Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 673 insertions, 0 deletions

diff --git a/qemu/roms/seabios/src/hw/floppy.c b/qemu/roms/seabios/src/hw/floppy.c
new file mode 100644
index 000000000..d60362a34
--- /dev/null
+++ b/qemu/roms/seabios/src/hw/floppy.c
@@ -0,0 +1,673 @@
+// 16bit code to access floppy drives.
+//
+// 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 LGPLv3 license.
+
+#include "biosvar.h" // SET_BDA
+#include "block.h" // struct drive_s
+#include "bregs.h" // struct bregs
+#include "config.h" // CONFIG_FLOPPY
+#include "malloc.h" // malloc_fseg
+#include "output.h" // dprintf
+#include "pci.h" // pci_to_bdf
+#include "pci_ids.h" // PCI_CLASS_BRIDGE_ISA
+#include "pic.h" // pic_eoi1
+#include "romfile.h" // romfile_loadint
+#include "rtc.h" // rtc_read
+#include "stacks.h" // yield
+#include "std/disk.h" // DISK_RET_SUCCESS
+#include "string.h" // memset
+#include "util.h" // timer_calc
+
+#define PORT_FD_BASE           0x03f0
+#define PORT_FD_DOR            0x03f2
+#define PORT_FD_STATUS         0x03f4
+#define PORT_FD_DATA           0x03f5
+#define PORT_FD_DIR            0x03f7
+
+#define FLOPPY_SIZE_CODE 0x02 // 512 byte sectors
+#define FLOPPY_DATALEN 0xff   // Not used - because size code is 0x02
+#define FLOPPY_MOTOR_TICKS 37 // ~2 seconds
+#define FLOPPY_FILLBYTE 0xf6
+#define FLOPPY_GAPLEN 0x1B
+#define FLOPPY_FORMAT_GAPLEN 0x6c
+#define FLOPPY_PIO_TIMEOUT 1000
+
+// New diskette parameter table adding 3 parameters from IBM
+// Since no provisions are made for multiple drive types, most
+// values in this table are ignored.  I set parameters for 1.44M
+// floppy here
+struct floppy_ext_dbt_s diskette_param_table2 VARFSEG = {
+    .dbt = {
+        .specify1       = 0xAF, // step rate 12ms, head unload 240ms
+        .specify2       = 0x02, // head load time 4ms, DMA used
+        .shutoff_ticks  = FLOPPY_MOTOR_TICKS, // ~2 seconds
+        .bps_code       = FLOPPY_SIZE_CODE,
+        .sectors        = 18,
+        .interblock_len = FLOPPY_GAPLEN,
+        .data_len       = FLOPPY_DATALEN,
+        .gap_len        = FLOPPY_FORMAT_GAPLEN,
+        .fill_byte      = FLOPPY_FILLBYTE,
+        .settle_time    = 0x0F, // 15ms
+        .startup_time   = 0x08, // 1 second
+    },
+    .max_track      = 79,   // maximum track
+    .data_rate      = 0,    // data transfer rate
+    .drive_type     = 4,    // drive type in cmos
+};
+
+struct floppyinfo_s {
+    struct chs_s chs;
+    u8 floppy_size;
+    u8 data_rate;
+};
+
+#define FLOPPY_SIZE_525 0x01
+#define FLOPPY_SIZE_350 0x02
+
+#define FLOPPY_RATE_500K 0x00
+#define FLOPPY_RATE_300K 0x01
+#define FLOPPY_RATE_250K 0x02
+#define FLOPPY_RATE_1M   0x03
+
+struct floppyinfo_s FloppyInfo[] VARFSEG = {
+    // Unknown
+    { {0, 0, 0}, 0x00, 0x00},
+    // 1 - 360KB, 5.25" - 2 heads, 40 tracks, 9 sectors
+    { {2, 40, 9}, FLOPPY_SIZE_525, FLOPPY_RATE_300K},
+    // 2 - 1.2MB, 5.25" - 2 heads, 80 tracks, 15 sectors
+    { {2, 80, 15}, FLOPPY_SIZE_525, FLOPPY_RATE_500K},
+    // 3 - 720KB, 3.5"  - 2 heads, 80 tracks, 9 sectors
+    { {2, 80, 9}, FLOPPY_SIZE_350, FLOPPY_RATE_250K},
+    // 4 - 1.44MB, 3.5" - 2 heads, 80 tracks, 18 sectors
+    { {2, 80, 18}, FLOPPY_SIZE_350, FLOPPY_RATE_500K},
+    // 5 - 2.88MB, 3.5" - 2 heads, 80 tracks, 36 sectors
+    { {2, 80, 36}, FLOPPY_SIZE_350, FLOPPY_RATE_1M},
+    // 6 - 160k, 5.25"  - 1 heads, 40 tracks, 8 sectors
+    { {1, 40, 8}, FLOPPY_SIZE_525, FLOPPY_RATE_250K},
