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
39 select HAVE_PERF_USER_STACK_DUMP
40 select HAVE_SYSCALL_TRACEPOINTS
43 select SYSCTL_EXCEPTION_TRACE
44 select HAVE_ARCH_TRACEHOOK
46 select MODULES_USE_ELF_RELA if MODULES
47 select MODULE_SECTIONS if MODULES
48 select THREAD_INFO_IN_TASK
49 select PCI_DOMAINS_GENERIC if PCI
52 select GENERIC_IRQ_MULTI_HANDLER
53 select GENERIC_ARCH_TOPOLOGY if SMP
54 select ARCH_HAS_PTE_SPECIAL
55 select ARCH_HAS_MMIOWB
56 select HAVE_EBPF_JIT if 64BIT
58 select ARCH_HAS_GIGANTIC_PAGE
59 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
60 select SPARSEMEM_STATIC if 32BIT
81 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
82 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
83 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
85 config ARCH_FLATMEM_ENABLE
88 config ARCH_SPARSEMEM_ENABLE
90 select SPARSEMEM_VMEMMAP_ENABLE
92 config ARCH_SELECT_MEMORY_MODEL
93 def_bool ARCH_SPARSEMEM_ENABLE
95 config ARCH_WANT_GENERAL_HUGETLB
98 config SYS_SUPPORTS_HUGETLBFS
101 config STACKTRACE_SUPPORT
104 config TRACE_IRQFLAGS_SUPPORT
110 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
112 config GENERIC_BUG_RELATIVE_POINTERS
115 config GENERIC_CALIBRATE_DELAY
121 config GENERIC_HWEIGHT
124 config FIX_EARLYCON_MEM
127 config PGTABLE_LEVELS
132 source "arch/riscv/Kconfig.socs"
140 This selects the base ISA that this kernel will target and must match
146 select GENERIC_LIB_ASHLDI3
147 select GENERIC_LIB_ASHRDI3
148 select GENERIC_LIB_LSHRDI3
149 select GENERIC_LIB_UCMPDI2
154 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
155 select HAVE_FUNCTION_TRACER
156 select HAVE_FUNCTION_GRAPH_TRACER
157 select HAVE_FTRACE_MCOUNT_RECORD
158 select HAVE_DYNAMIC_FTRACE
159 select HAVE_DYNAMIC_FTRACE_WITH_REGS
164 # We must be able to map all physical memory into the kernel, but the compiler
165 # is still a bit more efficient when generating code if it's setup in a manner
166 # such that it can only map 2GiB of memory.
168 prompt "Kernel Code Model"
169 default CMODEL_MEDLOW if 32BIT
170 default CMODEL_MEDANY if 64BIT
173 bool "medium low code model"
175 bool "medium any code model"
178 config MODULE_SECTIONS
180 select HAVE_MOD_ARCH_SPECIFIC
183 prompt "Maximum Physical Memory"
184 default MAXPHYSMEM_2GB if 32BIT
185 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
186 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
188 config MAXPHYSMEM_2GB
190 config MAXPHYSMEM_128GB
191 depends on 64BIT && CMODEL_MEDANY
197 bool "Symmetric Multi-Processing"
199 This enables support for systems with more than one CPU. If
200 you say N here, the kernel will run on single and
201 multiprocessor machines, but will use only one CPU of a
202 multiprocessor machine. If you say Y here, the kernel will run
203 on many, but not all, single processor machines. On a single
204 processor machine, the kernel will run faster if you say N
207 If you don't know what to do here, say N.
210 int "Maximum number of CPUs (2-32)"
225 bool "Emit compressed instructions when building Linux"
228 Adds "C" to the ISA subsets that the toolchain is allowed to emit
229 when building Linux, which results in compressed instructions in the
232 If you don't know what to do here, say Y.
234 menu "supported PMU type"
235 depends on PERF_EVENTS
237 config RISCV_BASE_PMU
238 bool "Base Performance Monitoring Unit"
241 A base PMU that serves as a reference implementation and has limited
242 feature of perf. It can run on any RISC-V machines so serves as the
243 fallback, but this option can also be disable to reduce kernel size.
251 Say N here if you want to disable all floating-point related procedure
254 If you don't know what to do here, say Y.
258 menu "Kernel features"
260 source "kernel/Kconfig.hz"
267 string "Built-in kernel command line"
269 For most platforms, the arguments for the kernel's command line
270 are provided at run-time, during boot. However, there are cases
271 where either no arguments are being provided or the provided
272 arguments are insufficient or even invalid.
274 When that occurs, it is possible to define a built-in command
275 line here and choose how the kernel should use it later on.
278 prompt "Built-in command line usage" if CMDLINE != ""
279 default CMDLINE_FALLBACK
281 Choose how the kernel will handle the provided built-in command
284 config CMDLINE_FALLBACK
285 bool "Use bootloader kernel arguments if available"
287 Use the built-in command line as fallback in case we get nothing
288 during boot. This is the default behaviour.
290 config CMDLINE_EXTEND
291 bool "Extend bootloader kernel arguments"
293 The command-line arguments provided during boot will be
294 appended to the built-in command line. This is useful in
295 cases where the provided arguments are insufficient and
296 you don't want to or cannot modify them.
300 bool "Always use the default kernel command string"
302 Always use the built-in command line, even if we get one during
303 boot. This is useful in case you need to override the provided
304 command line on systems where you don't have or want control
311 menu "Power management options"
313 source "kernel/power/Kconfig"