Re: [PATCH] arch: avr32: add dummy syscalls

From: Hans-Christian Egtvedt
Date: Tue Feb 05 2013 - 03:06:56 EST


Around Mon 04 Feb 2013 08:34:47 -0800 or thereabout, Håvard Skinnemoen wrote:
> On Mon, Feb 4, 2013 at 7:39 AM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>> On Sun, Feb 03, 2013 at 09:35:39PM -0800, H?vard Skinnemoen wrote:
>>>
>>> > But yes, 32bit/32bit/64bit/32bit is another interesting case -
>>> > fanotify_mark is 32/32/64/32/32. From what ABI says it would seem to
>>> > be r12/r11/r8:r9/r10/stack, but if I understand you correctly, we'll
>>> > end up wanting *two* arguments on stack...
>>>
>>> Yes, I think there may be a difference between the IAR and gcc ABI
>>> here. But I could be wrong.
>>
>> So it will use the gap in case of 32/32/64/32; the first two calls will
>> take index 0 and 1 (r12 and r11 resp.), the third will take 3 and 4
>> (r9:r8) and the fourth will take 2 (r10).
>
> Oh, cool. I guess I am wrong then. Thanks a lot for taking the time to
> figure this out, and sorry I misled you.
>
> If someone's got the toolchain installed (which I don't, sorry), it
> should be relatively straightforward to verify this by looking at the
> disassembly of a call to a function with a similar prototype.

The last avr32-linux toolchain I was able to build was 4.2.x, the openwrt
people got 4.3.x to build and produce a bootable system.

I have not tested the 4.4.x GCC port from Atmel.

--
mvh
Hans-Christian Egtvedt
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