[XS] Change in coreboot[main]: Makefile: unexport CFLAGS

[Martin L Roth (Code Review)]

Attention is currently required from: Felix Singer, Nico Huber, Torsten Schenk.

Martin L Roth has posted comments on this change by Torsten Schenk. ( https://review.coreboot.org/c/coreboot/+/83379?usp=email )

Change subject: Makefile: unexport CFLAGS
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Patch Set 1:

(1 comment)

File Makefile:

https://review.coreboot.org/c/coreboot/+/83379/comment/5f0f00d2_1fbadeb8?usp... :
PS1, Line 7: unexport CFLAGS
> Should we unexport LDFLAGS too? Anything else?

I think this is the wrong way to go about this.

coreboot shouldn't be using a bare CFLAGS variable in its own builds, so it shouldn't be getting set to need to be unexported.

This one should be updated to set it's own cflags:
util/marvell/doimage_mv/Makefile.mk:CFLAGS  = -g -O1 -I./../inc -DMV_CPU_LE -I $(TOP)/src/commonlib/bsd/include

This one isn't a problem since it's a part of a rule and setting cflags just before calling make.
src/security/vboot/Makefile.mk:	CFLAGS="$$(VBOOT_CFLAGS_$(1))" VBOOT2="y" \

Same here:
src/arch/arm64/Makefile.mk:	CFLAGS="$(BL31_CFLAGS)"

Also, if it's leaking into another build, just clear CFLAGS when doing the other build.