PCI AC97 emulation by malc.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3918 c046a42c-6fe2-441c-8c8c-71466251a162

5 files changed, 1382 insertions, 2 deletions

diff --git a/configure b/configure
index 6de2fbff7c..59fdc758ec 100755
--- a/configure
+++ b/configure
@@ -85,6 +85,7 @@ EXESUF=""
 gdbstub="yes"
 slirp="yes"
 adlib="no"
+ac97="no"
 oss="no"
 dsound="no"
 coreaudio="no"
@@ -280,6 +281,8 @@ for opt do
   ;;
   --enable-adlib) adlib="yes"
   ;;
+  --enable-ac97) ac97="yes"
+  ;;
   --disable-kqemu) kqemu="no"
   ;;
   --enable-profiler) profiler="yes"
@@ -406,6 +409,7 @@ echo "  --disable-sdl            disable SDL"
 echo "  --enable-cocoa           enable COCOA (Mac OS X only)"
 echo "  --enable-mingw32         enable Win32 cross compilation with mingw32"
 echo "  --enable-adlib           enable Adlib emulation"
+echo "  --enable-ac97            enable AC97 emulation"
 echo "  --enable-coreaudio       enable Coreaudio audio driver"
 echo "  --enable-alsa            enable ALSA audio driver"
 echo "  --enable-esd             enable EsoundD audio driver"
@@ -719,6 +723,7 @@ if test "$sdl" != "no" ; then
 fi
 echo "mingw32 support   $mingw32"
 echo "Adlib support     $adlib"
+echo "AC97 support      $ac97"
 echo "CoreAudio support $coreaudio"
 echo "ALSA support      $alsa"
 echo "EsounD support    $esd"
@@ -895,6 +900,10 @@ if test "$adlib" = "yes" ; then
   echo "CONFIG_ADLIB=yes" >> $config_mak
   echo "#define CONFIG_ADLIB 1" >> $config_h
 fi
+if test "$ac97" = "yes" ; then
+  echo "CONFIG_AC97=yes" >> $config_mak
+  echo "#define CONFIG_AC97 1" >> $config_h
+fi
 if test "$oss" = "yes" ; then
   echo "CONFIG_OSS=yes" >> $config_mak
   echo "#define CONFIG_OSS 1" >> $config_h
diff --git a/hw/ac97.c b/hw/ac97.c
new file mode 100644
index 0000000000..ba4ea1e513
--- /dev/null
+++ b/hw/ac97.c
@@ -0,0 +1,1349 @@
+/*
+ * Copyright (C) 2006 InnoTek Systemberatung GmbH
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License as published by the Free Software Foundation,
+ * in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
+ * distribution. VirtualBox OSE is distributed in the hope that it will
+ * be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * If you received this file as part of a commercial VirtualBox
+ * distribution, then only the terms of your commercial VirtualBox
+ * license agreement apply instead of the previous paragraph.
+ */
+
+#include "hw.h"
+#include "audiodev.h"
+#include "audio/audio.h"
+#include "pci.h"
+
+enum {
+    AC97_Reset                     = 0x00,
+    AC97_Master_Volume_Mute        = 0x02,
+    AC97_Headphone_Volume_Mute     = 0x04,
+    AC97_Master_Volume_Mono_Mute   = 0x06,
+    AC97_Master_Tone_RL            = 0x08,
+    AC97_PC_BEEP_Volume_Mute       = 0x0A,
+    AC97_Phone_Volume_Mute         = 0x0C,
+    AC97_Mic_Volume_Mute           = 0x0E,
+    AC97_Line_In_Volume_Mute       = 0x10,
+    AC97_CD_Volume_Mute            = 0x12,
+    AC97_Video_Volume_Mute         = 0x14,
+    AC97_Aux_Volume_Mute           = 0x16,
+    AC97_PCM_Out_Volume_Mute       = 0x18,
+    AC97_Record_Select             = 0x1A,
+    AC97_Record_Gain_Mute          = 0x1C,
+    AC97_Record_Gain_Mic_Mute      = 0x1E,
+    AC97_General_Purpose           = 0x20,
+    AC97_3D_Control                = 0x22,
+    AC97_AC_97_RESERVED            = 0x24,
+    AC97_Powerdown_Ctrl_Stat       = 0x26,
+    AC97_Extended_Audio_ID         = 0x28,
+    AC97_Extended_Audio_Ctrl_Stat  = 0x2A,
+    AC97_PCM_Front_DAC_Rate        = 0x2C,
+    AC97_PCM_Surround_DAC_Rate     = 0x2E,
+    AC97_PCM_LFE_DAC_Rate          = 0x30,
+    AC97_PCM_LR_ADC_Rate           = 0x32,
+    AC97_MIC_ADC_Rate              = 0x34,
+    AC97_6Ch_Vol_C_LFE_Mute        = 0x36,
+    AC97_6Ch_Vol_L_R_Surround_Mute = 0x38,
+    AC97_Vendor_Reserved           = 0x58,
+    AC97_Vendor_ID1                = 0x7c,
+    AC97_Vendor_ID2                = 0x7e
+};
+
+#define SOFT_VOLUME
+#define SR_FIFOE 16             /* rwc */
+#define SR_BCIS  8              /* rwc */
+#define SR_LVBCI 4              /* rwc */
+#define SR_CELV  2              /* ro */
+#define SR_DCH   1              /* ro */
+#define SR_VALID_MASK ((1 << 5) - 1)
+#define SR_WCLEAR_MASK (SR_FIFOE | SR_BCIS | SR_LVBCI)
+#define SR_RO_MASK (SR_DCH | SR_CELV)
+#define SR_INT_MASK (SR_FIFOE | SR_BCIS | SR_LVBCI)
+
+#define CR_IOCE  16             /* rw */
+#define CR_FEIE  8              /* rw */
+#define CR_LVBIE 4              /* rw */
+#define CR_RR    2              /* rw */
+#define CR_RPBM  1              /* rw */
+#define CR_VALID_MASK ((1 << 5) - 1)
+#define CR_DONT_CLEAR_MASK (CR_IOCE | CR_FEIE | CR_LVBIE)
+
+#define GC_WR    4              /* rw */
+#define GC_CR    2              /* rw */
+#define GC_VALID_MASK ((1 << 6) - 1)
+
+#define GS_MD3   (1<<17)        /* rw */
+#define GS_AD3   (1<<16)        /* rw */
+#define GS_RCS   (1<<15)        /* rwc */
+#define GS_B3S12 (1<<14)        /* ro */
+#define GS_B2S12 (1<<13)        /* ro */
+#define GS_B1S12 (1<<12)        /* ro */
+#define GS_S1R1  (1<<11)        /* rwc */
+#define GS_S0R1  (1<<10)        /* rwc */
+#define GS_S1CR  (1<<9)         /* ro */
+#define GS_S0CR  (1<<8)         /* ro */
+#define GS_MINT  (1<<7)         /* ro */
+#define GS_POINT (1<<6)         /* ro */
+#define GS_PIINT (1<<5)         /* ro */
+#define GS_RSRVD ((1<<4)|(1<<3))
+#define GS_MOINT (1<<2)         /* ro */
+#define GS_MIINT (1<<1)         /* ro */
