Re: Multi kernel tree support on the same distro?

[Akula2 <akula2.shark@gmail.com>]

On 1/7/07, Willy Tarreau <w@1wt.eu> wrote:
> > There are some difficulties with gcc versions between linux-2.4 and linux-2.6,
> > but I do not recall all of the details off of the top of my head.  If I recall
> > correctly, one of the issues is, linux-2.4 ?prefers? gcc-2.96, while newer
> > linux-2.6 support/prefer gcc-3.? or greater.

That's correct about gcc-3.4.x & gcc-4.1.x about 2.6 tree support.
This means 2.6 supports both gcc versions. Here are the binaries I do
use:-

http://download.fedora.redhat.com/pub/fedora/linux/core/3/i386/os/Fedora/RPMS/gcc-3.4.2-6.fc3.i386.rpm
http://download.fedora.redhat.com/pub/fedora/linux/core/3/i386/os/Fedora/RPMS/kernel-2.6.9-1.667.i686.rpm

Now issue remains with 2.4 tree. Is it possible to build/install
gcc-4.1.x along with gcc-3.4.x? This is what am trying to figure by
few tests on the FC3 base machine.
Can we call this as backward compatibility?

Any inputs here is helpful :-)

> Hmm, I think you did it the *hard* way. Gcc has been supporting
> multi-version for years. You just have to compile it with --suffix=-3.4
> or --suffix=4.1 to have a whole collection of gcc versions on your host.
> If you don't want to recompile gcc, simply rename the binaries and you're
> OK. When you build, you only have to do :
>
>   $ make bzImage modules CC=gcc-3.4
>
> I've been using it like this for years without problem. It's really
> convenient, and it also allows you to easily compare output codes and
> sizes between compilers.

I did understand this, thanks. I have one doubt: Imagine I have
built/installed these:-

2.4.34 & 2.6.20 kernels has these gcc-3.4.x & gcc-4.1.x compilers
built on say FC6 box. Now issue comes when I run an application. How
does it understand which library use?

example:
myArmWireless app. needs gcc-3.4.x, NOT gcc-2.6.x libs on say 2.4.34 kernel.

Will it take automatically? Or we need to pass args to target the
gcc-3.4.x libs?


Hope you guys consider these (my) questions as Novice, because am
trying to figure a design @ How-To build such multi kernel/gcc
systems.

> Regards,
> Willy

~Akula2