+    // 7 - 180k, 5.25"  - 1 heads, 40 tracks, 9 sectors
+    { {1, 40, 9}, FLOPPY_SIZE_525, FLOPPY_RATE_300K},
+    // 8 - 320k, 5.25"  - 2 heads, 40 tracks, 8 sectors
+    { {2, 40, 8}, FLOPPY_SIZE_525, FLOPPY_RATE_250K},
+};
+
+struct drive_s *
+init_floppy(int floppyid, int ftype)
+{
+    if (ftype <= 0 || ftype >= ARRAY_SIZE(FloppyInfo)) {
+        dprintf(1, "Bad floppy type %d\n", ftype);
+        return NULL;
+    }
+
+    struct drive_s *drive = malloc_fseg(sizeof(*drive));
+    if (!drive) {
+        warn_noalloc();
+        return NULL;
+    }
+    memset(drive, 0, sizeof(*drive));
+    drive->cntl_id = floppyid;
+    drive->type = DTYPE_FLOPPY;
+    drive->blksize = DISK_SECTOR_SIZE;
+    drive->floppy_type = ftype;
+    drive->sectors = (u64)-1;
+
+    memcpy(&drive->lchs, &FloppyInfo[ftype].chs
+           , sizeof(FloppyInfo[ftype].chs));
+    return drive;
+}
+
+static void
+addFloppy(int floppyid, int ftype)
+{
+    struct drive_s *drive = init_floppy(floppyid, ftype);
+    if (!drive)
+        return;
+    char *desc = znprintf(MAXDESCSIZE, "Floppy [drive %c]", 'A' + floppyid);
+    struct pci_device *pci = pci_find_class(PCI_CLASS_BRIDGE_ISA); /* isa-to-pci bridge */
+    int prio = bootprio_find_fdc_device(pci, PORT_FD_BASE, floppyid);
+    boot_add_floppy(drive, desc, prio);
+}
+
+void
+floppy_setup(void)
+{
+    memcpy(&diskette_param_table, &diskette_param_table2
+           , sizeof(diskette_param_table));
+    SET_IVT(0x1E, SEGOFF(SEG_BIOS
+                         , (u32)&diskette_param_table2 - BUILD_BIOS_ADDR));
+
+    if (! CONFIG_FLOPPY)
+        return;
+    dprintf(3, "init floppy drives\n");
+
+    if (CONFIG_QEMU) {
+        u8 type = rtc_read(CMOS_FLOPPY_DRIVE_TYPE);
+        if (type & 0xf0)
+            addFloppy(0, type >> 4);
+        if (type & 0x0f)
+            addFloppy(1, type & 0x0f);
+    } else {
+        u8 type = romfile_loadint("etc/floppy0", 0);
+        if (type)
+            addFloppy(0, type);
+        type = romfile_loadint("etc/floppy1", 0);
+        if (type)
+            addFloppy(1, type);
+    }
+
+    enable_hwirq(6, FUNC16(entry_0e));
+}
+
+// Find a floppy type that matches a given image size.
+int
+find_floppy_type(u32 size)
+{
+    int i;
+    for (i=1; i<ARRAY_SIZE(FloppyInfo); i++) {
+        struct chs_s *c = &FloppyInfo[i].chs;
+        if (c->cylinder * c->head * c->sector * DISK_SECTOR_SIZE == size)
+            return i;
+    }
+    return -1;
+}
+
+
+/****************************************************************
+ * Low-level floppy IO
+ ****************************************************************/
+
+u8 FloppyDOR VARLOW;
+
+static inline void
+floppy_dor_write(u8 val)
+{
+    outb(val, PORT_FD_DOR);
+    SET_LOW(FloppyDOR, val);
+}
+
+static void
+floppy_disable_controller(void)
+{
+    dprintf(2, "Floppy_disable_controller\n");
+    floppy_dor_write(0x00);
+}
+
+static int
+floppy_wait_irq(void)
+{
+    u8 frs = GET_BDA(floppy_recalibration_status);
+    SET_BDA(floppy_recalibration_status, frs & ~FRS_IRQ);
+    for (;;) {
+        if (!GET_BDA(floppy_motor_counter)) {
+            warn_timeout();
+            floppy_disable_controller();
+            return DISK_RET_ETIMEOUT;
+        }
+        frs = GET_BDA(floppy_recalibration_status);
+        if (frs & FRS_IRQ)
+            break;
+        // Could use yield_toirq() here, but that causes issues on
+        // bochs, so use yield() instead.
