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_MEMBLOCK_NODE_MAP
32 select HAVE_DMA_CONTIGUOUS
33 select HAVE_FUTEX_CMPXCHG if FUTEX
34 select HAVE_GENERIC_DMA_COHERENT
35 select HAVE_PERF_EVENTS
37 select RISCV_ISA_A if SMP
39 select SYSCTL_EXCEPTION_TRACE
40 select HAVE_ARCH_TRACEHOOK
42 select MODULES_USE_ELF_RELA if MODULES
43 select THREAD_INFO_IN_TASK
44 select PCI_DOMAINS_GENERIC if PCI
47 select GENERIC_IRQ_MULTI_HANDLER
48 select ARCH_HAS_PTE_SPECIAL
59 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
60 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
61 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
63 config STACKTRACE_SUPPORT
66 config TRACE_IRQFLAGS_SUPPORT
69 config RWSEM_GENERIC_SPINLOCK
75 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
77 config GENERIC_BUG_RELATIVE_POINTERS
80 config GENERIC_CALIBRATE_DELAY
86 config GENERIC_HWEIGHT
103 This selects the base ISA that this kernel will traget 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
155 select MODULE_SECTIONS if MODULES
161 bool "Symmetric Multi-Processing"
163 This enables support for systems with more than one CPU. If
164 you say N here, the kernel will run on single and
165 multiprocessor machines, but will use only one CPU of a
166 multiprocessor machine. If you say Y here, the kernel will run
167 on many, but not all, single processor machines. On a single
168 processor machine, the kernel will run faster if you say N
171 If you don't know what to do here, say N.
174 int "Maximum number of CPUs (2-32)"
189 bool "Emit compressed instructions when building Linux"
192 Adds "C" to the ISA subsets that the toolchain is allowed to emit
193 when building Linux, which results in compressed instructions in the
196 If you don't know what to do here, say Y.
201 menu "supported PMU type"
202 depends on PERF_EVENTS
204 config RISCV_BASE_PMU
205 bool "Base Performance Monitoring Unit"
208 A base PMU that serves as a reference implementation and has limited
209 feature of perf. It can run on any RISC-V machines so serves as the
210 fallback, but this option can also be disable to reduce kernel size.
218 Say N here if you want to disable all floating-point related procedure
221 If you don't know what to do here, say Y.
225 menu "Kernel features"
227 source "kernel/Kconfig.hz"
234 string "Built-in kernel command line"
236 For most platforms, the arguments for the kernel's command line
237 are provided at run-time, during boot. However, there are cases
238 where either no arguments are being provided or the provided
239 arguments are insufficient or even invalid.
241 When that occurs, it is possible to define a built-in command
242 line here and choose how the kernel should use it later on.
245 prompt "Built-in command line usage" if CMDLINE != ""
246 default CMDLINE_FALLBACK
248 Choose how the kernel will handle the provided built-in command
251 config CMDLINE_FALLBACK
252 bool "Use bootloader kernel arguments if available"
254 Use the built-in command line as fallback in case we get nothing
255 during boot. This is the default behaviour.
257 config CMDLINE_EXTEND
258 bool "Extend bootloader kernel arguments"
260 The command-line arguments provided during boot will be
261 appended to the built-in command line. This is useful in
262 cases where the provided arguments are insufficient and
263 you don't want to or cannot modify them.
267 bool "Always use the default kernel command string"
269 Always use the built-in command line, even if we get one during
270 boot. This is useful in case you need to override the provided
271 command line on systems where you don't have or want control
278 menu "Power management options"
280 source "kernel/power/Kconfig"