1# SPDX-License-Identifier: GPL-2.0-only 2# 3# For a description of the syntax of this configuration file, 4# see Documentation/kbuild/kconfig-language.rst. 5# 6 7config 64BIT 8 bool 9 10config 32BIT 11 bool 12 13config RISCV 14 def_bool y 15 select ARCH_CLOCKSOURCE_INIT 16 select ARCH_HAS_BINFMT_FLAT 17 select ARCH_HAS_DEBUG_VIRTUAL if MMU 18 select ARCH_HAS_DEBUG_WX 19 select ARCH_HAS_GCOV_PROFILE_ALL 20 select ARCH_HAS_GIGANTIC_PAGE 21 select ARCH_HAS_MMIOWB 22 select ARCH_HAS_PTE_SPECIAL 23 select ARCH_HAS_SET_DIRECT_MAP 24 select ARCH_HAS_SET_MEMORY 25 select ARCH_HAS_STRICT_KERNEL_RWX if MMU 26 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 27 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 28 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 29 select ARCH_WANT_FRAME_POINTERS 30 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 31 select CLONE_BACKWARDS 32 select COMMON_CLK 33 select EDAC_SUPPORT 34 select GENERIC_ARCH_TOPOLOGY if SMP 35 select GENERIC_ATOMIC64 if !64BIT 36 select GENERIC_CLOCKEVENTS 37 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 38 select GENERIC_IOREMAP 39 select GENERIC_IRQ_MULTI_HANDLER 40 select GENERIC_IRQ_SHOW 41 select GENERIC_PCI_IOMAP 42 select GENERIC_PTDUMP if MMU 43 select GENERIC_SCHED_CLOCK 44 select GENERIC_SMP_IDLE_THREAD 45 select GENERIC_STRNCPY_FROM_USER if MMU 46 select GENERIC_STRNLEN_USER if MMU 47 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 48 select HANDLE_DOMAIN_IRQ 49 select HAVE_ARCH_AUDITSYSCALL 50 select HAVE_ARCH_KASAN if MMU && 64BIT 51 select HAVE_ARCH_KGDB 52 select HAVE_ARCH_KGDB_QXFER_PKT 53 select HAVE_ARCH_MMAP_RND_BITS if MMU 54 select HAVE_ARCH_SECCOMP_FILTER 55 select HAVE_ARCH_TRACEHOOK 56 select HAVE_ASM_MODVERSIONS 57 select HAVE_DMA_CONTIGUOUS if MMU 58 select HAVE_EBPF_JIT if MMU 59 select HAVE_FUTEX_CMPXCHG if FUTEX 60 select HAVE_GENERIC_VDSO if MMU && 64BIT 61 select HAVE_PCI 62 select HAVE_PERF_EVENTS 63 select HAVE_PERF_REGS 64 select HAVE_PERF_USER_STACK_DUMP 65 select HAVE_SYSCALL_TRACEPOINTS 66 select IRQ_DOMAIN 67 select MODULES_USE_ELF_RELA if MODULES 68 select MODULE_SECTIONS if MODULES 69 select OF 70 select OF_EARLY_FLATTREE 71 select OF_IRQ 72 select PCI_DOMAINS_GENERIC if PCI 73 select PCI_MSI if PCI 74 select RISCV_INTC 75 select RISCV_TIMER 76 select SPARSEMEM_STATIC if 32BIT 77 select SPARSE_IRQ 78 select SYSCTL_EXCEPTION_TRACE 79 select THREAD_INFO_IN_TASK 80 81config ARCH_MMAP_RND_BITS_MIN 82 default 18 if 64BIT 83 default 8 84 85# max bits determined by the following formula: 86# VA_BITS - PAGE_SHIFT - 3 87config ARCH_MMAP_RND_BITS_MAX 88 default 24 if 64BIT # SV39 based 89 default 17 90 91# set if we run in machine mode, cleared if we run in supervisor mode 92config RISCV_M_MODE 93 bool 94 default !MMU 95 96# set if we are running in S-mode and can use SBI calls 97config RISCV_SBI 98 bool 99 depends on !RISCV_M_MODE 100 default y 101 102config MMU 103 bool "MMU-based Paged Memory Management Support" 104 default y 105 help 106 Select if you want MMU-based virtualised addressing space 107 support by paged memory management. If unsure, say 'Y'. 