d328ae22b7
Cleanup the MIPS tunings to match the new tuning README file. Also add a MIPS specific README file to explain the MIPS specifical architectural issues. Finally correct the variant configurations within the tune-mips32.inc. (From OE-Core rev: efbfa2ace3362393a20340af93e8dcab17a8619a) Signed-off-by: Mark Hatle <mark.hatle@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
1.2 KiB
2012/03/30 - Mark Hatle mark.hatle@windriver.com
- Initial Version
MIPS currently defines 12 ABIs. Combinations of: *) Big/Little Endian *) Hardware/Software Floating Point *) o32, n32, n64 ABI
TUNE_ARCH, the GNU canonical arch, is defined as:
mips${MIPSPKGSFX_BYTE}${MIPSPKGSFX_ENDIAN}
The package arch is defined in such a way to generated a standard naming scheme. The scheme is: [-nf][-n32]
TUNE_PKGARCH is defined as:
${MIPSPKGSFX_VARIANT_tune-${DEFAULTTUNE}}${MIPSPKGSFX_FPU}${MIPSPKGSFX_ABI}
The following is a list of MIPS specific variables:
MIPSPKGSFX_BYTE - This is defined as either blank and "64" for MIPS64 CPUs.
MIPSPKGSFX_ENDIAN - For bigendian hardware this is blank, otherwise it's defined as "el".
MIPSPKGSFX_VARIANT_tune- - In the default tunings it is set to the same value as TUNE_ARCH. In custom, optimized tunings, the value should be modified to more precisely describe the tuning.
MIPSPKGSFX_FPU - The value is set to "" or "-nf", where "-nf" indicates that the tune is using a non-floating point ABI.
MIPSPKGSFX_ABI - This is used to specify an alternative ABI when the previous values are not enough to distringuish the package. "-n32" is added when building for N32 ABI.