[SeaBIOS] [PATCH] Fixes to the floppy driver, so it works on real (not emulated) hardware
Nikolay Nikolov
nickysn at users.sourceforge.net
Tue Jan 30 04:41:47 CET 2018
Several fixes to the floppy driver, so it works on a real floppy controller
with a real floppy. Tested with Coreboot on a motherboard with an ITE IT8712
Super I/O chip (and its built-in floppy controller) and a 1.44MB floppy.
Only one floppy is supported for now and only 1.44MB, but more formats will be
added in the future.
Signed-off-by: Nikolay Nikolov <nickysn at users.sourceforge.net>
---
src/hw/floppy.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 69 insertions(+), 14 deletions(-)
diff --git a/src/hw/floppy.c b/src/hw/floppy.c
index f2577c5..674909d 100644
--- a/src/hw/floppy.c
+++ b/src/hw/floppy.c
@@ -34,6 +34,11 @@
#define FLOPPY_GAPLEN 0x1B
#define FLOPPY_FORMAT_GAPLEN 0x6c
#define FLOPPY_PIO_TIMEOUT 1000
+#define FLOPPY_IRQ_TIMEOUT 5000
+#define FLOPPY_STARTUP_TIME 8
+#define FLOPPY_MOTOR_HOLD 255 // Magic value, means motor must not be turned off
+#define FLOPPY_SPECIFY1 0xAF // step rate 12ms, head unload 240ms
+#define FLOPPY_SPECIFY2 0x02 // head load time 4ms, DMA used
// New diskette parameter table adding 3 parameters from IBM
// Since no provisions are made for multiple drive types, most
@@ -191,7 +196,8 @@ static void
floppy_disable_controller(void)
{
dprintf(2, "Floppy_disable_controller\n");
- floppy_dor_write(0x00);
+ // Clear the reset bit (enter reset state) and clear 'enable IRQ and DMA'
+ floppy_dor_write(GET_LOW(FloppyDOR) & ~0x0c);
}
static int
@@ -199,8 +205,9 @@ 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 (!GET_BDA(floppy_motor_counter)) {
+ if (timer_check(end)) {
warn_timeout();
floppy_disable_controller();
return DISK_RET_ETIMEOUT;
@@ -226,6 +233,7 @@ floppy_wait_irq(void)
#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
@@ -302,9 +310,12 @@ 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);
+ // Clear the reset bit (enter reset state), but set 'enable IRQ and DMA'
+ floppy_dor_write((GET_LOW(FloppyDOR) & ~0x04) | 0x08);
+ // Real hardware needs a 4 microsecond delay
+ udelay(4);
+ // Set the reset bit (normal operation) and keep 'enable IRQ and DMA' on
+ floppy_dor_write(GET_LOW(FloppyDOR) | 0x0c);
int ret = floppy_wait_irq();
if (ret)
return ret;
@@ -313,6 +324,30 @@ floppy_enable_controller(void)
return floppy_pio(FC_CHECKIRQ, param);
}
+static void
+floppy_turn_on_motor(u8 floppyid)
+{
+ // prevent the motor from being turned off
+ SET_BDA(floppy_motor_counter, FLOPPY_MOTOR_HOLD);
+
+ u8 motor_mask = 0x10 << floppyid;
+ if (GET_LOW(FloppyDOR) & motor_mask) {
+ // If the motor has been started, there's no need to wait for it again
+ floppy_dor_write(motor_mask | 0x0c | floppyid);
+ } else {
+ floppy_dor_write(motor_mask | 0x0c | floppyid);
+
+ msleep(FLOPPY_STARTUP_TIME * 125);
+ }
+}
+
+static void
+floppy_turn_off_motor_delayed(void)
+{
+ // reset the disk motor timeout value of INT 08
+ SET_BDA(floppy_motor_counter, FLOPPY_MOTOR_TICKS);
+}
+
// Activate a drive and send a command to it.
static int
floppy_drive_pio(u8 floppyid, int command, u8 *param)
@@ -324,11 +359,8 @@ floppy_drive_pio(u8 floppyid, int command, u8 *param)
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);
+ // Turn on motor of selected drive and wait for it to get up to speed
+ floppy_turn_on_motor(floppyid);
// Send command.
int ret = floppy_pio(command, param);
@@ -363,6 +395,15 @@ floppy_drive_recal(u8 floppyid)
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)
{
@@ -433,13 +474,23 @@ floppy_prep(struct drive_s *drive_gf, u8 cylinder)
!(GET_BDA(floppy_media_state[floppyid]) & FMS_MEDIA_DRIVE_ESTABLISHED)) {
// Recalibrate drive.
int ret = floppy_drive_recal(floppyid);
- if (ret)
+ if (ret) {
+ floppy_turn_off_motor_delayed();
return ret;
+ }
// Sense media.
ret = floppy_media_sense(drive_gf);
- if (ret)
+ if (ret) {
+ floppy_turn_off_motor_delayed();
+ return ret;
+ }
+
+ ret = floppy_drive_specify();
+ if (ret) {
+ floppy_turn_off_motor_delayed();
return ret;
+ }
}
// Seek to cylinder if needed.
@@ -449,8 +500,10 @@ floppy_prep(struct drive_s *drive_gf, u8 cylinder)
param[0] = floppyid;
param[1] = cylinder;
int ret = floppy_drive_pio(floppyid, FC_SEEK, param);
- if (ret)
+ if (ret) {
+ floppy_turn_off_motor_delayed();
return ret;
+ }
SET_BDA(floppy_track[floppyid], cylinder);
}
@@ -489,9 +542,11 @@ floppy_dma_cmd(struct disk_op_s *op, int count, int command, u8 *param)
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]);
+ floppy_turn_off_motor_delayed();
return DISK_RET_ECONTROLLER;
}
+ floppy_turn_off_motor_delayed();
return DISK_RET_SUCCESS;
}
@@ -663,7 +718,7 @@ floppy_tick(void)
// time to turn off drive(s)?
u8 fcount = GET_BDA(floppy_motor_counter);
- if (fcount) {
+ if (fcount && (fcount != FLOPPY_MOTOR_HOLD)) {
fcount--;
SET_BDA(floppy_motor_counter, fcount);
if (fcount == 0)
--
2.14.3
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