108 109config ZONE_DMA32 110 bool 111 default y if 64BIT 112 113config VA_BITS 114 int 115 default 32 if 32BIT 116 default 39 if 64BIT 117 118config PA_BITS 119 int 120 default 34 if 32BIT 121 default 56 if 64BIT 122 123config PAGE_OFFSET 124 hex 125 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB 126 default 0x80000000 if 64BIT && !MMU 127 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB 128 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB 129 130config ARCH_FLATMEM_ENABLE 131 def_bool y 132 133config ARCH_SPARSEMEM_ENABLE 134 def_bool y 135 depends on MMU 136 select SPARSEMEM_VMEMMAP_ENABLE 137 138config ARCH_SELECT_MEMORY_MODEL 139 def_bool ARCH_SPARSEMEM_ENABLE 140 141config ARCH_WANT_GENERAL_HUGETLB 142 def_bool y 143 144config ARCH_SUPPORTS_DEBUG_PAGEALLOC 145 def_bool y 146 147config SYS_SUPPORTS_HUGETLBFS 148 depends on MMU 149 def_bool y 150 151config STACKTRACE_SUPPORT 152 def_bool y 153 154config TRACE_IRQFLAGS_SUPPORT 155 def_bool y 156 157config GENERIC_BUG 158 def_bool y 159 depends on BUG 160 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 161 162config GENERIC_BUG_RELATIVE_POINTERS 163 bool 164 165config GENERIC_CALIBRATE_DELAY 166 def_bool y 167 168config GENERIC_CSUM 169 def_bool y 170 171config GENERIC_HWEIGHT 172 def_bool y 173 174config FIX_EARLYCON_MEM 175 def_bool MMU 176 177config PGTABLE_LEVELS 178 int 179 default 3 if 64BIT 180 default 2 181 182source "arch/riscv/Kconfig.socs" 183 184menu "Platform type" 185 186choice 187 prompt "Base ISA" 188 default ARCH_RV64I 189 help 190 This selects the base ISA that this kernel will target and must match 191 the target platform. 192 193config ARCH_RV32I 194 bool "RV32I" 195 select 32BIT 196 select GENERIC_LIB_ASHLDI3 197 select GENERIC_LIB_ASHRDI3 198 select GENERIC_LIB_LSHRDI3 199 select GENERIC_LIB_UCMPDI2 200 select MMU 201 202config ARCH_RV64I 203 bool "RV64I" 204 select 64BIT 205 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000 206 select HAVE_DYNAMIC_FTRACE if MMU 207 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE 208 select HAVE_FTRACE_MCOUNT_RECORD 209 select HAVE_FUNCTION_GRAPH_TRACER 210 select HAVE_FUNCTION_TRACER 211 select SWIOTLB if MMU 212 213endchoice 214 215# We must be able to map all physical memory into the kernel, but the compiler 216# is still a bit more efficient when generating code if it's setup in a manner 217# such that it can only map 2GiB of memory. 218choice 219 prompt "Kernel Code Model" 220 default CMODEL_MEDLOW if 32BIT 221 default CMODEL_MEDANY if 64BIT 222 223 config CMODEL_MEDLOW 224 bool "medium low code model" 225 config CMODEL_MEDANY 226 bool "medium any code model" 227endchoice 228 229config MODULE_SECTIONS 230 bool 231 select HAVE_MOD_ARCH_SPECIFIC 232 233choice 234 prompt "Maximum Physical Memory" 235 default MAXPHYSMEM_2GB if 32BIT 236 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW 237 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY 238 239 config MAXPHYSMEM_2GB 240 bool "2GiB" 241 config MAXPHYSMEM_128GB 242 depends on 64BIT && CMODEL_MEDANY 243 bool "128GiB" 244endchoice 245 246 247config SMP 248 bool "Symmetric Multi-Processing" 249 help 250 This enables support for systems with more than one CPU. If 251 you say N here, the kernel will run on single and 252 multiprocessor machines, but will use only one CPU of a 253 multiprocessor machine. If you say Y here, the kernel will run 254 on many, but not all, single processor machines. On a single 255 processor machine, the kernel will run faster if you say N 256 here. 257 258 If you don't know what to do here, say N. 259 260config NR_CPUS 261 int "Maximum number of CPUs (2-32)" 262 range 2 32 263 depends on SMP 264 default "8" 265 266config HOTPLUG_CPU 267 bool "Support for hot-pluggable CPUs" 268 depends on SMP 269 select GENERIC_IRQ_MIGRATION 270 help 271 272 Say Y here to experiment with turning CPUs off and on. CPUs 273 can be controlled through /sys/devices/system/cpu. 274 275 Say N if you want to disable CPU hotplug. 