Might be worth factoring out the -EL/-EB/-mabi into MIPS_FLAGS or something rather than repeating groups of ACFLAGS/AFLAGS/CFLAGS/LDFLAGS n times?

update comment?

Hmm, ACFLAGS does not appear to be set from CFLAGS. In sys.mk:

AS              ?=      as
AFLAGS          ?=
ACFLAGS         ?=

I had originally only set these for buildworld/buildkernel in Makefile.inc1 btw, but kan@'s changes in rS308711 are what led me to move them here to be beside the -EL/-EB.

I'm fine doing a _MIPS_FLAGS if we agree that is cleaner.

This is required for external GCC to compile assembly files that use ll/sc since external GCC requires an explicit CPUTYPE for o32 (it's default -march= for o32 is mips2)

My intention is to commit LD_EMULATION as a separate commit, but I think for review it provides better context to review the two commits together. This is the same idea as the explicit -mabi for the compiler driver. In the case of devel/mips-binutils, mips-freebsd-ld assumes o32 and requires explicit -m for n32 or n64. devel/mips64-binutils defaults to n64, but we don't have a 'mipsn32-binutils' or 'mipsn32-gcc'. Also, with these changes, you can just use mips-gcc and mips-binutils for all 3 ABIs now (so arguably we could remove the mips64-* toolchain packages).

As far as the duplication of Makefile.arm vs kern.pre.mk, that doesn't seem easy to untangle. OTOH, I noticed that Makefile.arm is missing some of the recent changes to SYSTEM_LD from kern.pre.mk (which I might also commit separate from LD_EMULATION).

Look at bsd.suffixes.mk (and others):

.S.o:

${CC:N${CCACHE_BIN}} ${CFLAGS} ${ACFLAGS} -c ${.IMPSRC} -o ${.TARGET}
${CTFCONVERT_CMD}

So ACFLAGS is additional flags for assembler not contained in CFLAGS.... kan's changes were wrong as well...

So this breaks lib/csu/mips/Makefile which uses:

crt1.s: crt1.c
        ${CC} ${CFLAGS} -S -o ${.TARGET} ${.CURDIR}/crt1.c
        sed ${SED_FIX_NOTE} ${.TARGET}

crt1.o: crt1.s
        ${CC} ${ACFLAGS} -c -o ${.TARGET} crt1.s

And apparently that _can't_ use CFLAGS directly but has to only use ACFLAGS per rS234502.

Actually, this is the same issue as above for lib/csu/<foo>/Makefile.

This worked on mips builds with GCC 4.2.1 and 6.3. If we think this approach is what we'd like to do I can expand it to other architectures.

This is likely due to the same csu Makefile issues and should probably be removed eventually as well.

Tripped over this during universe. No armeb kernels currently use firmware blobs which is why this doesn't break currently.