xref: /openbmc/linux/arch/riscv/Kconfig (revision 752beb5e)
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 ARCH_HAS_MMIOWB
52	select HAVE_EBPF_JIT if 64BIT
53
54config MMU
55	def_bool y
56
57config ZONE_DMA32
58	bool
59	default y if 64BIT
60
61config PAGE_OFFSET
62	hex
63	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
64	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
65	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
66
67config STACKTRACE_SUPPORT
68	def_bool y
69
70config TRACE_IRQFLAGS_SUPPORT
71	def_bool y
72
73config GENERIC_BUG
74	def_bool y
75	depends on BUG
76	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
77
78config GENERIC_BUG_RELATIVE_POINTERS
79	bool
80
81config GENERIC_CALIBRATE_DELAY
82	def_bool y
83
84config GENERIC_CSUM
85	def_bool y
86
87config GENERIC_HWEIGHT
88	def_bool y
89
90config FIX_EARLYCON_MEM
91	def_bool y
92
93config PGTABLE_LEVELS
94	int
95	default 3 if 64BIT
96	default 2
97
98menu "Platform type"
99
100choice
101	prompt "Base ISA"
102	default ARCH_RV64I
103	help
104	  This selects the base ISA that this kernel will target and must match
105	  the target platform.
106
107config ARCH_RV32I
108	bool "RV32I"
109	select 32BIT
110	select GENERIC_LIB_ASHLDI3
111	select GENERIC_LIB_ASHRDI3
112	select GENERIC_LIB_LSHRDI3
113	select GENERIC_LIB_UCMPDI2
114
115config ARCH_RV64I
116	bool "RV64I"
117	select 64BIT
118	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
119	select HAVE_FUNCTION_TRACER
120	select HAVE_FUNCTION_GRAPH_TRACER
121	select HAVE_FTRACE_MCOUNT_RECORD
122	select HAVE_DYNAMIC_FTRACE
123	select HAVE_DYNAMIC_FTRACE_WITH_REGS
124	select SWIOTLB
125
126endchoice
127
128# We must be able to map all physical memory into the kernel, but the compiler
129# is still a bit more efficient when generating code if it's setup in a manner
130# such that it can only map 2GiB of memory.
131choice
132	prompt "Kernel Code Model"
133	default CMODEL_MEDLOW if 32BIT
134	default CMODEL_MEDANY if 64BIT
135
136	config CMODEL_MEDLOW
137		bool "medium low code model"
138	config CMODEL_MEDANY
139		bool "medium any code model"
140endchoice
141
142config MODULE_SECTIONS
143	bool
144	select HAVE_MOD_ARCH_SPECIFIC
145
146choice
147	prompt "Maximum Physical Memory"
148	default MAXPHYSMEM_2GB if 32BIT
149	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
150	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
151
152	config MAXPHYSMEM_2GB
153		bool "2GiB"
154	config MAXPHYSMEM_128GB
155		depends on 64BIT && CMODEL_MEDANY
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
234	string "Built-in kernel command line"
235	help
236	  For most platforms, the arguments for the kernel's command line
237	  are provided at run-time, during boot. However, there are cases
238	  where either no arguments are being provided or the provided
239	  arguments are insufficient or even invalid.
240
241	  When that occurs, it is possible to define a built-in command
242	  line here and choose how the kernel should use it later on.
243
244choice
245	prompt "Built-in command line usage" if CMDLINE != ""
246	default CMDLINE_FALLBACK
247	help
248	  Choose how the kernel will handle the provided built-in command
249	  line.
250
251config CMDLINE_FALLBACK
252	bool "Use bootloader kernel arguments if available"
253	help
254	  Use the built-in command line as fallback in case we get nothing
255	  during boot. This is the default behaviour.
256
257config CMDLINE_EXTEND
258	bool "Extend bootloader kernel arguments"
259	help
260	  The command-line arguments provided during boot will be
261	  appended to the built-in command line. This is useful in
262	  cases where the provided arguments are insufficient and
263	  you don't want to or cannot modify them.
264
265
266config CMDLINE_FORCE
267	bool "Always use the default kernel command string"
268	help
269	  Always use the built-in command line, even if we get one during
270	  boot. This is useful in case you need to override the provided
271	  command line on systems where you don't have or want control
272	  over it.
273
274endchoice
275
276endmenu
277
278menu "Power management options"
279
280source "kernel/power/Kconfig"
281
282endmenu
283