+#define GS_GSCI  1              /* rwc */
+#define GS_RO_MASK (GS_B3S12|                   \
+                    GS_B2S12|                   \
+                    GS_B1S12|                   \
+                    GS_S1CR|                    \
+                    GS_S0CR|                    \
+                    GS_MINT|                    \
+                    GS_POINT|                   \
+                    GS_PIINT|                   \
+                    GS_RSRVD|                   \
+                    GS_MOINT|                   \
+                    GS_MIINT)
+#define GS_VALID_MASK ((1 << 18) - 1)
+#define GS_WCLEAR_MASK (GS_RCS|GS_S1R1|GS_S0R1|GS_GSCI)
+
+#define BD_IOC (1<<31)
+#define BD_BUP (1<<30)
+
+#define EACS_VRA 1
+#define EACS_VRM 8
+
+#define VOL_MASK 0x1f
+#define MUTE_SHIFT 15
+
+#define REC_MASK 7
+enum {
+    REC_MIC = 0,
+    REC_CD,
+    REC_VIDEO,
+    REC_AUX,
+    REC_LINE_IN,
+    REC_STEREO_MIX,
+    REC_MONO_MIX,
+    REC_PHONE
+};
+
+typedef struct BD {
+    uint32_t addr;
+    uint32_t ctl_len;
+} BD;
+
+typedef struct AC97BusMasterRegs {
+    uint32_t bdbar;             /* rw 0 */
+    uint8_t civ;                /* ro 0 */
+    uint8_t lvi;                /* rw 0 */
+    uint16_t sr;                /* rw 1 */
+    uint16_t picb;              /* ro 0 */
+    uint8_t piv;                /* ro 0 */
+    uint8_t cr;                 /* rw 0 */
+    unsigned int bd_valid;
+    BD bd;
+} AC97BusMasterRegs;
+
+typedef struct AC97LinkState {
+    PCIDevice *pci_dev;
+    QEMUSoundCard card;
+    uint32_t glob_cnt;
+    uint32_t glob_sta;
+    uint32_t cas;
+    uint32_t last_samp;
+    AC97BusMasterRegs bm_regs[3];
+    uint8_t mixer_data[256];
+    SWVoiceIn *voice_pi;
+    SWVoiceOut *voice_po;
+    SWVoiceIn *voice_mc;
+    uint8_t silence[128];
+    uint32_t base[2];
+    int bup_flag;
+} AC97LinkState;
+
+enum {
+    BUP_SET = 1,
+    BUP_LAST = 2
+};
+
+#ifdef DEBUG_AC97
+#define dolog(...) AUD_log ("ac97", __VA_ARGS__)
+#else
+#define dolog(...)
+#endif
+
+typedef struct PCIAC97LinkState {
+    PCIDevice dev;
+    AC97LinkState ac97;
+} PCIAC97LinkState;
+
+#define MKREGS(prefix, start)                   \
+enum {                                          \
+    prefix ## _BDBAR = start,                   \
+    prefix ## _CIV = start + 4,                 \
+    prefix ## _LVI = start + 5,                 \
+    prefix ## _SR = start + 6,                  \
+    prefix ## _PICB = start + 8,                \
+    prefix ## _PIV = start + 10,                \
+    prefix ## _CR = start + 11                  \
+}
+
+enum {
+    PI_INDEX = 0,
+    PO_INDEX,
+    MC_INDEX,
+    LAST_INDEX
+};
+
+MKREGS (PI, PI_INDEX * 16);
+MKREGS (PO, PO_INDEX * 16);
+MKREGS (MC, MC_INDEX * 16);
+
+enum {
+    GLOB_CNT = 0x2c,
+    GLOB_STA = 0x30,
+    CAS      = 0x34
+};
+
+#define GET_BM(index) (((index) >> 4) & 3)
+
+static void po_callback (void *opaque, int free);
+static void pi_callback (void *opaque, int avail);
+static void mc_callback (void *opaque, int avail);
+
+static void warm_reset (AC97LinkState *s)
+{
+    (void) s;
+}
+
+static void cold_reset (AC97LinkState * s)
+{
+    (void) s;
+}
+
+static void fetch_bd (AC97LinkState *s, AC97BusMasterRegs *r)
+{
+    uint8_t b[8];
+
+    cpu_physical_memory_read (r->bdbar + r->civ * 8, b, 8);
+    r->bd_valid = 1;
+    r->bd.addr = le32_to_cpu (*(uint32_t *) &b[0]) & ~3;
+    r->bd.ctl_len = le32_to_cpu (*(uint32_t *) &b[4]);
+    r->picb = r->bd.ctl_len & 0xffff;
+    dolog ("bd %2d addr=%#x ctl=%#06x len=%#x(%d bytes)\n",
+           r->civ, r->bd.addr, r->bd.ctl_len >> 16,
+           r->bd.ctl_len & 0xffff,
+           (r->bd.ctl_len & 0xffff) << 1);
+}
+
+static void update_sr (AC97LinkState *s, AC97BusMasterRegs *r, uint32_t new_sr)
+{
+    int event = 0;
+    int level = 0;
+    uint32_t new_mask = new_sr & SR_INT_MASK;
+    uint32_t old_mask = r->sr & SR_INT_MASK;
+    uint32_t masks[] = {GS_PIINT, GS_POINT, GS_MINT};
+
+    if (new_mask ^ old_mask) {
+        /** @todo is IRQ deasserted when only one of status bits is cleared? */
+        if (!new_mask) {
+            event = 1;
+            level = 0;
+        }
+        else {
+            if ((new_mask & SR_LVBCI) && (r->cr & CR_LVBIE)) {
+                event = 1;
+                level = 1;
+            }
+            if ((new_mask & SR_BCIS) && (r->cr & CR_IOCE)) {
+                event = 1;
+                level = 1;
+            }
+        }
+    }
+
+    r->sr = new_sr;
+
+    dolog ("IOC%d LVB%d sr=%#x event=%d level=%d\n",
+           r->sr & SR_BCIS, r->sr & SR_LVBCI,
+           r->sr,
+           event, level);
+
+    if (!event)
+        return;
+
+    if (level) {
+        s->glob_sta |= masks[r - s->bm_regs];
+        dolog ("set irq level=1\n");
+        qemu_set_irq(s->pci_dev->irq[0], 1);
+    }
+    else {
+        s->glob_sta &= ~masks[r - s->bm_regs];
+        dolog ("set irq level=0\n");
+        qemu_set_irq(s->pci_dev->irq[0], 0);
+    }
+}
+
+static void voice_set_active (AC97LinkState *s, int bm_index, int on)
+{
+    switch (bm_index) {
+    case PI_INDEX:
+        AUD_set_active_in (s->voice_pi, on);
+        break;
+
+    case PO_INDEX:
+        AUD_set_active_out (s->voice_po, on);
+        break;
+
+    case MC_INDEX:
+        AUD_set_active_in (s->voice_mc, on);
+        break;
+
+    default:
