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
39 select RISCV_ISA_A if SMP
41 select SYSCTL_EXCEPTION_TRACE
42 select HAVE_ARCH_TRACEHOOK
43 select MODULES_USE_ELF_RELA if MODULES
44 select THREAD_INFO_IN_TASK
46 select GENERIC_IRQ_MULTI_HANDLER
47 select ARCH_HAS_PTE_SPECIAL
58 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
59 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
60 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
62 config STACKTRACE_SUPPORT
65 config TRACE_IRQFLAGS_SUPPORT
68 config RWSEM_GENERIC_SPINLOCK
74 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
76 config GENERIC_BUG_RELATIVE_POINTERS
79 config GENERIC_CALIBRATE_DELAY
85 config GENERIC_HWEIGHT
102 This selects the base ISA that this kernel will traget and must match
108 select GENERIC_LIB_ASHLDI3
109 select GENERIC_LIB_ASHRDI3
110 select GENERIC_LIB_LSHRDI3
111 select GENERIC_LIB_UCMPDI2
112 select GENERIC_LIB_UMODDI3
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 bool "Built-in kernel command line"
236 For most platforms, it is firmware or second stage bootloader
237 that by default specifies the kernel command line options.
238 However, it might be necessary or advantageous to either override
239 the default kernel command line or add a few extra options to it.
240 For such cases, this option allows hardcoding command line options
241 directly into the kernel.
243 For that, choose 'Y' here and fill in the extra boot parameters
246 The built-in options will be concatenated to the default command
247 line if CMDLINE_FORCE is set to 'N'. Otherwise, the default
248 command line will be ignored and replaced by the built-in string.
251 string "Built-in kernel command string"
252 depends on CMDLINE_BOOL
255 Supply command-line options at build time by entering them here.
258 bool "Built-in command line overrides bootloader arguments"
259 depends on CMDLINE_BOOL
261 Set this option to 'Y' to have the kernel ignore the bootloader
262 or firmware command line. Instead, the built-in command line
263 will be used exclusively.
265 If you don't know what to do here, say N.
275 This feature enables support for PCI bus system. If you say Y
276 here, the kernel will include drivers and infrastructure code
277 to support PCI bus devices.
279 If you don't know what to do here, say Y.
284 config PCI_DOMAINS_GENERIC
287 source "drivers/pci/Kconfig"
291 menu "Power management options"
293 source kernel/power/Kconfig