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
30 select GENERIC_STRNLEN_USER
31 select GENERIC_SMP_IDLE_THREAD
32 select GENERIC_ATOMIC64 if !64BIT
33 select HAVE_ARCH_AUDITSYSCALL
34 select HAVE_MEMBLOCK_NODE_MAP
35 select HAVE_DMA_CONTIGUOUS
36 select HAVE_FUTEX_CMPXCHG if FUTEX
37 select HAVE_PERF_EVENTS
38 select HAVE_SYSCALL_TRACEPOINTS
41 select SYSCTL_EXCEPTION_TRACE
42 select HAVE_ARCH_TRACEHOOK
44 select MODULES_USE_ELF_RELA if MODULES
45 select MODULE_SECTIONS if MODULES
46 select THREAD_INFO_IN_TASK
47 select PCI_DOMAINS_GENERIC if PCI
50 select GENERIC_IRQ_MULTI_HANDLER
51 select ARCH_HAS_PTE_SPECIAL
52 select ARCH_HAS_MMIOWB
53 select HAVE_EBPF_JIT if 64BIT
55 select ARCH_HAS_GIGANTIC_PAGE
56 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
67 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
68 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
69 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
71 config ARCH_WANT_GENERAL_HUGETLB
74 config SYS_SUPPORTS_HUGETLBFS
77 config STACKTRACE_SUPPORT
80 config TRACE_IRQFLAGS_SUPPORT
86 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
88 config GENERIC_BUG_RELATIVE_POINTERS
91 config GENERIC_CALIBRATE_DELAY
97 config GENERIC_HWEIGHT
100 config FIX_EARLYCON_MEM
103 config PGTABLE_LEVELS
108 source "arch/riscv/Kconfig.socs"
116 This selects the base ISA that this kernel will target and must match
122 select GENERIC_LIB_ASHLDI3
123 select GENERIC_LIB_ASHRDI3
124 select GENERIC_LIB_LSHRDI3
125 select GENERIC_LIB_UCMPDI2
130 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
131 select HAVE_FUNCTION_TRACER
132 select HAVE_FUNCTION_GRAPH_TRACER
133 select HAVE_FTRACE_MCOUNT_RECORD
134 select HAVE_DYNAMIC_FTRACE
135 select HAVE_DYNAMIC_FTRACE_WITH_REGS
140 # We must be able to map all physical memory into the kernel, but the compiler
141 # is still a bit more efficient when generating code if it's setup in a manner
142 # such that it can only map 2GiB of memory.
144 prompt "Kernel Code Model"
145 default CMODEL_MEDLOW if 32BIT
146 default CMODEL_MEDANY if 64BIT
149 bool "medium low code model"
151 bool "medium any code model"
154 config MODULE_SECTIONS
156 select HAVE_MOD_ARCH_SPECIFIC
159 prompt "Maximum Physical Memory"
160 default MAXPHYSMEM_2GB if 32BIT
161 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
162 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
164 config MAXPHYSMEM_2GB
166 config MAXPHYSMEM_128GB
167 depends on 64BIT && CMODEL_MEDANY
173 bool "Symmetric Multi-Processing"
175 This enables support for systems with more than one CPU. If
176 you say N here, the kernel will run on single and
177 multiprocessor machines, but will use only one CPU of a
178 multiprocessor machine. If you say Y here, the kernel will run
179 on many, but not all, single processor machines. On a single
180 processor machine, the kernel will run faster if you say N
183 If you don't know what to do here, say N.
186 int "Maximum number of CPUs (2-32)"
201 bool "Emit compressed instructions when building Linux"
204 Adds "C" to the ISA subsets that the toolchain is allowed to emit
205 when building Linux, which results in compressed instructions in the
208 If you don't know what to do here, say Y.
210 menu "supported PMU type"
211 depends on PERF_EVENTS
213 config RISCV_BASE_PMU
214 bool "Base Performance Monitoring Unit"
217 A base PMU that serves as a reference implementation and has limited
218 feature of perf. It can run on any RISC-V machines so serves as the
219 fallback, but this option can also be disable to reduce kernel size.
227 Say N here if you want to disable all floating-point related procedure
230 If you don't know what to do here, say Y.
234 menu "Kernel features"
236 source "kernel/Kconfig.hz"
243 string "Built-in kernel command line"
245 For most platforms, the arguments for the kernel's command line
246 are provided at run-time, during boot. However, there are cases
247 where either no arguments are being provided or the provided
248 arguments are insufficient or even invalid.
250 When that occurs, it is possible to define a built-in command
251 line here and choose how the kernel should use it later on.
254 prompt "Built-in command line usage" if CMDLINE != ""
255 default CMDLINE_FALLBACK
257 Choose how the kernel will handle the provided built-in command
260 config CMDLINE_FALLBACK
261 bool "Use bootloader kernel arguments if available"
263 Use the built-in command line as fallback in case we get nothing
264 during boot. This is the default behaviour.
266 config CMDLINE_EXTEND
267 bool "Extend bootloader kernel arguments"
269 The command-line arguments provided during boot will be
270 appended to the built-in command line. This is useful in
271 cases where the provided arguments are insufficient and
272 you don't want to or cannot modify them.
276 bool "Always use the default kernel command string"
278 Always use the built-in command line, even if we get one during
279 boot. This is useful in case you need to override the provided
280 command line on systems where you don't have or want control
287 menu "Power management options"
289 source "kernel/power/Kconfig"