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 # even on 32-bit, physical (and DMA) addresses are > 32-bits
16 select PHYS_ADDR_T_64BIT
18 select OF_EARLY_FLATTREE
20 select ARCH_HAS_BINFMT_FLAT
21 select ARCH_WANT_FRAME_POINTERS
22 select CLONE_BACKWARDS
24 select GENERIC_CLOCKEVENTS
25 select GENERIC_CPU_DEVICES
26 select GENERIC_IRQ_SHOW
27 select GENERIC_PCI_IOMAP
28 select GENERIC_SCHED_CLOCK
29 select GENERIC_STRNCPY_FROM_USER if MMU
30 select GENERIC_STRNLEN_USER if MMU
31 select GENERIC_SMP_IDLE_THREAD
32 select GENERIC_ATOMIC64 if !64BIT
33 select GENERIC_IOREMAP
34 select HAVE_ARCH_AUDITSYSCALL
35 select HAVE_ARCH_SECCOMP_FILTER
36 select HAVE_ASM_MODVERSIONS
37 select HAVE_MEMBLOCK_NODE_MAP
38 select HAVE_DMA_CONTIGUOUS if MMU
39 select HAVE_FUTEX_CMPXCHG if FUTEX
40 select HAVE_PERF_EVENTS
42 select HAVE_PERF_USER_STACK_DUMP
43 select HAVE_SYSCALL_TRACEPOINTS
46 select SYSCTL_EXCEPTION_TRACE
47 select HAVE_ARCH_TRACEHOOK
49 select MODULES_USE_ELF_RELA if MODULES
50 select MODULE_SECTIONS if MODULES
51 select THREAD_INFO_IN_TASK
52 select PCI_DOMAINS_GENERIC if PCI
55 select UACCESS_MEMCPY if !MMU
56 select GENERIC_IRQ_MULTI_HANDLER
57 select GENERIC_ARCH_TOPOLOGY if SMP
58 select ARCH_HAS_PTE_SPECIAL
59 select ARCH_HAS_MMIOWB
60 select HAVE_EBPF_JIT if 64BIT
62 select ARCH_HAS_GIGANTIC_PAGE
63 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
64 select SPARSEMEM_STATIC if 32BIT
65 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
66 select HAVE_ARCH_MMAP_RND_BITS if MMU
67 select ARCH_HAS_GCOV_PROFILE_ALL
69 config ARCH_MMAP_RND_BITS_MIN
73 # max bits determined by the following formula:
74 # VA_BITS - PAGE_SHIFT - 3
75 config ARCH_MMAP_RND_BITS_MAX
76 default 24 if 64BIT # SV39 based
79 # set if we run in machine mode, cleared if we run in supervisor mode
84 # set if we are running in S-mode and can use SBI calls
87 depends on !RISCV_M_MODE
91 bool "MMU-based Paged Memory Management Support"
94 Select if you want MMU-based virtualised addressing space
95 support by paged memory management. If unsure, say 'Y'.
113 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
114 default 0x80000000 if 64BIT && !MMU
115 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
116 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
118 config ARCH_FLATMEM_ENABLE
121 config ARCH_SPARSEMEM_ENABLE
123 select SPARSEMEM_VMEMMAP_ENABLE
125 config ARCH_SELECT_MEMORY_MODEL
126 def_bool ARCH_SPARSEMEM_ENABLE
128 config ARCH_WANT_GENERAL_HUGETLB
131 config SYS_SUPPORTS_HUGETLBFS
134 config STACKTRACE_SUPPORT
137 config TRACE_IRQFLAGS_SUPPORT
143 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
145 config GENERIC_BUG_RELATIVE_POINTERS
148 config GENERIC_CALIBRATE_DELAY
154 config GENERIC_HWEIGHT
157 config FIX_EARLYCON_MEM
160 config PGTABLE_LEVELS
165 source "arch/riscv/Kconfig.socs"
173 This selects the base ISA that this kernel will target and must match
179 select GENERIC_LIB_ASHLDI3
180 select GENERIC_LIB_ASHRDI3
181 select GENERIC_LIB_LSHRDI3
182 select GENERIC_LIB_UCMPDI2
188 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
189 select HAVE_FUNCTION_TRACER
190 select HAVE_FUNCTION_GRAPH_TRACER
191 select HAVE_FTRACE_MCOUNT_RECORD
192 select HAVE_DYNAMIC_FTRACE if MMU
193 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
194 select SWIOTLB if MMU
198 # We must be able to map all physical memory into the kernel, but the compiler
199 # is still a bit more efficient when generating code if it's setup in a manner
200 # such that it can only map 2GiB of memory.
