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
23 select GENERIC_CLOCKEVENTS
24 select GENERIC_CPU_DEVICES
25 select GENERIC_IRQ_SHOW
26 select GENERIC_PCI_IOMAP
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
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
38 select RISCV_ISA_A if SMP
40 select SYSCTL_EXCEPTION_TRACE
41 select HAVE_ARCH_TRACEHOOK
42 select MODULES_USE_ELF_RELA if MODULES
43 select THREAD_INFO_IN_TASK
45 select GENERIC_IRQ_MULTI_HANDLER
46 select ARCH_HAS_PTE_SPECIAL
57 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
58 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
59 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
61 config STACKTRACE_SUPPORT
64 config TRACE_IRQFLAGS_SUPPORT
67 config RWSEM_GENERIC_SPINLOCK
73 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
75 config GENERIC_BUG_RELATIVE_POINTERS
78 config GENERIC_CALIBRATE_DELAY
84 config GENERIC_HWEIGHT
101 This selects the base ISA that this kernel will traget and must match
107 select GENERIC_LIB_ASHLDI3
108 select GENERIC_LIB_ASHRDI3
109 select GENERIC_LIB_LSHRDI3
110 select GENERIC_LIB_UCMPDI2
111 select GENERIC_LIB_UMODDI3
116 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
117 select HAVE_FUNCTION_TRACER
118 select HAVE_FUNCTION_GRAPH_TRACER
119 select HAVE_FTRACE_MCOUNT_RECORD
120 select HAVE_DYNAMIC_FTRACE
121 select HAVE_DYNAMIC_FTRACE_WITH_REGS
126 # We must be able to map all physical memory into the kernel, but the compiler
127 # is still a bit more efficient when generating code if it's setup in a manner
128 # such that it can only map 2GiB of memory.
130 prompt "Kernel Code Model"
131 default CMODEL_MEDLOW if 32BIT
132 default CMODEL_MEDANY if 64BIT
135 bool "medium low code model"
137 bool "medium any code model"
140 config MODULE_SECTIONS
142 select HAVE_MOD_ARCH_SPECIFIC
145 prompt "Maximum Physical Memory"
146 default MAXPHYSMEM_2GB if 32BIT
147 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
148 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
150 config MAXPHYSMEM_2GB
152 config MAXPHYSMEM_128GB
153 depends on 64BIT && CMODEL_MEDANY
154 select MODULE_SECTIONS if MODULES
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.
200 menu "supported PMU type"
201 depends on PERF_EVENTS
203 config RISCV_BASE_PMU
204 bool "Base Performance Monitoring Unit"
207 A base PMU that serves as a reference implementation and has limited
208 feature of perf. It can run on any RISC-V machines so serves as the
209 fallback, but this option can also be disable to reduce kernel size.
217 Say N here if you want to disable all floating-point related procedure
220 If you don't know what to do here, say Y.
224 menu "Kernel features"
226 source "kernel/Kconfig.hz"
233 bool "Built-in kernel command line"
235 For most platforms, it is firmware or second stage bootloader
236 that by default specifies the kernel command line options.
237 However, it might be necessary or advantageous to either override
238 the default kernel command line or add a few extra options to it.
239 For such cases, this option allows hardcoding command line options
240 directly into the kernel.
242 For that, choose 'Y' here and fill in the extra boot parameters
245 The built-in options will be concatenated to the default command
246 line if CMDLINE_FORCE is set to 'N'. Otherwise, the default
247 command line will be ignored and replaced by the built-in string.
250 string "Built-in kernel command string"
251 depends on CMDLINE_BOOL
254 Supply command-line options at build time by entering them here.
257 bool "Built-in command line overrides bootloader arguments"
258 depends on CMDLINE_BOOL
260 Set this option to 'Y' to have the kernel ignore the bootloader
261 or firmware command line. Instead, the built-in command line
262 will be used exclusively.
264 If you don't know what to do here, say N.
274 This feature enables support for PCI bus system. If you say Y
275 here, the kernel will include drivers and infrastructure code
276 to support PCI bus devices.
278 If you don't know what to do here, say Y.
283 config PCI_DOMAINS_GENERIC
286 source "drivers/pci/Kconfig"
290 menu "Power management options"
292 source kernel/power/Kconfig