Re: [avr-gcc-list] RE: avr-gcc-list Digest, Vol 6, Issue 10

[Joerg Wunsch]

"Larry Barello" <address@hidden> wrote:

> Speaking from a point of complete ignorance: can the elf->coff
> converter tool simply rename every segment found in the FLASH
> section into one .text section for the purposes of output?  Does the
> COFF parser care about different sections anyway?  All the linking
> has been done at this point, right?  So renaming sections shouldn't
> bother the code.

Only over my dead body. :-)

Well, remember that we're talking about GNU binutils here, and i
certainly do want to create a patch that is acceptable to the GNU
folks for later integration into the tool.  Anything else would cause
a neverending support nightmare.  So far, my patch is not very
AVR-COFF specific, i. e. it's supposed to allow for generating COFF
debugging information for other COFF formats as well.  There are
already a number of hacks required to cope with various twists in the
Atmel way of handling COFF... but i wouldn't expect anybody to agree
to such a hack.

Atmel has chosen COFF, so they should abide to the COFF model.  Hmm,
they're talking about using ELF some day, so it wouldn't help much for
us to concentrate on COFF anyway.

It might be possible to write a cool trick that dissects an input ELF
file, and reassembles one with the contents of various sections
concatenated.  I once tried this.  The IMHO correct way however would
be to load all sections that are marked `loadable' to their specified
addresses.  Let's see, it wasn't difficult to ask them to also load
the contents of .data into their simulator ROM, so perhaps it's also
possible to ask them to load any loadable section.  But i should first
fix the remaining bugs, and then see to get the patch accepted by GNU
This will ensure that all the future AVR COFF files produce by the
avr-gcc/avr-binutils officially have the Atmel vendor ID assigned to
us (0x9cc), and this vendor ID is the base for Atmel to allow for
toolchain-specific handling inside their COFF parser.

Btw., it's not to /rename/ sections, instead several sections have to
be /concatenated/.  This functionality is currently not available in
objcopy.
-- 
J"org Wunsch                                           Unix support engineer
address@hidden        http://www.interface-systems.de/~j/