Commit 5356f545 authored by Aneesh V's avatar Aneesh V Committed by Albert ARIBAUD

ARM: enable Thumb build

Enable Thumb build and ARM-Thumb interworking based on the new
config flag CONFIG_SYS_THUMB_BUILD
Signed-off-by: default avatarAneesh V <aneesh@ti.com>
Acked-by: default avatarMike Frysinger <vapier@gentoo.org>
parent 74236aca
......@@ -432,6 +432,14 @@ The following options need to be configured:
Select high exception vectors of the ARM core, e.g., do not
clear the V bit of the c1 register of CP15.
CONFIG_SYS_THUMB_BUILD
Use this flag to build U-Boot using the Thumb instruction
set for ARM architectures. Thumb instruction set provides
better code density. For ARM architectures that support
Thumb2 this flag will result in Thumb2 code generated by
GCC.
- Linux Kernel Interface:
CONFIG_CLOCKS_IN_MHZ
......
......@@ -33,25 +33,33 @@ endif
PLATFORM_CPPFLAGS += -DCONFIG_ARM -D__ARM__
# Explicitly specifiy 32-bit ARM ISA since toolchain default can be -mthumb:
PF_CPPFLAGS_ARM := $(call cc-option,-marm,)
# Choose between ARM/Thumb instruction sets
ifeq ($(CONFIG_SYS_THUMB_BUILD),y)
PF_CPPFLAGS_ARM := $(call cc-option, -mthumb -mthumb-interwork,\
$(call cc-option,-marm,)\
$(call cc-option,-mno-thumb-interwork,)\
)
else
PF_CPPFLAGS_ARM := $(call cc-option,-marm,) \
$(call cc-option,-mno-thumb-interwork,)
endif
# Try if EABI is supported, else fall back to old API,
# i. e. for example:
# - with ELDK 4.2 (EABI supported), use:
# -mabi=aapcs-linux -mno-thumb-interwork
# -mabi=aapcs-linux
# - with ELDK 4.1 (gcc 4.x, no EABI), use:
# -mabi=apcs-gnu -mno-thumb-interwork
# -mabi=apcs-gnu
# - with ELDK 3.1 (gcc 3.x), use:
# -mapcs-32 -mno-thumb-interwork
# -mapcs-32
PF_CPPFLAGS_ABI := $(call cc-option,\
-mabi=aapcs-linux -mno-thumb-interwork,\
-mabi=aapcs-linux,\
$(call cc-option,\
-mapcs-32,\
$(call cc-option,\
-mabi=apcs-gnu,\
)\
) $(call cc-option,-mno-thumb-interwork,)\
)\
)
PLATFORM_CPPFLAGS += $(PF_CPPFLAGS_ARM) $(PF_CPPFLAGS_ABI)
......
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