On Thursday 23 February 2012 11:34 PM, Mike Frysinger wrote:
On Thursday 23 February 2012 12:28:36 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?
might be simpler to do:
PF_CPPFLAGS_MARM := $(call cc-option,-marm)
PF_CPPFLAGS_THUMB := $(call cc-option,-mthumb -mthumb-interwork)
PF_CPPFLAGS_NO_THUMB := $(call cc-option,-mno-thumb-interwork)
ifeq ($(CONFIG_SYS_THUMB_BUILD),y)
PF_CPPFLAGS_ARM = $(PF_CPPFLAGS_THUMB)
else
PF_CPPFLAGS_ARM = $(PF_CPPFLAGS_MARM) $(PF_CPPFLAGS_NO_THUMB)
endif
Are you trying to avoid all '+='. If so, why?
"+=" does delayed evaluation and is the whole reason we started using ":=" in
makefiles for *computed* values
when you do:
FOO := $(call cc-option,-marm)
you're storing the result of the computation in $(FOO)
if you do:
FOO += $(call cc-option,-marm)
you're appending "$(call cc-option,-marm)" to $(FOO) and that won't actually
get computed until $(FOO) gets used
so if you append $(call ...) to $(CPPFLAGS), then you end up doing the cc-
option computation every time you compile a file that uses $(CPPFLAGS)
Get it. Thanks for explaining. I missed the computation part.
br,
Aneesh
-mike
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