sys7.1-doc-wip/OS/VMPatches.a
2019-07-27 22:37:48 +08:00

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;
; File: VMPatches.a
;
; Contains: patches related to VM; all of these are currently non-VM versions of VM calls
;
; Written by: Darin Adler and Jim Reekes
;
; Copyright: © 1990-1991 by Apple Computer, Inc., all rights reserved.
;
; Change History (most recent first):
;
; <3> 9/10/91 JSM Cleanup header.
; <2> 12/14/90 dba <JDR> get rid of VMCalls.a; save fewer registers (deferred
; functions can trash D0-D3/A0-A3, just like interrupt handlers)
; <1> 10/8/90 JDR First checked in. Patch DeferUserFn when not running VM.
;
load 'StandardEqu.d'
include 'LinkedPatchMacros.a'
;————————————————————————————————————————————————————————————————————————————————————————————————————
; This is a handy patch that only happens when VM is not running. The Sound Manager needs to call
; DeferUserFn very often and it seems silly to constantly check if VM is running before making the
; call. So I thought it would be a good idea to have the trap implemented even when VM isn't.
; This way you can always make the call and it will immediately call the user function, which is nice.
NonVMDeferUserFn PatchProc _DeferUserFn,(Plus,SE,II,Portable,IIci,notVM)
; parameters:
; a0 = pointer to function to call (no need to defer if there is no VM)
; d0 = parameter to pass to function (must be in A0 when function is called)
movem.l d1-d3/a0-a3,-(sp)
move.l a0,a1 ; move proc. pointer into another register
move.l d0,a0 ; get parameter into register for proc.
jsr (a1) ; call proc. with parameter
movem.l (sp)+,d1-d3/a0-a3
moveq #noErr,d0 ; return success
rts
EndProc
;————————————————————————————————————————————————————————————————————————————————————————————————————
End