1 # Target definition: architecture, optimisations, etc...
5 comment "General target options"
9 default "arm" if ARCH_ARM
10 default "mips" if ARCH_MIPS
11 default "x86" if ARCH_x86
12 default "x86_64" if ARCH_x86_64
16 prompt "Target architecture:"
22 select ARCH_SUPPORTS_BOTH_ENDIAN
23 select ARCH_SUPPORTS_LIBFLOAT
28 select ARCH_SUPPORTS_BOTH_ENDIAN
33 select ARCH_SUPPORTS_LIBFLOAT
41 config ARCH_SUPPORTS_BOTH_ENDIAN
48 depends on ARCH_SUPPORTS_BOTH_ENDIAN
56 prompt "Little endian"
60 comment "Target optimisations"
64 prompt "Achitecture level"
67 GCC uses this name to determine what kind of instructions it can emit
68 when generating assembly code. This option can be used in conjunction
69 with or instead of the ARCH_CPU option (above), or a (command-line)
72 This is the configuration flag --with-arch=XXXX, and the runtime flag
75 Pick a value from the gcc manual for your choosen gcc version and your
78 Leave blank if you don't know, or if your target architecture does not
83 prompt "Generate code for the specific ABI"
86 Generate code for the given ABI.
88 This is the configuration flag --with-abi=XXXX, and the runtime flag
91 Pick a value from the gcc manual for your choosen gcc version and your
94 Leave blank if you don't know, or if your target architecutre does not
99 prompt "Emit assembly for CPU"
102 This specifies the name of the target processor. GCC uses this name
103 to determine what kind of instructions it can emit when generating
106 This is the configuration flag --with-cpu=XXXX, and the runtime flag
109 Pick a value from the gcc manual for your choosen gcc version and your
112 Leave blank if you don't know, or if your target architecture does not
117 prompt "Tune for CPU"
120 This option is very similar to the ARCH_CPU option (above), except
121 that instead of specifying the actual target processor type, and hence
122 restricting which instructions can be used, it specifies that GCC should
123 tune the performance of the code as if the target were of the type
124 specified in this option, but still choosing the instructions that it
125 will generate based on the cpu specified by the ARCH_CPU option
126 (above), or a (command-line) -mcpu= option.
128 This is the configuration flag --with-tune=XXXX, and the runtime flag
131 Pick a value from the gcc manual for your choosen gcc version and your
134 Leave blank if you don't know, or if your target architecture does not
139 prompt "Use specific FPU"
142 On some targets (eg. ARM), you can specify the kind of FPU to emit
145 This is the configuration flag --with-fpu=XXX, and the runtime flag
148 See below wether to actually emit FP opcodes, or to emulate them.
150 Pick a value from the gcc manual for your choosen gcc version and your
153 Leave blank if you don't know, or if your target architecture does not
158 prompt "Floating point:"
162 prompt "hardware (FPU)"
164 Emit hardware floating point opcodes.
166 If you've got a processor with a FPU, then you want that.
167 If your hardware has no FPU, you still can use HW floating point, but
168 need to compile support for FPU emulation in your kernel. Needless to
169 say that emulating the FPU is /slooowwwww/...
171 One situation you'd want HW floating point without a FPU is if you get
172 binary blobs from different vendors that are compiling this way and
173 can't (don't wan't to) change.
179 Do not emit any hardware floating point opcode.
181 If your processor has no FPU, then you most probably want this, as it
182 is faster than emulating the FPU in the kernel.
186 config ARCH_SUPPORTS_LIBFLOAT
190 config ARCH_FLOAT_SW_LIBFLOAT
192 prompt "Use libfloat"
194 depends on ARCH_FLOAT_SW && ARCH_SUPPORTS_LIBFLOAT
196 For those targets upporting it, you can use libfloat for the software
197 floating point emulation.
199 Note that some versions of gcc have support code that supersedes libfloat,
200 while others don't. Known version of gcc that don't have support code are
201 versions prior to 3.0, and version above 4.0.
203 You should check gcc before deciding to use libfloat.
205 config LIBFLOAT_VERSION
207 default "990616.orig"
208 depends on ARCH_FLOAT_SW_LIBFLOAT
212 prompt "Target CFLAGS"
215 Used to add specific options when compiling libraries of the toolchain,
216 that will run on the target (eg. libc.so).
218 Note that the options above for CPU, tune, arch and FPU will be
219 automaticaly used. You don't need to specify them here.
221 Leave blank if you don't know better.