[U-Boot] [PATCH v2 3/5] ARM: enable Thumb build

Tom Rini
2012-02-23T17:51:18Z

On Thu, Feb 23, 2012 at 11:19:59PM +0530, Aneesh V wrote:
> On Thursday 23 February 2012 11:04 PM, Tom Rini wrote:
> >On Thu, Feb 23, 2012 at 10:58:36PM +0530, Aneesh V wrote:
> >>On Thursday 23 February 2012 08:27 PM, Mike Frysinger wrote:
> >>>On Thursday 23 February 2012 08:39:43 Aneesh V wrote:
> >>>>--- a/arch/arm/config.mk
> >>>>+++ b/arch/arm/config.mk
> >>>>
> >>>>-# Explicitly specifiy 32-bit ARM ISA since toolchain default can be
> >>>>-mthumb: +# 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,)
> >>>>+PF_CPPFLAGS_ARM += $(call cc-option,-mno-thumb-interwork,)
> >>>
> >>>this 2nd part is no good. "+=" is not the same thing as ":=".
> >>
> >>I don't understand the difference. '+=' is done after ':=' right?
> >
> >'+=' is evaluated every file we build, ':=' is evaluated once. We use
> >the latter to keep build times down.
> >
>
> Ok. so, are we trying to reduce the number of "+=", right?

Yes, it should already be at or near 0 uses.

--
Tom