Re: [PATCH] man2 : syscall.2 : document syscall calling conventions

[Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>]

[-- Attachment #1: Type: Text/Plain, Size: 884 bytes --]

On Sunday 07 April 2013 09:55:14 Kyle McMartin wrote:
> On Sun, Apr 07, 2013 at 12:00:50PM +0200, Michael Kerrisk (man-pages) wrote:
> > [Adding a few people to CC who may be able to help with Mike's doubts
> > on PA-RISC; folks, if any of you could have a quick look at the parisc
> > piece below, that would be helpful]
> 
> The syscall number is in %r20, everything else looks correct. The
> returned value is in %r28 and the args are %r26 through %r21.

just to be clear, the only insn you need is:
	ble 0x100(%sr2, %r0);

the kernel docs say sr2 holds the kernel gateway page (so i guess 0x100 is a 
known offset into that).  the docs don't mention r0 that i can see, so i'm 
guessing it's one of those "always 0" registers ?

the sysdep code has an ldi call in the branch delay slot (i think), but all 
that seems to do is load r20 with the syscall nr.
-mike

[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 836 bytes --]