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_ASM_MODVERSIONS
35 select HAVE_MEMBLOCK_NODE_MAP
36 select HAVE_DMA_CONTIGUOUS
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 HAVE_EBPF_JIT if 64BIT
59 select ARCH_HAS_GIGANTIC_PAGE
60 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
61 select SPARSEMEM_STATIC if 32BIT
82 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
83 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
84 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
86 config ARCH_FLATMEM_ENABLE
89 config ARCH_SPARSEMEM_ENABLE
91 select SPARSEMEM_VMEMMAP_ENABLE
93 config ARCH_SELECT_MEMORY_MODEL
94 def_bool ARCH_SPARSEMEM_ENABLE
96 config ARCH_WANT_GENERAL_HUGETLB
99 config SYS_SUPPORTS_HUGETLBFS
102 config STACKTRACE_SUPPORT
105 config TRACE_IRQFLAGS_SUPPORT
111 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
113 config GENERIC_BUG_RELATIVE_POINTERS
116 config GENERIC_CALIBRATE_DELAY
122 config GENERIC_HWEIGHT
125 config FIX_EARLYCON_MEM
128 config PGTABLE_LEVELS
133 source "arch/riscv/Kconfig.socs"
141 This selects the base ISA that this kernel will target and must match
147 select GENERIC_LIB_ASHLDI3
148 select GENERIC_LIB_ASHRDI3
149 select GENERIC_LIB_LSHRDI3
150 select GENERIC_LIB_UCMPDI2
155 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
156 select HAVE_FUNCTION_TRACER
157 select HAVE_FUNCTION_GRAPH_TRACER
158 select HAVE_FTRACE_MCOUNT_RECORD
159 select HAVE_DYNAMIC_FTRACE
160 select HAVE_DYNAMIC_FTRACE_WITH_REGS
165 # We must be able to map all physical memory into the kernel, but the compiler
166 # is still a bit more efficient when generating code if it's setup in a manner
167 # such that it can only map 2GiB of memory.
169 prompt "Kernel Code Model"
170 default CMODEL_MEDLOW if 32BIT
171 default CMODEL_MEDANY if 64BIT
174 bool "medium low code model"
176 bool "medium any code model"
179 config MODULE_SECTIONS
181 select HAVE_MOD_ARCH_SPECIFIC
184 prompt "Maximum Physical Memory"
185 default MAXPHYSMEM_2GB if 32BIT
186 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
187 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
189 config MAXPHYSMEM_2GB
191 config MAXPHYSMEM_128GB
192 depends on 64BIT && CMODEL_MEDANY
198 bool "Symmetric Multi-Processing"
200 This enables support for systems with more than one CPU. If
201 you say N here, the kernel will run on single and
202 multiprocessor machines, but will use only one CPU of a
203 multiprocessor machine. If you say Y here, the kernel will run
204 on many, but not all, single processor machines. On a single
205 processor machine, the kernel will run faster if you say N
208 If you don't know what to do here, say N.
211 int "Maximum number of CPUs (2-32)"
226 bool "Emit compressed instructions when building Linux"
229 Adds "C" to the ISA subsets that the toolchain is allowed to emit
230 when building Linux, which results in compressed instructions in the
233 If you don't know what to do here, say Y.
235 menu "supported PMU type"
236 depends on PERF_EVENTS
238 config RISCV_BASE_PMU
239 bool "Base Performance Monitoring Unit"
242 A base PMU that serves as a reference implementation and has limited
243 feature of perf. It can run on any RISC-V machines so serves as the
244 fallback, but this option can also be disable to reduce kernel size.
252 Say N here if you want to disable all floating-point related procedure
255 If you don't know what to do here, say Y.
259 menu "Kernel features"
261 source "kernel/Kconfig.hz"
268 string "Built-in kernel command line"
270 For most platforms, the arguments for the kernel's command line
271 are provided at run-time, during boot. However, there are cases
272 where either no arguments are being provided or the provided
273 arguments are insufficient or even invalid.
275 When that occurs, it is possible to define a built-in command
276 line here and choose how the kernel should use it later on.
279 prompt "Built-in command line usage" if CMDLINE != ""
280 default CMDLINE_FALLBACK
282 Choose how the kernel will handle the provided built-in command
285 config CMDLINE_FALLBACK
286 bool "Use bootloader kernel arguments if available"
288 Use the built-in command line as fallback in case we get nothing
289 during boot. This is the default behaviour.
291 config CMDLINE_EXTEND
292 bool "Extend bootloader kernel arguments"
294 The command-line arguments provided during boot will be
295 appended to the built-in command line. This is useful in
296 cases where the provided arguments are insufficient and
297 you don't want to or cannot modify them.
301 bool "Always use the default kernel command string"
303 Always use the built-in command line, even if we get one during
304 boot. This is useful in case you need to override the provided
305 command line on systems where you don't have or want control
312 menu "Power management options"
314 source "kernel/power/Kconfig"