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 GENERIC_ARCH_TOPOLOGY if SMP
52 select ARCH_HAS_PTE_SPECIAL
53 select ARCH_HAS_MMIOWB
54 select HAVE_EBPF_JIT if 64BIT
56 select ARCH_HAS_GIGANTIC_PAGE
57 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
58 select SPARSEMEM_STATIC if 32BIT
79 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
80 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
81 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
83 config ARCH_FLATMEM_ENABLE
86 config ARCH_SPARSEMEM_ENABLE
88 select SPARSEMEM_VMEMMAP_ENABLE
90 config ARCH_SELECT_MEMORY_MODEL
91 def_bool ARCH_SPARSEMEM_ENABLE
93 config ARCH_WANT_GENERAL_HUGETLB
96 config SYS_SUPPORTS_HUGETLBFS
99 config STACKTRACE_SUPPORT
102 config TRACE_IRQFLAGS_SUPPORT
108 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
110 config GENERIC_BUG_RELATIVE_POINTERS
113 config GENERIC_CALIBRATE_DELAY
119 config GENERIC_HWEIGHT
122 config FIX_EARLYCON_MEM
125 config PGTABLE_LEVELS
130 source "arch/riscv/Kconfig.socs"
138 This selects the base ISA that this kernel will target and must match
144 select GENERIC_LIB_ASHLDI3
145 select GENERIC_LIB_ASHRDI3
146 select GENERIC_LIB_LSHRDI3
147 select GENERIC_LIB_UCMPDI2
152 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
153 select HAVE_FUNCTION_TRACER
154 select HAVE_FUNCTION_GRAPH_TRACER
155 select HAVE_FTRACE_MCOUNT_RECORD
156 select HAVE_DYNAMIC_FTRACE
157 select HAVE_DYNAMIC_FTRACE_WITH_REGS
162 # We must be able to map all physical memory into the kernel, but the compiler
163 # is still a bit more efficient when generating code if it's setup in a manner
164 # such that it can only map 2GiB of memory.
166 prompt "Kernel Code Model"
167 default CMODEL_MEDLOW if 32BIT
168 default CMODEL_MEDANY if 64BIT
171 bool "medium low code model"
173 bool "medium any code model"
176 config MODULE_SECTIONS
178 select HAVE_MOD_ARCH_SPECIFIC
181 prompt "Maximum Physical Memory"
182 default MAXPHYSMEM_2GB if 32BIT
183 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
184 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
186 config MAXPHYSMEM_2GB
188 config MAXPHYSMEM_128GB
189 depends on 64BIT && CMODEL_MEDANY
195 bool "Symmetric Multi-Processing"
197 This enables support for systems with more than one CPU. If
198 you say N here, the kernel will run on single and
199 multiprocessor machines, but will use only one CPU of a
200 multiprocessor machine. If you say Y here, the kernel will run
201 on many, but not all, single processor machines. On a single
202 processor machine, the kernel will run faster if you say N
205 If you don't know what to do here, say N.
208 int "Maximum number of CPUs (2-32)"
223 bool "Emit compressed instructions when building Linux"
226 Adds "C" to the ISA subsets that the toolchain is allowed to emit
227 when building Linux, which results in compressed instructions in the
230 If you don't know what to do here, say Y.
232 menu "supported PMU type"
233 depends on PERF_EVENTS
235 config RISCV_BASE_PMU
236 bool "Base Performance Monitoring Unit"
239 A base PMU that serves as a reference implementation and has limited
240 feature of perf. It can run on any RISC-V machines so serves as the
241 fallback, but this option can also be disable to reduce kernel size.
249 Say N here if you want to disable all floating-point related procedure
252 If you don't know what to do here, say Y.
256 menu "Kernel features"
258 source "kernel/Kconfig.hz"
265 string "Built-in kernel command line"
267 For most platforms, the arguments for the kernel's command line
268 are provided at run-time, during boot. However, there are cases
269 where either no arguments are being provided or the provided
270 arguments are insufficient or even invalid.
272 When that occurs, it is possible to define a built-in command
273 line here and choose how the kernel should use it later on.
276 prompt "Built-in command line usage" if CMDLINE != ""
277 default CMDLINE_FALLBACK
279 Choose how the kernel will handle the provided built-in command
282 config CMDLINE_FALLBACK
283 bool "Use bootloader kernel arguments if available"
285 Use the built-in command line as fallback in case we get nothing
286 during boot. This is the default behaviour.
288 config CMDLINE_EXTEND
289 bool "Extend bootloader kernel arguments"
291 The command-line arguments provided during boot will be
292 appended to the built-in command line. This is useful in
293 cases where the provided arguments are insufficient and
294 you don't want to or cannot modify them.
298 bool "Always use the default kernel command string"
300 Always use the built-in command line, even if we get one during
301 boot. This is useful in case you need to override the provided
302 command line on systems where you don't have or want control
309 menu "Power management options"
311 source "kernel/power/Kconfig"