gusemu_hal.c

来自「xen虚拟机源代码安装包」· C语言 代码 · 共 555 行 · 第 1/2 页

/*
 * GUSEMU32 - bus interface part
 *
 * 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.
 */

/*
 * TODO: check mixer: see 7.20 of sdk for panning pos (applies to all gus models?)?
 */

#include "gustate.h"
#include "gusemu.h"

#define GUSregb(position) (*            (gusptr+(position)))
#define GUSregw(position) (*(GUSword *) (gusptr+(position)))
#define GUSregd(position) (*(GUSdword *)(gusptr+(position)))

/* size given in bytes */
unsigned int gus_read(GUSEmuState * state, int port, int size)
{
    int             value_read = 0;

    GUSbyte        *gusptr;
    gusptr = state->gusdatapos;
    GUSregd(portaccesses)++;

    switch (port & 0xff0f)
    {
        /* MixerCtrlReg (read not supported on GUS classic) */
        /* case 0x200: return GUSregb(MixerCtrlReg2x0); */
    case 0x206:                          /* IRQstatReg / SB2x6IRQ */
        /* adlib/sb bits set in port handlers */
        /* timer/voice bits set in gus_irqgen() */
        /* dma bit set in gus_dma_transferdata */
        /* midi not implemented yet */
        return GUSregb(IRQStatReg2x6);
    /* case 0x308:                       */ /* AdLib388 */
    case 0x208:
        if (GUSregb(GUS45TimerCtrl) & 1)
            return GUSregb(TimerStatus2x8);
        return GUSregb(AdLibStatus2x8);  /* AdLibStatus */
    case 0x309:                          /* AdLib389 */
    case 0x209:
        return GUSregb(AdLibData2x9);    /* AdLibData */
    case 0x20A:
        return GUSregb(AdLibCommand2xA); /* AdLib2x8_2xA */

#if 0
    case 0x20B:                          /* GUS hidden registers (read not supported on GUS classic) */
        switch (GUSregb(RegCtrl_2xF) & 0x07)
        {
        case 0:                                 /* IRQ/DMA select */
            if (GUSregb(MixerCtrlReg2x0) & 0x40)
                return GUSregb(IRQ_2xB);        /* control register select bit */
            else
                return GUSregb(DMA_2xB);
            /* case 1-5:                        */ /* general purpose emulation regs  */
            /*  return ...                      */ /* + status reset reg (write only) */
        case 6:
            return GUSregb(Jumper_2xB);         /* Joystick/MIDI enable (JumperReg) */
        default:;
        }
        break;
#endif

    case 0x20C:                          /* SB2xCd */
        value_read = GUSregb(SB2xCd);
        if (GUSregb(StatRead_2xF) & 0x20)
            GUSregb(SB2xCd) ^= 0x80; /* toggle MSB on read */
        return value_read;
        /* case 0x20D:                   */ /* SB2xD is write only -> 2xE writes to it*/
    case 0x20E:
        if (GUSregb(RegCtrl_2xF) & 0x80) /* 2xE read IRQ enabled? */
        {
            GUSregb(StatRead_2xF) |= 0x80;
            GUS_irqrequest(state, state->gusirq, 1);
        }
        return GUSregb(SB2xE);           /* SB2xE */
    case 0x20F:                          /* StatRead_2xF */
        /*set/clear fixed bits */
        /*value_read = (GUSregb(StatRead_2xF) & 0xf9)|1; */ /*(LSB not set on GUS classic!)*/
        value_read = (GUSregb(StatRead_2xF) & 0xf9);
        if (GUSregb(MixerCtrlReg2x0) & 0x08)
            value_read |= 2;    /* DMA/IRQ enabled flag */
        return value_read;
    /* case 0x300:                      */ /* MIDI (not implemented) */
    /* case 0x301:                      */ /* MIDI (not implemented) */
    case 0x302:
        return GUSregb(VoiceSelReg3x2); /* VoiceSelReg */
    case 0x303:
        return GUSregb(FunkSelReg3x3);  /* FunkSelReg */
    case 0x304:                         /* DataRegLoByte3x4 + DataRegWord3x4 */
    case 0x305:                         /* DataRegHiByte3x5 */
        switch (GUSregb(FunkSelReg3x3))
        {
    /* common functions */
        case 0x41:                      /* DramDMAContrReg */
            value_read = GUSregb(GUS41DMACtrl); /* &0xfb */
            GUSregb(GUS41DMACtrl) &= 0xbb;
            if (state->gusdma >= 4)
                value_read |= 0x04;
            if (GUSregb(IRQStatReg2x6) & 0x80)
            {
                value_read |= 0x40;
                GUSregb(IRQStatReg2x6) &= 0x7f;
                if (!GUSregb(IRQStatReg2x6))
                    GUS_irqclear(state, state->gusirq);
            }
            return (GUSbyte) value_read;
            /* DramDMAmemPosReg */
            /* case 0x42: value_read=GUSregw(GUS42DMAStart); break;*/
            /* 43h+44h write only */
        case 0x45:
            return GUSregb(GUS45TimerCtrl);         /* TimerCtrlReg */
            /* 46h+47h write only */
            /* 48h: samp freq - write only */
        case 0x49:
            return GUSregb(GUS49SampCtrl) & 0xbf;   /* SampCtrlReg */
        /* case 4bh:                                */ /* joystick trim not supported */
        /* case 0x4c: return GUSregb(GUS4cReset);   */ /* GUSreset: write only*/
    /* voice specific functions */
        case 0x80:
        case 0x81:
        case 0x82:
        case 0x83:
        case 0x84:
        case 0x85:
        case 0x86:
        case 0x87:
        case 0x88:
        case 0x89:
        case 0x8a:
        case 0x8b:
        case 0x8c:
        case 0x8d:
            {
                int             offset = 2 * (GUSregb(FunkSelReg3x3) & 0x0f);
                offset += ((int) GUSregb(VoiceSelReg3x2) & 0x1f) << 5; /* = Voice*32 + Funktion*2 */
                value_read = GUSregw(offset);
            }
            break;
    /* voice unspecific functions */
        case 0x8e:                                  /* NumVoice */
            return GUSregb(NumVoices);
        case 0x8f:                                  /* irqstatreg */
            /* (pseudo IRQ-FIFO is processed during a gus_write(0x3X3,0x8f)) */
            return GUSregb(SynVoiceIRQ8f);
        default:
            return 0xffff;
        }
        if (size == 1)
        {
            if ((port & 0xff0f) == 0x305)
                value_read = value_read >> 8;
            value_read &= 0xff;
        }
        return (GUSword) value_read;
    /* case 0x306:                                  */ /* Mixer/Version info */
        /*  return 0xff; */ /* Pre 3.6 boards, ICS mixer NOT present */
    case 0x307:                                     /* DRAMaccess */
        {
            GUSbyte        *adr;
            adr = state->himemaddr + (GUSregd(GUSDRAMPOS24bit) & 0xfffff);
            return *adr;
        }
    default:;
    }
    return 0xffff;
}

