1 # Target definition: architecture, optimisations, etc...
8 # Pre-declare target optimisation variables
9 config ARCH_SUPPORTS_BOTH_MMU
10 config ARCH_SUPPORTS_BOTH_ENDIAN
11 config ARCH_SUPPORTS_32
12 config ARCH_SUPPORTS_64
13 config ARCH_SUPPORT_ARCH
14 config ARCH_SUPPORT_ABI
15 config ARCH_SUPPORT_CPU
16 config ARCH_SUPPORT_TUNE
17 config ARCH_SUPPORT_FPU
19 config ARCH_DEFAULT_HAS_MMU
20 config ARCH_DEFAULT_BE
21 config ARCH_DEFAULT_LE
22 config ARCH_DEFAULT_32
23 config ARCH_DEFAULT_64
40 comment "General target options"
42 source "config.gen/arch.in"
44 #--------------------------------------
45 config ARCH_SUPPORTS_BOTH_MMU
49 config ARCH_DEFAULT_HAS_MMU
55 prompt "Use the MMU" if ARCH_SUPPORTS_BOTH_MMU
56 default n if ! ARCH_DEFAULT_HAS_MMU
57 default y if ARCH_DEFAULT_HAS_MMU
59 If your architecture has an MMU and you want to use it,
62 OTOH, if you don't want to use the MMU, or your arch
63 lacks an MMU, say 'N' here.
65 Note that some architectures (eg. ARM) has variants that
66 lacks an MMU (eg. ARM Cortex-M3), while other variants
67 have one (eg. ARM Cortex-A8).
69 #--------------------------------------
70 config ARCH_SUPPORTS_BOTH_ENDIAN
74 config ARCH_DEFAULT_BE
78 config ARCH_DEFAULT_LE
85 depends on ARCH_SUPPORTS_BOTH_ENDIAN
86 default ARCH_BE if ARCH_DEFAULT_BE
87 default ARCH_LE if ARCH_DEFAULT_LE
95 prompt "Little endian"
99 #--------------------------------------
100 config ARCH_SUPPORTS_32
104 config ARCH_SUPPORTS_64
108 config ARCH_DEFAULT_32
112 config ARCH_DEFAULT_64
118 default "32" if ARCH_32
119 default "64" if ARCH_64
124 default ARCH_32 if ARCH_DEFAULT_32
125 default ARCH_64 if ARCH_DEFAULT_64
130 depends on ARCH_SUPPORTS_32
135 depends on ARCH_SUPPORTS_64
139 source "config.gen/arch.in.2"
141 #--------------------------------------
142 comment "Target optimisations"
144 config ARCH_SUPPORT_ARCH
148 config ARCH_SUPPORT_ABI
152 config ARCH_SUPPORT_CPU
156 config ARCH_SUPPORT_TUNE
160 config ARCH_SUPPORT_FPU
166 prompt "Architecture level"
167 depends on ARCH_SUPPORT_ARCH
170 GCC uses this name to determine what kind of instructions it can emit
171 when generating assembly code. This option can be used in conjunction
172 with or instead of the ARCH_CPU option (above), or a (command-line)
175 This is the configuration flag --with-arch=XXXX, and the runtime flag
178 Pick a value from the gcc manual for your choosen gcc version and your
181 Leave blank if you don't know, or if your target architecture does not
186 prompt "Generate code for the specific ABI"
187 depends on ARCH_SUPPORT_ABI
190 Generate code for the given ABI.
192 This is the configuration flag --with-abi=XXXX, and the runtime flag
195 Pick a value from the gcc manual for your choosen gcc version and your
198 Leave blank if you don't know, or if your target architecutre does not
203 prompt "Emit assembly for CPU"
204 depends on ARCH_SUPPORT_CPU
207 This specifies the name of the target processor. GCC uses this name
208 to determine what kind of instructions it can emit when generating
211 This is the configuration flag --with-cpu=XXXX, and the runtime flag
214 Pick a value from the gcc manual for your choosen gcc version and your
217 Leave blank if you don't know, or if your target architecture does not
222 prompt "Tune for CPU"
223 depends on ARCH_SUPPORT_TUNE
226 This option is very similar to the ARCH_CPU option (above), except
227 that instead of specifying the actual target processor type, and hence
228 restricting which instructions can be used, it specifies that GCC should
229 tune the performance of the code as if the target were of the type
230 specified in this option, but still choosing the instructions that it
231 will generate based on the cpu specified by the ARCH_CPU option
232 (above), or a (command-line) -mcpu= option.
234 This is the configuration flag --with-tune=XXXX, and the runtime flag
237 Pick a value from the gcc manual for your choosen gcc version and your
240 Leave blank if you don't know, or if your target architecture does not
245 prompt "Use specific FPU"
246 depends on ARCH_SUPPORT_FPU
249 On some targets (eg. ARM), you can specify the kind of FPU to emit
252 This is the configuration flag --with-fpu=XXX, and the runtime flag
255 See below wether to actually emit FP opcodes, or to emulate them.
257 Pick a value from the gcc manual for your choosen gcc version and your
260 Leave blank if you don't know, or if your target architecture does not
265 prompt "Floating point:"
269 prompt "hardware (FPU)"
271 Emit hardware floating point opcodes.
273 If you've got a processor with a FPU, then you want that.
274 If your hardware has no FPU, you still can use HW floating point, but
275 need to compile support for FPU emulation in your kernel. Needless to
276 say that emulating the FPU is /slooowwwww/...
278 One situation you'd want HW floating point without a FPU is if you get
279 binary blobs from different vendors that are compiling this way and
280 can't (don't wan't to) change.
286 Do not emit any hardware floating point opcode.
288 If your processor has no FPU, then you most probably want this, as it
289 is faster than emulating the FPU in the kernel.
295 prompt "Target CFLAGS"
298 Used to add specific options when compiling libraries of the toolchain,
299 that will run on the target (eg. libc.so).
301 Note that the options above for ARCH, ABI, CPU, TUNE and FPU will be
302 automaticaly used. You don't need to specify them here.
304 Leave blank if you don't know better.
306 config TARGET_LDFLAGS
308 prompt "Target LDFLAGS"
311 Used to add specific options when linking libraries of the toolchain,
312 that will run on your target.
314 Leave blank if you don't know better.