| 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2009 Sam Lantinga |
| 4 | |
| 5 | This library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 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 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with this library; if not, write to the Free Software |
| 17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | |
| 19 | Sam Lantinga |
| 20 | slouken@libsdl.org |
| 21 | */ |
| 22 | |
| 23 | /* |
| 24 | * VBL queue routine |
| 25 | * |
| 26 | * Patrice Mandin |
| 27 | */ |
| 28 | |
| 29 | #define _vbl_queue 0x456 |
| 30 | #define _hz_200 0x4ba |
| 31 | |
| 32 | .text |
| 33 | |
| 34 | .globl _SDL_AtariVblInstall |
| 35 | .globl _SDL_AtariVblUninstall |
| 36 | |
| 37 | .globl _SDL_MintAudio_hasfpu |
| 38 | |
| 39 | /*--- Vector installer ---*/ |
| 40 | |
| 41 | _SDL_AtariVblInstall: |
| 42 | movel sp@(4),my_vector |
| 43 | lea _my_vbl,a0 |
| 44 | |
| 45 | clrw vbl_mutex |
| 46 | movel _hz_200.w, _SDL_Atari_hz200 |
| 47 | |
| 48 | /* Stop interrupts */ |
| 49 | |
| 50 | movew #0x2700,sr |
| 51 | |
| 52 | /* Read vbl_queue pointer */ |
| 53 | movel _vbl_queue.w,a1 |
| 54 | |
| 55 | /* Search a free place */ |
| 56 | moveq #7,d0 |
| 57 | bcl_search_place: |
| 58 | movel (a1),d1 |
| 59 | beqs place_found |
| 60 | addql #4,a1 |
| 61 | dbra d0,bcl_search_place |
| 62 | |
| 63 | /* Not found */ |
| 64 | moveq #1,d0 |
| 65 | bras exit_vbl_queue |
| 66 | |
| 67 | /* Then install ourselves */ |
| 68 | place_found: |
| 69 | movel a0,(a1) |
| 70 | moveq #0,d0 |
| 71 | |
| 72 | exit_vbl_queue: |
| 73 | /* Restart interrupts */ |
| 74 | movew #0x2300,sr |
| 75 | |
| 76 | rts |
| 77 | |
| 78 | /*--- Vector uninstaller ---*/ |
| 79 | |
| 80 | _SDL_AtariVblUninstall: |
| 81 | movel sp@(4),d0 |
| 82 | cmpl my_vector,d0 |
| 83 | bnes badvector |
| 84 | |
| 85 | movel #_my_vbl,d0 |
| 86 | |
| 87 | /* Stop interrupts */ |
| 88 | |
| 89 | movew #0x2700,sr |
| 90 | |
| 91 | /* Read vbl_queue pointer */ |
| 92 | movel _vbl_queue.w,a1 |
| 93 | |
| 94 | /* Search where we are */ |
| 95 | moveq #7,d1 |
| 96 | bcl2_search_place: |
| 97 | cmpl (a1),d0 |
| 98 | bnes next_place |
| 99 | clrl (a1) |
| 100 | moveq #0,d1 |
| 101 | next_place: |
| 102 | addql #4,a1 |
| 103 | dbra d1,bcl2_search_place |
| 104 | |
| 105 | /* Restart interrupts */ |
| 106 | movew #0x2300,sr |
| 107 | badvector: |
| 108 | rts |
| 109 | |
| 110 | /*--- Our vbl ---*/ |
| 111 | |
| 112 | _my_vbl: |
| 113 | /* Update _hz_200 */ |
| 114 | movel _hz_200.w, _SDL_Atari_hz200 |
| 115 | |
| 116 | /* Verify if this is not already running */ |
| 117 | |
| 118 | tstw vbl_mutex |
| 119 | bnes vbl_end |
| 120 | notw vbl_mutex |
| 121 | |
| 122 | moveml d0-d7/a0-a6,sp@- |
| 123 | |
| 124 | /* Save FPU if needed */ |
| 125 | tstw _SDL_MintAudio_hasfpu |
| 126 | beqs SDL_AtariVbl_nofpu1 |
| 127 | .chip 68060 |
| 128 | fsave sp@- |
| 129 | fmoveml fpcr/fpsr/fpiar,sp@- |
| 130 | fmovemx fp0-fp7,sp@- |
| 131 | .chip 68000 |
| 132 | SDL_AtariVbl_nofpu1: |
| 133 | |
| 134 | movel my_vector,a0 |
| 135 | jsr a0@ |
| 136 | |
| 137 | /* Restore FPU if needed */ |
| 138 | tstw _SDL_MintAudio_hasfpu |
| 139 | beqs SDL_AtariVbl_Xbios_nofpu2 |
| 140 | .chip 68060 |
| 141 | fmovemx sp@+,fp0-fp7 |
| 142 | fmoveml sp@+,fpcr/fpsr/fpiar |
| 143 | frestore sp@+ |
| 144 | .chip 68000 |
| 145 | SDL_AtariVbl_Xbios_nofpu2: |
| 146 | |
| 147 | moveml sp@+,d0-d7/a0-a6 |
| 148 | |
| 149 | clrw vbl_mutex |
| 150 | vbl_end: |
| 151 | rts |
| 152 | |
| 153 | .data |
| 154 | .even |
| 155 | .comm _SDL_Atari_hz200,4*1 |
| 156 | .even |
| 157 | .comm vbl_mutex,2*1 |
| 158 | .even |
| 159 | .comm my_vector,4*1 |