On Tue, Jul 13, 2010 at 03:24:35PM +0200, Loïc Minier wrote: > On Tue, Jul 13, 2010, Riku Voipio wrote: > > If dpkg had subarchitecture support, lpia wouldn't have been as big > > a issue. Ubuntu decided to shortcut and not add support for compatible > > subarchs in dpkg, and the result was what it always is when people make > > shortcuts... > > > > Subarchs could also be useful if we wanted to build softfp abi compatible > > armv6/armv7 armel builds of the whole debian repository. Of course we could > > do > > builds without subarchs, but then users would be unable distinguish which > > installed packages are for which cpu, and providing that via debian infra > > would not be possible.
> It sounds like you have good ideas about the subarch concept; would you > mind expanding on them a bit? Basicly close to what RPM does, so it is not my idea :) For example: On X86 one could have i486, i586, i686, atom, core2 - all being subarchs of i386 and crossinstallable. On ARM one could have armelv5, armelv6, armelv7, armelv7neon, .., all subarchs armel and crossinstallable. Before someone jumps "what about a ARMv6 with NEON but no VFP", obviously some discretion must be used when selecting subarchs to be supported. At package install time, package manager knows on what cpu we are running on, and can thus select which subarchs are supported. For example a ARMv6 machine could install armel.deb, armelv5.deb, armelv6.deb packages. >From debian/rules point of view, the package would still building for armel or i386. If we want, we can add a new DEB_HOST_* variable, but ideally supported cpu features would be identified ./configure -time from what gcc accepts with given defaults. Also, compatible subarchs mean we don't neccessarily need to compile (and mirror) every single package for every subarch. If a package doesn't actually use any float/double variables, we could jsut skip building it on vfp subarchs. If the package isn't performance critical at all, just compile it for the base arch. This way ubuntu wouldn't have just had to drop armv5 support when building armv6 stuff, or make it impossible for lpia users to install i386 .debs. Riku -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: http://lists.debian.org/[email protected]
