Re: [PATCH 0/1] Embedded Maintainer(s), linux-embedded@vger list

[Rob Landley <rob@landley.net>]

On Tuesday 10 June 2008 02:54:32 Sam Ravnborg wrote:
> > (Maybe I _am_ the only person who still cares about
> > building on a host without perl.  If I wasn't, somebody else would have
> > acked the patch...)
>
> perl is pretty standard

An implementation is not the same thing as a standard.  If you mean "there is 
one implementation everybody uses, ala excel and Word, and even the Perl guys 
can't reproduce it from scratch as parrot showed", then you're using a 
different definition of the word "standard" than I am.

Or do you mean it comes preinstalled on most modern systems, the way Windows 
does, and who could object to that?

I know from experience that it's an _amazing_ pain to try to cross compile the 
sucker...

> and I fail to see the benefits of avoiding it. 
> For embedded development I see even less benefits as I assume
> any sane embedded development environment are based on a
> cross-toolchain so you do the build on a high perfomance box.
>
> Building everything for my arm board on the arm board would be a disater
> for example.

I build everything for my arm board natively, on an arm system running under 
qemu, calling out to the cross compiler via distcc to accelerate the limited 
parts of the process that cross compiling doesn't actually break.  To get to 
that point, I cross compile just enough to get a native development 
environment, and then I avoid cross compiling from then on because it's an 
enormous source of complexity and random breakage.

I did this because throwing hardware at the problem is cheaper than throwing 
engineering time at the problem, because Moore's Law is on my side, and 
because I find native compiling (where possible) more straightforward and 
conceptually cleaner.

Before 2.6.25, I had a complete self-bootstrapping environment with seven 
packages (busybox, uClibc, make, gcc, binutils, bash, and linux).  Building 
glibc needs perl, if you're using a uClibc based system you may _never_ need 
Perl, and could go up through Linux From Scratch and beyond to a fairly 
powerful system.

I can probably natively build perl under the mini-native environment running 
inside qemu, but it wasn't needed before and there really wasn't a good 
reason to add it.  The task being performed and the build dependency brought 
in to perform it are hugely disproportionate.

Rob
-- 
"One of my most productive days was throwing away 1000 lines of code."
  - Ken Thompson.