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// 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 "pcidevice.h" // pci_find_class
#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
#define FLOPPY_IRQ_TIMEOUT 5000
#define FLOPPY_SPECIFY1 0xAF // step rate 12ms, head unload 240ms
#define FLOPPY_SPECIFY2 0x02 // head load time 4ms, DMA used
#define FLOPPY_STARTUP_TIME 8 // 1 second
#define FLOPPY_DOR_MOTOR_D 0x80 // Set to turn drive 3's motor ON
#define FLOPPY_DOR_MOTOR_C 0x40 // Set to turn drive 2's motor ON
#define FLOPPY_DOR_MOTOR_B 0x20 // Set to turn drive 1's motor ON
#define FLOPPY_DOR_MOTOR_A 0x10 // Set to turn drive 0's motor ON
#define FLOPPY_DOR_MOTOR_MASK 0xf0
#define FLOPPY_DOR_IRQ 0x08 // Set to enable IRQs and DMA
#define FLOPPY_DOR_RESET 0x04 // Clear = enter reset mode, Set = normal operation
#define FLOPPY_DOR_DSEL_MASK 0x03 // "Select" drive number for next access
// 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 = FLOPPY_SPECIFY1,
.specify2 = FLOPPY_SPECIFY2,
.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 = FLOPPY_STARTUP_TIME,
},
.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 u8
floppy_dor_read(void)
{
return GET_LOW(FloppyDOR);
}
static inline void
floppy_dor_write(u8 val)
{
outb(val, PORT_FD_DOR);
SET_LOW(FloppyDOR, val);
}
static inline void
floppy_dor_mask(u8 off, u8 on)
{
floppy_dor_write((floppy_dor_read() & ~off) | on);
}
static void
floppy_disable_controller(void)
{
dprintf(2, "Floppy_disable_controller\n");
// Clear the reset bit (enter reset state) and clear 'enable IRQ and DMA'
floppy_dor_mask(FLOPPY_DOR_IRQ | FLOPPY_DOR_RESET, 0);
}
static int
floppy_wait_irq(void)
{
u8 frs = GET_BDA(floppy_recalibration_status);
SET_BDA(floppy_recalibration_status, frs & ~FRS_IRQ);
u32 end = timer_calc(FLOPPY_IRQ_TIMEOUT);
for (;;) {
if (timer_check(end)) {
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)
#define FC_SPECIFY (0x03 | (2<<8) | (0<<12))
// 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");
// Clear the reset bit (enter reset state), but set 'enable IRQ and DMA'
floppy_dor_mask(FLOPPY_DOR_RESET, FLOPPY_DOR_IRQ);
// Real hardware needs a 4 microsecond delay
usleep(4);
// Set the reset bit (normal operation) and keep 'enable IRQ and DMA' on
floppy_dor_mask(0, FLOPPY_DOR_IRQ | FLOPPY_DOR_RESET);
int ret = floppy_wait_irq();
if (ret)
return ret;
// After the interrupt is received, send 4 SENSE INTERRUPT commands to
// clear the interrupt status for each of the four logical drives,
// supported by the controller.
// See section 7.4 - "Drive Polling" of the Intel 82077AA datasheet for
// a more detailed description of why this voodoo needs to be done.
// Without this, initialization fails on real controllers (but still works
// in QEMU)
u8 param[2];
int i;
for (i=0; i<4; i++) {
ret = floppy_pio(FC_CHECKIRQ, param);
if (ret)
return ret;
}
return DISK_RET_SUCCESS;
}
// 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 (!(floppy_dor_read() & FLOPPY_DOR_RESET)) {
int ret = floppy_enable_controller();
if (ret)
return ret;
}
// set the disk motor timeout value of INT 08 to the highest value
SET_BDA(floppy_motor_counter, 255);
// Check if the motor is already running
u8 motor_mask = FLOPPY_DOR_MOTOR_A << floppyid;
int motor_already_running = floppy_dor_read() & motor_mask;
// Turn on motor of selected drive, DMA & int enabled, normal operation
floppy_dor_write(motor_mask | FLOPPY_DOR_IRQ | FLOPPY_DOR_RESET | floppyid);
// If the motor was just started, wait for it to get up to speed
if (!motor_already_running && !CONFIG_QEMU)
msleep(FLOPPY_STARTUP_TIME * 125);
// Send command.
int ret = floppy_pio(command, param);
SET_BDA(floppy_motor_counter, FLOPPY_MOTOR_TICKS); // reset motor timeout
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_specify(void)
{
u8 param[2];
param[0] = FLOPPY_SPECIFY1;
param[1] = FLOPPY_SPECIFY2;
return floppy_pio(FC_SPECIFY, param);
}
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;
// Execute a SPECIFY command (sets the Step Rate Time,
// Head Load Time, Head Unload Time and the DMA enable/disable bit).
ret = floppy_drive_specify();
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_fl->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_fl->lchs.sector);
res.sector = (tmp % nls) + 1;
tmp /= nls;
u16 nlh = GET_GLOBALFLAT(op->drive_fl->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_fl, chs.cylinder);
if (ret)
return ret;
// send read-normal-data command to controller
u8 floppyid = GET_GLOBALFLAT(op->drive_fl->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_fl, chs.cylinder);
if (ret)
return ret;
// send write-normal-data command to controller
u8 floppyid = GET_GLOBALFLAT(op->drive_fl->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_fl, 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_fl, chs.cylinder);
if (ret)
return ret;
// send format-track command to controller
u8 floppyid = GET_GLOBALFLAT(op->drive_fl->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
floppy_process_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_mask(FLOPPY_DOR_MOTOR_MASK, 0);
}
}
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