Re: [gentoo-user] Changing CFLAGS

["Hemmann, Volker Armin" <volker.armin.hemmann@tu-clausthal.de>]

On Samstag, 28. April 2007, Alex Schuster wrote:

>
> What would be the best way to do this?

complete reinstallation.

> I thought about unpacking 
> a stage1 tarball, changing CFLAGS, calling bootstrap.sh and doing
> an emerge -e world, but this would overwrite things in /etc and
> clutter my file system with more things I do not really want,
> like creating entries in /dev. I would rather like to keep the
> current setup as it is.

use knoppix.
If you don't want to reinstall everything and the XP is just a temporary 
replacement, get a knoppix livecd. It lets you save things to a file, if you 
want to.
>
> I think that I saw a howto once about what to do in such a case,
> but at that time I did not need it, and now I cannot find it.

the howto is: remove the system and start from scratch.

>
>
> BTW: What exactly are the benefits from using march instead of
> mcpu? Is there a noticeable difference in speed anyway? With mcpu
> I would not have the trouble I am having now...

Your trouble started, when you switched to a completly different cpu... 

mcpu = only rearranging stuff so it might run better on the cpu specified. No 
instructions and features used, that are not available on all the other cpus 
from a family (in theory, a binary built with mcpu=athlon-xp should be able 
to run on a i486).

march = optimizing for the specified cpu. Using all features and instructions 
available, building stuff not able to run on other cpus. (so a resulting 
binary of march=athlon-xp won't run on a i486)

usually march is faster on the given cpu, mcpu is more compatible.

-- 
gentoo-user@gentoo.org mailing list