Re: [gentoo-user] CFLAGS Core2Duo

[Boyd Stephen Smith Jr.]

On Tuesday 19 December 2006 18:56, "W.Kenworthy" <billk@×××××××××.au> wrote 
about 'Re: [gentoo-user] CFLAGS Core2Duo':
> Is it still the case thats its impossible to upgrade a 32bit gentoo on
> athlon64 to 64 bit - requires a full reinstall?

Reinstall is the only officially supported manner.

However, with a little bit of work, it *is* possible to upgrade.  The 50km 
view is:
1. Build cross toolchain -- portage may not make this easy
2. Use said toolchain to build 64-bit kernel with 32-bit support.
2a.If you need any out-of-tree modules before step 6, rebuild them with the 
cross compiler -- portage *will* *not* make this easy.
3. Reboot into new kernel.
4. Change CHOST in make.conf
5. Update toolchain configuration/symlinks to treat what was a cross 
toolchain as the native toolchain
6. Rebuild remaining out-of-tree modules.

At this point, only your kernel and modules are 64-bit, but each time your 
update/reinstall a package it will become 64-bit.  For best results, it'd 
probably a good time to rebuild the toolchain again.  (Right now, the 
tollchain is 32-bit code that produces 64-bit code.)

There's also some sticky issues with lib vs. lib32 vs. lib64 
directories/symlinks and your ldconfig and you may need a few runs of 
fix_libtool_files.sh and/or revdep-rebuild as required.

It's possible, but not really fun and very fragile, which is why there's no 
support for it.  If you want to try, I'm willing to help, but I can't 
guarantee anything, and many on the list will be unwilling to help.

-- 
"If there's one thing we've established over the years,
it's that the vast majority of our users don't have the slightest
clue what's best for them in terms of package stability."
-- Gentoo Developer Ciaran McCreesh