Re: [avr-gcc-list] 8-bit relocations on AVR

[Andrew Zabolotny]

From Sun, 14 Feb 2010 11:12:03 +1100
Erik Christiansen <address@hidden> wrote:

> If you have no objection to each message having global labels, it is
> not only achievable (via the ldi or ldd relocations), but the need to
> store the string length is avoided:
> 
>    .section .text
>    
> ;  In the code somewhere, we compute the length when it's needed:
>    ldi r16,(end_msg1 - msg1)
> ;                               or, depending on needs:
>    ldd r20,Y+(end_msg1 - msg1)
>    
> msg1: .ascii "somestring"
> end_msg1:
> 
> Does that come close enough to meeting your needs?
Unfortunately, I can't imagine how this would help me.

Well, to be concrete, I'm implementing a simple FORTH virtual machine.
A FORTH "word" (it's what we call subroutines in other programming
languages) begins with a header, and this header contains the length of
the name (in fact, the length is contained in lower 5 bits, upper 3
bits are reserved for various flags) before the name itself.

This all works on x86 and x86_64 just fine, problem arised when I've
tried to port it to avr.

I can try to make a binutils patch, but I'm not even sure whom I need
to contact to push the patch upstream.

-- 
Andrew

signature.asc
Description: PGP signature