+        AUD_log ("ac97", "invalid bm_index(%d) in voice_set_active", bm_index);
+        break;
+    }
+}
+
+static void reset_bm_regs (AC97LinkState *s, AC97BusMasterRegs *r)
+{
+    dolog ("reset_bm_regs\n");
+    r->bdbar = 0;
+    r->civ = 0;
+    r->lvi = 0;
+    /** todo do we need to do that? */
+    update_sr (s, r, SR_DCH);
+    r->picb = 0;
+    r->piv = 0;
+    r->cr = r->cr & CR_DONT_CLEAR_MASK;
+    r->bd_valid = 0;
+
+    voice_set_active (s, r - s->bm_regs, 0);
+    memset (s->silence, 0, sizeof (s->silence));
+}
+
+static void mixer_store (AC97LinkState *s, uint32_t i, uint16_t v)
+{
+    if (i + 2 > sizeof (s->mixer_data)) {
+        dolog ("mixer_store: index %d out of bounds %d\n",
+               i, sizeof (s->mixer_data));
+        return;
+    }
+
+    s->mixer_data[i + 0] = v & 0xff;
+    s->mixer_data[i + 1] = v >> 8;
+}
+
+static uint16_t mixer_load (AC97LinkState *s, uint32_t i)
+{
+    uint16_t val = 0xffff;
+
+    if (i + 2 > sizeof (s->mixer_data)) {
+        dolog ("mixer_store: index %d out of bounds %d\n",
+               i, sizeof (s->mixer_data));
+    }
+    else {
+        val = s->mixer_data[i + 0] | (s->mixer_data[i + 1] << 8);
+    }
+
+    return val;
+}
+
+static void open_voice (AC97LinkState *s, int index, int freq)
+{
+    audsettings_t as;
+
+    as.freq = freq;
+    as.nchannels = 2;
+    as.fmt = AUD_FMT_S16;
+    as.endianness = 0;
+
+    switch (index) {
+    case PI_INDEX:
+        s->voice_pi = AUD_open_in (
+            &s->card,
+            s->voice_pi,
+            "ac97.pi",
+            s,
+            pi_callback,
+            &as
+            );
+        break;
+
+    case PO_INDEX:
+        s->voice_po = AUD_open_out (
+            &s->card,
+            s->voice_po,
+            "ac97.po",
+            s,
+            po_callback,
+            &as
+            );
+        break;
+
+    case MC_INDEX:
+        s->voice_mc = AUD_open_in (
+            &s->card,
+            s->voice_mc,
+            "ac97.mc",
+            s,
+            mc_callback,
+            &as
+            );
+        break;
+    }
+}
+
+static void reset_voices (AC97LinkState *s, uint8_t active[LAST_INDEX])
+{
+    uint16_t freq;
+
+    freq = mixer_load (s, AC97_PCM_LR_ADC_Rate);
+    open_voice (s, PI_INDEX, freq);
+    AUD_set_active_in (s->voice_pi, active[PI_INDEX]);
+
+    freq = mixer_load (s, AC97_PCM_Front_DAC_Rate);
+    open_voice (s, PO_INDEX, freq);
+    AUD_set_active_out (s->voice_po, active[PO_INDEX]);
+
+    freq = mixer_load (s, AC97_MIC_ADC_Rate);
+    open_voice (s, MC_INDEX, freq);
+    AUD_set_active_in (s->voice_mc, active[MC_INDEX]);
+}
+
+#ifdef USE_MIXER
+static void set_volume (AC97LinkState *s, int index,
+                        audmixerctl_t mt, uint32_t val)
+{
+    int mute = (val >> MUTE_SHIFT) & 1;
+    uint8_t rvol = VOL_MASK - (val & VOL_MASK);
+    uint8_t lvol = VOL_MASK - ((val >> 8) & VOL_MASK);
+    rvol = 255 * rvol / VOL_MASK;
+    lvol = 255 * lvol / VOL_MASK;
+
+#ifdef SOFT_VOLUME
+    if (index == AC97_Master_Volume_Mute) {
+        AUD_set_volume_out (s->voice_po, mute, lvol, rvol);
+    }
+    else {
+        AUD_set_volume (mt, &mute, &lvol, &rvol);
+    }
+#else
+    AUD_set_volume (mt, &mute, &lvol, &rvol);
+#endif
+
+    rvol = VOL_MASK - ((VOL_MASK * rvol) / 255);
+    lvol = VOL_MASK - ((VOL_MASK * lvol) / 255);
+    mixer_store (s, index, val);
+}
+
+static audrecsource_t ac97_to_aud_record_source (uint8_t i)
+{
+    switch (i) {
+    case REC_MIC:
+        return AUD_REC_MIC;
+
+    case REC_CD:
+        return AUD_REC_CD;
+
+    case REC_VIDEO:
+        return AUD_REC_VIDEO;
+
+    case REC_AUX:
+        return AUD_REC_AUX;
+
+    case REC_LINE_IN:
+        return AUD_REC_LINE_IN;
+
+    case REC_PHONE:
+        return AUD_REC_PHONE;
+
+    default:
+        dolog ("Unknown record source %d, using MIC\n", i);
+        return AUD_REC_MIC;
+    }
+}
+
+static uint8_t aud_to_ac97_record_source (audrecsource_t rs)
+{
+    switch (rs) {
+    case AUD_REC_MIC:
+        return REC_MIC;
+
+    case AUD_REC_CD:
+        return REC_CD;
+
+    case AUD_REC_VIDEO:
+        return REC_VIDEO;
+
+    case AUD_REC_AUX:
+        return REC_AUX;
+
+    case AUD_REC_LINE_IN:
+        return REC_LINE_IN;
+
+    case AUD_REC_PHONE:
+        return REC_PHONE;
+
+    default:
+        dolog ("Unknown audio recording source %d using MIC\n", rs);
+        return REC_MIC;
+    }
+}
+
+static void record_select (AC97LinkState *s, uint32_t val)
+{
+    uint8_t rs = val & REC_MASK;
+    uint8_t ls = (val >> 8) & REC_MASK;
+    audrecsource_t ars = ac97_to_aud_record_source (rs);
+    audrecsource_t als = ac97_to_aud_record_source (ls);
+    AUD_set_record_source (&als, &ars);
+    rs = aud_to_ac97_record_source (ars);
+    ls = aud_to_ac97_record_source (als);
+    mixer_store (s, AC97_Record_Select, rs | (ls << 8));
+}
+#endif
+
+static void mixer_reset (AC97LinkState *s)
+{
+    uint8_t active[LAST_INDEX];
+
+    dolog ("mixer_reset\n");
+    memset (s->mixer_data, 0, sizeof (s->mixer_data));
+    memset (active, 0, sizeof (active));
+    mixer_store (s, AC97_Reset                   , 0x0000); /* 6940 */
+    mixer_store (s, AC97_Master_Volume_Mono_Mute , 0x8000);
+    mixer_store (s, AC97_PC_BEEP_Volume_Mute     , 0x0000);
+
+    mixer_store (s, AC97_Phone_Volume_Mute       , 0x8008);
+    mixer_store (s, AC97_Mic_Volume_Mute         , 0x8008);
+    mixer_store (s, AC97_CD_Volume_Mute          , 0x8808);
