Re: Question on gas difference between 2.19.1 and 2.20

[Phil Blundell <pb at reciva dot com>]

On Tue, 2009-11-03 at 20:24 +0100, LluÃs Batlle wrote:
> jumpStart:
> 
> .section        ".reset_vector_sect",#alloc, #execinstr
> 
>         /* Check if we booted from DRAM. If we did someone already      */
>         /* initialize the DRAM controller                               */
> 
>         adr     r4, jumpStart           /* r4 <- current position of
> code   */ /* line 62 of the source file */
>         mov     r5, #~0xff

> Assembling with binutils 2.20 gas, I get:
> jump.S:62: Error: symbol .text is in a different section
> 
> Does anybody understand this behaviour? Maybe I am doing something
> wrong? I don't understand the meaning of that message in this context.

I am rather surprised that binutils 2.19.1 accepted this code.  What
output did it produce?

The "adr" pseudo-op is (approximately) an assembler shorthand for "add
rN, pc, #(dest - .)", i.e. it assembles to an arithmetic operation with
an immediate operand.  Using adr across sections is possible in theory,
albeit with restrictions, but I don't think either GAS nor GNU ld
understand the relocation types that you would need to make it work.

p.