diff options
Diffstat (limited to 'yocto-poky/meta/conf/machine/include/arm/feature-arm-thumb.inc')
-rw-r--r-- | yocto-poky/meta/conf/machine/include/arm/feature-arm-thumb.inc | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/yocto-poky/meta/conf/machine/include/arm/feature-arm-thumb.inc b/yocto-poky/meta/conf/machine/include/arm/feature-arm-thumb.inc new file mode 100644 index 000000000..563217186 --- /dev/null +++ b/yocto-poky/meta/conf/machine/include/arm/feature-arm-thumb.inc @@ -0,0 +1,49 @@ +# The instruction set the compiler should use when generating application +# code. The kernel is always compiled with arm code at present. arm code +# is the original 32 bit ARM instruction set, thumb code is the 16 bit +# encoded RISC sub-set. Thumb code is smaller (maybe 70% of the ARM size) +# but requires more instructions (140% for 70% smaller code) so may be +# slower. +TUNEVALID[thumb] = "Use thumb instructions instead of ARM" +ARM_THUMB_OPT = "${@['arm', 'thumb'][d.getVar('ARM_INSTRUCTION_SET', True) == 'thumb']}" +ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv4', 't', '', d)}" +ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv5', 't', '', d)}" +ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv6', 't', '', d)}" +ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7a', 't2', '', d)}" +ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7r', 't2', '', d)}" +ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7m', 't2', '', d)}" + +# If the device supports ARM, then respect ARM_THUMB_OPT (which can be "arm" or "thumb") +# If the defice doesn't support ARM, then always set "thumb" even when +# some recipe explicitly sets ARM_INSTRUCTION_SET to "arm" +ARM_M_OPT = "${@bb.utils.contains('TUNE_FEATURES', 'arm', '${ARM_THUMB_OPT}', 'thumb', d)}" +python () { + if bb.utils.contains('TUNE_FEATURES', 'thumb', 'False', 'True', d): + return + selected = d.getVar('ARM_INSTRUCTION_SET', True) + if selected == None: + return + used = d.getVar('ARM_M_OPT', True) + if selected != used: + pn = d.getVar('PN', True) + bb.warn("Recipe '%s' selects ARM_INSTRUCTION_SET to be '%s', but tune configuration overrides it to '%s'" % (pn, selected, used)) +} + +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', ' -m${ARM_M_OPT}', '', d)}" +OVERRIDES .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', ':thumb', '', d)}" + +# Add suffix from ARM_THUMB_SUFFIX only if after all this we still set ARM_M_OPT to thumb +ARMPKGSFX_THUMB .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', '${ARM_THUMB_SUFFIX}', '', d) if d.getVar('ARM_M_OPT', True) == 'thumb' else ''}" + +# Whether to compile with code to allow interworking between the two +# instruction sets. This allows thumb code to be executed on a primarily +# arm system and vice versa. It is strongly recommended that DISTROs not +# turn this off - the actual cost is very small. +TUNEVALID[no-thumb-interwork] = "Disable mixing of thumb and ARM functions" +THUMB_TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'no-thumb-interwork', ' -mno-thumb-interwork', ' -mthumb-interwork', d)}" +THUMB_OVERRIDES .= "${@bb.utils.contains('TUNE_FEATURES', 'no-thumb-interwork', ':thumb-interwork', '', d)}" +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', ' ${THUMB_TUNE_CCARGS}', '', d)}" +OVERRIDES .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', '${THUMB_OVERRIDES}', '', d)}" + +# what about armv7m devices which don't support -marm (e.g. Cortex-M3)? +TARGET_CC_KERNEL_ARCH += "${@bb.utils.contains('TUNE_FEATURES', 'thumb', '-mno-thumb-interwork -marm', '', d)}" |