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comparison src/timer/mint/SDL_vbltimer.S @ 281:c5010ab8ba35

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Added initial support for Atari (thanks Patrice!)
author Sam Lantinga <slouken@libsdl.org>
date Sun, 17 Feb 2002 19:54:28 +0000
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children e4bd0cf95506
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280:0ddcea45d829 281:c5010ab8ba35
1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
4
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 of the License, or (at your option) any later version.
9
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
14
15 You should have received a copy of the GNU Library General Public
16 License along with this library; if not, write to the Free
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
19 Sam Lantinga
20 slouken@libsdl.org
21 */
22
23 #ifdef SAVE_RCSID
24 static char rcsid =
25 "@(#) $Id$";
26 #endif
27
28 /*
29 * VBL queue routine
30 *
31 * Patrice Mandin
32 */
33
34 #define _vbl_queue 0x456
35
36 .text
37
38 .globl _SDL_AtariVblInstall
39 .globl _SDL_AtariVblUninstall
40
41 /*--- Vector installer ---*/
42
43 _SDL_AtariVblInstall:
44 movel sp@(4),my_vector
45 lea _my_vbl,a0
46
47 clrw vbl_mutex
48
49 /* Stop interrupts */
50
51 movew #0x2700,sr
52
53 /* Read vbl_queue pointer */
54 movel _vbl_queue.w,a1
55
56 /* Search a free place */
57 moveq #7,d0
58 bcl_search_place:
59 movel (a1),d1
60 beqs place_found
61 addql #4,a1
62 dbra d0,bcl_search_place
63
64 /* Not found */
65 moveq #1,d0
66 bras exit_vbl_queue
67
68 /* Then install ourselves */
69 place_found:
70 movel a0,(a1)
71 moveq #0,d0
72
73 exit_vbl_queue:
74 /* Restart interrupts */
75 movew #0x2300,sr
76
77 rts
78
79 /*--- Vector uninstaller ---*/
80
81 _SDL_AtariVblUninstall:
82 movel sp@(4),d0
83 cmpl my_vector,d0
84 bnes badvector
85
86 movel #_my_vbl,d0
87
88 /* Stop interrupts */
89
90 movew #0x2700,sr
91
92 /* Read vbl_queue pointer */
93 movel _vbl_queue.w,a1
94
95 /* Search where we are */
96 moveq #7,d1
97 bcl2_search_place:
98 cmpl (a1),d0
99 bnes next_place
100 clrl (a1)
101 moveq #0,d1
102 next_place:
103 addql #4,a1
104 dbra d1,bcl2_search_place
105
106 /* Restart interrupts */
107 movew #0x2300,sr
108 badvector:
109 rts
110
111 /*--- Our vbl ---*/
112
113 .text
114 .even
115 .ascii "XBRA"
116 .ascii "_SDL"
117 _my_vbl:
118 /* Verify if this is not already running */
119
120 tstw vbl_mutex
121 bnes vbl_end
122 notw vbl_mutex
123
124 moveml d0-d7/a0-a6,sp@-
125 movel my_vector,a0
126 jsr a0@
127 moveml sp@+,d0-d7/a0-a6
128
129 clrw vbl_mutex
130 vbl_end:
131 rts
132
133 .data
134 .even
135 .comm vbl_mutex,2*1
136 .even
137 .comm my_vector,4*1