xref: /linux/arch/riscv/Kconfig (revision 2209fda323e2fd2a2d0885595fd5097717f8d2aa)
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
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
37	select IRQ_DOMAIN
38	select NO_BOOTMEM
39	select RISCV_ISA_A if SMP
40	select SPARSE_IRQ
41	select SYSCTL_EXCEPTION_TRACE
42	select HAVE_ARCH_TRACEHOOK
43	select MODULES_USE_ELF_RELA if MODULES
44	select THREAD_INFO_IN_TASK
45	select RISCV_TIMER
46	select GENERIC_IRQ_MULTI_HANDLER
47	select ARCH_HAS_PTE_SPECIAL
48
49config MMU
50	def_bool y
51
52config ZONE_DMA32
53	bool
54	default y if 64BIT
55
56config PAGE_OFFSET
57	hex
58	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
59	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
60	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
61
62config STACKTRACE_SUPPORT
63	def_bool y
64
65config TRACE_IRQFLAGS_SUPPORT
66	def_bool y
67
68config RWSEM_GENERIC_SPINLOCK
69	def_bool y
70
71config GENERIC_BUG
72	def_bool y
73	depends on BUG
74	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
75
76config GENERIC_BUG_RELATIVE_POINTERS
77	bool
78
79config GENERIC_CALIBRATE_DELAY
80	def_bool y
81
82config GENERIC_CSUM
83	def_bool y
84
85config GENERIC_HWEIGHT
86	def_bool y
87
88config PGTABLE_LEVELS
89	int
90	default 3 if 64BIT
91	default 2
92
93config HAVE_KPROBES
94	def_bool n
95
96menu "Platform type"
97
98choice
99	prompt "Base ISA"
100	default ARCH_RV64I
101	help
102	  This selects the base ISA that this kernel will traget and must match
103	  the target platform.
104
105config ARCH_RV32I
106	bool "RV32I"
107	select 32BIT
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
113
114config ARCH_RV64I
115	bool "RV64I"
116	select 64BIT
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
123	select SWIOTLB
124
125endchoice
126
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.
130choice
131	prompt "Kernel Code Model"
132	default CMODEL_MEDLOW if 32BIT
133	default CMODEL_MEDANY if 64BIT
134
135	config CMODEL_MEDLOW
136		bool "medium low code model"
137	config CMODEL_MEDANY
138		bool "medium any code model"
139endchoice
140
141config MODULE_SECTIONS
142	bool
143	select HAVE_MOD_ARCH_SPECIFIC
144
145choice
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
150
151	config MAXPHYSMEM_2GB
152		bool "2GiB"
153	config MAXPHYSMEM_128GB
154		depends on 64BIT && CMODEL_MEDANY
155		select MODULE_SECTIONS if MODULES
156		bool "128GiB"
157endchoice
158
159
160config SMP
161	bool "Symmetric Multi-Processing"
162	help
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
169	  here.
170
171	  If you don't know what to do here, say N.
172
173config NR_CPUS
174	int "Maximum number of CPUs (2-32)"
175	range 2 32
176	depends on SMP
177	default "8"
178
179choice
180	prompt "CPU Tuning"
181	default TUNE_GENERIC
182
183config TUNE_GENERIC
184	bool "generic"
185
186endchoice
187
188config RISCV_ISA_C
189	bool "Emit compressed instructions when building Linux"
190	default y
191	help
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
194	   Linux binary.
195
196	   If you don't know what to do here, say Y.
197
198config RISCV_ISA_A
199	def_bool y
200
201menu "supported PMU type"
202	depends on PERF_EVENTS
203
204config RISCV_BASE_PMU
205	bool "Base Performance Monitoring Unit"
206	def_bool y
207	help
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.
211
212endmenu
213
214config FPU
215	bool "FPU support"
216	default y
217	help
218	  Say N here if you want to disable all floating-point related procedure
219	  in the kernel.
220
221	  If you don't know what to do here, say Y.
222
223endmenu
224
225menu "Kernel features"
226
227source "kernel/Kconfig.hz"
228
229endmenu
230
231menu "Boot options"
232
233config CMDLINE_BOOL
234	bool "Built-in kernel command line"
235	help
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.
242
243	  For that, choose 'Y' here and fill in the extra boot parameters
244	  in CONFIG_CMDLINE.
245
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.
249
250config CMDLINE
251	string "Built-in kernel command string"
252	depends on CMDLINE_BOOL
253	default ""
254	help
255	  Supply command-line options at build time by entering them here.
256
257config CMDLINE_FORCE
258	bool "Built-in command line overrides bootloader arguments"
259	depends on CMDLINE_BOOL
260	help
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.
264
265	  If you don't know what to do here, say N.
266
267endmenu
268
269menu "Bus support"
270
271config PCI
272	bool "PCI support"
273	select PCI_MSI
274	help
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.
278
279	  If you don't know what to do here, say Y.
280
281config PCI_DOMAINS
282	def_bool PCI
283
284config PCI_DOMAINS_GENERIC
285	def_bool PCI
286
287source "drivers/pci/Kconfig"
288
289endmenu
290
291menu "Power management options"
292
293source kernel/power/Kconfig
294
295endmenu
296