+        yield();
+    }
+
+    SET_BDA(floppy_recalibration_status, frs & ~FRS_IRQ);
+    return DISK_RET_SUCCESS;
+}
+
+// Floppy commands
+#define FCF_WAITIRQ 0x10000
+#define FC_CHECKIRQ    (0x08 | (0<<8) | (2<<12))
+#define FC_SEEK        (0x0f | (2<<8) | (0<<12) | FCF_WAITIRQ)
+#define FC_RECALIBRATE (0x07 | (1<<8) | (0<<12) | FCF_WAITIRQ)
+#define FC_READID      (0x4a | (1<<8) | (7<<12) | FCF_WAITIRQ)
+#define FC_READ        (0xe6 | (8<<8) | (7<<12) | FCF_WAITIRQ)
+#define FC_WRITE       (0xc5 | (8<<8) | (7<<12) | FCF_WAITIRQ)
+#define FC_FORMAT      (0x4d | (5<<8) | (7<<12) | FCF_WAITIRQ)
+
+// Send the specified command and it's parameters to the floppy controller.
+static int
+floppy_pio(int command, u8 *param)
+{
+    dprintf(9, "Floppy pio command %x\n", command);
+    // Send command and parameters to controller.
+    u32 end = timer_calc(FLOPPY_PIO_TIMEOUT);
+    int send = (command >> 8) & 0xf;
+    int i = 0;
+    for (;;) {
+        u8 sts = inb(PORT_FD_STATUS);
+        if (!(sts & 0x80)) {
+            if (timer_check(end)) {
+                warn_timeout();
+                floppy_disable_controller();
+                return DISK_RET_ETIMEOUT;
+            }
+            yield();
+            continue;
+        }
+        if (sts & 0x40) {
+            floppy_disable_controller();
+            return DISK_RET_ECONTROLLER;
+        }
+        if (i == 0)
+            outb(command & 0xff, PORT_FD_DATA);
+        else
+            outb(param[i-1], PORT_FD_DATA);
+        if (i++ >= send)
+            break;
+    }
+
+    // Wait for command to complete.
+    if (command & FCF_WAITIRQ) {
+        int ret = floppy_wait_irq();
+        if (ret)
+            return ret;
+    }
+
+    // Read response from controller.
+    end = timer_calc(FLOPPY_PIO_TIMEOUT);
+    int receive = (command >> 12) & 0xf;
+    i = 0;
+    for (;;) {
+        u8 sts = inb(PORT_FD_STATUS);
+        if (!(sts & 0x80)) {
+            if (timer_check(end)) {
+                warn_timeout();
+                floppy_disable_controller();
+                return DISK_RET_ETIMEOUT;
+            }
+            yield();
+            continue;
+        }
+        if (i >= receive) {
+            if (sts & 0x40) {
+                floppy_disable_controller();
+                return DISK_RET_ECONTROLLER;
+            }
+            break;
+        }
+        if (!(sts & 0x40)) {
+            floppy_disable_controller();
+            return DISK_RET_ECONTROLLER;
+        }
+        param[i++] = inb(PORT_FD_DATA);
+    }
+
+    return DISK_RET_SUCCESS;
+}
+
+static int
+floppy_enable_controller(void)
+{
+    dprintf(2, "Floppy_enable_controller\n");
+    SET_BDA(floppy_motor_counter, FLOPPY_MOTOR_TICKS);
+    floppy_dor_write(0x00);
+    floppy_dor_write(0x0c);
+    int ret = floppy_wait_irq();
+    if (ret)
+        return ret;
+
+    u8 param[2];
+    return floppy_pio(FC_CHECKIRQ, param);
+}
+
+// Activate a drive and send a command to it.
+static int
+floppy_drive_pio(u8 floppyid, int command, u8 *param)
+{
+    // Enable controller if it isn't running.
