[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Concerns about AMD64 port

* John Goerzen (jgoerzen@complete.org) wrote:
> On Thu, Feb 05, 2004 at 05:02:53PM +0100, Goswin von Brederlow wrote:
> > No, you would have to throw it away to change to a mixed mode. The
> > problem is getting the 64bit stuff out of the way of the 32 bit stuff
> > and not compiling for 64 bit.
> Why would you have to throw it away?  If the only problem really is the
> /lib64 thing, that's not hard to fix.

Because of changes to the packaging system that would be done to support
the mixed environment.  Basically the expectation is that you'd have to
reinstall to move to the mixed system, which means that if all you care
about is the result then the 64bit-only path doesn't help because it's
not directly on the path to the mixed system.

> So we put everything in /lib64 now, and add on /lib later.

The problem is that those amd64 debs that are build will almost
certainly have to be rebuilt after the decisions are made about how the
packageing system is going to handle them.  Let's take a concrete
example: zlib.  Compile it for 64bit amd64 and you get zlib, with the
libraries installed into /lib64 (under your example).  Now, if you want
to support installing both the 32bit zlib and the 64bit zlib you've got
a problem, they have the same name and dpkg won't allow it.  One
suggestion was to add another field for ABI which would allow you to
install packages with the same name, lots of bitching ensued about
breaking this somewhat cardinal rule.  Of course, one of the two
packages would need to have the ABI added anyway, so if that's done
you'd have to recompile/reinstall the amd64 zlib.  The other suggestion
was to change the name of the 64bit amd64 libraries to have a 64 in
them, ie: zlib -> zlib64.  This creates all kinds of fun problems with
the Depends rules and conflicts and whatnot.

That's why you're likely to have to rebuild everything for amd64 after
the changes to the packaging system are made which is why some people
don't see much point in a 64bit-only native Debian system now.
Personally, I think the multiarch stuff is going to take quite a while
longer to be finished and I think it'd be useful to have something for
people to use until then that's 64bit, but I'm in the minority on this.

> > Solving the problem just for amd64 by ignoring the 32bit support would
> > be a hell of a lot easier but work wasted when multiarch replaces it.
> I still don't buy that.  If the problem really is the location of libs,
> that is not a tough nut to crack for a single arch.

It's supporting installing i386 debs (unchanged) onto an amd64 system,
etc, etc.


Attachment: signature.asc
Description: Digital signature

Reply to: