Move common "command data block" functions to new file blockcmd.c.
[seabios.git] / src / ata.c
index d26eca9012a2abe770031a7a0f1edad2480dcc33..3c57f9f3b7045ae4dc91186f521833e4ac9801ac 100644 (file)
--- a/src/ata.c
+++ b/src/ata.c
 // Low level ATA disk access
 //
-// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2008,2009  Kevin O'Connor <kevin@koconnor.net>
 // Copyright (C) 2002  MandrakeSoft S.A.
 //
-// This file may be distributed under the terms of the GNU GPLv3 license.
+// This file may be distributed under the terms of the GNU LGPLv3 license.
 
-#include "ata.h" // ATA_*
 #include "types.h" // u8
 #include "ioport.h" // inb
-#include "util.h" // BX_INFO
+#include "util.h" // dprintf
 #include "cmos.h" // inb_cmos
+#include "pic.h" // enable_hwirq
+#include "biosvar.h" // GET_EBDA
+#include "pci.h" // foreachpci
+#include "pci_ids.h" // PCI_CLASS_STORAGE_OTHER
+#include "pci_regs.h" // PCI_INTERRUPT_LINE
+#include "boot.h" // add_bcv_hd
+#include "disk.h" // struct ata_s
+#include "ata.h" // ATA_CB_STAT
+#include "blockcmd.h" // CDB_CMD_READ_10
 
-#define TIMEOUT 0
-#define BSY 1
-#define NOT_BSY 2
-#define NOT_BSY_DRQ 3
-#define NOT_BSY_NOT_DRQ 4
-#define NOT_BSY_RDY 5
+#define IDE_TIMEOUT 32000 //32 seconds max for IDE ops
 
-#define IDE_TIMEOUT 32000u //32 seconds max for IDE ops
+struct ata_channel_s ATA_channels[CONFIG_MAX_ATA_INTERFACES] VAR16VISIBLE;
 
-#define DEBUGF1(fmt, args...) bprintf(0, fmt , ##args)
-#define DEBUGF(fmt, args...)
 
-// XXX - lots of redundancy in this file.
+/****************************************************************
+ * Helper functions
+ ****************************************************************/
 
-static int
-await_ide(u8 when_done, u16 base, u16 timeout)
+// Wait for the specified ide state
+static inline int
+await_ide(u8 mask, u8 flags, u16 base, u16 timeout)
 {
-    u32 time=0,last=0;
-    // for the times you're supposed to throw one away
-    u16 status = inb(base + ATA_CB_STAT);
+    u64 end = calc_future_tsc(timeout);
     for (;;) {
-        status = inb(base+ATA_CB_STAT);
-        time++;
-        u8 result;
-        if (when_done == BSY)
-            result = status & ATA_CB_STAT_BSY;
-        else if (when_done == NOT_BSY)
-            result = !(status & ATA_CB_STAT_BSY);
-        else if (when_done == NOT_BSY_DRQ)
-            result = !(status & ATA_CB_STAT_BSY) && (status & ATA_CB_STAT_DRQ);
-        else if (when_done == NOT_BSY_NOT_DRQ)
-            result = !(status & ATA_CB_STAT_BSY) && !(status & ATA_CB_STAT_DRQ);
-        else if (when_done == NOT_BSY_RDY)
-            result = !(status & ATA_CB_STAT_BSY) && (status & ATA_CB_STAT_RDY);
-        else if (when_done == TIMEOUT)
-            result = 0;
-
-        if (result)
-            return 0;
-        // mod 2048 each 16 ms
-        if (time>>16 != last) {
-            last = time >>16;
-            DEBUGF("await_ide: (TIMEOUT,BSY,!BSY,!BSY_DRQ,!BSY_!DRQ,!BSY_RDY)"
-                   " %d time= %d timeout= %d\n"
-                   , when_done, time>>11, timeout);
-        }
-        if (status & ATA_CB_STAT_ERR) {
-            DEBUGF("await_ide: ERROR (TIMEOUT,BSY,!BSY,!BSY_DRQ"
-                   ",!BSY_!DRQ,!BSY_RDY) %d time= %d timeout= %d\n"
-                   , when_done, time>>11, timeout);
+        u8 status = inb(base+ATA_CB_STAT);
+        if ((status & mask) == flags)
+            return status;
+        if (check_time(end)) {
+            warn_timeout();
             return -1;
         }
-        if ((timeout == 0) || ((time>>11) > timeout))
-            break;
+        yield();
     }
-    BX_INFO("IDE time out\n");
-    return -1;
 }
 
+// Wait for the device to be not-busy.
+static int
+await_not_bsy(u16 base)
+{
+    return await_ide(ATA_CB_STAT_BSY, 0, base, IDE_TIMEOUT);
+}
 
-// ---------------------------------------------------------------------------
-// ATA/ATAPI driver : software reset
-// ---------------------------------------------------------------------------
-// ATA-3
-// 8.2.1 Software reset - Device 0
-
-void
-ata_reset(u16 device)
+// Wait for the device to be ready.
+static int
+await_rdy(u16 base)
 {
-    u16 iobase1, iobase2;
-    u8  channel, slave, sn, sc;
-    u8  type;
+    return await_ide(ATA_CB_STAT_RDY, ATA_CB_STAT_RDY, base, IDE_TIMEOUT);
+}
 
-    channel = device / 2;
-    slave = device % 2;
+// Wait for ide state - pauses for one ata cycle first.
+static inline int
+pause_await_not_bsy(u16 iobase1, u16 iobase2)
+{
+    // Wait one PIO transfer cycle.
+    inb(iobase2 + ATA_CB_ASTAT);
 
-    iobase1 = GET_EBDA(ata.channels[channel].iobase1);
-    iobase2 = GET_EBDA(ata.channels[channel].iobase2);
+    return await_not_bsy(iobase1);
+}
 
-    // Reset
+// Wait for ide state - pause for 400ns first.
+static inline int
+ndelay_await_not_bsy(u16 iobase1)
+{
+    ndelay(400);
+    return await_not_bsy(iobase1);
+}
 
-    // 8.2.1 (a) -- set SRST in DC
+// Reset a drive
+static void
+ata_reset(struct drive_s *drive_g)
+{
+    u8 ataid = GET_GLOBAL(drive_g->cntl_id);
+    u8 channel = ataid / 2;
+    u8 slave = ataid % 2;
+    u16 iobase1 = GET_GLOBAL(ATA_channels[channel].iobase1);
+    u16 iobase2 = GET_GLOBAL(ATA_channels[channel].iobase2);
+
+    dprintf(6, "ata_reset drive=%p\n", drive_g);
+    // Pulse SRST
     outb(ATA_CB_DC_HD15 | ATA_CB_DC_NIEN | ATA_CB_DC_SRST, iobase2+ATA_CB_DC);
-
-    // 8.2.1 (b) -- wait for BSY
-    await_ide(BSY, iobase1, 20);
-
-    // 8.2.1 (f) -- clear SRST
+    udelay(5);
     outb(ATA_CB_DC_HD15 | ATA_CB_DC_NIEN, iobase2+ATA_CB_DC);
-
-    type=GET_EBDA(ata.devices[device].type);
-    if (type != ATA_TYPE_NONE) {
-
-        // 8.2.1 (g) -- check for sc==sn==0x01
-        // select device
-        outb(slave?ATA_CB_DH_DEV1:ATA_CB_DH_DEV0, iobase1+ATA_CB_DH);
-        sc = inb(iobase1+ATA_CB_SC);
-        sn = inb(iobase1+ATA_CB_SN);
-
-        if ( (sc==0x01) && (sn==0x01) ) {
-            if (type == ATA_TYPE_ATA) //ATA
-                await_ide(NOT_BSY_RDY, iobase1, IDE_TIMEOUT);
-            else //ATAPI
-                await_ide(NOT_BSY, iobase1, IDE_TIMEOUT);
+    msleep(2);
+
+    // wait for device to become not busy.
+    int status = await_not_bsy(iobase1);
+    if (status < 0)
+        goto done;
+    if (slave) {
+        // Change device.
+        u64 end = calc_future_tsc(IDE_TIMEOUT);
+        for (;;) {
+            outb(ATA_CB_DH_DEV1, iobase1 + ATA_CB_DH);
+            status = ndelay_await_not_bsy(iobase1);
+            if (status < 0)
+                goto done;
+            if (inb(iobase1 + ATA_CB_DH) == ATA_CB_DH_DEV1)
+                break;
+            // Change drive request failed to take effect - retry.
+            if (check_time(end)) {
+                warn_timeout();
+                goto done;
+            }
         }
-
-        // 8.2.1 (h) -- wait for not BSY
-        await_ide(NOT_BSY, iobase1, IDE_TIMEOUT);
+    } else {
+        // QEMU doesn't reset dh on reset, so set it explicitly.
+        outb(ATA_CB_DH_DEV0, iobase1 + ATA_CB_DH);
     }
 
+    // On a user-reset request, wait for RDY if it is an ATA device.
+    u8 type=GET_GLOBAL(drive_g->type);
+    if (type == DTYPE_ATA)
+        status = await_rdy(iobase1);
+
+done:
     // Enable interrupts
     outb(ATA_CB_DC_HD15, iobase2+ATA_CB_DC);
+
+    dprintf(6, "ata_reset exit status=%x\n", status);
 }
 
