| # 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)}" |