[avr-libc-dev] build per arch

[Theodore A. Roth]

I've started a new thread for this since I think it's worth
discussing...

On Fri, 23 Apr 2004, Joerg Wunsch wrote:
>
> I wonder whether the current way of building per `architecture' is
> still that optimal, or whether we should start a finer-grained build
> scenario (which unfortunately would require changes to the linker).

At first I didn't think that we'd need linker changes, but doing a bit
of digging shows that we would. :-(

This is what ${prefix}/avr/lib/ currently looks like after an install:

  <see attached "curr-avr-lib.txt">

We'd probably need to change things so that there would be a directory
for each device which looked like this (relative to ${prefix}/avr/lib/)
(showing only mega128 for brievity):

  ./atmega128/libc.a
  ./atmega128/libm.a
  ./atmega128/libprintf_min.a
  ./atmega128/libprintf_flt.a
  ./atmega128/libscanf_min.a
  ./atmega128/libscanf_flt.a
  ./atmega128/crtm128.o

or maybe like this:

  ./avr5/atmega128/libc.a
  ./avr5/atmega128/libm.a
  ./avr5/atmega128/libprintf_min.a
  ./avr5/atmega128/libprintf_flt.a
  ./avr5/atmega128/libscanf_min.a
  ./avr5/atmega128/libscanf_flt.a
  ./avr5/atmega128/crtm128.o

where everything in ./avr5/atmega128/ is compiled specificly for the
mega128. This would give us much more flexibility in tuning the libs for
a specific device.

Would we need a special linker script on a per device basis or could we
still use the arch based ones? I don't know...

Now would be a good time to start on this since binutils 2.15 is nearing
release (as far as I can tell) and we can get in early on the next
round.

I've already mentioned that I want to rip out all the multiarch stuff
from the configury (and update to use the new autoconf/automake tools).
It would probably make this easier for me to eliminate all the
build-per-arch and just do build-per-device.

Of course, this will cause the build to take a considerly long time, but
who cares, we've all got 3 GHz systems by now, right? 8-)

---
Ted Roth
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curr-avr-lib.txt
Description: Text document