-static void
-insw(u16 port, u16 segment, u16 offset, u16 count)
+// Check for drive RDY for 16bit interface command.
+static int
+isready(struct drive_s *drive_g)
 {
-    u16 i;
-    for (i=0; i<count; i++) {
-        u16 d = inw(port);
-        SET_FARVAR(segment, *(u16*)(offset + 2*i), d);
-    }
+    // Read the status from controller
+    u8 ataid = GET_GLOBAL(drive_g->cntl_id);
+    u8 channel = ataid / 2;
+    u16 iobase1 = GET_GLOBAL(ATA_channels[channel].iobase1);
+    u8 status = inb(iobase1 + ATA_CB_STAT);
+    if ((status & (ATA_CB_STAT_BSY|ATA_CB_STAT_RDY)) == ATA_CB_STAT_RDY)
+        return DISK_RET_SUCCESS;
+    return DISK_RET_ENOTREADY;
 }
 
-static void
-insl(u16 port, u16 segment, u16 offset, u16 count)
+// Default 16bit command demuxer for ATA and ATAPI devices.
+static int
+process_ata_misc_op(struct disk_op_s *op)
 {
-    u16 i;
-    for (i=0; i<count; i++) {
-        u32 d = inl(port);
-        SET_FARVAR(segment, *(u32*)(offset + 4*i), d);
+    if (!CONFIG_ATA)
+        return 0;
+
+    switch (op->command) {
+    case CMD_RESET:
+        ata_reset(op->drive_g);
+        return DISK_RET_SUCCESS;
+    case CMD_ISREADY:
+        return isready(op->drive_g);
+    case CMD_FORMAT:
+    case CMD_VERIFY:
+    case CMD_SEEK:
+        return DISK_RET_SUCCESS;
+    default:
+        op->count = 0;
+        return DISK_RET_EPARAM;
     }
 }
 
-static void
-outsw(u16 port, u16 segment, u16 offset, u16 count)
+
+/****************************************************************
+ * ATA send command
+ ****************************************************************/
+
+struct ata_pio_command {
+    u8 feature;
+    u8 sector_count;
+    u8 lba_low;
+    u8 lba_mid;
+    u8 lba_high;
+    u8 device;
+    u8 command;
+
+    u8 feature2;
+    u8 sector_count2;
+    u8 lba_low2;
+    u8 lba_mid2;
+    u8 lba_high2;
+};
+
+// Send an ata command to the drive.
+static int
+send_cmd(struct drive_s *drive_g, struct ata_pio_command *cmd)
 {
-    u16 i;
-    for (i=0; i<count; i++) {
-        u16 d = GET_FARVAR(segment, *(u16*)(offset + 2*i));
-        outw(d, port);
+    u8 ataid = GET_GLOBAL(drive_g->cntl_id);
+    u8 channel = ataid / 2;
+    u8 slave = ataid % 2;
+    u16 iobase1 = GET_GLOBAL(ATA_channels[channel].iobase1);
+
+    // Select device
+    int status = await_not_bsy(iobase1);
+    if (status < 0)
+        return status;
+    u8 newdh = ((cmd->device & ~ATA_CB_DH_DEV1)
+                | (slave ? ATA_CB_DH_DEV1 : ATA_CB_DH_DEV0));
+    u8 olddh = inb(iobase1 + ATA_CB_DH);
+    outb(newdh, iobase1 + ATA_CB_DH);
+    if ((olddh ^ newdh) & (1<<4)) {
+        // Was a device change - wait for device to become not busy.
+        status = ndelay_await_not_bsy(iobase1);
+        if (status < 0)
+            return status;
     }
-}
 
-static void
-outsl(u16 port, u16 segment, u16 offset, u16 count)
-{
-    u16 i;
-    for (i=0; i<count; i++) {
-        u32 d = GET_FARVAR(segment, *(u32*)(offset + 4*i));
-        outl(d, port);
+    // Check for ATA_CMD_(READ|WRITE)_(SECTORS|DMA)_EXT commands.
+    if ((cmd->command & ~0x11) == ATA_CMD_READ_SECTORS_EXT) {
+        outb(cmd->feature2, iobase1 + ATA_CB_FR);
+        outb(cmd->sector_count2, iobase1 + ATA_CB_SC);
+        outb(cmd->lba_low2, iobase1 + ATA_CB_SN);
+        outb(cmd->lba_mid2, iobase1 + ATA_CB_CL);
+        outb(cmd->lba_high2, iobase1 + ATA_CB_CH);
     }
+    outb(cmd->feature, iobase1 + ATA_CB_FR);
+    outb(cmd->sector_count, iobase1 + ATA_CB_SC);
+    outb(cmd->lba_low, iobase1 + ATA_CB_SN);
+    outb(cmd->lba_mid, iobase1 + ATA_CB_CL);
+    outb(cmd->lba_high, iobase1 + ATA_CB_CH);
+    outb(cmd->command, iobase1 + ATA_CB_CMD);
+
+    return 0;
 }
 
+// Wait for data after calling 'send_cmd'.
+static int
+ata_wait_data(u16 iobase1)
+{
+    int status = ndelay_await_not_bsy(iobase1);
+    if (status < 0)
+        return status;
 
-// ---------------------------------------------------------------------------
-// ATA/ATAPI driver : execute a data-in command
-// ---------------------------------------------------------------------------
-      // returns
-      // 0 : no error
-      // 1 : BUSY bit set
-      // 2 : read error
-      // 3 : expected DRQ=1
-      // 4 : no sectors left to read/verify
-      // 5 : more sectors to read/verify
-      // 6 : no sectors left to write
-      // 7 : more sectors to write
-u16
-ata_cmd_data_in(u16 device, u16 command, u16 count, u16 cylinder
-                , u16 head, u16 sector, u32 lba, u16 segment, u16 offset)
-{
-    DEBUGF("ata_cmd_data_in d=%d cmd=%d count=%d c=%d h=%d s=%d"
-           " lba=%d seg=%x off=%x\n"
-           , device, command, count, cylinder, head, sector
-           , lba, segment, offset);
-
-    u8 channel = device / 2;
-    u8 slave   = device % 2;
-
-    u16 iobase1 = GET_EBDA(ata.channels[channel].iobase1);
-    u16 iobase2 = GET_EBDA(ata.channels[channel].iobase2);
-    u8 mode     = GET_EBDA(ata.devices[device].mode);
-
-    // Reset count of transferred data
-    SET_EBDA(ata.trsfsectors,0);
-    SET_EBDA(ata.trsfbytes,0L);
-    u8 current = 0;
+    if (status & ATA_CB_STAT_ERR) {
+        dprintf(6, "send_cmd : read error (status=%02x err=%02x)\n"
+                , status, inb(iobase1 + ATA_CB_ERR));
+        return -4;
+    }
+    if (!(status & ATA_CB_STAT_DRQ)) {
+        dprintf(6, "send_cmd : DRQ not set (status %02x)\n", status);
+        return -5;
+    }
 
-    u8 status = inb(iobase1 + ATA_CB_STAT);
-    if (status & ATA_CB_STAT_BSY)
-        return 1;
+    return 0;
+}
 
+// Send an ata command that does not transfer any further data.
+int
+ata_cmd_nondata(struct drive_s *drive_g, struct ata_pio_command *cmd)
+{
+    u8 ataid = GET_GLOBAL(drive_g->cntl_id);
+    u8 channel = ataid / 2;
+    u16 iobase1 = GET_GLOBAL(ATA_channels[channel].iobase1);
+    u16 iobase2 = GET_GLOBAL(ATA_channels[channel].iobase2);
+
+    // Disable interrupts
     outb(ATA_CB_DC_HD15 | ATA_CB_DC_NIEN, iobase2 + ATA_CB_DC);
 
-    // sector will be 0 only on lba access. Convert to lba-chs
-    if (sector == 0) {
-        if ((count >= 1 << 8) || (lba + count >= 1UL << 28)) {
-            outb(0x00, iobase1 + ATA_CB_FR);
-            outb((count >> 8) & 0xff, iobase1 + ATA_CB_SC);
-            outb(lba >> 24, iobase1 + ATA_CB_SN);
-            outb(0, iobase1 + ATA_CB_CL);
-            outb(0, iobase1 + ATA_CB_CH);
-            command |= 0x04;
-            count &= (1UL << 8) - 1;
-            lba &= (1UL << 24) - 1;
-        }
-        sector = (u16) (lba & 0x000000ffL);
-        cylinder = (u16) ((lba>>8) & 0x0000ffffL);
-        head = ((u16) ((lba>>24) & 0x0000000fL)) | ATA_CB_DH_LBA;
+    int ret = send_cmd(drive_g, cmd);
+    if (ret)
+        goto fail;
+    ret = ndelay_await_not_bsy(iobase1);
+    if (ret < 0)
+        goto fail;
+
+    if (ret & ATA_CB_STAT_ERR) {
+        dprintf(6, "nondata cmd : read error (status=%02x err=%02x)\n"
+                , ret, inb(iobase1 + ATA_CB_ERR));
+        ret = -4;
+        goto fail;
     }
-
-    outb(0x00, iobase1 + ATA_CB_FR);
-    outb(count, iobase1 + ATA_CB_SC);
-    outb(sector, iobase1 + ATA_CB_SN);
-    outb(cylinder & 0x00ff, iobase1 + ATA_CB_CL);
-    outb(cylinder >> 8, iobase1 + ATA_CB_CH);
-    outb((slave ? ATA_CB_DH_DEV1 : ATA_CB_DH_DEV0) | (u8) head
-         , iobase1 + ATA_CB_DH);
-    outb(command, iobase1 + ATA_CB_CMD);
-
-    await_ide(NOT_BSY_DRQ, iobase1, IDE_TIMEOUT);
-    status = inb(iobase1 + ATA_CB_STAT);
-
-    if (status & ATA_CB_STAT_ERR) {
-        DEBUGF("ata_cmd_data_in : read error\n");
-        return 2;
-    } else if ( !(status & ATA_CB_STAT_DRQ) ) {
-        DEBUGF("ata_cmd_data_in : DRQ not set (status %02x)\n"
-               , (unsigned) status);
-        return 3;
+    if (ret & ATA_CB_STAT_DRQ) {
+        dprintf(6, "nondata cmd : DRQ set (status %02x)\n", ret);
+        ret = -5;
+        goto fail;
     }
 