+    mixer_store (s, AC97_Aux_Volume_Mute         , 0x8808);
+    mixer_store (s, AC97_Record_Gain_Mic_Mute    , 0x8000);
+    mixer_store (s, AC97_General_Purpose         , 0x0000);
+    mixer_store (s, AC97_3D_Control              , 0x0000);
+    mixer_store (s, AC97_Powerdown_Ctrl_Stat     , 0x000f);
+
+    /*
+     * Sigmatel 9700 (STAC9700)
+     */
+    mixer_store (s, AC97_Vendor_ID1              , 0x8384);
+    mixer_store (s, AC97_Vendor_ID2              , 0x7600); /* 7608 */
+
+    mixer_store (s, AC97_Extended_Audio_ID       , 0x0809);
+    mixer_store (s, AC97_Extended_Audio_Ctrl_Stat, 0x0009);
+    mixer_store (s, AC97_PCM_Front_DAC_Rate      , 0xbb80);
+    mixer_store (s, AC97_PCM_Surround_DAC_Rate   , 0xbb80);
+    mixer_store (s, AC97_PCM_LFE_DAC_Rate        , 0xbb80);
+    mixer_store (s, AC97_PCM_LR_ADC_Rate         , 0xbb80);
+    mixer_store (s, AC97_MIC_ADC_Rate            , 0xbb80);
+
+#ifdef USE_MIXER
+    record_select (s, 0);
+    set_volume (s, AC97_Master_Volume_Mute, AUD_MIXER_VOLUME  , 0x8000);
+    set_volume (s, AC97_PCM_Out_Volume_Mute, AUD_MIXER_PCM    , 0x8808);
+    set_volume (s, AC97_Line_In_Volume_Mute, AUD_MIXER_LINE_IN, 0x8808);
+#endif
+    reset_voices (s, active);
+}
+
+/**
+ * Native audio mixer
+ * I/O Reads
+ */
+static uint32_t nam_readb (void *opaque, uint32_t addr)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    dolog ("U nam readb %#x\n", addr);
+    s->cas = 0;
+    return ~0U;
+}
+
+static uint32_t nam_readw (void *opaque, uint32_t addr)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    uint32_t val = ~0U;
+    uint32_t index = addr - s->base[0];
+    s->cas = 0;
+    val = mixer_load (s, index);
+    return val;
+}
+
+static uint32_t nam_readl (void *opaque, uint32_t addr)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    dolog ("U nam readl %#x\n", addr);
+    s->cas = 0;
+    return ~0U;
+}
+
+/**
+ * Native audio mixer
+ * I/O Writes
+ */
+static void nam_writeb (void *opaque, uint32_t addr, uint32_t val)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    dolog ("U nam writeb %#x <- %#x\n", addr, val);
+    s->cas = 0;
+}
+
+static void nam_writew (void *opaque, uint32_t addr, uint32_t val)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    uint32_t index = addr - s->base[0];
+    s->cas = 0;
+    switch (index) {
+    case AC97_Reset:
+        mixer_reset (s);
+        break;
+    case AC97_Powerdown_Ctrl_Stat:
+        val &= ~0xf;
+        val |= mixer_load (s, index) & 0xf;
+        mixer_store (s, index, val);
+        break;
+#ifdef USE_MIXER
+    case AC97_Master_Volume_Mute:
+        set_volume (s, index, AUD_MIXER_VOLUME, val);
+        break;
+    case AC97_PCM_Out_Volume_Mute:
+        set_volume (s, index, AUD_MIXER_PCM, val);
+        break;
+    case AC97_Line_In_Volume_Mute:
+        set_volume (s, index, AUD_MIXER_LINE_IN, val);
+        break;
+    case AC97_Record_Select:
+        record_select (s, val);
+        break;
+#endif
+    case AC97_Vendor_ID1:
+    case AC97_Vendor_ID2:
+        dolog ("Attempt to write vendor ID to %#x\n", val);
+        break;
+    case AC97_Extended_Audio_ID:
+        dolog ("Attempt to write extended audio ID to %#x\n", val);
+        break;
+    case AC97_Extended_Audio_Ctrl_Stat:
+        if (!(val & EACS_VRA)) {
+            mixer_store (s, AC97_PCM_Front_DAC_Rate, 0xbb80);
+            mixer_store (s, AC97_PCM_LR_ADC_Rate,    0xbb80);
+            open_voice (s, PI_INDEX, 48000);
+            open_voice (s, PO_INDEX, 48000);
+        }
+        if (!(val & EACS_VRM)) {
+            mixer_store (s, AC97_MIC_ADC_Rate, 0xbb80);
+            open_voice (s, MC_INDEX, 48000);
+        }
+        dolog ("Setting extended audio control to %#x\n", val);
+        mixer_store (s, AC97_Extended_Audio_Ctrl_Stat, val);
+        break;
+    case AC97_PCM_Front_DAC_Rate:
+        if (mixer_load (s, AC97_Extended_Audio_Ctrl_Stat) & EACS_VRA) {
+            mixer_store (s, index, val);
+            dolog ("Set front DAC rate to %d\n", val);
+            open_voice (s, PO_INDEX, val);
+        }
+        else {
+            dolog ("Attempt to set front DAC rate to %d, "
+                   "but VRA is not set\n",
+                   val);
+        }
+        break;
+    case AC97_MIC_ADC_Rate:
+        if (mixer_load (s, AC97_Extended_Audio_Ctrl_Stat) & EACS_VRM) {
+            mixer_store (s, index, val);
+            dolog ("Set MIC ADC rate to %d\n", val);
+            open_voice (s, MC_INDEX, val);
+        }
+        else {
+            dolog ("Attempt to set MIC ADC rate to %d, "
+                   "but VRM is not set\n",
+                   val);
+        }
+        break;
+    case AC97_PCM_LR_ADC_Rate:
+        if (mixer_load (s, AC97_Extended_Audio_Ctrl_Stat) & EACS_VRA) {
+            mixer_store (s, index, val);
+            dolog ("Set front LR ADC rate to %d\n", val);
+            open_voice (s, PI_INDEX, val);
+        }
+        else {
+            dolog ("Attempt to set LR ADC rate to %d, but VRA is not set\n",
+                    val);
+        }
+        break;
+    default:
+        dolog ("U nam writew %#x <- %#x\n", addr, val);
+        mixer_store (s, index, val);
+        break;
+    }
+}
+
+static void nam_writel (void *opaque, uint32_t addr, uint32_t val)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    dolog ("U nam writel %#x <- %#x\n", addr, val);
