Re: Moving along Pure64

[Greg Johnson <gjohnson@lanl.gov>]

On Thu, Apr 01, 2004 at 10:38:21AM -0600, John Goerzen wrote:
> Hi,
> 
> We need a few things to happen to get pure64 going better.
> 
> At the top of the list is a gcc that can build 32- and 64-bit binaries
> but defaults to 64-bit mode.  This is more difficult than it may appear
> at first.

I was able to build a working cross compiler for building 32bit binaries
on x64-64.  The existing binutils are already biarch.  Unfortunately,
the harddrive my cross compiler was on failed.  If anybody's interested,
I might be able to recreate it. 

With the cross compiler, I could build a 64 bit kernel with 32 bit support.
The kernel (2.6.x) actually only has one C file that needs to be
compiled in 32bit mode.  That file is arch/x86_64/boot/compressed/misc.c
All the other 32bit objects are generated from assembly files which our
as can already handle.  The kernel makefiles have to be fixed, though to
call as rather than gcc for the .S files.

BTW, is the biarch gcc necessary for anything other than the kernel?

Greg