-    // FIXME : move seg/off translation here
+fail:
+    // Enable interrupts
+    outb(ATA_CB_DC_HD15, iobase2+ATA_CB_DC);
+
+    return ret;
+}
 
-    irq_enable();
 
-    while (1) {
+/****************************************************************
+ * ATA PIO transfers
+ ****************************************************************/
 
-        if (offset > 0xf800) {
-            offset -= 0x800;
-            segment += 0x80;
+// Transfer 'op->count' blocks (of 'blocksize' bytes) to/from drive
+// 'op->drive_g'.
+static int
+ata_pio_transfer(struct disk_op_s *op, int iswrite, int blocksize)
+{
+    dprintf(16, "ata_pio_transfer id=%p write=%d count=%d bs=%d buf=%p\n"
+            , op->drive_g, iswrite, op->count, blocksize, op->buf_fl);
+
+    u8 ataid = GET_GLOBAL(op->drive_g->cntl_id);
+    u8 channel = ataid / 2;
+    u16 iobase1 = GET_GLOBAL(ATA_channels[channel].iobase1);
+    u16 iobase2 = GET_GLOBAL(ATA_channels[channel].iobase2);
+    int count = op->count;
+    void *buf_fl = op->buf_fl;
+    int status;
+    for (;;) {
+        if (iswrite) {
+            // Write data to controller
+            dprintf(16, "Write sector id=%p dest=%p\n", op->drive_g, buf_fl);
+            if (CONFIG_ATA_PIO32)
+                outsl_fl(iobase1, buf_fl, blocksize / 4);
+            else
+                outsw_fl(iobase1, buf_fl, blocksize / 2);
+        } else {
+            // Read data from controller
+            dprintf(16, "Read sector id=%p dest=%p\n", op->drive_g, buf_fl);
+            if (CONFIG_ATA_PIO32)
+                insl_fl(iobase1, buf_fl, blocksize / 4);
+            else
+                insw_fl(iobase1, buf_fl, blocksize / 2);
         }
+        buf_fl += blocksize;
 
-        if (mode == ATA_MODE_PIO32)
-            insl(iobase1, segment, offset, 512 / 4);
-        else
-            insw(iobase1, segment, offset, 512 / 2);
-        offset += 512;
+        status = pause_await_not_bsy(iobase1, iobase2);
+        if (status < 0) {
+            // Error
+            op->count -= count;
+            return status;
+        }
 
-        current++;
-        SET_EBDA(ata.trsfsectors,current);
         count--;
-        await_ide(NOT_BSY, iobase1, IDE_TIMEOUT);
-        status = inb(iobase1 + ATA_CB_STAT);
-        if (count == 0) {
-            if ( (status & (ATA_CB_STAT_BSY | ATA_CB_STAT_RDY | ATA_CB_STAT_DRQ
-                            | ATA_CB_STAT_ERR) )
-                 != ATA_CB_STAT_RDY ) {
-                DEBUGF("ata_cmd_data_in : no sectors left (status %02x)\n"
-                       , (unsigned) status);
-                return 4;
-            }
+        if (!count)
             break;
-        }
-        else {
-            if ( (status & (ATA_CB_STAT_BSY | ATA_CB_STAT_RDY | ATA_CB_STAT_DRQ
-                            | ATA_CB_STAT_ERR) )
-                 != (ATA_CB_STAT_RDY | ATA_CB_STAT_DRQ) ) {
-                DEBUGF("ata_cmd_data_in : more sectors left (status %02x)\n"
-                       , (unsigned) status);
-                return 5;
-            }
-            continue;
+        status &= (ATA_CB_STAT_BSY | ATA_CB_STAT_DRQ | ATA_CB_STAT_ERR);
+        if (status != ATA_CB_STAT_DRQ) {
+            dprintf(6, "ata_pio_transfer : more sectors left (status %02x)\n"
+                    , status);
+            op->count -= count;
+            return -6;
         }
     }
-    // Enable interrupts
-    outb(ATA_CB_DC_HD15, iobase2+ATA_CB_DC);
+
+    status &= (ATA_CB_STAT_BSY | ATA_CB_STAT_DF | ATA_CB_STAT_DRQ
+               | ATA_CB_STAT_ERR);
+    if (!iswrite)
+        status &= ~ATA_CB_STAT_DF;
+    if (status != 0) {
+        dprintf(6, "ata_pio_transfer : no sectors left (status %02x)\n", status);
+        return -7;
+    }
+
     return 0;
 }
 
-// ---------------------------------------------------------------------------
-// ATA/ATAPI driver : execute a data-out command
-// ---------------------------------------------------------------------------
-      // returns
-      // 0 : no error
-      // 1 : BUSY bit set
-      // 2 : read error
-      // 3 : expected DRQ=1
-      // 4 : no sectors left to read/verify
-      // 5 : more sectors to read/verify
-      // 6 : no sectors left to write
-      // 7 : more sectors to write
-u16
-ata_cmd_data_out(u16 device, u16 command, u16 count, u16 cylinder
-                 , u16 head, u16 sector, u32 lba, u16 segment, u16 offset)
-{
-    DEBUGF("ata_cmd_data_out d=%d cmd=%d count=%d c=%d h=%d s=%d"
-           " lba=%d seg=%x off=%x\n"
-           , device, command, count, cylinder, head, sector
-           , lba, segment, offset);
-
-    u8 channel = device / 2;
-    u8 slave   = device % 2;
-
-    u16 iobase1 = GET_EBDA(ata.channels[channel].iobase1);
-    u16 iobase2 = GET_EBDA(ata.channels[channel].iobase2);
-    u8 mode     = GET_EBDA(ata.devices[device].mode);
-
-    // Reset count of transferred data
-    SET_EBDA(ata.trsfsectors,0);
-    SET_EBDA(ata.trsfbytes,0L);
-    u8 current = 0;
 
-    u8 status = inb(iobase1 + ATA_CB_STAT);
-    if (status & ATA_CB_STAT_BSY)
-        return 1;
+/****************************************************************
+ * ATA DMA transfers
+ ****************************************************************/
 
-    outb(ATA_CB_DC_HD15 | ATA_CB_DC_NIEN, iobase2 + ATA_CB_DC);
+#define BM_CMD    0
+#define  BM_CMD_MEMWRITE  0x08
+#define  BM_CMD_START     0x01
+#define BM_STATUS 2
+#define  BM_STATUS_IRQ    0x04
+#define  BM_STATUS_ERROR  0x02
+#define  BM_STATUS_ACTIVE 0x01
+#define BM_TABLE  4
 
-    // sector will be 0 only on lba access. Convert to lba-chs
-    if (sector == 0) {
-        if ((count >= 1 << 8) || (lba + count >= 1UL << 28)) {
-            outb(0x00, iobase1 + ATA_CB_FR);
-            outb((count >> 8) & 0xff, iobase1 + ATA_CB_SC);
-            outb(lba >> 24, iobase1 + ATA_CB_SN);
-            outb(0, iobase1 + ATA_CB_CL);
-            outb(0, iobase1 + ATA_CB_CH);
-            command |= 0x04;
-            count &= (1UL << 8) - 1;
-            lba &= (1UL << 24) - 1;
-        }
-        sector = (u16) (lba & 0x000000ffL);
-        cylinder = (u16) ((lba>>8) & 0x0000ffffL);
-        head = ((u16) ((lba>>24) & 0x0000000fL)) | ATA_CB_DH_LBA;
-    }
+struct sff_dma_prd {
+    u32 buf_fl;
+    u32 count;
+};
 