276 277choice 278 prompt "CPU Tuning" 279 default TUNE_GENERIC 280 281config TUNE_GENERIC 282 bool "generic" 283 284endchoice 285 286config RISCV_ISA_C 287 bool "Emit compressed instructions when building Linux" 288 default y 289 help 290 Adds "C" to the ISA subsets that the toolchain is allowed to emit 291 when building Linux, which results in compressed instructions in the 292 Linux binary. 293 294 If you don't know what to do here, say Y. 295 296menu "supported PMU type" 297 depends on PERF_EVENTS 298 299config RISCV_BASE_PMU 300 bool "Base Performance Monitoring Unit" 301 def_bool y 302 help 303 A base PMU that serves as a reference implementation and has limited 304 feature of perf. It can run on any RISC-V machines so serves as the 305 fallback, but this option can also be disable to reduce kernel size. 306 307endmenu 308 309config FPU 310 bool "FPU support" 311 default y 312 help 313 Say N here if you want to disable all floating-point related procedure 314 in the kernel. 315 316 If you don't know what to do here, say Y. 317 318endmenu 319 320menu "Kernel features" 321 322source "kernel/Kconfig.hz" 323 324config SECCOMP 325 bool "Enable seccomp to safely compute untrusted bytecode" 326 help 327 This kernel feature is useful for number crunching applications 328 that may need to compute untrusted bytecode during their 329 execution. By using pipes or other transports made available to 330 the process as file descriptors supporting the read/write 331 syscalls, it's possible to isolate those applications in 332 their own address space using seccomp. Once seccomp is 333 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 334 and the task is only allowed to execute a few safe syscalls 335 defined by each seccomp mode. 336 337config RISCV_SBI_V01 338 bool "SBI v0.1 support" 339 default y 340 depends on RISCV_SBI 341 help 342 This config allows kernel to use SBI v0.1 APIs. This will be 343 deprecated in future once legacy M-mode software are no longer in use. 344endmenu 345 346menu "Boot options" 347 348config CMDLINE 349 string "Built-in kernel command line" 350 help 351 For most platforms, the arguments for the kernel's command line 352 are provided at run-time, during boot. However, there are cases 353 where either no arguments are being provided or the provided 354 arguments are insufficient or even invalid. 355 356 When that occurs, it is possible to define a built-in command 357 line here and choose how the kernel should use it later on. 358 359choice 360 prompt "Built-in command line usage" if CMDLINE != "" 361 default CMDLINE_FALLBACK 362 help 363 Choose how the kernel will handle the provided built-in command 364 line. 365 366config CMDLINE_FALLBACK 367 bool "Use bootloader kernel arguments if available" 368 help 369 Use the built-in command line as fallback in case we get nothing 370 during boot. This is the default behaviour. 371 372config CMDLINE_EXTEND 373 bool "Extend bootloader kernel arguments" 374 help 375 The command-line arguments provided during boot will be 376 appended to the built-in command line. This is useful in 377 cases where the provided arguments are insufficient and 378 you don't want to or cannot modify them. 379 380 381config CMDLINE_FORCE 382 bool "Always use the default kernel command string" 383 help 384 Always use the built-in command line, even if we get one during 385 boot. This is useful in case you need to override the provided 386 command line on systems where you don't have or want control 387 over it. 388 389endchoice 390 391endmenu 392 393config BUILTIN_DTB 394 def_bool n 395 depends on RISCV_M_MODE 396 depends on OF 397 398menu "Power management options" 399 400source "kernel/power/Kconfig" 401 402endmenu 403