Files
poky/meta/conf/machine/include/tune-thumb.inc
Richard Purdie d74176473a conf/machine/include: Set TUNE_CCARGS instead of TARGET_CC_ARCH
Since we're updating the tune file format, it makes sense to abstract
the compiler tune arguments at this point too. This means that should
these need to be overridden at any point, the original values can
still be obtained in a similar manner to the other TUNE* variables.

Whilst this isn't strictly necessary for any current need, its likely
good practise to standardise this behaviour.

(From OE-Core rev: 3a3c69a1bc3cf0b6f6a3b13d86c12ed21798d48e)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
2011-07-25 12:06:30 +01:00

33 lines
1.6 KiB
HTML

#tune file for thumb instructions
ARM_INSTRUCTION_SET ?= "arm"
# "arm" "thumb"
# 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.
THUMB_INTERWORK ?= "yes"
# "yes" "no"
# 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.
OVERRIDE_THUMB = "${@['', ':thumb'][bb.data.getVar('ARM_INSTRUCTION_SET', d, 1) == 'thumb']}"
OVERRIDE_INTERWORK = "${@['', ':thumb-interwork'][bb.data.getVar('THUMB_INTERWORK', d, 1) == 'yes']}"
OVERRIDES .= "${OVERRIDE_THUMB}${OVERRIDE_INTERWORK}"
# Compiler and linker options for application code and kernel code. These
# options ensure that the compiler has the correct settings for the selected
# instruction set and interworking.
ARM_INTERWORK_M_OPT = "${@['-mno-thumb-interwork', '-mthumb-interwork'][bb.data.getVar('THUMB_INTERWORK', d, 1) == 'yes']}"
ARM_THUMB_M_OPT = "${@['-mno-thumb', '-mthumb'][bb.data.getVar('ARM_INSTRUCTION_SET', d, 1) == 'thumb']}"
#
TUNE_CCARGS += "${ARM_INTERWORK_M_OPT} ${ARM_THUMB_M_OPT}"
TARGET_CC_KERNEL_ARCH += "-mno-thumb-interwork -mno-thumb"