-    outb(0x00, iobase1 + ATA_CB_FR);
-    outb(count, iobase1 + ATA_CB_SC);
-    outb(sector, iobase1 + ATA_CB_SN);
-    outb(cylinder & 0x00ff, iobase1 + ATA_CB_CL);
-    outb(cylinder >> 8, iobase1 + ATA_CB_CH);
-    outb((slave ? ATA_CB_DH_DEV1 : ATA_CB_DH_DEV0) | (u8) head
-         , iobase1 + ATA_CB_DH);
-    outb(command, iobase1 + ATA_CB_CMD);
-
-    await_ide(NOT_BSY_DRQ, iobase1, IDE_TIMEOUT);
-    status = inb(iobase1 + ATA_CB_STAT);
-
-    if (status & ATA_CB_STAT_ERR) {
-        DEBUGF("ata_cmd_data_out : read error\n");
-        return 2;
-    } else if ( !(status & ATA_CB_STAT_DRQ) ) {
-        DEBUGF("ata_cmd_data_out : DRQ not set (status %02x)\n"
-               , (unsigned) status);
-        return 3;
+// Check if DMA available and setup transfer if so.
+static int
+ata_try_dma(struct disk_op_s *op, int iswrite, int blocksize)
+{
+    if (! CONFIG_ATA_DMA)
+        return -1;
+    u32 dest = (u32)op->buf_fl;
+    if (dest & 1)
+        // Need minimum alignment of 1.
+        return -1;
+    u8 ataid = GET_GLOBAL(op->drive_g->cntl_id);
+    u8 channel = ataid / 2;
+    u16 iomaster = GET_GLOBAL(ATA_channels[channel].iomaster);
+    if (! iomaster)
+        return -1;
+    u32 bytes = op->count * blocksize;
+    if (! bytes)
+        return -1;
+
+    // Build PRD dma structure.
+    struct sff_dma_prd *dma = MAKE_FLATPTR(
+        get_ebda_seg()
+        , (void*)offsetof(struct extended_bios_data_area_s, extra_stack));
+    struct sff_dma_prd *origdma = dma;
+    while (bytes) {
+        if (dma >= &origdma[16])
+            // Too many descriptors..
+            return -1;
+        u32 count = bytes;
+        if (count > 0x10000)
+            count = 0x10000;
+        u32 max = 0x10000 - (dest & 0xffff);
+        if (count > max)
+            count = max;
+
+        SET_FLATPTR(dma->buf_fl, dest);
+        bytes -= count;
+        if (!bytes)
+            // Last descriptor.
+            count |= 1<<31;
+        dprintf(16, "dma@%p: %08x %08x\n", dma, dest, count);
+        dest += count;
+        SET_FLATPTR(dma->count, count);
+        dma++;
     }
 
-    // FIXME : move seg/off translation here
+    // Program bus-master controller.
+    outl((u32)origdma, iomaster + BM_TABLE);
+    u8 oldcmd = inb(iomaster + BM_CMD) & ~(BM_CMD_MEMWRITE|BM_CMD_START);
+    outb(oldcmd | (iswrite ? 0x00 : BM_CMD_MEMWRITE), iomaster + BM_CMD);
+    outb(BM_STATUS_ERROR|BM_STATUS_IRQ, iomaster + BM_STATUS);
 
-    irq_enable();
+    return 0;
+}
 
-    while (1) {
+// Transfer data using DMA.
+static int
+ata_dma_transfer(struct disk_op_s *op)
+{
+    if (! CONFIG_ATA_DMA)
+        return -1;
+    dprintf(16, "ata_dma_transfer id=%p buf=%p\n"
+            , op->drive_g, op->buf_fl);
 
-        if (offset > 0xf800) {
-            offset -= 0x800;
-            segment += 0x80;
-        }
+    u8 ataid = GET_GLOBAL(op->drive_g->cntl_id);
+    u8 channel = ataid / 2;
+    u16 iomaster = GET_GLOBAL(ATA_channels[channel].iomaster);
 
-        if (mode == ATA_MODE_PIO32)
-            outsl(iobase1, segment, offset, 512 / 4);
-        else
-            outsw(iobase1, segment, offset, 512 / 2);
-        offset += 512;
+    // Start bus-master controller.
+    u8 oldcmd = inb(iomaster + BM_CMD);
+    outb(oldcmd | BM_CMD_START, iomaster + BM_CMD);
 
-        current++;
-        SET_EBDA(ata.trsfsectors,current);
-        count--;
-        status = inb(iobase1 + ATA_CB_STAT);
-        if (count == 0) {
-            if ( (status & (ATA_CB_STAT_BSY | ATA_CB_STAT_RDY | ATA_CB_STAT_DF
-                            | ATA_CB_STAT_DRQ | ATA_CB_STAT_ERR) )
-                 != ATA_CB_STAT_RDY ) {
-                DEBUGF("ata_cmd_data_out : no sectors left (status %02x)\n"
-                       , (unsigned) status);
-                return 6;
-            }
+    u64 end = calc_future_tsc(IDE_TIMEOUT);
+    u8 status;
+    for (;;) {
+        status = inb(iomaster + BM_STATUS);
+        if (status & BM_STATUS_IRQ)
+            break;
+        // Transfer in progress
+        if (check_time(end)) {
+            // Timeout.
+            warn_timeout();
             break;
-        } else {
-            if ( (status & (ATA_CB_STAT_BSY | ATA_CB_STAT_RDY | ATA_CB_STAT_DRQ
-                            | ATA_CB_STAT_ERR) )
-                 != (ATA_CB_STAT_RDY | ATA_CB_STAT_DRQ) ) {
-                DEBUGF("ata_cmd_data_out : more sectors left (status %02x)\n"
-                       , (unsigned) status);
-                return 7;
-            }
-            continue;
         }
+        yield();
     }
-    // Enable interrupts
-    outb(ATA_CB_DC_HD15, iobase2+ATA_CB_DC);
-    return 0;
+    outb(oldcmd & ~BM_CMD_START, iomaster + BM_CMD);
+
+    u16 iobase1 = GET_GLOBAL(ATA_channels[channel].iobase1);
+    u16 iobase2 = GET_GLOBAL(ATA_channels[channel].iobase2);
+    int idestatus = pause_await_not_bsy(iobase1, iobase2);
+
+    if ((status & (BM_STATUS_IRQ|BM_STATUS_ACTIVE)) == BM_STATUS_IRQ
+        && idestatus >= 0x00
+        && (idestatus & (ATA_CB_STAT_BSY | ATA_CB_STAT_DF | ATA_CB_STAT_DRQ
+                         | ATA_CB_STAT_ERR)) == 0x00)
+        // Success.
+        return 0;
+
+    dprintf(6, "IDE DMA error (dma=%x ide=%x/%x/%x)\n", status, idestatus
+            , inb(iobase2 + ATA_CB_ASTAT), inb(iobase1 + ATA_CB_ERR));
+    op->count = 0;
+    return -1;
 }
 
-// ---------------------------------------------------------------------------
-// ATA/ATAPI driver : execute a packet command
-// ---------------------------------------------------------------------------
-      // returns
-      // 0 : no error
-      // 1 : error in parameters
-      // 2 : BUSY bit set
-      // 3 : error
-      // 4 : not ready
-u16
-ata_cmd_packet(u16 device, u8 *cmdbuf, u8 cmdlen, u16 header
-               , u32 length, u8 inout, u16 bufseg, u16 bufoff)
-{
-    u16 iobase1, iobase2;
-    u16 lcount, lbefore, lafter, count;
-    u8  channel, slave;
-    u8  status, mode, lmode;
-    u32 transfer;
-
-    channel = device / 2;
-    slave = device % 2;
-
-    // Data out is not supported yet
-    if (inout == ATA_DATA_OUT) {
-        BX_INFO("ata_cmd_packet: DATA_OUT not supported yet\n");
-        return 1;
-    }
 
-    // The header length must be even
-    if (header & 1) {
-        DEBUGF("ata_cmd_packet : header must be even (%04x)\n", header);
-        return 1;
-    }
+/****************************************************************
+ * ATA hard drive functions
+ ****************************************************************/
 
-    iobase1 = GET_EBDA(ata.channels[channel].iobase1);
-    iobase2 = GET_EBDA(ata.channels[channel].iobase2);
-    mode    = GET_EBDA(ata.devices[device].mode);
-    transfer= 0L;
+// Transfer data to harddrive using PIO protocol.
+static int
+ata_pio_cmd_data(struct disk_op_s *op, int iswrite, struct ata_pio_command *cmd)
+{
+    u8 ataid = GET_GLOBAL(op->drive_g->cntl_id);
+    u8 channel = ataid / 2;
+    u16 iobase1 = GET_GLOBAL(ATA_channels[channel].iobase1);
+    u16 iobase2 = GET_GLOBAL(ATA_channels[channel].iobase2);
 
-    if (cmdlen < 12)
-        cmdlen=12;
-    if (cmdlen > 12)
-        cmdlen=16;
-    cmdlen>>=1;
+    // Disable interrupts
+    outb(ATA_CB_DC_HD15 | ATA_CB_DC_NIEN, iobase2 + ATA_CB_DC);
 
-    // Reset count of transferred data
-    SET_EBDA(ata.trsfsectors,0);
-    SET_EBDA(ata.trsfbytes,0L);
+    int ret = send_cmd(op->drive_g, cmd);
+    if (ret)
+        goto fail;
+    ret = ata_wait_data(iobase1);
+    if (ret)
+        goto fail;
+    ret = ata_pio_transfer(op, iswrite, DISK_SECTOR_SIZE);
 
-    status = inb(iobase1 + ATA_CB_STAT);
-    if (status & ATA_CB_STAT_BSY)
-        return 2;
+fail:
+    // Enable interrupts
+    outb(ATA_CB_DC_HD15, iobase2+ATA_CB_DC);
+    return ret;
+}
 
-    outb(ATA_CB_DC_HD15 | ATA_CB_DC_NIEN, iobase2 + ATA_CB_DC);
-    outb(0x00, iobase1 + ATA_CB_FR);
-    outb(0x00, iobase1 + ATA_CB_SC);
-    outb(0x00, iobase1 + ATA_CB_SN);
-    outb(0xfff0 & 0x00ff, iobase1 + ATA_CB_CL);
-    outb(0xfff0 >> 8, iobase1 + ATA_CB_CH);
-    outb(slave ? ATA_CB_DH_DEV1 : ATA_CB_DH_DEV0, iobase1 + ATA_CB_DH);
-    outb(ATA_CMD_PACKET, iobase1 + ATA_CB_CMD);
-
-    // Device should ok to receive command
-    await_ide(NOT_BSY_DRQ, iobase1, IDE_TIMEOUT);
-    status = inb(iobase1 + ATA_CB_STAT);
+// Transfer data to harddrive using DMA protocol.
+static int
+ata_dma_cmd_data(struct disk_op_s *op, struct ata_pio_command *cmd)
+{
+    if (! CONFIG_ATA_DMA)
+        return -1;
+    int ret = send_cmd(op->drive_g, cmd);
+    if (ret)
+        return ret;
+    return ata_dma_transfer(op);
+}
 
