Mercurial > sdl-ios-xcode
comparison src/timer/mint/SDL_vbltimer.S @ 3955:40b6b5744e05 SDL-1.2
Avoid switch to supervisor mode in SDL_GetTicks, by updating system counter from vbl interrupt
author | Patrice Mandin <patmandin@gmail.com> |
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date | Sat, 09 Jun 2007 19:52:05 +0000 |
parents | cfe850b334e7 |
children | 99210400e8b9 |
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3954:649fba69eccd | 3955:40b6b5744e05 |
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25 * | 25 * |
26 * Patrice Mandin | 26 * Patrice Mandin |
27 */ | 27 */ |
28 | 28 |
29 #define _vbl_queue 0x456 | 29 #define _vbl_queue 0x456 |
30 #define _hz_200 0x4ba | |
30 | 31 |
31 .text | 32 .text |
32 | 33 |
33 .globl _SDL_AtariVblInstall | 34 .globl _SDL_AtariVblInstall |
34 .globl _SDL_AtariVblUninstall | 35 .globl _SDL_AtariVblUninstall |
40 _SDL_AtariVblInstall: | 41 _SDL_AtariVblInstall: |
41 movel sp@(4),my_vector | 42 movel sp@(4),my_vector |
42 lea _my_vbl,a0 | 43 lea _my_vbl,a0 |
43 | 44 |
44 clrw vbl_mutex | 45 clrw vbl_mutex |
46 movel _hz_200.w, _SDL_Atari_hz200 | |
45 | 47 |
46 /* Stop interrupts */ | 48 /* Stop interrupts */ |
47 | 49 |
48 movew #0x2700,sr | 50 movew #0x2700,sr |
49 | 51 |
106 rts | 108 rts |
107 | 109 |
108 /*--- Our vbl ---*/ | 110 /*--- Our vbl ---*/ |
109 | 111 |
110 _my_vbl: | 112 _my_vbl: |
113 /* Update _hz_200 */ | |
114 movel _hz_200.w, _SDL_Atari_hz200 | |
115 | |
111 /* Verify if this is not already running */ | 116 /* Verify if this is not already running */ |
112 | 117 |
113 tstw vbl_mutex | 118 tstw vbl_mutex |
114 bnes vbl_end | 119 bnes vbl_end |
115 notw vbl_mutex | 120 notw vbl_mutex |
145 vbl_end: | 150 vbl_end: |
146 rts | 151 rts |
147 | 152 |
148 .data | 153 .data |
149 .even | 154 .even |
155 .comm _SDL_Atari_hz200,4*1 | |
156 .even | |
150 .comm vbl_mutex,2*1 | 157 .comm vbl_mutex,2*1 |
151 .even | 158 .even |
152 .comm my_vector,4*1 | 159 .comm my_vector,4*1 |