Re: [avrdude-dev] [task #5093] Add support for reading ELF files.

[Joerg Wunsch]

As Colin O'Flynn wrote:

> > Alas, each AVR might have a different default fuse, so we cannot
> > simply use 0xff as the default value.

> If we got the default fuse programmed in the avrdude configuration
> file, you could also add a command that brought the AVR back to
> "factory" state. Handy if you were prototyping with a device than
> wanted to put it away into a drawer, or just pulled a random device
> out of a drawer... make the fuse bytes something sane.

The defaults need to go into avr-libc, one way or the other.  My
current idea is to add the blurb to gcrt1.S, as this file is
custom-compiled for each and any different AVR, so per-device defaults
(which come in the form of macros from <avr/ioXXX.h>) can easily be
compiled into it.  These defaults will then be overwritten by the
user-API macros like LFUSE() etc., replacing the library defaults.

The final load file (as avrdude sees it) will the either see the
library's defaults, or the customized values.

I think the idea might work, but I'm afraid I won't be able to draft a
proof-of-concept implementation of the entire toolchain before leaving
for vacation next week.

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)