How 2 build a Gentoo system for a P4 while running Athlon

rgbtxus · n00b Joined: 02 May 2003 Posts: 39

I wanted to build a Gentoo installation on a spare disk so I could pop it into a P4 system as a mostly built system and cut the down time of the P4 system from a few days to a few hours. The system I have to build on is an Athlon based Gentoo. I figured I could just do a stage 2 install setting march=pentium4 -mno-sse2. It seemed that this way the non specialialzed tool chain could do the work. Unfortunately it looks like something triggered a compile of a new gcc and somewhere in the middle of doing that it tried to assemble some P4 assembly code noticed it was on an Athlon and complained loudly.

So, it there some easy way to compile a Gentoo optimized for a P4 while running on an Athlon? (The P4 system is >1000 miles away at the moment
so I can't do the build there)

TIA for any pointers,
Rick

yabbadabbadont · Posted: Fri May 02, 2003 11:31 pm Post subject:

I don't have access to my Gentoo system right now, but don't the comments in make.conf say that using -mcpu instead of -march will provide some optimization without breaking compatibility with other processors?

krusty_ar · Posted: Sat May 03, 2003 1:14 am Post subject:

rgbtxus · n00b Joined: 02 May 2003 Posts: 39

cyrillic · Posted: Sat May 03, 2003 2:24 am Post subject:

Installing P4 optimized binaries on your Athlon system won't work, but you can use an Athlon to compile P4 binary packages :

rgbtxus · n00b Joined: 02 May 2003 Posts: 39

Lemma · Posted: Tue Jul 15, 2003 10:20 am Post subject:

Chris Finch · Posted: Wed Jul 30, 2003 11:24 am Post subject:

There is a problem with your method. Some Makefiles use their own CPU detection code and set optimization for the CPU detected (i.e. Athlon and not P4 in your case). The following is a snippet of the mplayer ebuild

Lemma · Posted: Wed Jul 30, 2003 12:42 pm Post subject:

Hm, I haven't had any problem as of yet, but then I don't use mplayer or other programs like it on those machines - only on my laptop. But, as you say, there may be other programs that use that method, meaning I will run into problem - sooner or later... :-(

_________________
Always make it as simple as possible, but no simpler
/Einstein

Chris Finch · Posted: Wed Jul 30, 2003 2:10 pm Post subject:

Not necessarily. Have a look at the output of

Lemma · Posted: Wed Jul 30, 2003 2:48 pm Post subject:

Ok, thx. I will try that as see what comes up :-)

_________________
Always make it as simple as possible, but no simpler
/Einstein

Lemma · Posted: Tue Aug 12, 2003 11:35 am Post subject:

Ok, done.
What I get is:

A few that are important for me but not many ,grub (can't live without ;-)

) wine, apache for some configurations. mplayer/xine and the libs that come with is (like decss) are not part of the codebase on my servers so no problem there. Thank's for making me aware of the problem!
_________________
Always make it as simple as possible, but no simpler
/Einstein