Add support for ARM to the efi boot1 and loader

[andrew]

Summary

This adds support to boot ARM with the efi loader. The kernel side
is still missing.

[emaste]

overall looks fine to me

sys/arm/include/metadata.h

37–38 ↗

(On Diff #4697)

What do you think about making these uint64_ts with the intent that the same metatada could be used everywhere?

sys/boot/efi/boot1/Makefile

40 ↗

(On Diff #4697)

Out of curiosity why does only arm boot1 need it?

sys/boot/efi/include/arm/efibind.h

1–3 ↗

(On Diff #4697)

can we share a common efibind.h?

[emaste]

sys/boot/efi/boot1/Makefile

40 ↗

(On Diff #4697)

Also, this should be LDADD+= ${LIBSTAND}, no?

[andrew]

sys/arm/include/metadata.h

37–38 ↗

(On Diff #4697)

They probably should be, we could have > 4GiB of ram with LPAE.

sys/boot/efi/boot1/Makefile

40 ↗

(On Diff #4697)

It's for the runtime functions the compiler assumes are available. As an alternative may be able to use compiler-rt. I'll add a comment explaining this.

I think this is correct, it should have DPADD+= ${LIBSTAND}. LIBSTAND is only correct when DESTDIR is set so may not be in buildenv.

sys/boot/efi/include/arm/efibind.h

1–3 ↗

(On Diff #4697)

I think we could share large chunks, but would need to investigate further.

[emaste]

sys/boot/efi/boot1/Makefile

40 ↗

(On Diff #4697)

It turns out we also need it for i386. Perhaps it makes sense to just include it unconditionally, and let the linker use it if needed or not.

sys/boot/efi/include/arm/efibind.h

1–3 ↗

(On Diff #4697)

Yeah, perhaps with a few #ifdefs in it.

[emaste]

sys/boot/efi/loader/arch/arm/reloc.c

38 ↗

(On Diff #4697)

ElfW_Dyn instead?

71–76 ↗

(On Diff #4697)

I think we should use a common reloc.c with a bit of #ifdefery instead, actually - the i386/amd64/arm/arm64 implementations of this file are going to be >80% common, without more divergence over time I think.

#if defined(__arm__)
case R_ARM_RELATIVE:
#elif defined(__i386__)
case R_386_RELATIVE:
#endif
    /* Address relative to the base address. */
    newaddr = (unsigned long *)(ImageBase + rel->r_offset);
    *newaddr += ImageBase;
    break;

[andrew]

Closed by commit rS281156 (authored by @andrew).