xref: /linux/arch/riscv/Kconfig (revision 8636a1f9677db4f883f29a072f401303acfc2edd)
1#
2# For a description of the syntax of this configuration file,
3# see Documentation/kbuild/kconfig-language.txt.
4#
5
6config 64BIT
7	bool
8
9config 32BIT
10	bool
11
12config RISCV
13	def_bool y
14	# even on 32-bit, physical (and DMA) addresses are > 32-bits
15	select PHYS_ADDR_T_64BIT
16	select OF
17	select OF_EARLY_FLATTREE
18	select OF_IRQ
19	select ARCH_WANT_FRAME_POINTERS
20	select CLONE_BACKWARDS
21	select COMMON_CLK
22	select DMA_DIRECT_OPS
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
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
36	select IRQ_DOMAIN
37	select RISCV_ISA_A if SMP
38	select SPARSE_IRQ
39	select SYSCTL_EXCEPTION_TRACE
40	select HAVE_ARCH_TRACEHOOK
41	select MODULES_USE_ELF_RELA if MODULES
42	select THREAD_INFO_IN_TASK
43	select RISCV_TIMER
44	select GENERIC_IRQ_MULTI_HANDLER
45	select ARCH_HAS_PTE_SPECIAL
46
47config MMU
48	def_bool y
49
50config ZONE_DMA32
51	bool
52	default y if 64BIT
53
54config PAGE_OFFSET
55	hex
56	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
57	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
58	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
59
60config STACKTRACE_SUPPORT
61	def_bool y
62
63config TRACE_IRQFLAGS_SUPPORT
64	def_bool y
65
66config RWSEM_GENERIC_SPINLOCK
67	def_bool y
68
69config GENERIC_BUG
70	def_bool y
71	depends on BUG
72	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
73
74config GENERIC_BUG_RELATIVE_POINTERS
75	bool
76
77config GENERIC_CALIBRATE_DELAY
78	def_bool y
79
80config GENERIC_CSUM
81	def_bool y
82
83config GENERIC_HWEIGHT
84	def_bool y
85
86config PGTABLE_LEVELS
87	int
88	default 3 if 64BIT
89	default 2
90
91config HAVE_KPROBES
92	def_bool n
93
94menu "Platform type"
95
96choice
97	prompt "Base ISA"
98	default ARCH_RV64I
99	help
100	  This selects the base ISA that this kernel will traget and must match
101	  the target platform.
102
103config ARCH_RV32I
104	bool "RV32I"
105	select 32BIT
106	select GENERIC_LIB_ASHLDI3
107	select GENERIC_LIB_ASHRDI3
108	select GENERIC_LIB_LSHRDI3
109	select GENERIC_LIB_UCMPDI2
110
111config ARCH_RV64I
112	bool "RV64I"
113	select 64BIT
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
120	select SWIOTLB
121
122endchoice
123
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.
127choice
128	prompt "Kernel Code Model"
129	default CMODEL_MEDLOW if 32BIT
130	default CMODEL_MEDANY if 64BIT
131
132	config CMODEL_MEDLOW
133		bool "medium low code model"
134	config CMODEL_MEDANY
135		bool "medium any code model"
136endchoice
137
138config MODULE_SECTIONS
139	bool
140	select HAVE_MOD_ARCH_SPECIFIC
141
142choice
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
147
148	config MAXPHYSMEM_2GB
149		bool "2GiB"
150	config MAXPHYSMEM_128GB
151		depends on 64BIT && CMODEL_MEDANY
152		select MODULE_SECTIONS if MODULES
153		bool "128GiB"
154endchoice
155
156
157config SMP
158	bool "Symmetric Multi-Processing"
159	help
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
166	  here.
167
168	  If you don't know what to do here, say N.
169
170config NR_CPUS
171	int "Maximum number of CPUs (2-32)"
172	range 2 32
173	depends on SMP
174	default "8"
175
176choice
177	prompt "CPU Tuning"
178	default TUNE_GENERIC
179
180config TUNE_GENERIC
181	bool "generic"
182
183endchoice
184
185config RISCV_ISA_C
186	bool "Emit compressed instructions when building Linux"
187	default y
188	help
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
191	   Linux binary.
192
193	   If you don't know what to do here, say Y.
194
195config RISCV_ISA_A
196	def_bool y
197
198menu "supported PMU type"
199	depends on PERF_EVENTS
200
201config RISCV_BASE_PMU
202	bool "Base Performance Monitoring Unit"
203	def_bool y
204	help
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.
208
209endmenu
210
211config FPU
212	bool "FPU support"
213	default y
214	help
215	  Say N here if you want to disable all floating-point related procedure
216	  in the kernel.
217
218	  If you don't know what to do here, say Y.
219
220endmenu
221
222menu "Kernel features"
223
224source "kernel/Kconfig.hz"
225
226endmenu
227
228menu "Boot options"
229
230config CMDLINE_BOOL
231	bool "Built-in kernel command line"
232	help
233	  For most platforms, it is firmware or second stage bootloader
234	  that by default specifies the kernel command line options.
235	  However, it might be necessary or advantageous to either override
236	  the default kernel command line or add a few extra options to it.
237	  For such cases, this option allows hardcoding command line options
238	  directly into the kernel.
239
240	  For that, choose 'Y' here and fill in the extra boot parameters
241	  in CONFIG_CMDLINE.
242
243	  The built-in options will be concatenated to the default command
244	  line if CMDLINE_FORCE is set to 'N'. Otherwise, the default
245	  command line will be ignored and replaced by the built-in string.
246
247config CMDLINE
248	string "Built-in kernel command string"
249	depends on CMDLINE_BOOL
250	default ""
251	help
252	  Supply command-line options at build time by entering them here.
253
254config CMDLINE_FORCE
255	bool "Built-in command line overrides bootloader arguments"
256	depends on CMDLINE_BOOL
257	help
258	  Set this option to 'Y' to have the kernel ignore the bootloader
259	  or firmware command line.  Instead, the built-in command line
260	  will be used exclusively.
261
262	  If you don't know what to do here, say N.
263
264endmenu
265
266menu "Bus support"
267
268config PCI
269	bool "PCI support"
270	select PCI_MSI
271	help
272	  This feature enables support for PCI bus system. If you say Y
273	  here, the kernel will include drivers and infrastructure code
274	  to support PCI bus devices.
275
276	  If you don't know what to do here, say Y.
277
278config PCI_DOMAINS
279	def_bool PCI
280
281config PCI_DOMAINS_GENERIC
282	def_bool PCI
283
284source "drivers/pci/Kconfig"
285
286endmenu
287
288menu "Power management options"
289
290source "kernel/power/Kconfig"
291
292endmenu
293