2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
14 # even on 32-bit, physical (and DMA) addresses are > 32-bits
15 select PHYS_ADDR_T_64BIT
17 select OF_EARLY_FLATTREE
19 select ARCH_WANT_FRAME_POINTERS
20 select CLONE_BACKWARDS
22 select GENERIC_CLOCKEVENTS
23 select GENERIC_CPU_DEVICES
24 select GENERIC_IRQ_SHOW
25 select GENERIC_PCI_IOMAP
26 select GENERIC_SCHED_CLOCK
27 select GENERIC_STRNCPY_FROM_USER
28 select GENERIC_STRNLEN_USER
29 select GENERIC_SMP_IDLE_THREAD
30 select GENERIC_ATOMIC64 if !64BIT
31 select HAVE_ARCH_AUDITSYSCALL
32 select HAVE_MEMBLOCK_NODE_MAP
33 select HAVE_DMA_CONTIGUOUS
34 select HAVE_FUTEX_CMPXCHG if FUTEX
35 select HAVE_PERF_EVENTS
36 select HAVE_SYSCALL_TRACEPOINTS
39 select SYSCTL_EXCEPTION_TRACE
40 select HAVE_ARCH_TRACEHOOK
42 select MODULES_USE_ELF_RELA if MODULES
43 select MODULE_SECTIONS if MODULES
44 select THREAD_INFO_IN_TASK
45 select PCI_DOMAINS_GENERIC if PCI
48 select GENERIC_IRQ_MULTI_HANDLER
49 select ARCH_HAS_PTE_SPECIAL
50 select ARCH_HAS_MMIOWB
51 select HAVE_EBPF_JIT if 64BIT
62 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
63 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
64 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
66 config STACKTRACE_SUPPORT
69 config TRACE_IRQFLAGS_SUPPORT
75 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
77 config GENERIC_BUG_RELATIVE_POINTERS
80 config GENERIC_CALIBRATE_DELAY
86 config GENERIC_HWEIGHT
89 config FIX_EARLYCON_MEM
103 This selects the base ISA that this kernel will target and must match
109 select GENERIC_LIB_ASHLDI3
110 select GENERIC_LIB_ASHRDI3
111 select GENERIC_LIB_LSHRDI3
112 select GENERIC_LIB_UCMPDI2
117 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
118 select HAVE_FUNCTION_TRACER
119 select HAVE_FUNCTION_GRAPH_TRACER
120 select HAVE_FTRACE_MCOUNT_RECORD
121 select HAVE_DYNAMIC_FTRACE
122 select HAVE_DYNAMIC_FTRACE_WITH_REGS
127 # We must be able to map all physical memory into the kernel, but the compiler
128 # is still a bit more efficient when generating code if it's setup in a manner
129 # such that it can only map 2GiB of memory.
131 prompt "Kernel Code Model"
132 default CMODEL_MEDLOW if 32BIT
133 default CMODEL_MEDANY if 64BIT
136 bool "medium low code model"
138 bool "medium any code model"
141 config MODULE_SECTIONS
143 select HAVE_MOD_ARCH_SPECIFIC
146 prompt "Maximum Physical Memory"
147 default MAXPHYSMEM_2GB if 32BIT
148 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
149 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
151 config MAXPHYSMEM_2GB
153 config MAXPHYSMEM_128GB
154 depends on 64BIT && CMODEL_MEDANY
160 bool "Symmetric Multi-Processing"
162 This enables support for systems with more than one CPU. If
163 you say N here, the kernel will run on single and
164 multiprocessor machines, but will use only one CPU of a
165 multiprocessor machine. If you say Y here, the kernel will run
166 on many, but not all, single processor machines. On a single
167 processor machine, the kernel will run faster if you say N
170 If you don't know what to do here, say N.
173 int "Maximum number of CPUs (2-32)"
188 bool "Emit compressed instructions when building Linux"
191 Adds "C" to the ISA subsets that the toolchain is allowed to emit
192 when building Linux, which results in compressed instructions in the
195 If you don't know what to do here, say Y.
197 menu "supported PMU type"
198 depends on PERF_EVENTS
200 config RISCV_BASE_PMU
201 bool "Base Performance Monitoring Unit"
204 A base PMU that serves as a reference implementation and has limited
205 feature of perf. It can run on any RISC-V machines so serves as the
206 fallback, but this option can also be disable to reduce kernel size.
214 Say N here if you want to disable all floating-point related procedure
217 If you don't know what to do here, say Y.
221 menu "Kernel features"
223 source "kernel/Kconfig.hz"
230 string "Built-in kernel command line"
232 For most platforms, the arguments for the kernel's command line
233 are provided at run-time, during boot. However, there are cases
234 where either no arguments are being provided or the provided
235 arguments are insufficient or even invalid.
237 When that occurs, it is possible to define a built-in command
238 line here and choose how the kernel should use it later on.
241 prompt "Built-in command line usage" if CMDLINE != ""
242 default CMDLINE_FALLBACK
244 Choose how the kernel will handle the provided built-in command
247 config CMDLINE_FALLBACK
248 bool "Use bootloader kernel arguments if available"
250 Use the built-in command line as fallback in case we get nothing
251 during boot. This is the default behaviour.
253 config CMDLINE_EXTEND
254 bool "Extend bootloader kernel arguments"
256 The command-line arguments provided during boot will be
257 appended to the built-in command line. This is useful in
258 cases where the provided arguments are insufficient and
259 you don't want to or cannot modify them.
263 bool "Always use the default kernel command string"
265 Always use the built-in command line, even if we get one during
266 boot. This is useful in case you need to override the provided
267 command line on systems where you don't have or want control
274 menu "Power management options"
276 source "kernel/power/Kconfig"