-    if (status & ATA_CB_STAT_ERR) {
-        DEBUGF("ata_cmd_packet : error, status is %02x\n", status);
-        return 3;
-    } else if ( !(status & ATA_CB_STAT_DRQ) ) {
-        DEBUGF("ata_cmd_packet : DRQ not set (status %02x)\n"
-               , (unsigned) status);
-        return 4;
-    }
+// Read/write count blocks from a harddrive.
+static int
+ata_readwrite(struct disk_op_s *op, int iswrite)
+{
+    u64 lba = op->lba;
 
-    // Send command to device
-    irq_enable();
+    int usepio = ata_try_dma(op, iswrite, DISK_SECTOR_SIZE);
+
+    struct ata_pio_command cmd;
+    memset(&cmd, 0, sizeof(cmd));
 
-    outsw(iobase1, GET_SEG(SS), (u32)cmdbuf, cmdlen);
+    if (op->count >= (1<<8) || lba + op->count >= (1<<28)) {
+        cmd.sector_count2 = op->count >> 8;
+        cmd.lba_low2 = lba >> 24;
+        cmd.lba_mid2 = lba >> 32;
+        cmd.lba_high2 = lba >> 40;
+        lba &= 0xffffff;
 
-    if (inout == ATA_DATA_NO) {
-        await_ide(NOT_BSY, iobase1, IDE_TIMEOUT);
-        status = inb(iobase1 + ATA_CB_STAT);
+        if (usepio)
+            cmd.command = (iswrite ? ATA_CMD_WRITE_SECTORS_EXT
+                           : ATA_CMD_READ_SECTORS_EXT);
+        else
+            cmd.command = (iswrite ? ATA_CMD_WRITE_DMA_EXT
+                           : ATA_CMD_READ_DMA_EXT);
     } else {
-        u16 loops = 0;
-        u8 sc;
-        while (1) {
-
-            if (loops == 0) {//first time through
-                status = inb(iobase2 + ATA_CB_ASTAT);
-                await_ide(NOT_BSY_DRQ, iobase1, IDE_TIMEOUT);
-            } else
-                await_ide(NOT_BSY, iobase1, IDE_TIMEOUT);
-            loops++;
-
-            status = inb(iobase1 + ATA_CB_STAT);
-            sc = inb(iobase1 + ATA_CB_SC);
-
-            // Check if command completed
-            if(((inb(iobase1 + ATA_CB_SC)&0x7)==0x3) &&
-               ((status & (ATA_CB_STAT_RDY | ATA_CB_STAT_ERR)) == ATA_CB_STAT_RDY))
-                break;
+        if (usepio)
+            cmd.command = (iswrite ? ATA_CMD_WRITE_SECTORS
+                           : ATA_CMD_READ_SECTORS);
+        else
+            cmd.command = (iswrite ? ATA_CMD_WRITE_DMA
+                           : ATA_CMD_READ_DMA);
+    }
 
-            if (status & ATA_CB_STAT_ERR) {
-                DEBUGF("ata_cmd_packet : error (status %02x)\n", status);
-                return 3;
-            }
+    cmd.sector_count = op->count;
+    cmd.lba_low = lba;
+    cmd.lba_mid = lba >> 8;
+    cmd.lba_high = lba >> 16;
+    cmd.device = ((lba >> 24) & 0xf) | ATA_CB_DH_LBA;
+
+    int ret;
+    if (usepio)
+        ret = ata_pio_cmd_data(op, iswrite, &cmd);
+    else
+        ret = ata_dma_cmd_data(op, &cmd);
+    if (ret)
+        return DISK_RET_EBADTRACK;
+    return DISK_RET_SUCCESS;
+}
 
-            // Normalize address
-            bufseg += (bufoff / 16);
-            bufoff %= 16;
-
-            // Get the byte count
-            lcount =  ((u16)(inb(iobase1 + ATA_CB_CH))<<8)+inb(iobase1 + ATA_CB_CL);
-
-            // adjust to read what we want
-            if (header > lcount) {
-                lbefore=lcount;
-                header-=lcount;
-                lcount=0;
-            } else {
-                lbefore=header;
-                header=0;
-                lcount-=lbefore;
-            }
+// 16bit command demuxer for ATA harddrives.
+int
+process_ata_op(struct disk_op_s *op)
+{
+    if (!CONFIG_ATA)
+        return 0;
+
+    switch (op->command) {
+    case CMD_READ:
+        return ata_readwrite(op, 0);
+    case CMD_WRITE:
+        return ata_readwrite(op, 1);
+    default:
+        return process_ata_misc_op(op);
+    }
+}
 
-            if (lcount > length) {
-                lafter=lcount-length;
-                lcount=length;
-                length=0;
-            } else {
-                lafter=0;
-                length-=lcount;
-            }
 
-            // Save byte count
-            count = lcount;
-
-            DEBUGF("Trying to read %04x bytes (%04x %04x %04x) "
-                   , lbefore+lcount+lafter, lbefore, lcount, lafter);
-            DEBUGF("to 0x%04x:0x%04x\n", bufseg, bufoff);
-
-            // If counts not dividable by 4, use 16bits mode
-            lmode = mode;
-            if (lbefore & 0x03) lmode=ATA_MODE_PIO16;
-            if (lcount  & 0x03) lmode=ATA_MODE_PIO16;
-            if (lafter  & 0x03) lmode=ATA_MODE_PIO16;
-
-            // adds an extra byte if count are odd. before is always even
-            if (lcount & 0x01) {
-                lcount+=1;
-                if ((lafter > 0) && (lafter & 0x01)) {
-                    lafter-=1;
-                }
-            }
+/****************************************************************
+ * ATAPI functions
+ ****************************************************************/
 
-            if (lmode == ATA_MODE_PIO32) {
-                lcount>>=2; lbefore>>=2; lafter>>=2;
-            } else {
-                lcount>>=1; lbefore>>=1; lafter>>=1;
-            }
-
-            int i;
-            for (i=0; i<lbefore; i++)
-                if (lmode == ATA_MODE_PIO32)
-                    inl(iobase1);
-                else
-                    inw(iobase1);
+#define CDROM_CDB_SIZE 12
 
-            if (lmode == ATA_MODE_PIO32)
-                insl(iobase1, bufseg, bufoff, lcount);
-            else
-                insw(iobase1, bufseg, bufoff, lcount);
+// Low-level atapi command transmit function.
+int
+atapi_cmd_data(struct disk_op_s *op, void *cdbcmd, u16 blocksize)
+{
+    u8 ataid = GET_GLOBAL(op->drive_g->cntl_id);
+    u8 channel = ataid / 2;
+    u16 iobase1 = GET_GLOBAL(ATA_channels[channel].iobase1);
+    u16 iobase2 = GET_GLOBAL(ATA_channels[channel].iobase2);
+
+    struct ata_pio_command cmd;
+    memset(&cmd, 0, sizeof(cmd));
+    cmd.lba_mid = blocksize;
+    cmd.lba_high = blocksize >> 8;
+    cmd.command = ATA_CMD_PACKET;
+
+    // Disable interrupts
+    outb(ATA_CB_DC_HD15 | ATA_CB_DC_NIEN, iobase2 + ATA_CB_DC);
 
-            for (i=0; i<lafter; i++)
-                if (lmode == ATA_MODE_PIO32)
-                    inl(iobase1);
-                else
-                    inw(iobase1);
+    int ret = send_cmd(op->drive_g, &cmd);
+    if (ret)
+        goto fail;
+    ret = ata_wait_data(iobase1);
+    if (ret)
+        goto fail;
 
-            // Compute new buffer address
-            bufoff += count;
+    // Send command to device
+    outsw_fl(iobase1, MAKE_FLATPTR(GET_SEG(SS), cdbcmd), CDROM_CDB_SIZE / 2);
 
-            // Save transferred bytes count
-            transfer += count;
-            SET_EBDA(ata.trsfbytes,transfer);
-        }
+    int status = pause_await_not_bsy(iobase1, iobase2);
+    if (status < 0) {
+        ret = status;
+        goto fail;
     }
 
-    // Final check, device must be ready
-    if ( (status & (ATA_CB_STAT_BSY | ATA_CB_STAT_RDY | ATA_CB_STAT_DF
-                    | ATA_CB_STAT_DRQ | ATA_CB_STAT_ERR) )
-         != ATA_CB_STAT_RDY ) {
-        DEBUGF("ata_cmd_packet : not ready (status %02x)\n"
-               , (unsigned) status);
-        return 4;
+    if (status & ATA_CB_STAT_ERR) {
+        u8 err = inb(iobase1 + ATA_CB_ERR);
+        // skip "Not Ready"
+        if (err != 0x20)
+            dprintf(6, "send_atapi_cmd : read error (status=%02x err=%02x)\n"
+                    , status, err);
+        ret = -2;
+        goto fail;
     }
+    if (!(status & ATA_CB_STAT_DRQ)) {
+        dprintf(6, "send_atapi_cmd : DRQ not set (status %02x)\n", status);
+        ret = -3;
+        goto fail;
+    }
+
+    ret = ata_pio_transfer(op, 0, blocksize);
 