+    if (!(GET_LOW(FloppyDOR) & 0x04)) {
+        int ret = floppy_enable_controller();
+        if (ret)
+            return ret;
+    }
+
+    // reset the disk motor timeout value of INT 08
+    SET_BDA(floppy_motor_counter, FLOPPY_MOTOR_TICKS);
+
+    // Turn on motor of selected drive, DMA & int enabled, normal operation
+    floppy_dor_write((floppyid ? 0x20 : 0x10) | 0x0c | floppyid);
+
+    // Send command.
+    int ret = floppy_pio(command, param);
+    if (ret)
+        return ret;
+
+    // Check IRQ command is needed after irq commands with no results
+    if ((command & FCF_WAITIRQ) && ((command >> 12) & 0xf) == 0)
+        return floppy_pio(FC_CHECKIRQ, param);
+    return DISK_RET_SUCCESS;
+}
+
+
+/****************************************************************
+ * Floppy media sense and seeking
+ ****************************************************************/
+
+static int
+floppy_drive_recal(u8 floppyid)
+{
+    dprintf(2, "Floppy_drive_recal %d\n", floppyid);
+    // send Recalibrate command to controller
+    u8 param[2];
+    param[0] = floppyid;
+    int ret = floppy_drive_pio(floppyid, FC_RECALIBRATE, param);
+    if (ret)
+        return ret;
+
+    u8 frs = GET_BDA(floppy_recalibration_status);
+    SET_BDA(floppy_recalibration_status, frs | (1<<floppyid));
+    SET_BDA(floppy_track[floppyid], 0);
+    return DISK_RET_SUCCESS;
+}
+
+static int
+floppy_drive_readid(u8 floppyid, u8 data_rate, u8 head)
+{
+    // Set data rate.
+    outb(data_rate, PORT_FD_DIR);
+
+    // send Read Sector Id command
+    u8 param[7];
+    param[0] = (head << 2) | floppyid; // HD DR1 DR2
+    int ret = floppy_drive_pio(floppyid, FC_READID, param);
+    if (ret)
+        return ret;
+    if (param[0] & 0xc0)
+        return -1;
+    return 0;
+}
+
+static int
+floppy_media_sense(struct drive_s *drive_gf)
+{
+    u8 ftype = GET_GLOBALFLAT(drive_gf->floppy_type), stype = ftype;
+    u8 floppyid = GET_GLOBALFLAT(drive_gf->cntl_id);
+
+    u8 data_rate = GET_GLOBAL(FloppyInfo[stype].data_rate);
+    int ret = floppy_drive_readid(floppyid, data_rate, 0);
+    if (ret) {
+        // Attempt media sense.
+        for (stype=1; ; stype++) {
+            if (stype >= ARRAY_SIZE(FloppyInfo))
+                return DISK_RET_EMEDIA;
+            if (stype==ftype
+                || (GET_GLOBAL(FloppyInfo[stype].floppy_size)
+                    != GET_GLOBAL(FloppyInfo[ftype].floppy_size))
+                || (GET_GLOBAL(FloppyInfo[stype].chs.head)
+                    > GET_GLOBAL(FloppyInfo[ftype].chs.head))
+                || (GET_GLOBAL(FloppyInfo[stype].chs.cylinder)
+                    > GET_GLOBAL(FloppyInfo[ftype].chs.cylinder))
+                || (GET_GLOBAL(FloppyInfo[stype].chs.sector)
+                    > GET_GLOBAL(FloppyInfo[ftype].chs.sector)))
+                continue;
+            data_rate = GET_GLOBAL(FloppyInfo[stype].data_rate);
+            ret = floppy_drive_readid(floppyid, data_rate, 0);
+            if (!ret)
+                break;
+        }
+    }
+    dprintf(2, "Floppy_media_sense on drive %d found rate %d\n"
+            , floppyid, data_rate);
+
+    u8 old_data_rate = GET_BDA(floppy_media_state[floppyid]) >> 6;
+    SET_BDA(floppy_last_data_rate, (old_data_rate<<2) | (data_rate<<6));
+    u8 media = (stype == 1 ? 0x04 : (stype == 2 ? 0x05 : 0x07));
+    u8 fms = (data_rate<<6) | FMS_MEDIA_DRIVE_ESTABLISHED | media;
+    if (GET_GLOBAL(FloppyInfo[stype].chs.cylinder)
+        < GET_GLOBAL(FloppyInfo[ftype].chs.cylinder))
+        fms |= FMS_DOUBLE_STEPPING;
+    SET_BDA(floppy_media_state[floppyid], fms);
+
+    return DISK_RET_SUCCESS;
+}
+
+// Prepare a floppy for a data transfer.