+    s->cas = 0;
+}
+
+/**
+ * Native audio bus master
+ * I/O Reads
+ */
+static uint32_t nabm_readb (void *opaque, uint32_t addr)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    AC97BusMasterRegs *r = NULL;
+    uint32_t index = addr - s->base[1];
+    uint32_t val = ~0U;
+
+    switch (index) {
+    case CAS:
+        dolog ("CAS %d\n", s->cas);
+        val = s->cas;
+        s->cas = 1;
+        break;
+    case PI_CIV:
+    case PO_CIV:
+    case MC_CIV:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->civ;
+        dolog ("CIV[%d] -> %#x\n", GET_BM (index), val);
+        break;
+    case PI_LVI:
+    case PO_LVI:
+    case MC_LVI:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->lvi;
+        dolog ("LVI[%d] -> %#x\n", GET_BM (index), val);
+        break;
+    case PI_PIV:
+    case PO_PIV:
+    case MC_PIV:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->piv;
+        dolog ("PIV[%d] -> %#x\n", GET_BM (index), val);
+        break;
+    case PI_CR:
+    case PO_CR:
+    case MC_CR:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->cr;
+        dolog ("CR[%d] -> %#x\n", GET_BM (index), val);
+        break;
+    case PI_SR:
+    case PO_SR:
+    case MC_SR:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->sr & 0xff;
+        dolog ("SRb[%d] -> %#x\n", GET_BM (index), val);
+        break;
+    default:
+        dolog ("U nabm readb %#x -> %#x\n", addr, val);
+        break;
+    }
+    return val;
+}
+
+static uint32_t nabm_readw (void *opaque, uint32_t addr)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    AC97BusMasterRegs *r = NULL;
+    uint32_t index = addr - s->base[1];
+    uint32_t val = ~0U;
+
+    switch (index) {
+    case PI_SR:
+    case PO_SR:
+    case MC_SR:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->sr;
+        dolog ("SR[%d] -> %#x\n", GET_BM (index), val);
+        break;
+    case PI_PICB:
+    case PO_PICB:
+    case MC_PICB:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->picb;
+        dolog ("PICB[%d] -> %#x\n", GET_BM (index), val);
+        break;
+    default:
+        dolog ("U nabm readw %#x -> %#x\n", addr, val);
+        break;
+    }
+    return val;
+}
+
+static uint32_t nabm_readl (void *opaque, uint32_t addr)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    AC97BusMasterRegs *r = NULL;
+    uint32_t index = addr - s->base[1];
+    uint32_t val = ~0U;
+
+    switch (index) {
+    case PI_BDBAR:
+    case PO_BDBAR:
+    case MC_BDBAR:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->bdbar;
+        dolog ("BMADDR[%d] -> %#x\n", GET_BM (index), val);
+        break;
+    case PI_CIV:
+    case PO_CIV:
+    case MC_CIV:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->civ | (r->lvi << 8) | (r->sr << 16);
+        dolog ("CIV LVI SR[%d] -> %#x, %#x, %#x\n", GET_BM (index),
+               r->civ, r->lvi, r->sr);
+        break;
+    case PI_PICB:
+    case PO_PICB:
+    case MC_PICB:
+        r = &s->bm_regs[GET_BM (index)];
+        val = r->picb | (r->piv << 16) | (r->cr << 24);
+        dolog ("PICB PIV CR[%d] -> %#x %#x %#x %#x\n", GET_BM (index),
+               val, r->picb, r->piv, r->cr);
+        break;
+    case GLOB_CNT:
+        val = s->glob_cnt;
+        dolog ("glob_cnt -> %#x\n", val);
+        break;
+    case GLOB_STA:
+        val = s->glob_sta | GS_S0CR;
+        dolog ("glob_sta -> %#x\n", val);
+        break;
+    default:
+        dolog ("U nabm readl %#x -> %#x\n", addr, val);
+        break;
+    }
+    return val;
+}
+
+/**
+ * Native audio bus master
+ * I/O Writes
+ */
+static void nabm_writeb (void *opaque, uint32_t addr, uint32_t val)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    AC97BusMasterRegs *r = NULL;
+    uint32_t index = addr - s->base[1];
+    switch (index) {
+    case PI_LVI:
+    case PO_LVI:
+    case MC_LVI:
+        r = &s->bm_regs[GET_BM (index)];
+        if ((r->cr & CR_RPBM) && (r->sr & SR_DCH)) {
+            r->sr &= ~(SR_DCH | SR_CELV);
+            r->civ = r->piv;
+            r->piv = (r->piv + 1) % 32;
+            fetch_bd (s, r);
+        }
+        r->lvi = val % 32;
+        dolog ("LVI[%d] <- %#x\n", GET_BM (index), val);
+        break;
+    case PI_CR:
+    case PO_CR:
+    case MC_CR:
+        r = &s->bm_regs[GET_BM (index)];
+        if (val & CR_RR) {
+            reset_bm_regs (s, r);
+        }
+        else {
+            r->cr = val & CR_VALID_MASK;
+            if (!(r->cr & CR_RPBM)) {
+                voice_set_active (s, r - s->bm_regs, 0);
+                r->sr |= SR_DCH;
+            }
+            else {
+                r->civ = r->piv;
+                r->piv = (r->piv + 1) % 32;
+                fetch_bd (s, r);
+                r->sr &= ~SR_DCH;
+                voice_set_active (s, r - s->bm_regs, 1);
+            }
+        }
+        dolog ("CR[%d] <- %#x (cr %#x)\n", GET_BM (index), val, r->cr);
+        break;
+    case PI_SR:
+    case PO_SR:
+    case MC_SR:
+        r = &s->bm_regs[GET_BM (index)];
+        r->sr |= val & ~(SR_RO_MASK | SR_WCLEAR_MASK);
+        update_sr (s, r, r->sr & ~(val & SR_WCLEAR_MASK));
+        dolog ("SR[%d] <- %#x (sr %#x)\n", GET_BM (index), val, r->sr);
+        break;
+    default:
+        dolog ("U nabm writeb %#x <- %#x\n", addr, val);
+        break;
+    }
+}
+
+static void nabm_writew (void *opaque, uint32_t addr, uint32_t val)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    AC97BusMasterRegs *r = NULL;
