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 HAVE_ARCH_AUDITSYSCALL
34 select HAVE_ARCH_SECCOMP_FILTER
35 select HAVE_ASM_MODVERSIONS
36 select HAVE_MEMBLOCK_NODE_MAP
37 select HAVE_DMA_CONTIGUOUS if MMU
38 select HAVE_FUTEX_CMPXCHG if FUTEX
39 select HAVE_PERF_EVENTS
41 select HAVE_PERF_USER_STACK_DUMP
42 select HAVE_SYSCALL_TRACEPOINTS
45 select SYSCTL_EXCEPTION_TRACE
46 select HAVE_ARCH_TRACEHOOK
48 select MODULES_USE_ELF_RELA if MODULES
49 select MODULE_SECTIONS if MODULES
50 select THREAD_INFO_IN_TASK
51 select PCI_DOMAINS_GENERIC if PCI
54 select UACCESS_MEMCPY if !MMU
55 select GENERIC_IRQ_MULTI_HANDLER
56 select GENERIC_ARCH_TOPOLOGY if SMP
57 select ARCH_HAS_PTE_SPECIAL
58 select ARCH_HAS_MMIOWB
59 select HAVE_EBPF_JIT if 64BIT
61 select ARCH_HAS_GIGANTIC_PAGE
62 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
63 select SPARSEMEM_STATIC if 32BIT
64 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
65 select HAVE_ARCH_MMAP_RND_BITS if MMU
67 config ARCH_MMAP_RND_BITS_MIN
71 # max bits determined by the following formula:
72 # VA_BITS - PAGE_SHIFT - 3
73 config ARCH_MMAP_RND_BITS_MAX
74 default 24 if 64BIT # SV39 based
77 # set if we run in machine mode, cleared if we run in supervisor mode
82 # set if we are running in S-mode and can use SBI calls
85 depends on !RISCV_M_MODE
89 bool "MMU-based Paged Memory Management Support"
92 Select if you want MMU-based virtualised addressing space
93 support by paged memory management. If unsure, say 'Y'.
111 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
112 default 0x80000000 if 64BIT && !MMU
113 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
114 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
116 config ARCH_FLATMEM_ENABLE
119 config ARCH_SPARSEMEM_ENABLE
121 select SPARSEMEM_VMEMMAP_ENABLE
123 config ARCH_SELECT_MEMORY_MODEL
124 def_bool ARCH_SPARSEMEM_ENABLE
126 config ARCH_WANT_GENERAL_HUGETLB
129 config SYS_SUPPORTS_HUGETLBFS
132 config STACKTRACE_SUPPORT
135 config TRACE_IRQFLAGS_SUPPORT
141 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
143 config GENERIC_BUG_RELATIVE_POINTERS
146 config GENERIC_CALIBRATE_DELAY
152 config GENERIC_HWEIGHT
155 config FIX_EARLYCON_MEM
158 config PGTABLE_LEVELS
163 source "arch/riscv/Kconfig.socs"
171 This selects the base ISA that this kernel will target and must match
177 select GENERIC_LIB_ASHLDI3
178 select GENERIC_LIB_ASHRDI3
179 select GENERIC_LIB_LSHRDI3
180 select GENERIC_LIB_UCMPDI2
186 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
187 select HAVE_FUNCTION_TRACER
188 select HAVE_FUNCTION_GRAPH_TRACER
189 select HAVE_FTRACE_MCOUNT_RECORD
190 select HAVE_DYNAMIC_FTRACE if MMU
191 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
192 select SWIOTLB if MMU
196 # We must be able to map all physical memory into the kernel, but the compiler
197 # is still a bit more efficient when generating code if it's setup in a manner
198 # such that it can only map 2GiB of memory.
200 prompt "Kernel Code Model"
201 default CMODEL_MEDLOW if 32BIT
202 default CMODEL_MEDANY if 64BIT
205 bool "medium low code model"
207 bool "medium any code model"
210 config MODULE_SECTIONS
212 select HAVE_MOD_ARCH_SPECIFIC
215 prompt "Maximum Physical Memory"
216 default MAXPHYSMEM_2GB if 32BIT
217 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
218 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
220 config MAXPHYSMEM_2GB
222 config MAXPHYSMEM_128GB
223 depends on 64BIT && CMODEL_MEDANY
229 bool "Symmetric Multi-Processing"
231 This enables support for systems with more than one CPU. If
232 you say N here, the kernel will run on single and
233 multiprocessor machines, but will use only one CPU of a
234 multiprocessor machine. If you say Y here, the kernel will run
235 on many, but not all, single processor machines. On a single
236 processor machine, the kernel will run faster if you say N
239 If you don't know what to do here, say N.
242 int "Maximum number of CPUs (2-32)"
257 bool "Emit compressed instructions when building Linux"
260 Adds "C" to the ISA subsets that the toolchain is allowed to emit
261 when building Linux, which results in compressed instructions in the
264 If you don't know what to do here, say Y.
266 menu "supported PMU type"
267 depends on PERF_EVENTS
269 config RISCV_BASE_PMU
270 bool "Base Performance Monitoring Unit"
273 A base PMU that serves as a reference implementation and has limited
274 feature of perf. It can run on any RISC-V machines so serves as the
275 fallback, but this option can also be disable to reduce kernel size.
283 Say N here if you want to disable all floating-point related procedure
286 If you don't know what to do here, say Y.
290 menu "Kernel features"
292 source "kernel/Kconfig.hz"
295 bool "Enable seccomp to safely compute untrusted bytecode"
297 This kernel feature is useful for number crunching applications
298 that may need to compute untrusted bytecode during their
299 execution. By using pipes or other transports made available to
300 the process as file descriptors supporting the read/write
301 syscalls, it's possible to isolate those applications in
302 their own address space using seccomp. Once seccomp is
303 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
304 and the task is only allowed to execute a few safe syscalls
305 defined by each seccomp mode.
312 string "Built-in kernel command line"
314 For most platforms, the arguments for the kernel's command line
315 are provided at run-time, during boot. However, there are cases
316 where either no arguments are being provided or the provided
317 arguments are insufficient or even invalid.
319 When that occurs, it is possible to define a built-in command
320 line here and choose how the kernel should use it later on.
323 prompt "Built-in command line usage" if CMDLINE != ""
324 default CMDLINE_FALLBACK
326 Choose how the kernel will handle the provided built-in command
329 config CMDLINE_FALLBACK
330 bool "Use bootloader kernel arguments if available"
332 Use the built-in command line as fallback in case we get nothing
333 during boot. This is the default behaviour.
335 config CMDLINE_EXTEND
336 bool "Extend bootloader kernel arguments"
338 The command-line arguments provided during boot will be
339 appended to the built-in command line. This is useful in
340 cases where the provided arguments are insufficient and
341 you don't want to or cannot modify them.
345 bool "Always use the default kernel command string"
347 Always use the built-in command line, even if we get one during
348 boot. This is useful in case you need to override the provided
349 command line on systems where you don't have or want control
356 menu "Power management options"
358 source "kernel/power/Kconfig"