Re: [PATCH] Add support for building on x86_64

[Jeremy Katz]

On Wed, 2003-01-01 at 10:16, Yoshinori K. Okuji wrote:
> At 29 Dec 2002 02:29:48 -0500,
> Jeremy Katz wrote:
> > The attached patch lets GRUB build on x86_64 assuming you have a
> > multilib compatible build environment set up (ie, gcc -m32 gives you
> > 32-bit binaries)
> 
> I don't know much about x86-64. Does it work in the same way as IA-32
> until 64-bit mode is enabled?

The processor natively supports running 64-bit and 32-bit code at the
same time.  To the point that you can install a 32-bit OS (ie, you can
install a standard Debian or Red Hat Linux) or you can install a 64-bit
OS.  It's the latter case that this patch is needed for, so that you can
build the boot loader; in the former, host_cpu won't be x86_64, it will
just be ix86.

Jeremy