linux cross-development (was: Re: /dev/null: No such file or directory)

[Alexander Leidinger]

Quoting John E Hein <jhein at timing.com> (from Thu, 21 Sep 2006 13:57:47 -0600):

> Alexander Leidinger wrote at 07:55 +0200 on Sep 21, 2006:
>  > Quoting John E Hein <jhein at timing.com> (from Wed, 20 Sep 2006   
> 13:48:48 -0600):
>  > > Alexander Leidinger wrote at 21:24 +0200 on Sep 20, 2006:
>  > >  > Any ideas how to provide a chroot while not losing the fallthrough if
>  > >  > not chrooted (and we try to identify other files/dirs where we want a
>  > >  > fallthrough)?
>  > >
>  > > That smells a little like unionfs.
>  >
>  > Feel free to provide a description how to achieve this. I don't see
>  > it at first look.
>
> I haven't thought about it.  It just sounded a bit like unionfs.

Yes, but the pitfalls are in the details.

>  > And I don't like to mount stuff at installation time or to request
>  > to mount something to get it working.
>
> I agree.

> Okay, I see that linux_base & linux_dist can co-exist.  But I still see
> some problems...
>
> I'd have to change our build to get the source code into the gentoo
> chroot.  Plus right now, the app is built as a FreeBSD port, so I'd

You would have to do this (chroot) with the linux_base too.

> have to get the FreeBSD ports infrastructure (and make(1)) working
> under the gentoo chroot, too.  That could be a lot of work.

If you have a build machine which is just that, so you don't need the  
linux_base for something else, you can try the  
linux_base-gentoo-stage3 port instead for the generation of the  
package. We do this for the linux_kdump port, but it only uses the  
linuc-gcc to preprocess some files to get the linux-numbers instead of  
the FreeBSD ones when using the FreeBSD-gcc to generate a FreeBSD  
executable which is able to decode the linux syscalls when ktracing  
them. If you know what you are doing, you don't need to chroot (I  
don't chroot in the linux_kdump port), but you have to be very careful.

> Also, if I build in the gentoo chroot, but deploy the app to be run
> under linux_base, I suspect there may be library conflicts (this is
> not unlike the problems that have been mentioned for linux_devtools).

For the standard libs (glibc) I don't think there are more problems  
than on any native linux system (I would expect less problems), for  
other ones (gtk) you should notice the difference immediatly and then  
you can try to find a suitable one for either the gentoo build env or  
for linux_base (I would expect you are lucky and it just works, module  
bugs in the code of the libs).

Bye,
Alexander.

-- 
The one sure way to make a lazy man look
respectable is to put a fishing rod in his hand.

http://www.Leidinger.net    Alexander @ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org       netchild @ FreeBSD.org  : PGP ID = 72077137