xref: /OK3568_Linux_fs/yocto/poky/meta/conf/machine/include/arm/README (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun2012/03/30 - Mark Hatle <mark.hatle@windriver.com>
2*4882a593Smuzhiyun - Initial Revision
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunThe ARM architecture definitions are split among a number of files.
5*4882a593SmuzhiyunThe primary definitions for the variables are handled by the core
6*4882a593Smuzhiyunarch-arm.inc file.
7*4882a593Smuzhiyun
8*4882a593SmuzhiyunTUNE_ARCH is set to either "arm" or "armeb" depending on the value
9*4882a593Smuzhiyunof the existence of the "bigendian" feature in a given tune.
10*4882a593Smuzhiyun
11*4882a593SmuzhiyunA small set of ARM specific variables have been defined to allow
12*4882a593SmuzhiyunTUNE_PKGARCH to be automatically defined.  Optimized tunings must NOT
13*4882a593Smuzhiyunchange the definiton of TUNE_PKGARCH.  TUNE_PKGACH:tune-<tune> will be
14*4882a593Smuzhiyunignored.  The format of the package arch is enforced by the TUNE_PKGARCH
15*4882a593Smuzhiyundefault.  The format must be of the form:
16*4882a593Smuzhiyun<armversion>[t][e][hf][b][-vfp][-neon]
17*4882a593Smuzhiyun
18*4882a593SmuzhiyunTUNE_PKGARCH is defined as:
19*4882a593Smuzhiyun${ARMPKGARCH}${ARMPKGSFX_THUMB}${ARMPKGSFX_DSP}${ARMPKGSFX_EABI}${ARMPKGSFX_ENDIAN}${ARMPKGSFX_FPU}
20*4882a593Smuzhiyun
21*4882a593SmuzhiyunARMPKGARCH - This is the core package arch component specified by each
22*4882a593Smuzhiyuntuning.  This is the primary identifier of a tuning.  Usual values are:
23*4882a593Smuzhiyunarm, armv4, armv5, armv6, armv7a, etc.
24*4882a593Smuzhiyun
25*4882a593SmuzhiyunARMPKGSFX_THUMB - This is the thumb specific suffix.  Curently it is
26*4882a593Smuzhiyundefined in feature-arm-thumb.inc.
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunARMPKGSFX_DSP - This is the DSP specific suffix.  Currently this is set
29*4882a593Smuzhiyunto 'e' when on armv5 and the dsp feature is enabled.
30*4882a593Smuzhiyun
31*4882a593SmuzhiyunARMPKGSFX_EABI - This is the eabi specific suffix.  There are currently
32*4882a593Smuzhiyuntwo defined ABIs specificed, standard EABI and Hard Float (VFP) EABI.
33*4882a593SmuzhiyunWhen the callconvention-hard is enabled, "hf" is specified, otherwise it
34*4882a593Smuzhiyunis blank.
35*4882a593Smuzhiyun
36*4882a593SmuzhiyunARMPKGSFX_ENDIAN - This is the endian specific suffix.  It is defined in
37*4882a593Smuzhiyunthe core arch-arm.inc file.
38*4882a593Smuzhiyun
39*4882a593SmuzhiyunARMPKGSFX_FPU - This is the FPU specific suffix.  The suffix indicates
40*4882a593Smuzhiyunspecific FPU optimizations.  'vfp' and 'neon' are both defined.
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