| /* |
| SDL - Simple DirectMedia Layer |
| Copyright (C) 1997-2006 Sam Lantinga |
| |
| This library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| This library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with this library; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| |
| Sam Lantinga |
| slouken@libsdl.org |
| */ |
| |
| /* |
| * VBL queue routine |
| * |
| * Patrice Mandin |
| */ |
| |
| #define _vbl_queue 0x456 |
| #define _hz_200 0x4ba |
| |
| .text |
| |
| .globl _SDL_AtariVblInstall |
| .globl _SDL_AtariVblUninstall |
| |
| .globl _SDL_MintAudio_hasfpu |
| |
| /*--- Vector installer ---*/ |
| |
| _SDL_AtariVblInstall: |
| movel sp@(4),my_vector |
| lea _my_vbl,a0 |
| |
| clrw vbl_mutex |
| movel _hz_200.w, _SDL_Atari_hz200 |
| |
| /* Stop interrupts */ |
| |
| movew #0x2700,sr |
| |
| /* Read vbl_queue pointer */ |
| movel _vbl_queue.w,a1 |
| |
| /* Search a free place */ |
| moveq #7,d0 |
| bcl_search_place: |
| movel (a1),d1 |
| beqs place_found |
| addql #4,a1 |
| dbra d0,bcl_search_place |
| |
| /* Not found */ |
| moveq #1,d0 |
| bras exit_vbl_queue |
| |
| /* Then install ourselves */ |
| place_found: |
| movel a0,(a1) |
| moveq #0,d0 |
| |
| exit_vbl_queue: |
| /* Restart interrupts */ |
| movew #0x2300,sr |
| |
| rts |
| |
| /*--- Vector uninstaller ---*/ |
| |
| _SDL_AtariVblUninstall: |
| movel sp@(4),d0 |
| cmpl my_vector,d0 |
| bnes badvector |
| |
| movel #_my_vbl,d0 |
| |
| /* Stop interrupts */ |
| |
| movew #0x2700,sr |
| |
| /* Read vbl_queue pointer */ |
| movel _vbl_queue.w,a1 |
| |
| /* Search where we are */ |
| moveq #7,d1 |
| bcl2_search_place: |
| cmpl (a1),d0 |
| bnes next_place |
| clrl (a1) |
| moveq #0,d1 |
| next_place: |
| addql #4,a1 |
| dbra d1,bcl2_search_place |
| |
| /* Restart interrupts */ |
| movew #0x2300,sr |
| badvector: |
| rts |
| |
| /*--- Our vbl ---*/ |
| |
| _my_vbl: |
| /* Update _hz_200 */ |
| movel _hz_200.w, _SDL_Atari_hz200 |
| |
| /* Verify if this is not already running */ |
| |
| tstw vbl_mutex |
| bnes vbl_end |
| notw vbl_mutex |
| |
| moveml d0-d7/a0-a6,sp@- |
| |
| /* Save FPU if needed */ |
| tstw _SDL_MintAudio_hasfpu |
| beqs SDL_AtariVbl_nofpu1 |
| .chip 68060 |
| fsave sp@- |
| fmoveml fpcr/fpsr/fpiar,sp@- |
| fmovemx fp0-fp7,sp@- |
| .chip 68000 |
| SDL_AtariVbl_nofpu1: |
| |
| movel my_vector,a0 |
| jsr a0@ |
| |
| /* Restore FPU if needed */ |
| tstw _SDL_MintAudio_hasfpu |
| beqs SDL_AtariVbl_Xbios_nofpu2 |
| .chip 68060 |
| fmovemx sp@+,fp0-fp7 |
| fmoveml sp@+,fpcr/fpsr/fpiar |
| frestore sp@+ |
| .chip 68000 |
| SDL_AtariVbl_Xbios_nofpu2: |
| |
| moveml sp@+,d0-d7/a0-a6 |
| |
| clrw vbl_mutex |
| vbl_end: |
| rts |
| |
| .data |
| .even |
| .comm _SDL_Atari_hz200,4*1 |
| .even |
| .comm vbl_mutex,2*1 |
| .even |
| .comm my_vector,4*1 |