Path: chuka.playstation.co.uk!news
From: Jim <jim@micronetics.com>
Newsgroups: scee.yaroze.programming.gnu_compiler
Subject: VSyncCallback bug
Date: Thu, 31 Jul 1997 10:11:26 +0100
Organization: PlayStation Net Yaroze (SCEE)
Lines: 25
Message-ID: <33E056BE.2D131340@micronetics.com>
NNTP-Posting-Host: jim.micronetics.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 4.0b4 [en] (Win95; I)
X-Priority: 3 (Normal)

Hi All,


I think I've finally found a solution to the VSyncCallback problem where
you would not be able to access globals from within the callback its
self.

This is because $gp is not restored for the call back.  
Add this line as the very first of the callback function.

__asm__ volatile ("la $28, _gp")

and have 

extern long _gp;

as a global somewhere.

Besure to remove the callback before your prog exits.

I would appriciate someone confirming this actually works as I only
played with it a little.

Cheers
JiM