ARM linker stub changes - placement, PIC

Daniel Jacobowitz drow@false.org
Tue Feb 24 14:45:00 GMT 2009


On Tue, Feb 24, 2009 at 03:18:14PM +0100, Christophe LYON wrote:
> On 24.02.2009 04:09, Daniel Jacobowitz wrote:
>
>> hardware interrupt controller.  So this should stop dropping stubs on
>> top of the reset vector.  No change in testsuite results, but a lot
>> of churn in the expected output.
>
> Indeed, thanks for the effort!
>
> One comment, not linked to this patch: on several occasions, I can see  
> that andeq r0,r0,r0 (arm) / lsls r0,r0,r0 (thumb) is used as padding  
> (opcode=0). Shouldn't there be proper "nop"s instead? (see for instance  
> farcall-mix2 test)

I noticed that too.  Yes, there should be.  But it's tricky: the nop
instructions depend on the mode and architecture.  I believe NOP
padding is normally done by the linker script specifying a bit
pattern, isn't it?

We have a local patch to make the assembler generate real nops for
.p2align.  It's brand new, I'm sure we'll be posting it soon.

> Thanks, both look OK to me.

Thanks.

-- 
Daniel Jacobowitz
CodeSourcery



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