+    uint32_t index = addr - s->base[1];
+    switch (index) {
+    case PI_SR:
+    case PO_SR:
+    case MC_SR:
+        r = &s->bm_regs[GET_BM (index)];
+        r->sr |= val & ~(SR_RO_MASK | SR_WCLEAR_MASK);
+        update_sr (s, r, r->sr & ~(val & SR_WCLEAR_MASK));
+        dolog ("SR[%d] <- %#x (sr %#x)\n", GET_BM (index), val, r->sr);
+        break;
+    default:
+        dolog ("U nabm writew %#x <- %#x\n", addr, val);
+        break;
+    }
+}
+
+static void nabm_writel (void *opaque, uint32_t addr, uint32_t val)
+{
+    PCIAC97LinkState *d = opaque;
+    AC97LinkState *s = &d->ac97;
+    AC97BusMasterRegs *r = NULL;
+    uint32_t index = addr - s->base[1];
+    switch (index) {
+    case PI_BDBAR:
+    case PO_BDBAR:
+    case MC_BDBAR:
+        r = &s->bm_regs[GET_BM (index)];
+        r->bdbar = val & ~3;
+        dolog ("BDBAR[%d] <- %#x (bdbar %#x)\n",
+               GET_BM (index), val, r->bdbar);
+        break;
+    case GLOB_CNT:
+        if (val & GC_WR)
+            warm_reset (s);
+        if (val & GC_CR)
+            cold_reset (s);
+        if (!(val & (GC_WR | GC_CR)))
+            s->glob_cnt = val & GC_VALID_MASK;
+        dolog ("glob_cnt <- %#x (glob_cnt %#x)\n", val, s->glob_cnt);
+        break;
+    case GLOB_STA:
+        s->glob_sta &= ~(val & GS_WCLEAR_MASK);
+        s->glob_sta |= (val & ~(GS_WCLEAR_MASK | GS_RO_MASK)) & GS_VALID_MASK;
+        dolog ("glob_sta <- %#x (glob_sta %#x)\n", val, s->glob_sta);
+        break;
+    default:
+        dolog ("U nabm writel %#x <- %#x\n", addr, val);
+        break;
+    }
+}
+
+static int write_audio (AC97LinkState *s, AC97BusMasterRegs *r,
+                        int max, int *stop)
+{
+    uint8_t tmpbuf[4096];
+    uint32_t addr = r->bd.addr;
+    uint32_t temp = r->picb << 1;
+    uint32_t written = 0;
+    int to_copy = 0;
+    temp = audio_MIN (temp, max);
+
+    if (!temp) {
+        *stop = 1;
+        return 0;
+    }
+
+    while (temp) {
+        int copied;
+        to_copy = audio_MIN (temp, sizeof (tmpbuf));
+        cpu_physical_memory_read (addr, tmpbuf, to_copy);
+        copied = AUD_write (s->voice_po, tmpbuf, to_copy);
+        dolog ("write_audio max=%x to_copy=%x copied=%x\n",
+               max, to_copy, copied);
+        if (!copied) {
+            *stop = 1;
+            break;
+        }
+        temp -= copied;
+        addr += copied;
+        written += copied;
+    }
+
+    if (!temp) {
+        if (to_copy < 4) {
+            dolog ("whoops\n");
+            s->last_samp = 0;
+        }
+        else {
+            s->last_samp = *(uint32_t *) &tmpbuf[to_copy - 4];
+        }
+    }
+
+    r->bd.addr = addr;
+    return written;
+}
+
+static void write_bup (AC97LinkState *s, int elapsed)
+{
+    int written = 0;
+
+    dolog ("write_bup\n");
+    if (!(s->bup_flag & BUP_SET)) {
+        if (s->bup_flag & BUP_LAST) {
+            int i;
+            uint8_t *p = s->silence;
+            for (i = 0; i < sizeof (s->silence) / 4; i++, p += 4) {
+                *(uint32_t *) p = s->last_samp;
+            }
+        }
+        else {
+            memset (s->silence, 0, sizeof (s->silence));
+        }
+        s->bup_flag |= BUP_SET;
+    }
+
+    while (elapsed) {
+        int temp = audio_MIN (elapsed, sizeof (s->silence));
+        while (temp) {
+            int copied = AUD_write (s->voice_po, s->silence, temp);
+            if (!copied)
+                return;
+            temp -= copied;
+            elapsed -= copied;
+            written += copied;
+        }
+    }
+}
+
+static int read_audio (AC97LinkState *s, AC97BusMasterRegs *r,
+                       int max, int *stop)
+{
+    uint8_t tmpbuf[4096];
+    uint32_t addr = r->bd.addr;
+    uint32_t temp = r->picb << 1;
+    uint32_t nread = 0;
+    int to_copy = 0;
+    SWVoiceIn *voice = (r - s->bm_regs) == MC_INDEX ? s->voice_mc : s->voice_pi;
+
+    temp = audio_MIN (temp, max);
+
+    if (!temp) {
+        *stop = 1;
+        return 0;
+    }
+
+    while (temp) {
+        int acquired;
+        to_copy = audio_MIN (temp, sizeof (tmpbuf));
+        acquired = AUD_read (voice, tmpbuf, to_copy);
+        if (!acquired) {
+            *stop = 1;
+            break;
+        }
+        cpu_physical_memory_write (addr, tmpbuf, acquired);
+        temp -= acquired;
+        addr += acquired;
+        nread += acquired;
+    }
+
+    r->bd.addr = addr;
+    return nread;
+}
+
+static void transfer_audio (AC97LinkState *s, int index, int elapsed)
+{
+    AC97BusMasterRegs *r = &s->bm_regs[index];
+    int written = 0, stop = 0;
+
+    if (r->sr & SR_DCH) {
+        if (r->cr & CR_RPBM) {
+            switch (index) {
+            case PO_INDEX:
+                write_bup (s, elapsed);
+                break;
+            }
+        }
+        return;
+    }
+
+    while ((elapsed >> 1) && !stop) {
+        int temp;
+
+        if (!r->bd_valid) {
+            dolog ("invalid bd\n");
+            fetch_bd (s, r);
+        }
+
+        if (!r->picb) {
+            dolog ("fresh bd %d is empty %#x %#x\n",
+                   r->civ, r->bd.addr, r->bd.ctl_len);
+            if (r->civ == r->lvi) {
+                r->sr |= SR_DCH; /* CELV? */
+                s->bup_flag = 0;
+                break;
+            }
+            r->sr &= ~SR_CELV;
+            r->civ = r->piv;
+            r->piv = (r->piv + 1) % 32;
