On Wed, Aug 01, 2012 at 03:15:45PM -0700, V, Aneesh wrote:
I didn't want to break any older ARM architectures that don't support the bx instruction but use this code.
Which is earlier than armv4t, right? On quick look it didn't seem there is anything older than that in u-boot. But yes, it's perhaps better to be safe.
Yes, in particular bx is available in armv4t but not armv4, and there are architectures being compiled -march=armv4 in u-boot:
$ grep march arch/arm/cpu/*/config.mk arch/arm/cpu/arm1136/config.mk:PLATFORM_CPPFLAGS += -march=armv5 arch/arm/cpu/arm1176/config.mk:PLATFORM_CPPFLAGS += -march=armv5t arch/arm/cpu/arm720t/config.mk:PLATFORM_CPPFLAGS += -march=armv4 -mtune=arm7tdmi arch/arm/cpu/arm920t/config.mk:PLATFORM_CPPFLAGS += -march=armv4 arch/arm/cpu/arm925t/config.mk:PLATFORM_CPPFLAGS += -march=armv4 arch/arm/cpu/arm926ejs/config.mk:PLATFORM_CPPFLAGS += -march=armv5te arch/arm/cpu/arm946es/config.mk:PLATFORM_CPPFLAGS += -march=armv4 arch/arm/cpu/arm_intcm/config.mk:PLATFORM_CPPFLAGS += -march=armv4 arch/arm/cpu/armv7/config.mk:PF_CPPFLAGS_ARMV7 := $(call cc-option, -march=armv7-a, -march=armv5) arch/arm/cpu/ixp/config.mk:PLATFORM_CPPFLAGS += -mbig-endian -march=armv5te -mtune=strongarm1100 arch/arm/cpu/lh7a40x/config.mk:PLATFORM_CPPFLAGS += -march=armv4 arch/arm/cpu/pxa/config.mk:PLATFORM_CPPFLAGS += -march=armv5te -mtune=xscale arch/arm/cpu/s3c44b0/config.mk:PLATFORM_CPPFLAGS += -march=armv4 -mtune=arm7tdmi -msoft-float arch/arm/cpu/sa1100/config.mk:PLATFORM_CPPFLAGS += -march=armv4 -mtune=strongarm1100
Probably some of these are actually armv4t, but I don't want to touch them :^)
-Allen