void gus_write(GUSEmuState * state, int port, int size, unsigned int data)
{
    GUSbyte        *gusptr;
    gusptr = state->gusdatapos;
    GUSregd(portaccesses)++;

    switch (port & 0xff0f)
    {
    case 0x200:                 /* MixerCtrlReg */
        GUSregb(MixerCtrlReg2x0) = (GUSbyte) data;
        break;
    case 0x206:                 /* IRQstatReg / SB2x6IRQ */
        if (GUSregb(GUS45TimerCtrl) & 0x20) /* SB IRQ enabled? -> set 2x6IRQ bit */
        {
            GUSregb(TimerStatus2x8) |= 0x08;
            GUSregb(IRQStatReg2x6) = 0x10;
            GUS_irqrequest(state, state->gusirq, 1);
        }
        break;
    case 0x308:                /* AdLib 388h */
    case 0x208:                /* AdLibCommandReg */
        GUSregb(AdLibCommand2xA) = (GUSbyte) data;
        break;
    case 0x309:                /* AdLib 389h */
    case 0x209:                /* AdLibDataReg */
        if ((GUSregb(AdLibCommand2xA) == 0x04) && (!(GUSregb(GUS45TimerCtrl) & 1))) /* GUS auto timer mode enabled? */
        {
            if (data & 0x80)
                GUSregb(TimerStatus2x8) &= 0x1f; /* AdLib IRQ reset? -> clear maskable adl. timer int regs */
            else
                GUSregb(TimerDataReg2x9) = (GUSbyte) data;
        }
        else
        {
            GUSregb(AdLibData2x9) = (GUSbyte) data;
            if (GUSregb(GUS45TimerCtrl) & 0x02)
            {
                GUSregb(TimerStatus2x8) |= 0x01;
                GUSregb(IRQStatReg2x6) = 0x10;
                GUS_irqrequest(state, state->gusirq, 1);
            }
        }
        break;
    case 0x20A:
        GUSregb(AdLibStatus2x8) = (GUSbyte) data;
        break;                 /* AdLibStatus2x8 */
    case 0x20B:                /* GUS hidden registers */
        switch (GUSregb(RegCtrl_2xF) & 0x7)
        {
        case 0:
            if (GUSregb(MixerCtrlReg2x0) & 0x40)
                GUSregb(IRQ_2xB) = (GUSbyte) data; /* control register select bit */
            else
                GUSregb(DMA_2xB) = (GUSbyte) data;
            break;
            /* case 1-4: general purpose emulation regs */
        case 5:                                    /* clear stat reg 2xF */
            GUSregb(StatRead_2xF) = 0; /* ToDo: is this identical with GUS classic? */
            if (!GUSregb(IRQStatReg2x6))
                GUS_irqclear(state, state->gusirq);
            break;
        case 6:                                    /* Jumper reg (Joystick/MIDI enable) */
            GUSregb(Jumper_2xB) = (GUSbyte) data;
            break;
        default:;
        }
        break;
    case 0x20C:                /* SB2xCd */
        if (GUSregb(GUS45TimerCtrl) & 0x20)
        {
            GUSregb(TimerStatus2x8) |= 0x10; /* SB IRQ enabled? -> set 2xCIRQ bit */
            GUSregb(IRQStatReg2x6) = 0x10;
            GUS_irqrequest(state, state->gusirq, 1);
        }
    case 0x20D:                /* SB2xCd no IRQ */
        GUSregb(SB2xCd) = (GUSbyte) data;
        break;
    case 0x20E:                /* SB2xE */
        GUSregb(SB2xE) = (GUSbyte) data;
        break;
    case 0x20F:
        GUSregb(RegCtrl_2xF) = (GUSbyte) data;
        break;                 /* CtrlReg2xF */
    case 0x302:                /* VoiceSelReg */
        GUSregb(VoiceSelReg3x2) = (GUSbyte) data;
        break;
    case 0x303:                /* FunkSelReg */
        GUSregb(FunkSelReg3x3) = (GUSbyte) data;
        if ((GUSbyte) data == 0x8f) /* set irqstatreg, get voicereg and clear IRQ */
        {