/* SDL - Simple DirectMedia Layer Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org */ /* Audio interrupts Patrice Mandin, Didier Méquignon */ .text .globl _SDL_MintAudio_Callback .globl _SDL_MintAudio_XbiosInterrupt .globl _SDL_MintAudio_XbiosInterruptMeasureClock .globl _SDL_MintAudio_Dma8Interrupt .globl _SDL_MintAudio_StfaInterrupt .globl _SDL_MintAudio_mutex .globl _SDL_MintAudio_audiobuf .globl _SDL_MintAudio_numbuf .globl _SDL_MintAudio_audiosize .globl _SDL_MintAudio_clocktics .globl _SDL_MintAudio_hasfpu .globl _SDL_MintAudio_stfa /* How it works: - Audio is playing buffer #0 (resp. #1) - We must calculate a sample in buffer #1 (resp. #0) so we first call the callback to do it - Then we swap the buffers */ #define savptr 0x4a2 #define savamt 0x46 /*--- Xbios interrupt vector to measure Falcon external clock ---*/ _SDL_MintAudio_XbiosInterruptMeasureClock: /* 1 mS */ btst #0,0xFFFF8901:w /* state DMA sound */ beqs SDL_MintAudio_EndIntMeasure addql #1,_SDL_MintAudio_clocktics SDL_MintAudio_EndIntMeasure: bclr #5,0xFFFFFA0F:w /* Clear service bit */ rte /*--- Xbios interrupt vector ---*/ _SDL_MintAudio_XbiosInterrupt: /* Reenable interrupts, so other interrupts can work */ movew #0x2300,sr /* Clear service bit, so other MFP interrupts can work */ bclr #5,0xfffffa0f:w /* Check if we are not already running */ tstw _SDL_MintAudio_mutex bne SDL_MintAudio_XbiosEnd notw _SDL_MintAudio_mutex /* Swap buffers */ eorw #1,_SDL_MintAudio_numbuf moveml d0-d7/a0-a6,sp@- /* Save FPU if needed */ tstw _SDL_MintAudio_hasfpu beqs SDL_MintAudio_Xbios_nofpu1 .chip 68060 fsave sp@- fmoveml fpcr/fpsr/fpiar,sp@- fmovemx fp0-fp7,sp@- .chip 68000 SDL_MintAudio_Xbios_nofpu1: /* Callback */ jsr _SDL_MintAudio_Callback /* Restore FPU if needed */ tstw _SDL_MintAudio_hasfpu beqs SDL_MintAudio_Xbios_nofpu2 .chip 68060 fmovemx sp@+,fp0-fp7 fmoveml sp@+,fpcr/fpsr/fpiar frestore sp@+ .chip 68000 SDL_MintAudio_Xbios_nofpu2: /* Reserve space for registers */ subl #savamt,savptr /* Set new buffer */ moveq #0,d0 movel _SDL_MintAudio_audiosize,d1 movew _SDL_MintAudio_numbuf,d0 lsll #2,d0 lea _SDL_MintAudio_audiobuf,a0 movel a0@(d0:l),a1 lea a1@(d1:l),a2 movel a2,sp@- movel a1,sp@- clrw sp@- movew #131,sp@- trap #14 lea sp@(12),sp /* Restore registers space */ addl #savamt,savptr moveml sp@+,d0-d7/a0-a6 clrw _SDL_MintAudio_mutex SDL_MintAudio_XbiosEnd: rte /*--- DMA 8 bits interrupt vector ---*/ _SDL_MintAudio_Dma8Interrupt: /* Reenable interrupts, so other interrupts can work */ movew #0x2300,sr /* Clear service bit, so other MFP interrupts can work */ bclr #5,0xfffffa0f:w /* Check if we are not already running */ tstw _SDL_MintAudio_mutex bne SDL_MintAudio_Dma8End notw _SDL_MintAudio_mutex /* Swap buffers */ eorw #1,_SDL_MintAudio_numbuf moveml d0-d1/a0-a1,sp@- /* Save FPU if needed */ tstw _SDL_MintAudio_hasfpu beqs SDL_MintAudio_Dma8_nofpu1 .chip 68060 fsave sp@- fmoveml fpcr/fpsr/fpiar,sp@- fmovemx fp0-fp7,sp@- .chip 68000 SDL_MintAudio_Dma8_nofpu1: /* Callback */ jsr _SDL_MintAudio_Callback /* Restore FPU if needed */ tstw _SDL_MintAudio_hasfpu beqs SDL_MintAudio_Dma8_nofpu2 .chip 68060 fmovemx sp@+,fp0-fp7 fmoveml sp@+,fpcr/fpsr/fpiar frestore sp@+ .chip 68000 SDL_MintAudio_Dma8_nofpu2: /* Set new buffer */ moveq #0,d0 movew _SDL_MintAudio_numbuf,d0 lslw #2,d0 lea _SDL_MintAudio_audiobuf,a0 movel a0@(d0:w),d1 /* Modify DMA addresses */ lea 0xffff8900:w,a0 moveb d1,a0@(0x07) /* Start address */ rorl #8,d1 moveb d1,a0@(0x05) rorl #8,d1 moveb d1,a0@(0x03) swap d1 addl _SDL_MintAudio_audiosize,d1 moveb d1,a0@(0x13) /* End address */ rorl #8,d1 moveb d1,a0@(0x11) rorl #8,d1 moveb d1,a0@(0x0f) moveml sp@+,d0-d1/a0-a1 clrw _SDL_MintAudio_mutex SDL_MintAudio_Dma8End: rte /*--- STFA interrupt vector ---*/ STFA_SOUND_START = 6 STFA_SOUND_END = STFA_SOUND_START+8 _SDL_MintAudio_StfaInterrupt: /* Reenable interrupts, so other interrupts can work */ movew #0x2300,sr /* Check if we are not already running */ tstw _SDL_MintAudio_mutex bnes SDL_MintAudio_StfaEnd notw _SDL_MintAudio_mutex /* Swap buffers */ eorw #1,_SDL_MintAudio_numbuf moveml d0-d7/a0-a6,sp@- /* Save FPU if needed */ tstw _SDL_MintAudio_hasfpu beqs SDL_MintAudio_Stfa_nofpu1 .chip 68060 fsave sp@- fmoveml fpcr/fpsr/fpiar,sp@- fmovemx fp0-fp7,sp@- .chip 68000 SDL_MintAudio_Stfa_nofpu1: /* Callback */ jsr _SDL_MintAudio_Callback /* Restore FPU if needed */ tstw _SDL_MintAudio_hasfpu beqs SDL_MintAudio_Stfa_nofpu2 .chip 68060 fmovemx sp@+,fp0-fp7 fmoveml sp@+,fpcr/fpsr/fpiar frestore sp@+ .chip 68000 SDL_MintAudio_Stfa_nofpu2: /* Set new buffer */ moveq #0,d0 movel _SDL_MintAudio_stfa,a1 movew _SDL_MintAudio_numbuf,d0 lslw #2,d0 lea _SDL_MintAudio_audiobuf,a0 movel a0@(d0:w),d1 /* Modify STFA replay buffers */ movel d1,a1@(STFA_SOUND_START) addl _SDL_MintAudio_audiosize,d1 movel d1,a1@(STFA_SOUND_END) moveml sp@+,d0-d7/a0-a6 clrw _SDL_MintAudio_mutex SDL_MintAudio_StfaEnd: rte