EBPF_JIT if MMU
60 select ARCH_HAS_GIGANTIC_PAGE
61 select ARCH_HAS_SET_DIRECT_MAP
62 select ARCH_HAS_SET_MEMORY
63 select ARCH_HAS_STRICT_KERNEL_RWX if MMU
64 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
65 select SPARSEMEM_STATIC if 32BIT
66 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
67 select HAVE_ARCH_MMAP_RND_BITS if MMU
68 select ARCH_HAS_GCOV_PROFILE_ALL
69 select HAVE_COPY_THREAD_TLS
70 select HAVE_ARCH_KASAN if MMU && 64BIT
72 select HAVE_ARCH_KGDB_QXFER_PKT
74 config ARCH_MMAP_RND_BITS_MIN
78 # max bits determined by the following formula:
79 # VA_BITS - PAGE_SHIFT - 3
80 config ARCH_MMAP_RND_BITS_MAX
81 default 24 if 64BIT # SV39 based
84 # set if we run in machine mode, cleared if we run in supervisor mode
89 # set if we are running in S-mode and can use SBI calls
92 depends on !RISCV_M_MODE
96 bool "MMU-based Paged Memory Management Support"
99 Select if you want MMU-based virtualised addressing space
100 support by paged memory management. If unsure, say 'Y'.
118 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
119 default 0x80000000 if 64BIT && !MMU
120 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
121 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
123 config ARCH_FLATMEM_ENABLE
126 config ARCH_SPARSEMEM_ENABLE
129 select SPARSEMEM_VMEMMAP_ENABLE
131 config ARCH_SELECT_MEMORY_MODEL
132 def_bool ARCH_SPARSEMEM_ENABLE
134 config ARCH_WANT_GENERAL_HUGETLB
137 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
140 config SYS_SUPPORTS_HUGETLBFS
144 config STACKTRACE_SUPPORT
147 config TRACE_IRQFLAGS_SUPPORT
153 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
155 config GENERIC_BUG_RELATIVE_POINTERS
158 config GENERIC_CALIBRATE_DELAY
164 config GENERIC_HWEIGHT
167 config FIX_EARLYCON_MEM
170 config PGTABLE_LEVELS
175 source "arch/riscv/Kconfig.socs"
183 This selects the base ISA that this kernel will target and must match
189 select GENERIC_LIB_ASHLDI3
190 select GENERIC_LIB_ASHRDI3
191 select GENERIC_LIB_LSHRDI3
192 select GENERIC_LIB_UCMPDI2
198 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
199 select HAVE_FUNCTION_TRACER
200 select HAVE_FUNCTION_GRAPH_TRACER
201 select HAVE_FTRACE_MCOUNT_RECORD
202 select HAVE_DYNAMIC_FTRACE if MMU
203 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
204 select SWIOTLB if MMU
208 # We must be able to map all physical memory into the kernel, but the compiler
209 # is still a bit more efficient when generating code if it's setup in a manner
210 # such that it can only map 2GiB of memory.
212 prompt "Kernel Code Model"
213 default CMODEL_MEDLOW if 32BIT
214 default CMODEL_MEDANY if 64BIT
217 bool "medium low code model"
219 bool "medium any code model"
222 config MODULE_SECTIONS
224 select HAVE_MOD_ARCH_SPECIFIC
227 prompt "Maximum Physical Memory"
228 default MAXPHYSMEM_2GB if 32BIT
229 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
230 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
232 config MAXPHYSMEM_2GB
234 config MAXPHYSMEM_128GB
235 depends on 64BIT && CMODEL_MEDANY
241 bool "Symmetric Multi-Processing"
243 This enables support for systems with more than one CPU. If
244 you say N here, the kernel will run on single and
245 multiprocessor machines, but will use only one CPU of a
246 multiprocessor machine. If you say Y here, the kernel will run
247 on many, but not all, single processor machines. On a single
248 processor machine, the kernel will run faster if you say N
251 If you don't know what to do here, say N.
254 int "Maximum number of CPUs (2-32)"
260 bool "Support for hot-pluggable CPUs"
262 select GENERIC_IRQ_MIGRATION
265 Say Y here to experiment with turning CPUs off and on. CPUs
266 can be controlled through /sys/devices/system/cpu.
268 Say N if you want to disable CPU hotplug.
280 bool "Emit compressed instructions when building Linux"
283 Adds "C" to the ISA subsets that the toolchain is allowed to emit
284 when building Linux, which results in compressed instructions in the
287 If you don't know what to do here, say Y.
289 menu "supported PMU type"
290 depends on PERF_EVENTS
292 config RISCV_BASE_PMU
293 bool "Base Performance Monitoring Unit"
296 A base PMU that serves as a reference implementation and has limited
297 feature of perf. It can run on any RISC-V machines so serves as the
298 fallback, but this option can also be disable to reduce kernel size.
306 Say N here if you want to disable all floating-point related procedure
309 If you don't know what to do here, say Y.
313 menu "Kernel features"
315 source "kernel/Kconfig.hz"
318 bool "Enable seccomp to safely compute untrusted bytecode"
320 This kernel feature is useful for number crunching applications
321 that may need to compute untrusted bytecode during their
322 execution. By using pipes or other transports made available to
323 the process as file descriptors supporting the read/write
324 syscalls, it's possible to isolate those applications in
325 their own address space using seccomp. Once seccomp is
326 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
327 and the task is only allowed to execute a few safe syscalls
328 defined by each seccomp mode.
331 bool "SBI v0.1 support"
335 This config allows kernel to use SBI v0.1 APIs. This will be
336 deprecated in future once legacy M-mode software are no longer in use.
342 string "Built-in kernel command line"
344 For most platforms, the arguments for the kernel's command line
345 are provided at run-time, during boot. However, there are cases
346 where either no arguments are being provided or the provided
347 arguments are insufficient or even invalid.
349 When that occurs, it is possible to define a built-in command
350 line here and choose how the kernel should use it later on.
353 prompt "Built-in command line usage" if CMDLINE != ""
354 default CMDLINE_FALLBACK
356 Choose how the kernel will handle the provided built-in command
359 config CMDLINE_FALLBACK
360 bool "Use bootloader kernel arguments if available"
362 Use the built-in command line as fallback in case we get nothing
363 during boot. This is the default behaviour.
365 config CMDLINE_EXTEND
366 bool "Extend bootloader kernel arguments"
368 The command-line arguments provided during boot will be
369 appended to the built-in command line. This is useful in
370 cases where the provided arguments are insufficient and
371 you don't want to or cannot modify them.
375 bool "Always use the default kernel command string"
377 Always use the built-in command line, even if we get one during
378 boot. This is useful in case you need to override the provided
379 command line on systems where you don't have or want control
388 depends on RISCV_M_MODE
391 menu "Power management options"
393 source "kernel/power/Kconfig"