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"
62 prompt "Threading implentation to use:"
63 default THREADS_NPTL if LIBC_SUPPORT_NPTL
64 default THREADS_LINUXTHREADS if LIBC_SUPPORT_LINUXTHREADS && ! LIBC_SUPPORT_NPTL
65 default THREADS_NONE if ! LIBC_SUPPORT_LINUXTHREADS && ! LIBC_SUPPORT_NPTL
69 prompt "nptl (EXPERIMENTAL)"
70 depends on LIBC_SUPPORT_NPTL
71 depends on EXPERIMENTAL
73 config THREADS_LINUXTHREADS
76 depends on LIBC_SUPPORT_LINUXTHREADS
86 default "nptl" if THREADS_NPTL
87 default "linuxthreads" if THREADS_LINUXTHREADS
88 default "none" if THREADS_NONE
90 comment "Target optimisations"
94 prompt "Achitecture level"
97 GCC uses this name to determine what kind of instructions it can emit
98 when generating assembly code. This option can be used in conjunction
99 with or instead of the ARCH_CPU option (above), or a (command-line)
102 This is the configuration flag --with-arch=XXXX, and the runtime flag
105 Pick a value from the gcc manual for your choosen gcc version and your
108 Leave blank if you don't know, or if your target architecture does not
113 prompt "Generate code for the specific ABI"
116 Generate code for the given ABI.
118 This is the configuration flag --with-abi=XXXX, and the runtime flag
121 Pick a value from the gcc manual for your choosen gcc version and your
124 Leave blank if you don't know, or if your target architecutre does not
129 prompt "Emit assembly for CPU"
132 This specifies the name of the target ARM processor. GCC uses this name
133 to determine what kind of instructions it can emit when generating
136 This is the configuration flag --with-cpu=XXXX, and the runtime flag
139 Pick a value from the gcc manual for your choosen gcc version and your
142 Leave blank if you don't know, or if your target architecture does not
147 prompt "Tune for CPU"
150 This option is very similar to the ARCH_CPU option (above), except
151 that instead of specifying the actual target processor type, and hence
152 restricting which instructions can be used, it specifies that GCC should
153 tune the performance of the code as if the target were of the type
154 specified in this option, but still choosing the instructions that it
155 will generate based on the cpu specified by the ARCH_CPU option
156 (above), or a (command-line) -mcpu= option.
158 This is the configuration flag --with-tune=XXXX, and the runtime flag
161 Pick a value from the gcc manual for your choosen gcc version and your
164 Leave blank if you don't know, or if your target architecture does not
169 prompt "Use specific FPU"
172 On some targets (eg. ARM), you can specify the kind of FPU to emit
175 This is the configuration flag --with-fpu=XXX, and the runtime flag
178 See below wether to actually emit FP opcodes, or to emulate them.
180 Pick a value from the gcc manual for your choosen gcc version and your
183 Leave blank if you don't know, or if your target architecture does not
188 prompt "Floating point:"
192 prompt "hardware (FPU)"
194 Emit hardware floating point opcodes.
196 If you've got a processor with a FPU, then you want that.
197 If your hardware has no FPU, you still can use HW floating point, but
198 need to compile support for FPU emulation in your kernel. Needless to
199 say that emulating the FPU is /slooowwwww/...
201 One situation you'd want HW floating point without a FPU is if you get
202 binary blobs from different vendors that are compiling this way and
203 can't (don't wan't to) change.
209 Do not emit any hardware floating point opcode.
211 If your processor has no FPU, then you most probably want this, as it
212 is faster than emulating the FPU in the kernel.
216 config ARCH_SUPPORTS_LIBFLOAT
220 config ARCH_FLOAT_SW_LIBFLOAT
222 prompt "Use libfloat"
224 depends on ARCH_FLOAT_SW && ARCH_SUPPORTS_LIBFLOAT
226 For those targets upporting it, you can use libfloat for the software
227 floating point emulation.
229 Note that some versions of gcc have support code that supersedes libfloat,
230 while others don't. Known version of gcc that don't have support code are
231 versions prior to 3.0, and version above 4.0.
233 You should check gcc before deciding to use libfloat.
235 config LIBFLOAT_VERSION
237 default "990616.orig"
238 depends on ARCH_FLOAT_SW_LIBFLOAT
242 prompt "Target CFLAGS"
245 Used to add specific options when compiling libraries of the toolchain,
246 that will run on the target (eg. libc.so).
248 Note that the options above for CPU, tune, arch and FPU will be
249 automaticaly used. You don't need to specify them here.
251 Leave blank if you don't know better.