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
41 select MODULES_USE_ELF_RELA if MODULES
42 select THREAD_INFO_IN_TASK
44 select GENERIC_IRQ_MULTI_HANDLER
45 select ARCH_HAS_PTE_SPECIAL
56 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
57 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
58 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
60 config STACKTRACE_SUPPORT
63 config TRACE_IRQFLAGS_SUPPORT
66 config RWSEM_GENERIC_SPINLOCK
72 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
74 config GENERIC_BUG_RELATIVE_POINTERS
77 config GENERIC_CALIBRATE_DELAY
83 config GENERIC_HWEIGHT
100 This selects the base ISA that this kernel will traget and must match
106 select GENERIC_LIB_ASHLDI3
107 select GENERIC_LIB_ASHRDI3
108 select GENERIC_LIB_LSHRDI3
109 select GENERIC_LIB_UCMPDI2
114 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
115 select HAVE_FUNCTION_TRACER
116 select HAVE_FUNCTION_GRAPH_TRACER
117 select HAVE_FTRACE_MCOUNT_RECORD
118 select HAVE_DYNAMIC_FTRACE
119 select HAVE_DYNAMIC_FTRACE_WITH_REGS
124 # We must be able to map all physical memory into the kernel, but the compiler
125 # is still a bit more efficient when generating code if it's setup in a manner
126 # such that it can only map 2GiB of memory.
128 prompt "Kernel Code Model"
129 default CMODEL_MEDLOW if 32BIT
130 default CMODEL_MEDANY if 64BIT
133 bool "medium low code model"
135 bool "medium any code model"
138 config MODULE_SECTIONS
140 select HAVE_MOD_ARCH_SPECIFIC
143 prompt "Maximum Physical Memory"
144 default MAXPHYSMEM_2GB if 32BIT
145 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
146 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
148 config MAXPHYSMEM_2GB
150 config MAXPHYSMEM_128GB
151 depends on 64BIT && CMODEL_MEDANY
152 select MODULE_SECTIONS if MODULES
158 bool "Symmetric Multi-Processing"
160 This enables support for systems with more than one CPU. If
161 you say N here, the kernel will run on single and
162 multiprocessor machines, but will use only one CPU of a
163 multiprocessor machine. If you say Y here, the kernel will run
164 on many, but not all, single processor machines. On a single
165 processor machine, the kernel will run faster if you say N
168 If you don't know what to do here, say N.
171 int "Maximum number of CPUs (2-32)"
186 bool "Emit compressed instructions when building Linux"
189 Adds "C" to the ISA subsets that the toolchain is allowed to emit
190 when building Linux, which results in compressed instructions in the
193 If you don't know what to do here, say Y.
198 menu "supported PMU type"
199 depends on PERF_EVENTS
201 config RISCV_BASE_PMU
202 bool "Base Performance Monitoring Unit"
205 A base PMU that serves as a reference implementation and has limited
206 feature of perf. It can run on any RISC-V machines so serves as the
207 fallback, but this option can also be disable to reduce kernel size.
215 Say N here if you want to disable all floating-point related procedure
218 If you don't know what to do here, say Y.
222 menu "Kernel features"
224 source "kernel/Kconfig.hz"
231 string "Built-in kernel command line"
233 For most platforms, the arguments for the kernel's command line
234 are provided at run-time, during boot. However, there are cases
235 where either no arguments are being provided or the provided
236 arguments are insufficient or even invalid.
238 When that occurs, it is possible to define a built-in command
239 line here and choose how the kernel should use it later on.
242 prompt "Built-in command line usage" if CMDLINE != ""
243 default CMDLINE_FALLBACK
245 Choose how the kernel will handle the provided built-in command
248 config CMDLINE_FALLBACK
249 bool "Use bootloader kernel arguments if available"
251 Use the built-in command line as fallback in case we get nothing
252 during boot. This is the default behaviour.
254 config CMDLINE_EXTEND
255 bool "Extend bootloader kernel arguments"
257 The command-line arguments provided during boot will be
258 appended to the built-in command line. This is useful in
259 cases where the provided arguments are insufficient and
260 you don't want to or cannot modify them.
264 bool "Always use the default kernel command string"
266 Always use the built-in command line, even if we get one during
267 boot. This is useful in case you need to override the provided
268 command line on systems where you don't have or want control
281 This feature enables support for PCI bus system. If you say Y
282 here, the kernel will include drivers and infrastructure code
283 to support PCI bus devices.
285 If you don't know what to do here, say Y.
290 config PCI_DOMAINS_GENERIC
293 source "drivers/pci/Kconfig"
297 menu "Power management options"
299 source kernel/power/Kconfig