xref: /openbmc/linux/arch/riscv/Kconfig (revision 023e4163)
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 GENERIC_CLOCKEVENTS
23	select GENERIC_CPU_DEVICES
24	select GENERIC_IRQ_SHOW
25	select GENERIC_PCI_IOMAP
26	select GENERIC_SCHED_CLOCK
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_ARCH_AUDITSYSCALL
32	select HAVE_MEMBLOCK_NODE_MAP
33	select HAVE_DMA_CONTIGUOUS
34	select HAVE_FUTEX_CMPXCHG if FUTEX
35	select HAVE_PERF_EVENTS
36	select HAVE_SYSCALL_TRACEPOINTS
37	select IRQ_DOMAIN
38	select RISCV_ISA_A if SMP
39	select SPARSE_IRQ
40	select SYSCTL_EXCEPTION_TRACE
41	select HAVE_ARCH_TRACEHOOK
42	select HAVE_PCI
43	select MODULES_USE_ELF_RELA if MODULES
44	select MODULE_SECTIONS if MODULES
45	select THREAD_INFO_IN_TASK
46	select PCI_DOMAINS_GENERIC if PCI
47	select PCI_MSI if PCI
48	select RISCV_TIMER
49	select GENERIC_IRQ_MULTI_HANDLER
50	select ARCH_HAS_PTE_SPECIAL
51	select HAVE_EBPF_JIT if 64BIT
52
53config MMU
54	def_bool y
55
56config ZONE_DMA32
57	bool
58	default y if 64BIT
59
60config PAGE_OFFSET
61	hex
62	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
63	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
64	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
65
66config STACKTRACE_SUPPORT
67	def_bool y
68
69config TRACE_IRQFLAGS_SUPPORT
70	def_bool y
71
72config RWSEM_GENERIC_SPINLOCK
73	def_bool y
74
75config GENERIC_BUG
76	def_bool y
77	depends on BUG
78	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
79
80config GENERIC_BUG_RELATIVE_POINTERS
81	bool
82
83config GENERIC_CALIBRATE_DELAY
84	def_bool y
85
86config GENERIC_CSUM
87	def_bool y
88
89config GENERIC_HWEIGHT
90	def_bool y
91
92config FIX_EARLYCON_MEM
93	def_bool y
94
95config PGTABLE_LEVELS
96	int
97	default 3 if 64BIT
98	default 2
99
100menu "Platform type"
101
102choice
103	prompt "Base ISA"
104	default ARCH_RV64I
105	help
106	  This selects the base ISA that this kernel will target and must match
107	  the target platform.
108
109config ARCH_RV32I
110	bool "RV32I"
111	select 32BIT
112	select GENERIC_LIB_ASHLDI3
113	select GENERIC_LIB_ASHRDI3
114	select GENERIC_LIB_LSHRDI3
115	select GENERIC_LIB_UCMPDI2
116
117config ARCH_RV64I
118	bool "RV64I"
119	select 64BIT
120	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
121	select HAVE_FUNCTION_TRACER
122	select HAVE_FUNCTION_GRAPH_TRACER
123	select HAVE_FTRACE_MCOUNT_RECORD
124	select HAVE_DYNAMIC_FTRACE
125	select HAVE_DYNAMIC_FTRACE_WITH_REGS
126	select SWIOTLB
127
128endchoice
129
130# We must be able to map all physical memory into the kernel, but the compiler
131# is still a bit more efficient when generating code if it's setup in a manner
132# such that it can only map 2GiB of memory.
133choice
134	prompt "Kernel Code Model"
135	default CMODEL_MEDLOW if 32BIT
136	default CMODEL_MEDANY if 64BIT
137
138	config CMODEL_MEDLOW
139		bool "medium low code model"
140	config CMODEL_MEDANY
141		bool "medium any code model"
142endchoice
143
144config MODULE_SECTIONS
145	bool
146	select HAVE_MOD_ARCH_SPECIFIC
147
148choice
149	prompt "Maximum Physical Memory"
150	default MAXPHYSMEM_2GB if 32BIT
151	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
152	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
153
154	config MAXPHYSMEM_2GB
155		bool "2GiB"
156	config MAXPHYSMEM_128GB
157		depends on 64BIT && CMODEL_MEDANY
158		bool "128GiB"
159endchoice
160
161
162config SMP
163	bool "Symmetric Multi-Processing"
164	help
165	  This enables support for systems with more than one CPU.  If
166	  you say N here, the kernel will run on single and
167	  multiprocessor machines, but will use only one CPU of a
168	  multiprocessor machine. If you say Y here, the kernel will run
169	  on many, but not all, single processor machines. On a single
170	  processor machine, the kernel will run faster if you say N
171	  here.
172
173	  If you don't know what to do here, say N.
174
175config NR_CPUS
176	int "Maximum number of CPUs (2-32)"
177	range 2 32
178	depends on SMP
179	default "8"
180
181choice
182	prompt "CPU Tuning"
183	default TUNE_GENERIC
184
185config TUNE_GENERIC
186	bool "generic"
187
188endchoice
189
190config RISCV_ISA_C
191	bool "Emit compressed instructions when building Linux"
192	default y
193	help
194	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
195	   when building Linux, which results in compressed instructions in the
196	   Linux binary.
197
198	   If you don't know what to do here, say Y.
199
200config RISCV_ISA_A
201	def_bool y
202
203menu "supported PMU type"
204	depends on PERF_EVENTS
205
206config RISCV_BASE_PMU
207	bool "Base Performance Monitoring Unit"
208	def_bool y
209	help
210	  A base PMU that serves as a reference implementation and has limited
211	  feature of perf.  It can run on any RISC-V machines so serves as the
212	  fallback, but this option can also be disable to reduce kernel size.
213
214endmenu
215
216config FPU
217	bool "FPU support"
218	default y
219	help
220	  Say N here if you want to disable all floating-point related procedure
221	  in the kernel.
222
223	  If you don't know what to do here, say Y.
224
225endmenu
226
227menu "Kernel features"
228
229source "kernel/Kconfig.hz"
230
231endmenu
232
233menu "Boot options"
234
235config CMDLINE
236	string "Built-in kernel command line"
237	help
238	  For most platforms, the arguments for the kernel's command line
239	  are provided at run-time, during boot. However, there are cases
240	  where either no arguments are being provided or the provided
241	  arguments are insufficient or even invalid.
242
243	  When that occurs, it is possible to define a built-in command
244	  line here and choose how the kernel should use it later on.
245
246choice
247	prompt "Built-in command line usage" if CMDLINE != ""
248	default CMDLINE_FALLBACK
249	help
250	  Choose how the kernel will handle the provided built-in command
251	  line.
252
253config CMDLINE_FALLBACK
254	bool "Use bootloader kernel arguments if available"
255	help
256	  Use the built-in command line as fallback in case we get nothing
257	  during boot. This is the default behaviour.
258
259config CMDLINE_EXTEND
260	bool "Extend bootloader kernel arguments"
261	help
262	  The command-line arguments provided during boot will be
263	  appended to the built-in command line. This is useful in
264	  cases where the provided arguments are insufficient and
265	  you don't want to or cannot modify them.
266
267
268config CMDLINE_FORCE
269	bool "Always use the default kernel command string"
270	help
271	  Always use the built-in command line, even if we get one during
272	  boot. This is useful in case you need to override the provided
273	  command line on systems where you don't have or want control
274	  over it.
275
276endchoice
277
278endmenu
279
280menu "Power management options"
281
282source "kernel/power/Kconfig"
283
284endmenu
285