+fail:
     // Enable interrupts
     outb(ATA_CB_DC_HD15, iobase2+ATA_CB_DC);
-    return 0;
+    if (ret)
+        return DISK_RET_EBADTRACK;
+    return DISK_RET_SUCCESS;
 }
 
-u16
-cdrom_read(u16 device, u32 lba, u32 count, u16 segment, u16 offset, u16 skip)
+// 16bit command demuxer for ATAPI cdroms.
+int
+process_atapi_op(struct disk_op_s *op)
 {
-    u16 sectors = (count + 2048 - 1) / 2048;
+    switch (op->command) {
+    case CMD_READ:
+        return cdb_read(op);
+    case CMD_FORMAT:
+    case CMD_WRITE:
+        return DISK_RET_EWRITEPROTECT;
+    default:
+        return process_ata_misc_op(op);
+    }
+}
+
 
-    u8 atacmd[12];
-    memset(atacmd, 0, sizeof(atacmd));
-    atacmd[0]=0x28;                      // READ command
-    atacmd[7]=(sectors & 0xff00) >> 8;   // Sectors
-    atacmd[8]=(sectors & 0x00ff);        // Sectors
-    atacmd[2]=(lba & 0xff000000) >> 24;  // LBA
-    atacmd[3]=(lba & 0x00ff0000) >> 16;
-    atacmd[4]=(lba & 0x0000ff00) >> 8;
-    atacmd[5]=(lba & 0x000000ff);
+/****************************************************************
+ * ATA detect and init
+ ****************************************************************/
 
-    return ata_cmd_packet(device, atacmd, sizeof(atacmd)
-                          , skip, count, ATA_DATA_IN
-                          , segment, offset);
+// Send an identify device or identify device packet command.
+static int
+send_ata_identity(struct drive_s *drive_g, u16 *buffer, int command)
+{
+    memset(buffer, 0, DISK_SECTOR_SIZE);
+
+    struct disk_op_s dop;
+    memset(&dop, 0, sizeof(dop));
+    dop.drive_g = drive_g;
+    dop.count = 1;
+    dop.lba = 1;
+    dop.buf_fl = MAKE_FLATPTR(GET_SEG(SS), buffer);
+
+    struct ata_pio_command cmd;
+    memset(&cmd, 0, sizeof(cmd));
+    cmd.command = command;
+
+    return ata_pio_cmd_data(&dop, 0, &cmd);
 }
 
-// ---------------------------------------------------------------------------
-// ATA/ATAPI driver : device detection
-// ---------------------------------------------------------------------------
+// Extract the ATA/ATAPI version info.
+static int
+extract_version(u16 *buffer)
+{
+    // Extract ATA/ATAPI version.
+    u16 ataversion = buffer[80];
+    u8 version;
+    for (version=15; version>0; version--)
+        if (ataversion & (1<<version))
+            break;
+    return version;
+}
 
-void
-ata_detect()
-{
-    u8  hdcount, cdcount, device, type;
-    u8  buffer[0x0200];
-    memset(buffer, 0, sizeof(buffer));
-
-#if CONFIG_MAX_ATA_INTERFACES > 0
-    SET_EBDA(ata.channels[0].iface,ATA_IFACE_ISA);
-    SET_EBDA(ata.channels[0].iobase1,0x1f0);
-    SET_EBDA(ata.channels[0].iobase2,0x3f0);
-    SET_EBDA(ata.channels[0].irq,14);
-#endif
-#if CONFIG_MAX_ATA_INTERFACES > 1
-    SET_EBDA(ata.channels[1].iface,ATA_IFACE_ISA);
-    SET_EBDA(ata.channels[1].iobase1,0x170);
-    SET_EBDA(ata.channels[1].iobase2,0x370);
-    SET_EBDA(ata.channels[1].irq,15);
-#endif
-#if CONFIG_MAX_ATA_INTERFACES > 2
-    SET_EBDA(ata.channels[2].iface,ATA_IFACE_ISA);
-    SET_EBDA(ata.channels[2].iobase1,0x1e8);
-    SET_EBDA(ata.channels[2].iobase2,0x3e0);
-    SET_EBDA(ata.channels[2].irq,12);
-#endif
-#if CONFIG_MAX_ATA_INTERFACES > 3
-    SET_EBDA(ata.channels[3].iface,ATA_IFACE_ISA);
-    SET_EBDA(ata.channels[3].iobase1,0x168);
-    SET_EBDA(ata.channels[3].iobase2,0x360);
-    SET_EBDA(ata.channels[3].irq,11);
-#endif
-#if CONFIG_MAX_ATA_INTERFACES > 4
-#error Please fill the ATA interface informations
-#endif
+// Extract common information from IDENTIFY commands.
+static void
+extract_identify(struct drive_s *drive_g, u16 *buffer)
+{
+    dprintf(3, "Identify w0=%x w2=%x\n", buffer[0], buffer[2]);
+
+    // Read model name
+    char *model = drive_g->model;
+    int maxsize = ARRAY_SIZE(drive_g->model);
+    int i;
+    for (i=0; i<maxsize/2; i++) {
+        u16 v = buffer[27+i];
+        model[i*2] = v >> 8;
+        model[i*2+1] = v & 0xff;
+    }
+    model[maxsize-1] = 0x00;
 
-    // Device detection
-    hdcount=cdcount=0;
+    // Trim trailing spaces from model name.
+    for (i=maxsize-2; i>0 && model[i] == 0x20; i--)
+        model[i] = 0x00;
 
-    for(device=0; device<CONFIG_MAX_ATA_DEVICES; device++) {
-        u16 iobase1, iobase2;
-        u8  channel, slave, shift;
-        u8  sc, sn, cl, ch, st;
+    // Common flags.
+    SET_GLOBAL(drive_g->removable, (buffer[0] & 0x80) ? 1 : 0);
+    SET_GLOBAL(drive_g->cntl_info, extract_version(buffer));
+}
 
-        channel = device / 2;
-        slave = device % 2;
+// Print out a description of the given atapi drive.
+void
+describe_atapi(struct drive_s *drive_g)
+{
+    u8 ataid = drive_g->cntl_id;
+    u8 channel = ataid / 2;
+    u8 slave = ataid % 2;
+    u8 version = drive_g->cntl_info;
+    int iscd = drive_g->floppy_type;
+    printf("ata%d-%d: %s ATAPI-%d %s", channel, slave
+           , drive_g->model, version
+           , (iscd ? "CD-Rom/DVD-Rom" : "Device"));
+}
 
-        iobase1 =GET_EBDA(ata.channels[channel].iobase1);
-        iobase2 =GET_EBDA(ata.channels[channel].iobase2);
+// Detect if the given drive is an atapi - initialize it if so.
+static struct drive_s *
+init_drive_atapi(struct drive_s *dummy, u16 *buffer)
+{
+    // Send an IDENTIFY_DEVICE_PACKET command to device
+    int ret = send_ata_identity(dummy, buffer, ATA_CMD_IDENTIFY_PACKET_DEVICE);
+    if (ret)
+        return NULL;
+
+    // Success - setup as ATAPI.
+    struct drive_s *drive_g = malloc_fseg(sizeof(*drive_g));
+    if (! drive_g) {
+        warn_noalloc();
+        return NULL;
+    }
+    memset(drive_g, 0, sizeof(*drive_g));
+    SET_GLOBAL(drive_g->cntl_id, dummy->cntl_id);
+    extract_identify(drive_g, buffer);
+    SET_GLOBAL(drive_g->type, DTYPE_ATAPI);
+    SET_GLOBAL(drive_g->blksize, CDROM_SECTOR_SIZE);
+    SET_GLOBAL(drive_g->sectors, (u64)-1);
+    u8 iscd = ((buffer[0] >> 8) & 0x1f) == 0x05;
+    SET_GLOBAL(drive_g->floppy_type, iscd);
+
+    // fill cdidmap
+    if (iscd)
+        map_cd_drive(drive_g);
+
+    return drive_g;
+}
 
-        // Disable interrupts
-        outb(ATA_CB_DC_HD15 | ATA_CB_DC_NIEN, iobase2+ATA_CB_DC);
+// Print out a description of the given ata drive.
+void
+describe_ata(struct drive_s *drive_g)
+{
+    u8 ataid = drive_g->cntl_id;
+    u8 channel = ataid / 2;
+    u8 slave = ataid % 2;
+    u64 sectors = drive_g->sectors;
+    u8 version = drive_g->cntl_info;
+    char *model = drive_g->model;
+    printf("ata%d-%d: %s ATA-%d Hard-Disk", channel, slave, model, version);
+    u64 sizeinmb = sectors >> 11;
+    if (sizeinmb < (1 << 16))
+        printf(" (%u MiBytes)", (u32)sizeinmb);
+    else
+        printf(" (%u GiBytes)", (u32)(sizeinmb >> 10));
+}
 
