mirror of
https://github.com/elliotnunn/supermario.git
synced 2024-11-26 16:49:18 +00:00
59 lines
1.8 KiB
Plaintext
59 lines
1.8 KiB
Plaintext
|
; ======================================================================
|
||
|
|
; VMPatch.a © 1988 by Apple Computer Inc
|
||
|
|
; by Chris Derossi 4/10/89
|
||
|
|
; ======================================================================
|
||
|
|
|
||
|
|
PrNonPortable EQU 1 ; We're building System SW. This is ok.
|
||
|
|
|
||
|
|
PRINT OFF
|
||
|
|
INCLUDE 'Traps.a'
|
||
|
|
INCLUDE 'SysEqu.a'
|
||
|
|
INCLUDE 'ToolEqu.a'
|
||
|
|
INCLUDE 'Private.a'
|
||
|
|
INCLUDE 'quickequ.a'
|
||
|
|
INCLUDE 'colorequ.a'
|
||
|
|
INCLUDE 'VMCalls.a'
|
||
|
|
PRINT ON
|
||
|
|
|
||
|
|
; ======================================================================
|
||
|
|
; Header to main init code.
|
||
|
|
; ======================================================================
|
||
|
|
|
||
|
|
MACHINE MC68020
|
||
|
|
|
||
|
|
VMPatch PROC EXPORT
|
||
|
|
|
||
|
|
; During a page fault exception, MacVM continues to service the cursor interrupt. Now that
|
||
|
|
; the cursor code is not in ROM, and not in the System heap, it must not get paged out.
|
||
|
|
; Otherwise, nested page faults could occur, and this is bad.
|
||
|
|
;
|
||
|
|
; This patch tells MacVM to keep the cursor code in memory at all times. This patch does
|
||
|
|
; nothing if MacVM isn't around.
|
||
|
|
;
|
||
|
|
; Note: This patch knows that the cursor code is pointed to by JCrsrTask, and ends at the
|
||
|
|
; location pointed to by JScrnAddr.
|
||
|
|
|
||
|
|
|
||
|
|
Unimplemented EQU $A89F ; the Unimplemented trap number
|
||
|
|
MemoryDispatch EQU $A05C ; trap number for MacVM Dispatcher
|
||
|
|
|
||
|
|
; Does the MacVM dispatch trap exist?
|
||
|
|
|
||
|
|
MOVE.W #MemoryDispatch, D0 ; MacVM Trap number
|
||
|
|
_GetTrapAddress ,NewOS ; get the address of _MemoryDispatch
|
||
|
|
MOVEA.L A0, A1 ; Hold it for a sec
|
||
|
|
MOVE.W #Unimplemented, D0 ; get address of Unimplemented trap
|
||
|
|
_GetTrapAddress
|
||
|
|
CMPA.L A0,A1 ; see if MacVM is around
|
||
|
|
BEQ.S @0 ; if not, we're done
|
||
|
|
|
||
|
|
MOVE.L jCrsrTask, A0 ; Point to cursor code
|
||
|
|
MOVE.L jScrnAddr, A1 ; Get end of code
|
||
|
|
SUBA.L jCrsrTask, A1 ; Calculate length of cursor code
|
||
|
|
_HoldMemory ; Tell VM to keep it around
|
||
|
|
|
||
|
|
@0
|
||
|
|
RTS
|
||
|
|
|
||
|
|
END
|