+            fetch_bd (s, r);
+            return;
+        }
+
+        switch (index) {
+        case PO_INDEX:
+            temp = write_audio (s, r, elapsed, &stop);
+            written += temp;
+            elapsed -= temp;
+            r->picb -= (temp >> 1);
+            break;
+
+        case PI_INDEX:
+        case MC_INDEX:
+            temp = read_audio (s, r, elapsed, &stop);
+            elapsed -= temp;
+            r->picb -= (temp >> 1);
+            break;
+        }
+
+        if (!r->picb) {
+            uint32_t new_sr = r->sr & ~SR_CELV;
+
+            if (r->bd.ctl_len & BD_IOC) {
+                new_sr |= SR_BCIS;
+            }
+
+            if (r->civ == r->lvi) {
+                dolog ("Underrun civ (%d) == lvi (%d)\n", r->civ, r->lvi);
+
+                new_sr |= SR_LVBCI | SR_DCH | SR_CELV;
+                stop = 1;
+                s->bup_flag = (r->bd.ctl_len & BD_BUP) ? BUP_LAST : 0;
+            }
+            else {
+                r->civ = r->piv;
+                r->piv = (r->piv + 1) % 32;
+                fetch_bd (s, r);
+            }
+
+            update_sr (s, r, new_sr);
+        }
+    }
+}
+
+static void pi_callback (void *opaque, int avail)
+{
+    transfer_audio (opaque, PI_INDEX, avail);
+}
+
+static void mc_callback (void *opaque, int avail)
+{
+    transfer_audio (opaque, MC_INDEX, avail);
+}
+
+static void po_callback (void *opaque, int free)
+{
+    transfer_audio (opaque, PO_INDEX, free);
+}
+
+static void ac97_save (QEMUFile *f, void *opaque)
+{
+    size_t i;
+    uint8_t active[LAST_INDEX];
+    AC97LinkState *s = opaque;
+
+    qemu_put_be32s (f, &s->glob_cnt);
+    qemu_put_be32s (f, &s->glob_sta);
+    qemu_put_be32s (f, &s->cas);
+
+    for (i = 0; i < sizeof (s->bm_regs) / sizeof (s->bm_regs[0]); ++i) {
+        AC97BusMasterRegs *r = &s->bm_regs[i];
+        qemu_put_be32s (f, &r->bdbar);
+        qemu_put_8s (f, &r->civ);
+        qemu_put_8s (f, &r->lvi);
+        qemu_put_be16s (f, &r->sr);
+        qemu_put_be16s (f, &r->picb);
+        qemu_put_8s (f, &r->piv);
+        qemu_put_8s (f, &r->cr);
+        qemu_put_be32s (f, &r->bd_valid);
+        qemu_put_be32s (f, &r->bd.addr);
+        qemu_put_be32s (f, &r->bd.ctl_len);
+    }
+    qemu_put_buffer (f, s->mixer_data, sizeof (s->mixer_data));
+
+    active[PI_INDEX] = AUD_is_active_in (s->voice_pi) ? 1 : 0;
+    active[PO_INDEX] = AUD_is_active_out (s->voice_po) ? 1 : 0;
+    active[MC_INDEX] = AUD_is_active_in (s->voice_mc) ? 1 : 0;
+    qemu_put_buffer (f, active, sizeof (active));
+}
+
+static int ac97_load (QEMUFile *f, void *opaque, int version_id)
+{
+    size_t i;
+    uint8_t active[LAST_INDEX];
+    AC97LinkState *s = opaque;
+
+    if (version_id != 1)
+        return -EINVAL;
+
+    qemu_get_be32s (f, &s->glob_cnt);
+    qemu_get_be32s (f, &s->glob_sta);
+    qemu_get_be32s (f, &s->cas);
+
+    for (i = 0; i < sizeof (s->bm_regs) / sizeof (s->bm_regs[0]); ++i) {
+        AC97BusMasterRegs *r = &s->bm_regs[i];
+        qemu_get_be32s (f, &r->bdbar);
+        qemu_get_8s (f, &r->civ);
+        qemu_get_8s (f, &r->lvi);
+        qemu_get_be16s (f, &r->sr);
+        qemu_get_be16s (f, &r->picb);
+        qemu_get_8s (f, &r->piv);
+        qemu_get_8s (f, &r->cr);
+        qemu_get_be32s (f, &r->bd_valid);
+        qemu_get_be32s (f, &r->bd.addr);
+        qemu_get_be32s (f, &r->bd.ctl_len);
+    }
+    qemu_get_buffer (f, s->mixer_data, sizeof (s->mixer_data));
+    qemu_get_buffer (f, active, sizeof (active));
+
+#ifdef USE_MIXER
+    record_select (s, mixer_load (s, AC97_Record_Select));
+#define V_(a, b) set_volume (s, a, b, mixer_load (s, a))
+    V_ (AC97_Master_Volume_Mute, AUD_MIXER_VOLUME);
+    V_ (AC97_PCM_Out_Volume_Mute, AUD_MIXER_PCM);
+    V_ (AC97_Line_In_Volume_Mute, AUD_MIXER_LINE_IN);
+#undef V_
+#endif
+    reset_voices (s, active);
+
+    s->bup_flag = 0;
+    s->last_samp = 0;
+    return 0;
+}
+
+static void ac97_map (PCIDevice *pci_dev, int region_num,
+                      uint32_t addr, uint32_t size, int type)
+{
+    PCIAC97LinkState *d = (PCIAC97LinkState *) pci_dev;
+    AC97LinkState *s = &d->ac97;
+
+    if (!region_num) {
+        s->base[0] = addr;
+        register_ioport_read (addr, 256 * 1, 1, nam_readb, d);
+        register_ioport_read (addr, 256 * 2, 2, nam_readw, d);
+        register_ioport_read (addr, 256 * 4, 4, nam_readl, d);
+        register_ioport_write (addr, 256 * 1, 1, nam_writeb, d);
+        register_ioport_write (addr, 256 * 2, 2, nam_writew, d);
+        register_ioport_write (addr, 256 * 4, 4, nam_writel, d);
+    }
+    else {
+        s->base[1] = addr;
+        register_ioport_read (addr, 64 * 1, 1, nabm_readb, d);
+        register_ioport_read (addr, 64 * 2, 2, nabm_readw, d);
+        register_ioport_read (addr, 64 * 4, 4, nabm_readl, d);
+        register_ioport_write (addr, 64 * 1, 1, nabm_writeb, d);
+        register_ioport_write (addr, 64 * 2, 2, nabm_writew, d);
+        register_ioport_write (addr, 64 * 4, 4, nabm_writel, d);
+    }
+}
+
+static void ac97_on_reset (void *opaque)
+{
+    AC97LinkState *s = opaque;
+
+    reset_bm_regs (s, &s->bm_regs[0]);
+    reset_bm_regs (s, &s->bm_regs[1]);
+    reset_bm_regs (s, &s->bm_regs[2]);
+
+    /*
+     * Reset the mixer too. The Windows XP driver seems to rely on
+     * this. At least it wants to read the vendor id before it resets
+     * the codec manually.
