Re: additions to dpkg-architecture
Brendan O'Dea <email@example.com> writes:
> On Fri, Jun 23, 2006 at 06:54:49PM +0200, Volker Grabsch wrote:
>>I propose to add more CPU types to dpkg-architecture. In particular,
>>I'd like to see the different i386 architectures there, i.e.
>>i586, i686, k6, ...
>>For instance, some programs with lots of calculations (e.g. mplayer)
>>are compiled with different processor optimizations (e.g. mplayer-i586).
>>Such packages are created by very redundant entries in debian/rules.
>>Exactly such redundancy is removed by dpkg-cross.
> While there are certainly some packages which may benefit from
> compilation with sub-architecture optimisations, those packages are the
> exception rather than the norm.
> It may make sense to provide multiple versions of the kernel for
> example, and perhaps glibc... but coreutils? grep?
> Do you propose re-building all packages for each sub-arch? If so,
> please consider the resulting increace in archive size and impact on
That would be quite wastefull as anyone can see.
> If only a sub-set, how are you intending to change dpkg, apt and/or the
> archive software to handle opportunistic installation of sub-arch
> packages with fallback (i.e. try foo.i686, fallback to foo.i386)?
You add multiple entries to apts sources.list or have an extra file
listing allowed subarchs for a system (autodetection can't be used to
allow installing on a different cpu than the final sytem will use).
Apt then fetches multiple packages files and simply the order of the
sources.list entries (or the archs in the extra file) will say what to
prefer if there are overlaps.
If you don't want to patch dpkg/apt for subarchs you can simply setup
an archive with main, main-i586 and main-i686 all with packages for
architecture i386 but different -mcpu/arch settings for gcc. Apt
already handles that just fine.