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Diffstat (limited to 'hw/audio/gusemu.h')
| -rw-r--r-- | hw/audio/gusemu.h | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/hw/audio/gusemu.h b/hw/audio/gusemu.h new file mode 100644 index 000000000..ab591eefb --- /dev/null +++ b/hw/audio/gusemu.h @@ -0,0 +1,88 @@ +/* + * GUSEMU32 - API + * + * Copyright (C) 2000-2007 Tibor "TS" Schütz + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#ifndef GUSEMU_H +#define GUSEMU_H + +typedef struct _GUSEmuState +{ + uint8_t *himemaddr; /* 1024*1024 bytes used for storing uploaded samples (+32 additional bytes for read padding) */ + uint8_t *gusdatapos; /* (gusdataend-gusdata) bytes used for storing emulated GF1/mixer register states (32*32+4 bytes in initial GUSemu32 version) */ + uint32_t gusirq; + uint32_t gusdma; + unsigned int timer1fraction; + unsigned int timer2fraction; + void *opaque; +} GUSEmuState; + +/* ** Callback functions needed: */ +/* NMI is defined as hwirq=-1 (not supported (yet?)) */ +/* GUS_irqrequest returns the number of IRQs actually scheduled into the virtual machine */ +/* Level triggered IRQ simulations normally return 1 */ +/* Event triggered IRQ simulation can safely ignore GUS_irqclear calls */ +int GUS_irqrequest(GUSEmuState *state, int hwirq, int num);/* needed in both mixer and bus emulation functions. */ +void GUS_irqclear( GUSEmuState *state, int hwirq); /* used by gus_write() only - can be left empty for mixer functions */ +void GUS_dmarequest(GUSEmuState *state); /* used by gus_write() only - can be left empty for mixer functions */ + +/* ** ISA bus interface functions: */ + +/* Port I/O handlers */ +/* support the following ports: */ +/* 2x0,2x6,2x8...2xF,3x0...3x7; */ +/* optional: 388,389 (at least writes should be forwarded or some GUS detection algorithms will fail) */ +/* data is passed in host byte order */ +unsigned int gus_read( GUSEmuState *state, int port, int size); +void gus_write(GUSEmuState *state, int port, int size, unsigned int data); +/* size is given in bytes (1 for byte, 2 for word) */ + +/* DMA data transfer function */ +/* data pointed to is passed in native x86 order */ +void gus_dma_transferdata(GUSEmuState *state, char *dma_addr, unsigned int count, int TC); +/* Called back by GUS_start_DMA as soon as the emulated DMA controller is ready for a transfer to or from GUS */ +/* (might be immediately if the DMA controller was programmed first) */ +/* dma_addr is an already translated address directly pointing to the beginning of the memory block */ +/* do not forget to update DMA states after the call, including the DREQ and TC flags */ +/* it is possible to break down a single transfer into multiple ones, but take care that: */ +/* -dma_count is actually count-1 */ +/* -before and during a transfer, DREQ is set and TC cleared */ +/* -when calling gus_dma_transferdata(), TC is only set true for call transferring the last byte */ +/* -after the last transfer, DREQ is cleared and TC is set */ + +/* ** GF1 mixer emulation functions: */ +/* Usually, gus_irqgen should be called directly after gus_mixvoices if you can meet the recommended ranges. */ +/* If the interrupts are executed immediately (i.e., are synchronous), it may be useful to break this */ +/* down into a sequence of gus_mixvoice();gus_irqgen(); calls while mixing an audio block. */ +/* If the interrupts are asynchronous, it may be needed to use a separate thread mixing into a temporary */ +/* audio buffer in order to avoid quality loss caused by large numsamples and elapsed_time values. */ + +void gus_mixvoices(GUSEmuState *state, unsigned int playback_freq, unsigned int numsamples, int16_t *bufferpos); +/* recommended range: 10 < numsamples < 100 */ +/* lower values may result in increased rounding error, higher values often cause audible timing delays */ + +void gus_irqgen(GUSEmuState *state, unsigned int elapsed_time); +/* recommended range: 80us < elapsed_time < max(1000us, numsamples/playback_freq) */ +/* lower values won´t provide any benefit at all, higher values can cause audible timing delays */ +/* note: masked timers are also calculated by this function, thus it might be needed even without any IRQs in use! */ + +#endif /* GUSEMU_H */ |