svn commit: r330004 - in head/stand: . arm efi forth i386 mips powerpc sparc64

[John Baldwin]

On Tuesday, February 27, 2018 09:28:49 AM Kyle Evans wrote:
> On Sun, Feb 25, 2018 at 9:16 PM, Warner Losh <imp at freebsd.org> wrote:
> > Author: imp
> > Date: Mon Feb 26 03:16:04 2018
> > New Revision: 330004
> > URL: https://svnweb.freebsd.org/changeset/base/330004
> >
> > Log:
> >   Add NO_OBJ to those directories that don't make anything.
> >
> >   For directories that don't many anything, add NO_OBJ=t just before we
> >   include bsd.init.mk. This prevents them from creating an OBJ
> >   directory. In addition, prevent defs.mk from creating the machine
> >   related links in these cases. They aren't needed and break, at least
> >   on stable, the read-only src tree build.
> >
> 
> Any objection to also removing efi from i386 SUBDIR? It seems silly
> to be explicitly adding it when we know nothing here is applicable and
> it's going to take some amount of work to get there.

Actually, I believe the only thing it needs is for the i386 kernel to
understand the EFI memory map.  If you made the i386 EFI loader fake up the
SMAP metadata from the EFI memory map you could probably boot an unmodified
i386 kernel.  (It would be better to teach the i386 kernel to handle the EFI
memory map though.)  It's more a matter of does someone care enough to
actually get a test environment going to test it.

One would also eventually want to teach the i386 kernel about efifb as well
as EFI runtime services, but that shouldn't be strictly required for booting
an i386 kernel via EFI.

-- 
John Baldwin