-        // Look for device
-        outb(slave ? ATA_CB_DH_DEV1 : ATA_CB_DH_DEV0, iobase1+ATA_CB_DH);
-        outb(0x55, iobase1+ATA_CB_SC);
-        outb(0xaa, iobase1+ATA_CB_SN);
-        outb(0xaa, iobase1+ATA_CB_SC);
-        outb(0x55, iobase1+ATA_CB_SN);
-        outb(0x55, iobase1+ATA_CB_SC);
-        outb(0xaa, iobase1+ATA_CB_SN);
+// Detect if the given drive is a regular ata drive - initialize it if so.
+static struct drive_s *
+init_drive_ata(struct drive_s *dummy, u16 *buffer)
+{
+    // Send an IDENTIFY_DEVICE command to device
+    int ret = send_ata_identity(dummy, buffer, ATA_CMD_IDENTIFY_DEVICE);
+    if (ret)
+        return NULL;
+
+    // Success - setup as ATA.
+    struct drive_s *drive_g = malloc_fseg(sizeof(*drive_g));
+    if (! drive_g) {
+        warn_noalloc();
+        return NULL;
+    }
+    memset(drive_g, 0, sizeof(*drive_g));
+    SET_GLOBAL(drive_g->cntl_id, dummy->cntl_id);
+    extract_identify(drive_g, buffer);
+    SET_GLOBAL(drive_g->type, DTYPE_ATA);
+    SET_GLOBAL(drive_g->blksize, DISK_SECTOR_SIZE);
+
+    SET_GLOBAL(drive_g->pchs.cylinders, buffer[1]);
+    SET_GLOBAL(drive_g->pchs.heads, buffer[3]);
+    SET_GLOBAL(drive_g->pchs.spt, buffer[6]);
+
+    u64 sectors;
+    if (buffer[83] & (1 << 10)) // word 83 - lba48 support
+        sectors = *(u64*)&buffer[100]; // word 100-103
+    else
+        sectors = *(u32*)&buffer[60]; // word 60 and word 61
+    SET_GLOBAL(drive_g->sectors, sectors);
+
+    // Setup disk geometry translation.
+    setup_translation(drive_g);
+
+    // Register with bcv system.
+    add_bcv_internal(drive_g);
+
+    return drive_g;
+}
 
-        // If we found something
-        sc = inb(iobase1+ATA_CB_SC);
-        sn = inb(iobase1+ATA_CB_SN);
-
-        if ( (sc == 0x55) && (sn == 0xaa) ) {
-            SET_EBDA(ata.devices[device].type,ATA_TYPE_UNKNOWN);
-
-            // reset the channel
-            ata_reset(device);
-
-            // check for ATA or ATAPI
-            outb(slave ? ATA_CB_DH_DEV1 : ATA_CB_DH_DEV0, iobase1+ATA_CB_DH);
-            sc = inb(iobase1+ATA_CB_SC);
-            sn = inb(iobase1+ATA_CB_SN);
-            if ((sc==0x01) && (sn==0x01)) {
-                cl = inb(iobase1+ATA_CB_CL);
-                ch = inb(iobase1+ATA_CB_CH);
-                st = inb(iobase1+ATA_CB_STAT);
-
-                if ((cl==0x14) && (ch==0xeb)) {
-                    SET_EBDA(ata.devices[device].type,ATA_TYPE_ATAPI);
-                } else if ((cl==0x00) && (ch==0x00) && (st!=0x00)) {
-                    SET_EBDA(ata.devices[device].type,ATA_TYPE_ATA);
-                } else if ((cl==0xff) && (ch==0xff)) {
-                    SET_EBDA(ata.devices[device].type,ATA_TYPE_NONE);
-                }
-            }
-        }
+static u64 SpinupEnd;
 
-        type=GET_EBDA(ata.devices[device].type);
-
-        // Now we send a IDENTIFY command to ATA device
-        if(type == ATA_TYPE_ATA) {
-            u32 sectors;
-            u16 cylinders, heads, spt, blksize;
-            u8  translation, removable, mode;
-
-            //Temporary values to do the transfer
-            SET_EBDA(ata.devices[device].device,ATA_DEVICE_HD);
-            SET_EBDA(ata.devices[device].mode, ATA_MODE_PIO16);
-
-            u16 ret = ata_cmd_data_in(device,ATA_CMD_IDENTIFY_DEVICE
-                                      , 1, 0, 0, 0, 0L
-                                      , GET_SEG(SS), (u32)buffer);
-            if (ret)
-                BX_PANIC("ata-detect: Failed to detect ATA device\n");
-
-            removable = (buffer[0] & 0x80) ? 1 : 0;
-            mode      = buffer[96] ? ATA_MODE_PIO32 : ATA_MODE_PIO16;
-            blksize   = *(u16*)&buffer[10];
-
-            cylinders = *(u16*)&buffer[1*2]; // word 1
-            heads     = *(u16*)&buffer[3*2]; // word 3
-            spt       = *(u16*)&buffer[6*2]; // word 6
-
-            sectors   = *(u32*)&buffer[60*2]; // word 60 and word 61
-
-            SET_EBDA(ata.devices[device].device,ATA_DEVICE_HD);
-            SET_EBDA(ata.devices[device].removable, removable);
-            SET_EBDA(ata.devices[device].mode, mode);
-            SET_EBDA(ata.devices[device].blksize, blksize);
-            SET_EBDA(ata.devices[device].pchs.heads, heads);
-            SET_EBDA(ata.devices[device].pchs.cylinders, cylinders);
-            SET_EBDA(ata.devices[device].pchs.spt, spt);
-            SET_EBDA(ata.devices[device].sectors, sectors);
-            BX_INFO("ata%d-%d: PCHS=%u/%d/%d translation=", channel, slave,cylinders, heads, spt);
-
-            translation = inb_cmos(CMOS_BIOS_DISKTRANSFLAG + channel/2);
-            for (shift=device%4; shift>0; shift--)
-                translation >>= 2;
-            translation &= 0x03;
-
-            SET_EBDA(ata.devices[device].translation, translation);
-
-            switch (translation) {
-            case ATA_TRANSLATION_NONE:
-                BX_INFO("none");
-                break;
-            case ATA_TRANSLATION_LBA:
-                BX_INFO("lba");
-                break;
-            case ATA_TRANSLATION_LARGE:
-                BX_INFO("large");
-                break;
-            case ATA_TRANSLATION_RECHS:
-                BX_INFO("r-echs");
-                break;
-            }
-            switch (translation) {
-            case ATA_TRANSLATION_NONE:
-                break;
-            case ATA_TRANSLATION_LBA:
-                spt = 63;
-                sectors /= 63;
-                heads = sectors / 1024;
-                if (heads>128) heads = 255;
-                else if (heads>64) heads = 128;
-                else if (heads>32) heads = 64;
-                else if (heads>16) heads = 32;
-                else heads=16;
-                cylinders = sectors / heads;
-                break;
-            case ATA_TRANSLATION_RECHS:
-                // Take care not to overflow
-                if (heads==16) {
-                    if(cylinders>61439) cylinders=61439;
-                    heads=15;
-                    cylinders = (u16)((u32)(cylinders)*16/15);
-                }
-                // then go through the large bitshift process
-            case ATA_TRANSLATION_LARGE:
-                while(cylinders > 1024) {
-                    cylinders >>= 1;
-                    heads <<= 1;
-
-                    // If we max out the head count
-                    if (heads > 127) break;
-                }
-                break;
-            }
-            // clip to 1024 cylinders in lchs
-            if (cylinders > 1024)
-                cylinders=1024;
-            BX_INFO(" LCHS=%d/%d/%d\n", cylinders, heads, spt);
-
-            SET_EBDA(ata.devices[device].lchs.heads, heads);
-            SET_EBDA(ata.devices[device].lchs.cylinders, cylinders);
-            SET_EBDA(ata.devices[device].lchs.spt, spt);
-
-            // fill hdidmap
-            SET_EBDA(ata.idmap[0][hdcount], device);
-            hdcount++;
+// Wait for non-busy status and check for "floating bus" condition.
+static int
+powerup_await_non_bsy(u16 base)
+{
+    u8 orstatus = 0;
+    u8 status;
+    for (;;) {
+        status = inb(base+ATA_CB_STAT);
+        if (!(status & ATA_CB_STAT_BSY))
+            break;
+        orstatus |= status;
+        if (orstatus == 0xff) {
+            dprintf(1, "powerup IDE floating\n");
+            return orstatus;
         }
+        if (check_time(SpinupEnd)) {
+            warn_timeout();
+            return -1;
+        }
+        yield();
+    }
+    dprintf(6, "powerup iobase=%x st=%x\n", base, status);
+    return status;
+}
 
-        // Now we send a IDENTIFY command to ATAPI device
-        if(type == ATA_TYPE_ATAPI) {
+// Detect any drives attached to a given controller.
+static void
+ata_detect(void *data)
+{
+    struct ata_channel_s *atachannel = data;
+    int startid = (atachannel - ATA_channels) * 2;
+    struct drive_s dummy;
+    memset(&dummy, 0, sizeof(dummy));
+    // Device detection
+    int ataid, last_reset_ataid=-1;
+    for (ataid=startid; ataid<startid+2; ataid++) {
+        u8 channel = ataid / 2;
+        u8 slave = ataid % 2;
 
-            u8  type, removable, mode;
-            u16 blksize;
+        u16 iobase1 = GET_GLOBAL(ATA_channels[channel].iobase1);
+        if (!iobase1)
+            break;
 
-            //Temporary values to do the transfer
-            SET_EBDA(ata.devices[device].device,ATA_DEVICE_CDROM);
-            SET_EBDA(ata.devices[device].mode, ATA_MODE_PIO16);
+        // Wait for not-bsy.
+        int status = powerup_await_non_bsy(iobase1);
+        if (status < 0)
+            continue;
+        u8 newdh = slave ? ATA_CB_DH_DEV1 : ATA_CB_DH_DEV0;
+        outb(newdh, iobase1+ATA_CB_DH);
+        ndelay(400);
+        status = powerup_await_non_bsy(iobase1);
+        if (status < 0)
+            continue;
 
