Re: Why are we cross-compiling Debian?

[Thiemo Seufer <ths@networkno.de>]

Neil Williams wrote:
> OK, this is a radical thought - one of those light bulb moments and the
> light may actually be from an oncoming train but - why are we
> cross-compiling binaries that are already available as native binaries?
> 
> 1. Emdebian is Debian stripped-out - a smaller Debian for smaller
> devices.
> 2. Emdebian has always sought to use the best of Debian - we may be
> missing a trick by *not* making the best use of one of Debian's most
> powerful features: the buildd system.
> 3. Emdebian is supporting the same architectures as Debian supports
> upstream, just the devices are smaller.
> 4. It's been staring us in the face since the creation of dpkg-cross.
> 
> The idea is this: If we are proposing to cross-compile binaries that
> already exist as native binaries in Debian, we had better have a *very*
> good reason. I'm thinking that optimising binaries for size may not be
> sufficient cause and may actually be making a rod for our own backs.

Rebuilding binaries allows for
- optimimizing binaries for size, better use of (newer) instructions
  which aren't in the common generic set, use of (e.g. DSP-like)
  instruction set extensions
- cutting down the dependency chain by disabling unused features
- linking with smaller replacements (uClibc vs. glibc)

I think the tradeoffs involved here don't allow a simple solution
unless we choose not to support certain classes of systems.


Thiemo