Re: [avr-gcc-list] Put text string after interrupt vectors

[Lars Noschinski]

* Erik Christiansen <address@hidden> [2005-08-16 14:02]:
> On Mon, Aug 15, 2005 at 12:32:04PM +0200, Lars Noschinski wrote:
> > I'm rewriting an assembler program to C, which had a signature string
> > at 0x20 in the flash memory.
[...]
> Have you considered what is in the first 0x20 code bytes? If the
> signature is placed there, what are you hoping happens to the interrupt
> vectors? (IIRC the mega64 vectors go to 0x30, for example. :-)

The used device carries either an at90s4433 or an atmega8 which have
both less than 0x20 interrupt vectors, so there shouldn't be any
problems.

(and if we use a bigger controller later it is very likely that the
circuit is also redesigned ;))

> > Is there a way to tell gcc (or ld) to put the signature at 0x20? If not,
> > is there at least a way to guarantee, that the signature is "anywhere
> > near the beginning" of the flash memory?
>
> What about putting the .signature section's start just above the
> vectors, and providing .text with a section start above that? This is an
> ideal time to write a custom linker script, since you'll need to move
> "*(.vectors)" out of .text, to do that. :-)

Ah, I had no idea what complexity is hidden in the linking process :)

Thanks (also to Dave), I'll try your hints in the next few days.