+     */
+    mixer_reset (s);
+}
+
+int ac97_init (PCIBus *bus, AudioState *audio)
+{
+    PCIAC97LinkState *d;
+    AC97LinkState *s;
+    uint8_t *c;
+
+    if (!bus) {
+        AUD_log ("ac97", "No PCI bus\n");
+        return -1;
+    }
+
+    if (!audio) {
+        AUD_log ("ac97", "No audio state\n");
+        return -1;
+    }
+
+    d = (PCIAC97LinkState *) pci_register_device (bus, "AC97",
+                                                  sizeof (PCIAC97LinkState),
+                                                  -1, NULL, NULL);
+
+    if (!d) {
+        AUD_log ("ac97", "Failed to register PCI device\n");
+        return -1;
+    }
+
+    s = &d->ac97;
+    s->pci_dev = &d->dev;
+    c = d->dev.config;
+    c[0x00] = 0x86;      /* vid vendor id intel ro */
+    c[0x01] = 0x80;      /* intel */
+
+    c[0x02] = 0x15;      /* did device id 82801 ro */
+    c[0x03] = 0x24;      /* 82801aa */
+
+    c[0x04] = 0x00;      /* pcicmd pci command rw, ro */
+    c[0x05] = 0x00;
+
+    c[0x06] = 0x80;      /* pcists pci status rwc, ro */
+    c[0x07] = 0x02;
+
+    c[0x08] = 0x01;      /* rid revision ro */
+    c[0x09] = 0x00;      /* pi programming interface ro */
+    c[0x0a] = 0x01;      /* scc sub class code ro */
+    c[0x0b] = 0x04;      /* bcc base class code ro */
+    c[0x0e] = 0x00;      /* headtyp header type ro */
+
+    c[0x10] = 0x01;      /* nabmar native audio mixer base
+                            address rw */
+    c[0x11] = 0x00;
+    c[0x12] = 0x00;
+    c[0x13] = 0x00;
+
+    c[0x14] = 0x01;      /* nabmbar native audio bus mastering
+                            base address rw */
+    c[0x15] = 0x00;
+    c[0x16] = 0x00;
+    c[0x17] = 0x00;
+
+    c[0x2c] = 0x86;      /* svid subsystem vendor id rwo */
+    c[0x2d] = 0x80;
+
+    c[0x2e] = 0x00;      /* sid subsystem id rwo */
+    c[0x2f] = 0x00;
+
+    c[0x3c] = 0x00;      /* intr_ln interrupt line rw */
+    c[0x3d] = 0x01;      /* intr_pn interrupt pin ro */
+
+    pci_register_io_region (&d->dev, 0, 256 * 4, PCI_ADDRESS_SPACE_IO, ac97_map);
+    pci_register_io_region (&d->dev, 1, 64 * 4, PCI_ADDRESS_SPACE_IO, ac97_map);
+    register_savevm ("ac97", 0, 1, ac97_save, ac97_load, s);
+    qemu_register_reset (ac97_on_reset, s);
+    AUD_register_card (audio, "ac97", &s->card);
+    ac97_on_reset (s);
+    return 0;
+}
diff --git a/hw/audiodev.h b/hw/audiodev.h
index 18cdf67084..3c02f19ff9 100644
--- a/hw/audiodev.h
+++ b/hw/audiodev.h
@@ -10,3 +10,5 @@ int Adlib_init (AudioState *s, qemu_irq *pic);
 /* gus.c */
 int GUS_init (AudioState *s, qemu_irq *pic);
 
+/* ac97.c */
+int ac97_init (PCIBus *buf, AudioState *s);
diff --git a/qemu-doc.texi b/qemu-doc.texi
index a9c2e2e78f..7f3a3615df 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -166,6 +166,8 @@ Creative SoundBlaster 16 sound card
 @item
 ENSONIQ AudioPCI ES1370 sound card
 @item
+Intel 82801AA AC97 Audio compatible sound card
+@item
 Adlib(OPL2) - Yamaha YM3812 compatible chip
 @item
 PCI UHCI USB controller and a virtual USB hub.
@@ -173,8 +175,8 @@ PCI UHCI USB controller and a virtual USB hub.
 
 SMP is supported with up to 255 CPUs.
 
-Note that adlib is only available when QEMU was configured with
--enable-adlib
+Note that adlib and ac97 are only available when QEMU was configured
+with --enable-adlib, --enable-ac97 respectively.
 
 QEMU uses the PC BIOS from the Bochs project and the Plex86/Bochs LGPL
 VGA BIOS.
@@ -334,10 +336,18 @@ available sound hardware.
 @example
 qemu -soundhw sb16,adlib hda
 qemu -soundhw es1370 hda
+qemu -soundhw ac97 hda
 qemu -soundhw all hda
 qemu -soundhw ?
 @end example
 
+Note that Linux's i810_audio OSS kernel (for AC97) module might
+require manually specifying clocking.
+
+@example
+modprobe i810_audio clocking=48000
+@end example
+
 @item -localtime
 Set the real time clock to local time (the default is to UTC
 time). This option is needed to have correct date in MS-DOS or
diff --git a/vl.c b/vl.c
index 4875519df7..8cbcd38c21 100644
--- a/vl.c
+++ b/vl.c
@@ -7990,6 +7990,16 @@ struct soundhw soundhw[] = {
     },
 #endif
 
+#ifdef CONFIG_AC97
+    {
+        "ac97",
+        "Intel 82801AA AC97 Audio",
+        0,
+        0,
+        { .init_pci = ac97_init }
+    },
+#endif
+
     {
         "es1370",
         "ENSONIQ AudioPCI ES1370",