diff src/audio/mint/SDL_mintaudiointerrupt.S @ 398:d219b0e02f5f

Added Atari audio support (thanks Patrice!)
author Sam Lantinga <slouken@libsdl.org>
date Mon, 10 Jun 2002 20:42:53 +0000
parents
children 1338c24e30cb
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/audio/mint/SDL_mintaudiointerrupt.S	Mon Jun 10 20:42:53 2002 +0000
@@ -0,0 +1,183 @@
+/*
+ *	Audio interrupt routines
+ *
+ *	Patrice Mandin
+ */
+
+	.text
+
+	.globl	_SDL_MintAudio_Callback
+
+	.globl	_SDL_MintAudio_IntDma
+	.globl	_SDL_MintAudio_IntXbios
+	.globl	_SDL_MintAudio_IntGsxb
+
+	.globl	_SDL_MintAudio_mutex
+	.globl	_SDL_MintAudio_audiobuf
+	.globl	_SDL_MintAudio_numbuf
+	.globl	_SDL_MintAudio_audiosize
+
+/*
+	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
+*/
+
+/*--- DMA 8 bits interrupt vector ---*/
+
+	.text
+_SDL_MintAudio_IntDma:
+
+	/* Check if we are not already running */
+	tstw	_SDL_MintAudio_mutex
+	bnes	intdma_end
+	notw	_SDL_MintAudio_mutex
+	
+	/* Reenable interrupts */
+	movew	#0x2300,sr
+
+	/* Swap buffers */
+	moveml	d0-d1/a0-a1,sp@-
+
+	movel	_SDL_MintAudio_numbuf,d0
+	movel	_SDL_MintAudio_audiobuf,d1
+	eorl	#1,d0
+	beqs	intdma_buffer0
+	movel	_SDL_MintAudio_audiobuf+4,d1
+intdma_buffer0:
+	movel	d0,_SDL_MintAudio_numbuf
+
+	/* Callback */
+	movel	d1,sp@-
+	jsr	_SDL_MintAudio_Callback
+	movel	sp@+,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
+intdma_end:
+	bclr	#5,0xfffffa0f:w
+	rte
+
+/*--- Xbios interrupt vector ---*/
+
+	.text
+_SDL_MintAudio_IntXbios:
+
+	/* Check if we are not already running */
+	tstw	_SDL_MintAudio_mutex
+	bnes	intxbios_end
+	notw	_SDL_MintAudio_mutex
+	
+	/* Reenable interrupts */
+	movew	#0x2300,sr
+
+	/* Swap buffers */
+	moveml	d0-d2/a0-a2,sp@-
+
+	movel	_SDL_MintAudio_numbuf,d0
+	movel	_SDL_MintAudio_audiobuf,a0
+	eorl	#1,d0
+	beqs	intxbios_buffer0
+	movel	_SDL_MintAudio_audiobuf+4,a0
+intxbios_buffer0:
+	movel	d0,_SDL_MintAudio_numbuf
+
+	/* Callback */
+	moveml	a0,sp@-
+	jsr	_SDL_MintAudio_Callback
+	moveml	sp@+,a0
+
+	/* Setbuffer xbios function */
+	movel	_SDL_MintAudio_audiosize,d1
+	lea	a0@(0,d1:l),a1
+
+	movel	a1,sp@-
+	movel	a0,sp@-
+	clrw	sp@-
+	movew	#131,sp@-
+	trap	#14
+	lea	sp@(12),sp
+
+	moveml	sp@+,d0-d2/a0-a2
+
+	clrw	_SDL_MintAudio_mutex
+intxbios_end:
+	bclr	#5,0xfffffa0f:w
+	rte
+
+/*--- GSXB interrupt vector ---*/
+
+	.text
+_SDL_MintAudio_IntGsxb:
+
+	/* Check if we are not already running */
+	tstw	_SDL_MintAudio_mutex
+	bnes	intgsxb_end
+	notw	_SDL_MintAudio_mutex
+
+	/* Swap buffers */
+	moveml	d0-d2/a0-a2,sp@-
+
+	movel	_SDL_MintAudio_numbuf,d0
+	movel	_SDL_MintAudio_audiobuf,a0
+	eorl	#1,d0
+	beqs	intgsxb_buffer0
+	movel	_SDL_MintAudio_audiobuf+4,a0
+intgsxb_buffer0:
+	movel	d0,_SDL_MintAudio_numbuf
+
+	/* Callback */
+	moveml	a0,sp@-
+	jsr	_SDL_MintAudio_Callback
+	moveml	sp@+,a0
+
+	/* Setbuffer xbios function */
+	movel	_SDL_MintAudio_audiosize,d1
+	lea	a0@(0,d1:l),a1
+
+	movel	a1,sp@-
+	movel	a0,sp@-
+	clrw	sp@-
+	movew	#131,sp@-
+	trap	#14
+	lea	sp@(12),sp
+
+	moveml	sp@+,d0-d2/a0-a2
+
+	clrw	_SDL_MintAudio_mutex
+intgsxb_end:
+	rts
+
+/*--- Common variables ---*/
+
+	.data
+	.even
+	.comm	_SDL_MintAudio_mutex,4
+	.even
+	.comm	_SDL_MintAudio_audiobuf,8
+	.even
+	.comm	_SDL_MintAudio_numbuf,4
+	.even
+	.comm	_SDL_MintAudio_audiosize,4
+