Add a sysctl to export the EFI memory map.

[jhb]

Summary

Add a sysctl to export the EFI memory map along with a handler in the
sysctl(8) binary to format it.

Test Plan

I don't have an EFI-booting machine handy to test this, so I'm hoping
to cajole someone else into testing this for me.

[emaste]

sbin/sysctl/sysctl.c

913 ↗

(On Diff #1600)

Bah, your other commit hasn't trickled into my git repo yet:

/tank/emaste/src/freebsd/sbin/sysctl/sysctl.c:913:9: error: incompatible pointer types assigning to 'int (*)(int, void *)' from 'int (size_t, void *)' [-Werror,-Wincompatible-pointer-types]
                        func = S_efi_map;                                       
                             ^ ~~~~~~~~~

[emaste]

Looks fine to me and produces reasonable output.

Virtual column could be omitted perhaps since it's all 0x0, although it may be useful to see if something else does get reported there for some reason.

sys/amd64/amd64/machdep.c

2141 ↗

(On Diff #1600)

Perhaps this warrants a comment.

[jhb]

Can you reply to the commit with some sample output? I'm curious to see what it looks like.

sys/amd64/amd64/machdep.c

2141 ↗

(On Diff #1600)

This is actually true of all the metadata passed from the loader to the kernel. There is a uint32_t preceding the pointer of each blob that contains the length of the blob.

[jhb]

Closed by commit rS271495 (authored by @jhb).