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Message-ID: <4FBBED1F.5010307@cavium.com>
Date:   Tue, 22 May 2012 12:46:39 -0700
From:   David Daney <david.daney@cavium.com>
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To:     Songmao Tian <kingkongmao@gmail.com>
CC:     linux-mips <linux-mips@linux-mips.org>
Subject: Re: handle_sys question
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On 05/22/2012 02:40 AM, Songmao Tian wrote:
> Hello all:
>     In handle_sys there's a
> 50
> <http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=arch/mips/kernel/scall32-o32.S;h=a632bc144efa1b9ca977a582864530e33ee039cb;hb=72c04af9a2d57b7945cf3de8e71461bd80695d50#l50>
>          sw      a3, PT_R26(sp)          # save a3 for syscall restarting
>
> I woner why it need to save  a3 in R26(k0) slot in the stack?
>

It has to go somewhere.  The K0 and K1 slots aren't used to save other 
things.

David Daney