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 || !RISCV_ISA_A
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_GENERIC_DMA_COHERENT
36 select HAVE_PERF_EVENTS
37 select HAVE_SYSCALL_TRACEPOINTS
39 select RISCV_ISA_A if SMP
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 HAVE_EBPF_JIT if 64BIT
63 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
64 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
65 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
67 config STACKTRACE_SUPPORT
70 config TRACE_IRQFLAGS_SUPPORT
73 config RWSEM_GENERIC_SPINLOCK
79 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
81 config GENERIC_BUG_RELATIVE_POINTERS
84 config GENERIC_CALIBRATE_DELAY
90 config GENERIC_HWEIGHT
107 This selects the base ISA that this kernel will target and must match
113 select GENERIC_LIB_ASHLDI3
114 select GENERIC_LIB_ASHRDI3
115 select GENERIC_LIB_LSHRDI3
116 select GENERIC_LIB_UCMPDI2
121 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
122 select HAVE_FUNCTION_TRACER
123 select HAVE_FUNCTION_GRAPH_TRACER
124 select HAVE_FTRACE_MCOUNT_RECORD
125 select HAVE_DYNAMIC_FTRACE
126 select HAVE_DYNAMIC_FTRACE_WITH_REGS
131 # We must be able to map all physical memory into the kernel, but the compiler
132 # is still a bit more efficient when generating code if it's setup in a manner
133 # such that it can only map 2GiB of memory.
135 prompt "Kernel Code Model"
136 default CMODEL_MEDLOW if 32BIT
137 default CMODEL_MEDANY if 64BIT
140 bool "medium low code model"
142 bool "medium any code model"
145 config MODULE_SECTIONS
147 select HAVE_MOD_ARCH_SPECIFIC
150 prompt "Maximum Physical Memory"
151 default MAXPHYSMEM_2GB if 32BIT
152 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
153 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
155 config MAXPHYSMEM_2GB
157 config MAXPHYSMEM_128GB
158 depends on 64BIT && CMODEL_MEDANY
164 bool "Symmetric Multi-Processing"
166 This enables support for systems with more than one CPU. If
167 you say N here, the kernel will run on single and
168 multiprocessor machines, but will use only one CPU of a
169 multiprocessor machine. If you say Y here, the kernel will run
170 on many, but not all, single processor machines. On a single
171 processor machine, the kernel will run faster if you say N
174 If you don't know what to do here, say N.
177 int "Maximum number of CPUs (2-32)"
192 bool "Emit compressed instructions when building Linux"
195 Adds "C" to the ISA subsets that the toolchain is allowed to emit
196 when building Linux, which results in compressed instructions in the
199 If you don't know what to do here, say Y.
204 menu "supported PMU type"
205 depends on PERF_EVENTS
207 config RISCV_BASE_PMU
208 bool "Base Performance Monitoring Unit"
211 A base PMU that serves as a reference implementation and has limited
212 feature of perf. It can run on any RISC-V machines so serves as the
213 fallback, but this option can also be disable to reduce kernel size.
221 Say N here if you want to disable all floating-point related procedure
224 If you don't know what to do here, say Y.
228 menu "Kernel features"
230 source "kernel/Kconfig.hz"
237 string "Built-in kernel command line"
239 For most platforms, the arguments for the kernel's command line
240 are provided at run-time, during boot. However, there are cases
241 where either no arguments are being provided or the provided
242 arguments are insufficient or even invalid.
244 When that occurs, it is possible to define a built-in command
245 line here and choose how the kernel should use it later on.
248 prompt "Built-in command line usage" if CMDLINE != ""
249 default CMDLINE_FALLBACK
251 Choose how the kernel will handle the provided built-in command
254 config CMDLINE_FALLBACK
255 bool "Use bootloader kernel arguments if available"
257 Use the built-in command line as fallback in case we get nothing
258 during boot. This is the default behaviour.
260 config CMDLINE_EXTEND
261 bool "Extend bootloader kernel arguments"
263 The command-line arguments provided during boot will be
264 appended to the built-in command line. This is useful in
265 cases where the provided arguments are insufficient and
266 you don't want to or cannot modify them.
270 bool "Always use the default kernel command string"
272 Always use the built-in command line, even if we get one during
273 boot. This is useful in case you need to override the provided
274 command line on systems where you don't have or want control
281 menu "Power management options"
283 source "kernel/power/Kconfig"