Path: utzoo!news-server.csri.toronto.edu!rpi!uupsi!sunic!news.funet.fi!ra!rosenber
From: rosenber@ra.abo.fi (Robin Rosenberg INF)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: Problem with SetFunction()
Message-ID: <ROSENBER.91Mar18201225@ra.abo.fi>
Date: 18 Mar 91 18:12:25 GMT
References: <13531@darkstar.ucsc.edu>
Sender: rosenber@ra.abo.fi
Organization: Abo Akademi University, Finland
Lines: 32
In-reply-to: davids@ucscf.UCSC.EDU's message of 18 Mar 91 03:45:31 GMT

In article <13531@darkstar.ucsc.edu> davids@ucscf.UCSC.EDU (Dave Schreiber) writes:

>I've been trying to patch AllocMem() as an experiment, and haven't been
>able to get it to work.  I manage to patch it correctly with SetFunction(),
>but when I try to print a carriage return using printf, the machine crashes
>with a 8000 0006 error (CHK instruction).  Here's the code:

1. Stack checking off

2. Make sure your global as accessible, either
compile for absoulute addressing or declare your patch function using
__saveds to get A4 right.

3. AllocMem has THREE parameters: size(d0),types(d1) and execbase(a6).
Declared them properly when writing the patch. Something like. Declare
the pointer to the old function the same way.

void * (* __asm __saveds oldallocmem)(
register __d0 ULONG size,
register __d1 ULONG types,
register __a6 struct ExecBase *SysBase);

void *__asm __saveds myallocmem(
	register __d0 ULONG size,
	register __d1 ULONG types,
	register __a6 struct ExecBase *SysBase)
{
	return (*oldallocmem)(size,types,SysBase);
}

-----
	Robin