+static int
+floppy_prep(struct drive_s *drive_gf, u8 cylinder)
+{
+    u8 floppyid = GET_GLOBALFLAT(drive_gf->cntl_id);
+    if (!(GET_BDA(floppy_recalibration_status) & (1<<floppyid)) ||
+        !(GET_BDA(floppy_media_state[floppyid]) & FMS_MEDIA_DRIVE_ESTABLISHED)) {
+        // Recalibrate drive.
+        int ret = floppy_drive_recal(floppyid);
+        if (ret)
+            return ret;
+
+        // Sense media.
+        ret = floppy_media_sense(drive_gf);
+        if (ret)
+            return ret;
+    }
+
+    // Seek to cylinder if needed.
+    u8 lastcyl = GET_BDA(floppy_track[floppyid]);
+    if (cylinder != lastcyl) {
+        u8 param[2];
+        param[0] = floppyid;
+        param[1] = cylinder;
+        int ret = floppy_drive_pio(floppyid, FC_SEEK, param);
+        if (ret)
+            return ret;
+        SET_BDA(floppy_track[floppyid], cylinder);
+    }
+
+    return DISK_RET_SUCCESS;
+}
+
+
+/****************************************************************
+ * Floppy DMA transfer
+ ****************************************************************/
+
+// Perform a floppy transfer command (setup DMA and issue PIO).
+static int
+floppy_dma_cmd(struct disk_op_s *op, int count, int command, u8 *param)
+{
+    // Setup DMA controller
+    int isWrite = command != FC_READ;
+    int ret = dma_floppy((u32)op->buf_fl, count, isWrite);
+    if (ret)
+        return DISK_RET_EBOUNDARY;
+
+    // Invoke floppy controller
+    u8 floppyid = GET_GLOBALFLAT(op->drive_gf->cntl_id);
+    ret = floppy_drive_pio(floppyid, command, param);
+    if (ret)
+        return ret;
+
+    // Populate floppy_return_status in BDA
+    int i;
+    for (i=0; i<7; i++)
+        SET_BDA(floppy_return_status[i], param[i]);
+
+    if (param[0] & 0xc0) {
+        if (param[1] & 0x02)
+            return DISK_RET_EWRITEPROTECT;
+        dprintf(1, "floppy error: %02x %02x %02x %02x %02x %02x %02x\n"
+                , param[0], param[1], param[2], param[3]
+                , param[4], param[5], param[6]);
+        return DISK_RET_ECONTROLLER;
+    }
+
+    return DISK_RET_SUCCESS;
+}
+
+
+/****************************************************************
+ * Floppy handlers
+ ****************************************************************/
+
+static struct chs_s
+lba2chs(struct disk_op_s *op)
+{
+    struct chs_s res = { };
+
+    u32 tmp = op->lba;
+    u16 nls = GET_GLOBALFLAT(op->drive_gf->lchs.sector);
+    res.sector = (tmp % nls) + 1;
+
+    tmp /= nls;
+    u16 nlh = GET_GLOBALFLAT(op->drive_gf->lchs.head);
+    res.head = tmp % nlh;
+
+    tmp /= nlh;
+    res.cylinder = tmp;
+
+    return res;
+}
+
+// diskette controller reset
+static int
+floppy_reset(struct disk_op_s *op)
+{
+    SET_BDA(floppy_recalibration_status, 0);
+    SET_BDA(floppy_media_state[0], 0);
+    SET_BDA(floppy_media_state[1], 0);
+    SET_BDA(floppy_track[0], 0);
+    SET_BDA(floppy_track[1], 0);
+    SET_BDA(floppy_last_data_rate, 0);
+    floppy_disable_controller();
+    return floppy_enable_controller();
+}
+
+// Read Diskette Sectors
+static int
+floppy_read(struct disk_op_s *op)
+{
+    struct chs_s chs = lba2chs(op);
+    int ret = floppy_prep(op->drive_gf, chs.cylinder);
+    if (ret)
+        return ret;
+
+    // send read-normal-data command to controller
+    u8 floppyid = GET_GLOBALFLAT(op->drive_gf->cntl_id);
+    u8 param[8];
