[Nottingham] Gentoo convert 32bits system to 64bits?

[Martin]

On 24/07/10 07:41, Paul Housley wrote:
>> I've transplanted a 32bits Gentoo system from some very old hardware
> 
>> onto new 64bits hardware. So... Can that now be recompiled for the
> 
>> 64bits?
> 
> This is a question I've been through when I upgraded to 64bit.
> The Gentoo web site says that you cannot compile a 64bit system from a
> 32bit system.  You need to start which the amd64 installation disk.
> See: http://www.gentoo.org/doc/en/gentoo-amd64-faq.xml

Yep, I think I rediscovered that!

My cunning plan was to upgrade to the latest gcc:

http://www.gentoo.org/doc/en/gcc-upgrading.xml

and then upgrade the chosts:

http://www.gentoo.org/doc/en/change-chost.xml

with a cunning 'build the binary packages only' and then install
everything from the pre-built binaries in one great big-bang-and-reboot.


Unfortunately, autoconf/automake/gcc quite correctly complained about
trying to do cross-compiling...

:-(


So... I wound up using an x86_64 Ubuntu 10.04 that I have on a memory
stick to use as the 64-bit base system to do a Gentoo stage3 install via
a wild spaghetti of mounts, mount -o bind, and chroot onto the diskless
system.

Worked first time!

Now working through re-adding all my customisations.


And I've been nicely reminded about how phenomenally flexible linux is
in general, and how customisable Gentoo is especially.

The cost in all that is in the time needed to set it all up... Then
again, my heavily customised Mandriva system takes a fair while to
re-morph a new upgrade to all the customisations of the previous version...


I think that sums up why I use Gentoo in some places, and Mandriva and
(K)ubuntu in other places... You can install and get a new system online
in just a few minutes. Tweaking it may take a little longer...


All good fun!

Cheers,
Martin


ps:

Once the Gentoo stage3 install is completed and you've done the initial
configs and reboot, before installing further packages, it's a good idea
to do an update in case there is more recent stuff since the stage3
versions. I use:

emerge --sync

emerge -pu portage
emerge -u portage

emerge -p gentoo-sources
emerge gentoo-sources

emerge -vDup system
emerge -vDu system 2>&1 | tee /var/tmp/emerge_system.log
emerge -vDup world
emerge -vDu world 2>&1 | tee /var/tmp/emerge_world.log

The logs are so that you can see what happened!

Options:
-D = "deep"
-b = saves binary build packages also
-N - update for new 'use flag' settings made
-u = update
-p = pretend



-- 
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Martin Lomas
martin at ml1.co.uk
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