202 prompt "Kernel Code Model"
203 default CMODEL_MEDLOW if 32BIT
204 default CMODEL_MEDANY if 64BIT
207 bool "medium low code model"
209 bool "medium any code model"
212 config MODULE_SECTIONS
214 select HAVE_MOD_ARCH_SPECIFIC
217 prompt "Maximum Physical Memory"
218 default MAXPHYSMEM_2GB if 32BIT
219 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
220 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
222 config MAXPHYSMEM_2GB
224 config MAXPHYSMEM_128GB
225 depends on 64BIT && CMODEL_MEDANY
231 bool "Symmetric Multi-Processing"
233 This enables support for systems with more than one CPU. If
234 you say N here, the kernel will run on single and
235 multiprocessor machines, but will use only one CPU of a
236 multiprocessor machine. If you say Y here, the kernel will run
237 on many, but not all, single processor machines. On a single
238 processor machine, the kernel will run faster if you say N
241 If you don't know what to do here, say N.
244 int "Maximum number of CPUs (2-32)"
259 bool "Emit compressed instructions when building Linux"
262 Adds "C" to the ISA subsets that the toolchain is allowed to emit
263 when building Linux, which results in compressed instructions in the
266 If you don't know what to do here, say Y.
268 menu "supported PMU type"
269 depends on PERF_EVENTS
271 config RISCV_BASE_PMU
272 bool "Base Performance Monitoring Unit"
275 A base PMU that serves as a reference implementation and has limited
276 feature of perf. It can run on any RISC-V machines so serves as the
277 fallback, but this option can also be disable to reduce kernel size.
285 Say N here if you want to disable all floating-point related procedure
288 If you don't know what to do here, say Y.
292 menu "Kernel features"
294 source "kernel/Kconfig.hz"
297 bool "Enable seccomp to safely compute untrusted bytecode"
299 This kernel feature is useful for number crunching applications
300 that may need to compute untrusted bytecode during their
301 execution. By using pipes or other transports made available to
302 the process as file descriptors supporting the read/write
303 syscalls, it's possible to isolate those applications in
304 their own address space using seccomp. Once seccomp is
305 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
306 and the task is only allowed to execute a few safe syscalls
307 defined by each seccomp mode.
314 string "Built-in kernel command line"
316 For most platforms, the arguments for the kernel's command line
317 are provided at run-time, during boot. However, there are cases
318 where either no arguments are being provided or the provided
319 arguments are insufficient or even invalid.
321 When that occurs, it is possible to define a built-in command
322 line here and choose how the kernel should use it later on.
325 prompt "Built-in command line usage" if CMDLINE != ""
326 default CMDLINE_FALLBACK
328 Choose how the kernel will handle the provided built-in command
331 config CMDLINE_FALLBACK
332 bool "Use bootloader kernel arguments if available"
334 Use the built-in command line as fallback in case we get nothing
335 during boot. This is the default behaviour.
337 config CMDLINE_EXTEND
338 bool "Extend bootloader kernel arguments"
340 The command-line arguments provided during boot will be
341 appended to the built-in command line. This is useful in
342 cases where the provided arguments are insufficient and
343 you don't want to or cannot modify them.
347 bool "Always use the default kernel command string"
349 Always use the built-in command line, even if we get one during
350 boot. This is useful in case you need to override the provided
351 command line on systems where you don't have or want control
358 menu "Power management options"
360 source "kernel/power/Kconfig"