Re: Breakage from grub-mkconfig changes for grub-file

[Colin Watson]

On Mon, Dec 23, 2013 at 11:21:38PM +0100, Vladimir 'φ-coder/phcoder' Serbinenko 
wrote:
> On 23.12.2013 23:01, Colin Watson wrote:
> >   This should be redesigned so that there is some way to declare in a
> >   grub.d script that it requires multi-platform support and should be
> >   run multiple times.  (It *must* be this way round so that upgrades
> >   work properly.)
> 
> The idea was that platform-independent scripts were still runnable,
> they'll just produce the same output N times and this list is just an
> optimisations, specially to avoid running os-prober N times.

Granted, but in some cases those scripts might not be idempotent:
consider a user-written "42_custom" (or whatever) script that adds a
menu entry, for instance.

> The alternative will be to have something along the lines of different
> hashbang or implementing this functionality as sh functions.

How about this simpler option: any script that needs to be run for each
platform could have a magic comment that we grep for in grub-mkconfig.

> >   The platform names used in grub-mkconfig (x86 i386-xen-pae x86_64-xen
> >   mips mipsel sparc64 powerpc ia64 arm arm64) are not the same as the
> >   platform names used in the GRUB build system, but yet they're exported
> >   across the interface to /etc/grub.d/ as GRUB_PLATFORM.  This is messy
> >   and confusing, and it's not clear what promises we make about future
> >   changes here.
> > 
> >   We should rationalise this before issuing anything as part of a stable
> >   release, perhaps by adopting the same target_cpu/platform terminology
> >   used in the build system.  Furthermore, if we made the namespaces
> >   match up then it would be fairly straightforward to only run grub.d
> >   scripts for platforms for which we have installed GRUB modules, which
> >   seems as though it would be sensible.
> 
> GRUB platform names don't match with the OS compatibility. On x86 other
> than xen you can use the same kernel on all the platforms. On ARM, for
> what is arm-uboot platform for us may require different kernels for
> different hardware.

OK, but if it is a different concept then it should have a different
name, not "platform" - otherwise it just seems confusing.

-- 
Colin Watson                                       address@hidden