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Re: AMD64 and lib64

There is a lot of discussion on this list about /lib on the one hand and /lib64 on the other hand. However, the gripping hand is nicely summarized by Kevin's response. For reasons outside the control of the AMD64 porting team, it is fairly clear there will _not_ be a biarch port for general use (i.e. in stable) before 2009. 

As I see it, Martin (as DPL) has to choose among the following options:
1. Insist that the dpkg maintainers integrate biarch support into mainstream i386 _now_, 2. Bless the current pure 64 bit port as being the definitive Debian release (prior to multiarch), 3. Formally state that Debian has no roadmap for offering a 64 bit x86 release in this decade.
Biarch basically died because (1) did not happen; it was not by the choice of the amd64 port team.
The controlling Debian decision makers are asserting that if we can't do 32 bit compatibility then we don't do 64 bit. _I_ want to run 64 bit code right now. I'd prefer to administer as Debian but, if I can't, I'll run Gentoo for the next few years. Maybe I'll be able to reinstall Debian using multiarch after DebConf 9.
I don't understand _why_ the decision makers are acting like that. The key things I need that are still 32 bit specific are (1) fglrx and (2) pctel. Both of these require a 32 bit kernel as well as a 32 bit userspace, so they inherently don't work under biarch. Biarch uses a 64 bit kernel that has a 32 bit calling interface and so cannot run drivers that are written to only run on a 32 bit kernel. Clearly, biarch has no value for me.
Port "amd64" is what the name says, a port to have Debian run on the 64 bit architecture developed by AMD. It isn't called "amd64i386" to imply that it can also run things on the 32 bit architecture developed by Intel. It also isn't called "amd64i386ppc" - which would be useful for a network booted environment. 

Alex.

Kevin Rosenberg wrote:


Martin Michlmayr - Debian Project Leader wrote:

I talked to Chris Yeoh of the Linux Standards Base (LSB) recently and
mentioned that the current port uses /lib rather than /lib64 (the
latter is required by the LSB).  He strongly advised against using
/lib plus /lib64 symlinks, and he kindly elaborated the problem below.
How do you address these concerns and how much work would it be to use
/lib64 (libtool could be patched to use that path by default, but how
many libraries don't use it?).


Personally, I like the so-called biarch (/lib64 for 64-bit libraries
and /lib for 32-bit binaries). I run SuSE on two of my systems so I
have very good 32-bit and 64-bit binary compatibility. These are the
only non-Debian systems on my network. I run some non-free 32-bit
binary packages on them as well as Oracle's AMD64 binary.

I'd like to see Debian support biarch. The initial Debian AMD64 port
was biarch. However, due to the effort to modify each source package
to use /lib64, only a small fraction of the source packages in Debian
were compiled for biarch. I understand that the biarch packages are
still on Alioth. I've heard people say that /lib64 is ugly. Perhaps my
sense of asthetics isn't as keen or narrow, but it does not bother me
and it certainly solves the issue of binary compatibility.


From watching the activity on #debian-amd64, it appears that biarch is

effectivley dead and has been so for a number of months. I'm not aware
of anyone currently working on biarch. I believe one of the reasons
for its death is that the dpkg maintainer wasn't interested in working
on supporting biarch until the purported "dpkg 2.0" was developed
sometime after sarge ships.

I am running the pure64 Debian port in several chroots and it's
working fine. For an AMD64 system, I think the Debian pure64 port is a
better choice than running i386. As others have stated, you can still
run 32-bit binaries in a Debian i386 chroot. Obviously, this is not as
seamless or integrated as a biarch system. Yet, I still think the
Debian pure64 port is a win compared to running i386.

You likely know more about multiarch that me. But the consensus on
#debian-amd64 seems to be that multiarch is a more robust replacement
for biarch. It seems there are people who are willing to work on
multiarch, but not on biarch.
My thoughts in summary: - biarch is very good, but I don't forsee anyone developing it for 
  Debian. I'd like to be shown to be wrong on this, so if someone
  wants to work on this -- this is a good time to speak up.
  If you really need a biarch system, it's easiest to just run a
  different operating system.
- The debian pure64 port runs well and is a better OS for an AMD64
  system than the i386 distribution. Some people will need a 32-bit chroot
  for compatibility. I've had some, but not complete, luck with the
  ia32-libs package for compatibility with 32-bit binaries
- multiarch is a transition approach for pure64 for running 32-bit
  and 64-bit binaries. However, I'm not aware it will solve issues
  with running 32-bit binaries that are compiled for the LSB.

My recommendations:
  Unless one or more people come forward and say they will work on
  supporting biarch, I think the pure64 bit port should be accepted
  into sid as the best solution that Debian can provide.
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