-            u16 ret = ata_cmd_data_in(device,ATA_CMD_IDENTIFY_DEVICE_PACKET
-                                      , 1, 0, 0, 0, 0L
-                                      , GET_SEG(SS), (u32)buffer);
-            if (ret != 0)
-                BX_PANIC("ata-detect: Failed to detect ATAPI device\n");
+        // Check if ioport registers look valid.
+        outb(newdh, iobase1+ATA_CB_DH);
+        u8 dh = inb(iobase1+ATA_CB_DH);
+        outb(0x55, iobase1+ATA_CB_SC);
+        outb(0xaa, iobase1+ATA_CB_SN);
+        u8 sc = inb(iobase1+ATA_CB_SC);
+        u8 sn = inb(iobase1+ATA_CB_SN);
+        dprintf(6, "ata_detect ataid=%d sc=%x sn=%x dh=%x\n"
+                , ataid, sc, sn, dh);
+        if (sc != 0x55 || sn != 0xaa || dh != newdh)
+            continue;
 
-            type      = buffer[1] & 0x1f;
-            removable = (buffer[0] & 0x80) ? 1 : 0;
-            mode      = buffer[96] ? ATA_MODE_PIO32 : ATA_MODE_PIO16;
-            blksize   = 2048;
+        // Prepare new drive.
+        dummy.cntl_id = ataid;
 
-            SET_EBDA(ata.devices[device].device, type);
-            SET_EBDA(ata.devices[device].removable, removable);
-            SET_EBDA(ata.devices[device].mode, mode);
-            SET_EBDA(ata.devices[device].blksize, blksize);
+        // reset the channel
+        if (slave && ataid == last_reset_ataid + 1) {
+            // The drive was just reset - no need to reset it again.
+        } else {
+            ata_reset(&dummy);
+            last_reset_ataid = ataid;
+        }
 
-            // fill cdidmap
-            SET_EBDA(ata.idmap[1][cdcount], device);
-            cdcount++;
+        // check for ATAPI
+        u16 buffer[256];
+        struct drive_s *drive_g = init_drive_atapi(&dummy, buffer);
+        if (!drive_g) {
+            // Didn't find an ATAPI drive - look for ATA drive.
+            u8 st = inb(iobase1+ATA_CB_STAT);
+            if (!st)
+                // Status not set - can't be a valid drive.
+                continue;
+
+            // Wait for RDY.
+            int ret = await_rdy(iobase1);
+            if (ret < 0)
+                continue;
+
+            // check for ATA.
+            drive_g = init_drive_ata(&dummy, buffer);
+            if (!drive_g)
+                // No ATA drive found
+                continue;
         }
 
-        u32 sizeinmb = 0;
-        u16 ataversion;
-        u8  c, i, version=0, model[41];
-
-        switch (type) {
-        case ATA_TYPE_ATA:
-            sizeinmb = GET_EBDA(ata.devices[device].sectors);
-            sizeinmb >>= 11;
-        case ATA_TYPE_ATAPI:
-            // Read ATA/ATAPI version
-            ataversion=((u16)(buffer[161])<<8) | buffer[160];
-            for(version=15;version>0;version--) {
-                if ((ataversion&(1<<version))!=0)
-                    break;
-            }
+        u16 resetresult = buffer[93];
+        dprintf(6, "ata_detect resetresult=%04x\n", resetresult);
+        if (!slave && (resetresult & 0xdf61) == 0x4041)
+            // resetresult looks valid and device 0 is responding to
+            // device 1 requests - device 1 must not be present - skip
+            // detection.
+            ataid++;
+    }
+}
 
-            // Read model name
-            for (i=0;i<20;i++) {
-                model[i*2] = buffer[(i*2)+54+1];
-                model[(i*2)+1] = buffer[(i*2)+54];
-            }
+// Initialize an ata controller and detect its drives.
+static void
+init_controller(struct ata_channel_s *atachannel
+                , int bdf, int irq, u32 port1, u32 port2, u32 master)
+{
+    SET_GLOBAL(atachannel->irq, irq);
+    SET_GLOBAL(atachannel->pci_bdf, bdf);
+    SET_GLOBAL(atachannel->iobase1, port1);
+    SET_GLOBAL(atachannel->iobase2, port2);
+    SET_GLOBAL(atachannel->iomaster, master);
+    dprintf(1, "ATA controller %d at %x/%x/%x (irq %d dev %x)\n"
+            , atachannel - ATA_channels, port1, port2, master, irq, bdf);
+    run_thread(ata_detect, atachannel);
+}
 
-            // Reformat
-            model[40] = 0x00;
-            for (i=39;i>0;i--) {
-                if (model[i]==0x20)
-                    model[i] = 0x00;
-                else
-                    break;
-            }
+#define IRQ_ATA1 14
+#define IRQ_ATA2 15
+
+// Locate and init ata controllers.
+static void
+ata_init(void)
+{
+    // Scan PCI bus for ATA adapters
+    int count=0, pcicount=0;
+    int bdf, max;
+    foreachpci(bdf, max) {
+        pcicount++;
+        if (pci_config_readw(bdf, PCI_CLASS_DEVICE) != PCI_CLASS_STORAGE_IDE)
+            continue;
+        if (count >= ARRAY_SIZE(ATA_channels))
             break;
+
+        u8 pciirq = pci_config_readb(bdf, PCI_INTERRUPT_LINE);
+        u8 prog_if = pci_config_readb(bdf, PCI_CLASS_PROG);
+        int master = 0;
+        if (CONFIG_ATA_DMA && prog_if & 0x80) {
+            // Check for bus-mastering.
+            u32 bar = pci_config_readl(bdf, PCI_BASE_ADDRESS_4);
+            if (bar & PCI_BASE_ADDRESS_SPACE_IO) {
+                master = bar & PCI_BASE_ADDRESS_IO_MASK;
+                pci_config_maskw(bdf, PCI_COMMAND, 0, PCI_COMMAND_MASTER);
+            }
         }
 
-        switch (type) {
-        case ATA_TYPE_ATA:
-            printf("ata%d %s: ",channel,slave?" slave":"master");
-            i=0;
-            while ((c=model[i++]))
-                printf("%c",c);
-            if (sizeinmb < (1UL<<16))
-                printf(" ATA-%d Hard-Disk (%u MBytes)\n", version, (u16)sizeinmb);
-            else
-                printf(" ATA-%d Hard-Disk (%u GBytes)\n", version, (u16)(sizeinmb>>10));
-            break;
-        case ATA_TYPE_ATAPI:
-            printf("ata%d %s: ",channel,slave?" slave":"master");
-            i=0;
-            while ((c=model[i++]))
-                printf("%c",c);
-            if (GET_EBDA(ata.devices[device].device)==ATA_DEVICE_CDROM)
-                printf(" ATAPI-%d CD-Rom/DVD-Rom\n",version);
-            else
-                printf(" ATAPI-%d Device\n",version);
-            break;
-        case ATA_TYPE_UNKNOWN:
-            printf("ata%d %s: Unknown device\n",channel,slave?" slave":"master");
-            break;
+        u32 port1, port2, irq;
+        if (prog_if & 1) {
+            port1 = pci_config_readl(bdf, PCI_BASE_ADDRESS_0) & ~3;
+            port2 = pci_config_readl(bdf, PCI_BASE_ADDRESS_1) & ~3;
+            irq = pciirq;
+        } else {
+            port1 = PORT_ATA1_CMD_BASE;
+            port2 = PORT_ATA1_CTRL_BASE;
+            irq = IRQ_ATA1;
+        }
+        init_controller(&ATA_channels[count], bdf, irq, port1, port2, master);
+        count++;
+
+        if (prog_if & 4) {
+            port1 = pci_config_readl(bdf, PCI_BASE_ADDRESS_2) & ~3;
+            port2 = pci_config_readl(bdf, PCI_BASE_ADDRESS_3) & ~3;
+            irq = pciirq;
+        } else {
+            port1 = PORT_ATA2_CMD_BASE;
+            port2 = PORT_ATA2_CTRL_BASE;
+            irq = IRQ_ATA2;
         }
+        init_controller(&ATA_channels[count], bdf, irq, port1, port2
+                        , master ? master + 8 : 0);
+        count++;
     }
 
-    // Store the devices counts
-    SET_EBDA(ata.hdcount, hdcount);
-    SET_EBDA(ata.cdcount, cdcount);
-    SET_BDA(disk_count, hdcount);
+    if (!CONFIG_COREBOOT && !pcicount && ARRAY_SIZE(ATA_channels) >= 2) {
+        // No PCI devices found - probably a QEMU "-M isapc" machine.
+        // Try using ISA ports for ATA controllers.
+        init_controller(&ATA_channels[0], -1, IRQ_ATA1
+                        , PORT_ATA1_CMD_BASE, PORT_ATA1_CTRL_BASE, 0);
+        init_controller(&ATA_channels[1], -1, IRQ_ATA2
+                        , PORT_ATA2_CMD_BASE, PORT_ATA2_CTRL_BASE, 0);
+    }
+}
+
+void
+ata_setup(void)
+{
+    ASSERT32FLAT();
+    if (!CONFIG_ATA)
+        return;
+
+    dprintf(3, "init hard drives\n");
+
+    SpinupEnd = calc_future_tsc(IDE_TIMEOUT);
+    ata_init();
 
-    printf("\n");
+    SET_BDA(disk_control_byte, 0xc0);
 
-    // FIXME : should use bios=cmos|auto|disable bits
-    // FIXME : should know about translation bits
-    // FIXME : move hard_drive_post here
+    enable_hwirq(14, entry_76);
 }