+    param[0] = (chs.head << 2) | floppyid; // HD DR1 DR2
+    param[1] = chs.cylinder;
+    param[2] = chs.head;
+    param[3] = chs.sector;
+    param[4] = FLOPPY_SIZE_CODE;
+    param[5] = chs.sector + op->count - 1; // last sector to read on track
+    param[6] = FLOPPY_GAPLEN;
+    param[7] = FLOPPY_DATALEN;
+    return floppy_dma_cmd(op, op->count * DISK_SECTOR_SIZE, FC_READ, param);
+}
+
+// Write Diskette Sectors
+static int
+floppy_write(struct disk_op_s *op)
+{
+    struct chs_s chs = lba2chs(op);
+    int ret = floppy_prep(op->drive_gf, chs.cylinder);
+    if (ret)
+        return ret;
+
+    // send write-normal-data command to controller
+    u8 floppyid = GET_GLOBALFLAT(op->drive_gf->cntl_id);
+    u8 param[8];
+    param[0] = (chs.head << 2) | floppyid; // HD DR1 DR2
+    param[1] = chs.cylinder;
+    param[2] = chs.head;
+    param[3] = chs.sector;
+    param[4] = FLOPPY_SIZE_CODE;
+    param[5] = chs.sector + op->count - 1; // last sector to write on track
+    param[6] = FLOPPY_GAPLEN;
+    param[7] = FLOPPY_DATALEN;
+    return floppy_dma_cmd(op, op->count * DISK_SECTOR_SIZE, FC_WRITE, param);
+}
+
+// Verify Diskette Sectors
+static int
+floppy_verify(struct disk_op_s *op)
+{
+    struct chs_s chs = lba2chs(op);
+    int ret = floppy_prep(op->drive_gf, chs.cylinder);
+    if (ret)
+        return ret;
+
+    // This command isn't implemented - just return success.
+    return DISK_RET_SUCCESS;
+}
+
+// format diskette track
+static int
+floppy_format(struct disk_op_s *op)
+{
+    struct chs_s chs = lba2chs(op);
+    int ret = floppy_prep(op->drive_gf, chs.cylinder);
+    if (ret)
+        return ret;
+
+    // send format-track command to controller
+    u8 floppyid = GET_GLOBALFLAT(op->drive_gf->cntl_id);
+    u8 param[7];
+    param[0] = (chs.head << 2) | floppyid; // HD DR1 DR2
+    param[1] = FLOPPY_SIZE_CODE;
+    param[2] = op->count; // number of sectors per track
+    param[3] = FLOPPY_FORMAT_GAPLEN;
+    param[4] = FLOPPY_FILLBYTE;
+    return floppy_dma_cmd(op, op->count * 4, FC_FORMAT, param);
+}
+
+int
+process_floppy_op(struct disk_op_s *op)
+{
+    if (!CONFIG_FLOPPY)
+        return 0;
+
+    switch (op->command) {
+    case CMD_RESET:
+        return floppy_reset(op);
+    case CMD_READ:
+        return floppy_read(op);
+    case CMD_WRITE:
+        return floppy_write(op);
+    case CMD_VERIFY:
+        return floppy_verify(op);
+    case CMD_FORMAT:
+        return floppy_format(op);
+    default:
+        return DISK_RET_EPARAM;
+    }
+}
+
+
+/****************************************************************
+ * HW irqs
+ ****************************************************************/
+
+// INT 0Eh Diskette Hardware ISR Entry Point
+void VISIBLE16
+handle_0e(void)
+{
+    if (! CONFIG_FLOPPY)
+        return;
+    debug_isr(DEBUG_ISR_0e);
+
+    // diskette interrupt has occurred
+    u8 frs = GET_BDA(floppy_recalibration_status);
+    SET_BDA(floppy_recalibration_status, frs | FRS_IRQ);
+
+    pic_eoi1();
+}
+
+// Called from int08 handler.
+void
+floppy_tick(void)
+{
+    if (! CONFIG_FLOPPY)
+        return;
+
+    // time to turn off drive(s)?
+    u8 fcount = GET_BDA(floppy_motor_counter);
+    if (fcount) {
+        fcount--;
+        SET_BDA(floppy_motor_counter, fcount);
+        if (fcount == 0)
+            // turn motor(s) off
+            floppy_dor_write(GET_LOW(FloppyDOR) & ~0xf0);
+    }
+}