1 # SPDX-License-Identifier: GPL-2.0-only
3 # For a description of the syntax of this configuration file,
4 # see Documentation/kbuild/kconfig-language.rst.
15 # even on 32-bit, physical (and DMA) addresses are > 32-bits
16 select PHYS_ADDR_T_64BIT
18 select OF_EARLY_FLATTREE
20 select ARCH_HAS_BINFMT_FLAT
21 select ARCH_WANT_FRAME_POINTERS
22 select CLONE_BACKWARDS
24 select GENERIC_CLOCKEVENTS
25 select GENERIC_CPU_DEVICES
26 select GENERIC_IRQ_SHOW
27 select GENERIC_PCI_IOMAP
28 select GENERIC_SCHED_CLOCK
29 select GENERIC_STRNCPY_FROM_USER
30 select GENERIC_STRNLEN_USER
31 select GENERIC_SMP_IDLE_THREAD
32 select GENERIC_ATOMIC64 if !64BIT
33 select HAVE_ARCH_AUDITSYSCALL
34 select HAVE_ASM_MODVERSIONS
35 select HAVE_MEMBLOCK_NODE_MAP
36 select HAVE_DMA_CONTIGUOUS
37 select HAVE_FUTEX_CMPXCHG if FUTEX
38 select HAVE_PERF_EVENTS
40 select HAVE_PERF_USER_STACK_DUMP
41 select HAVE_SYSCALL_TRACEPOINTS
44 select SYSCTL_EXCEPTION_TRACE
45 select HAVE_ARCH_TRACEHOOK
47 select MODULES_USE_ELF_RELA if MODULES
48 select MODULE_SECTIONS if MODULES
49 select THREAD_INFO_IN_TASK
50 select PCI_DOMAINS_GENERIC if PCI
53 select GENERIC_IRQ_MULTI_HANDLER
54 select GENERIC_ARCH_TOPOLOGY if SMP
55 select ARCH_HAS_PTE_SPECIAL
56 select ARCH_HAS_MMIOWB
57 select HAVE_EBPF_JIT if 64BIT
59 select ARCH_HAS_GIGANTIC_PAGE
60 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
61 select SPARSEMEM_STATIC if 32BIT
62 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
63 select HAVE_ARCH_MMAP_RND_BITS
65 config ARCH_MMAP_RND_BITS_MIN
69 # max bits determined by the following formula:
70 # VA_BITS - PAGE_SHIFT - 3
71 config ARCH_MMAP_RND_BITS_MAX
72 default 24 if 64BIT # SV39 based
75 # set if we run in machine mode, cleared if we run in supervisor mode
79 # set if we are running in S-mode and can use SBI calls
82 depends on !RISCV_M_MODE
104 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
105 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
106 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
108 config ARCH_FLATMEM_ENABLE
111 config ARCH_SPARSEMEM_ENABLE
113 select SPARSEMEM_VMEMMAP_ENABLE
115 config ARCH_SELECT_MEMORY_MODEL
116 def_bool ARCH_SPARSEMEM_ENABLE
118 config ARCH_WANT_GENERAL_HUGETLB
121 config SYS_SUPPORTS_HUGETLBFS
124 config STACKTRACE_SUPPORT
127 config TRACE_IRQFLAGS_SUPPORT
133 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
135 config GENERIC_BUG_RELATIVE_POINTERS
138 config GENERIC_CALIBRATE_DELAY
144 config GENERIC_HWEIGHT
147 config FIX_EARLYCON_MEM
150 config PGTABLE_LEVELS
155 source "arch/riscv/Kconfig.socs"
163 This selects the base ISA that this kernel will target and must match
169 select GENERIC_LIB_ASHLDI3
170 select GENERIC_LIB_ASHRDI3
171 select GENERIC_LIB_LSHRDI3
172 select GENERIC_LIB_UCMPDI2
177 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
178 select HAVE_FUNCTION_TRACER
179 select HAVE_FUNCTION_GRAPH_TRACER
180 select HAVE_FTRACE_MCOUNT_RECORD
181 select HAVE_DYNAMIC_FTRACE
182 select HAVE_DYNAMIC_FTRACE_WITH_REGS
187 # We must be able to map all physical memory into the kernel, but the compiler
188 # is still a bit more efficient when generating code if it's setup in a manner
189 # such that it can only map 2GiB of memory.
191 prompt "Kernel Code Model"
192 default CMODEL_MEDLOW if 32BIT
193 default CMODEL_MEDANY if 64BIT
196 bool "medium low code model"
198 bool "medium any code model"
201 config MODULE_SECTIONS
203 select HAVE_MOD_ARCH_SPECIFIC
206 prompt "Maximum Physical Memory"
207 default MAXPHYSMEM_2GB if 32BIT
208 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
209 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
211 config MAXPHYSMEM_2GB
213 config MAXPHYSMEM_128GB
214 depends on 64BIT && CMODEL_MEDANY
220 bool "Symmetric Multi-Processing"
222 This enables support for systems with more than one CPU. If
223 you say N here, the kernel will run on single and
224 multiprocessor machines, but will use only one CPU of a
225 multiprocessor machine. If you say Y here, the kernel will run
226 on many, but not all, single processor machines. On a single
227 processor machine, the kernel will run faster if you say N
230 If you don't know what to do here, say N.
233 int "Maximum number of CPUs (2-32)"
248 bool "Emit compressed instructions when building Linux"
251 Adds "C" to the ISA subsets that the toolchain is allowed to emit
252 when building Linux, which results in compressed instructions in the
255 If you don't know what to do here, say Y.
257 menu "supported PMU type"
258 depends on PERF_EVENTS
260 config RISCV_BASE_PMU
261 bool "Base Performance Monitoring Unit"
264 A base PMU that serves as a reference implementation and has limited
265 feature of perf. It can run on any RISC-V machines so serves as the
266 fallback, but this option can also be disable to reduce kernel size.
274 Say N here if you want to disable all floating-point related procedure
277 If you don't know what to do here, say Y.
281 menu "Kernel features"
283 source "kernel/Kconfig.hz"
290 string "Built-in kernel command line"
292 For most platforms, the arguments for the kernel's command line
293 are provided at run-time, during boot. However, there are cases
294 where either no arguments are being provided or the provided
295 arguments are insufficient or even invalid.
297 When that occurs, it is possible to define a built-in command
298 line here and choose how the kernel should use it later on.
301 prompt "Built-in command line usage" if CMDLINE != ""
302 default CMDLINE_FALLBACK
304 Choose how the kernel will handle the provided built-in command
307 config CMDLINE_FALLBACK
308 bool "Use bootloader kernel arguments if available"
310 Use the built-in command line as fallback in case we get nothing
311 during boot. This is the default behaviour.
313 config CMDLINE_EXTEND
314 bool "Extend bootloader kernel arguments"
316 The command-line arguments provided during boot will be
317 appended to the built-in command line. This is useful in
318 cases where the provided arguments are insufficient and
319 you don't want to or cannot modify them.
323 bool "Always use the default kernel command string"
325 Always use the built-in command line, even if we get one during
326 boot. This is useful in case you need to override the provided
327 command line on systems where you don't have or want control
334 menu "Power management options"
336 source "kernel/power/Kconfig"