library/amiga_callhooka.asm
*
* $Id: amiga_callhooka.asm,v 1.3 2006-01-08 12:04:22 obarthel Exp $
*
* :ts=8
*
* Portable ISO 'C' (1994) runtime library for the Amiga computer
* Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Neither the name of Olaf Barthel nor the names of contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
section text,code
h_Entry equ 8
xdef _CallHookA
****************************************************************************
* new hook standard
* use struct Hook (with minnode at the top)
*
* *** register calling convention: ***
* A0 - pointer to hook itself
* A1 - pointer to parameter packed ("message")
* A2 - Hook specific address data ("object," e.g, gadget )
*
* *** C conventions: ***
* Note that parameters are in unusual register order: a0, a2, a1.
* This is to provide a performance boost for assembly language
* programming (the object in a2 is most frequently untouched).
* It is also no problem in "register direct" C function parameters.
*
* calling through a hook
* CallHook( hook, object, msgid, p1, p2, ... );
* CallHookA( hook, object, msgpkt );
*
* using a C function: CFunction( hook, object, message );
* hook.h_Entry = HookEntry;
* hook.h_SubEntry = CFunction;
*
****************************************************************************
* C calling hook interface for prepared message packet
_CallHookA:
movem.l a2/a6,-(sp)
move.l 12(sp),a0
move.l 16(sp),a2
move.l 20(sp),a1
pea.l hook_return(pc)
move.l h_Entry(a0),-(sp)
rts
hook_return:
movem.l (sp)+,a2/a6
rts
end