[SeaBIOS] [coreboot] Patch number 2 - floppy "dor" test

[Kevin O'Connor]

On Thu, Dec 05, 2013 at 10:55:37AM +0100, Gelip wrote:
> 08.313: Booting from Floppy...
> 08.313: check_recal_drive 0
> 08.313: floppy_drive_recal 0
> 08.313: floppy_select_drive 0
> 08.313: dor=0
> 08.313: floppy_enable_controller dor=0
> 08.348: now dor=4
> 10.296: floppy_disable_controller
> 10.296: invalid basic_access:96:
> 10.296:    a=00000200  b=00000000  c=00000001  d=00000000 ds=0000 es=07c0 ss=dd80
> 10.296:   si=00000000 di=00000000 bp=00000000 sp=0000fb08 cs=f000 ip=c996  f=0202
> 10.297: Boot failed: could not read the boot disk

Okay - I think I see what is happening.  Can you try the patch below
(which is against seabios git master - the compile problem you had
yesterday should be fixed).  This patch isn't fully correct, but I'd
like to see if it helps.

-Kevin


diff --git a/src/hw/floppy.c b/src/hw/floppy.c
index d43b489..a8e5b2a 100644
--- a/src/hw/floppy.c
+++ b/src/hw/floppy.c
@@ -183,6 +183,7 @@ find_floppy_type(u32 size)
 static void
 floppy_disable_controller(void)
 {
+    dprintf(1, "floppy_disable_controller\n");
     outb(inb(PORT_FD_DOR) & ~0x04, PORT_FD_DOR);
 }
 
@@ -219,6 +220,7 @@ struct floppy_pio_s {
 static int
 floppy_pio(struct floppy_pio_s *pio)
 {
+    dprintf(1, "floppy_pio\n");
     // Send command to controller.
     u32 end = timer_calc(FLOPPY_PIO_TIMEOUT);
     int i = 0;
@@ -274,39 +276,35 @@ floppy_pio(struct floppy_pio_s *pio)
 }
 
 static int
-floppy_enable_controller(void)
-{
-    outb(inb(PORT_FD_DOR) | 0x04, PORT_FD_DOR);
-    int ret = floppy_wait_irq();
-    if (ret)
-        return ret;
-
-    struct floppy_pio_s pio;
-    pio.cmdlen = 1;
-    pio.resplen = 2;
-    pio.waitirq = 0;
-    pio.data[0] = 0x08;  // 08: Check Interrupt Status
-    return floppy_pio(&pio);
-}
-
-static int
 floppy_select_drive(u8 floppyid)
 {
+    dprintf(1, "floppy_select_drive %d\n", floppyid);
     // reset the disk motor timeout value of INT 08
     SET_BDA(floppy_motor_counter, FLOPPY_MOTOR_TICKS);
 
-    // Enable controller if it isn't running.
-    u8 dor = inb(PORT_FD_DOR);
-    if (!(dor & 0x04)) {
-        int ret = floppy_enable_controller();
+    u8 origdor = inb(PORT_FD_DOR);
+    dprintf(1, "dor=%x\n", origdor);
+    // Turn on motor of selected drive, DMA & int enabled, normal operation
+    outb((floppyid ? 0x20 : 0x10) | 0x0c | floppyid, PORT_FD_DOR);
+
+    if (!(origdor & 0x04)) {
+        dprintf(1, "now dor=%x\n", inb(PORT_FD_DOR));
+        // Controller was just enabled - wait for irq.
+        int ret = floppy_wait_irq();
+        if (ret)
+            return ret;
+
+        struct floppy_pio_s pio;
+        pio.cmdlen = 1;
+        pio.resplen = 2;
+        pio.waitirq = 0;
+        pio.data[0] = 0x08;  // 08: Check Interrupt Status
+        ret = floppy_pio(&pio);
         if (ret)
             return ret;
+        dprintf(1, "port irq dor=%x\n", inb(PORT_FD_DOR));
     }
 
-    // Turn on motor of selected drive, DMA & int enabled, normal operation
-    dor = (floppyid ? 0x20 : 0x10) | 0x0c | floppyid;
-    outb(dor, PORT_FD_DOR);
-
     return DISK_RET_SUCCESS;
 }
 
@@ -324,6 +322,7 @@ set_diskette_current_cyl(u8 floppyid, u8 cyl)
 static int
 floppy_drive_recal(u8 floppyid)
 {
+    dprintf(1, "floppy_drive_recal %d\n", floppyid);
     int ret = floppy_select_drive(floppyid);
     if (ret)
         return ret;
@@ -356,6 +355,8 @@ floppy_drive_recal(u8 floppyid)
 static int
 floppy_drive_readid(u8 floppyid, u8 data_rate, u8 head)
 {
+    dprintf(1, "floppy_drive_readid %d rate=%x head=%x\n"
+            , floppyid, data_rate, head);
     int ret = floppy_select_drive(floppyid);
     if (ret)
         return ret;
@@ -383,6 +384,7 @@ 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);
+    dprintf(1, "floppy_media_sense %d ftype=%x\n", floppyid, ftype);
 
     u8 data_rate = GET_GLOBAL(FloppyInfo[stype].data_rate);
     int ret = floppy_drive_readid(floppyid, data_rate, 0);
@@ -416,6 +418,8 @@ floppy_media_sense(struct drive_s *drive_gf)
         < GET_GLOBAL(FloppyInfo[ftype].chs.cylinder))
         fms |= FMS_DOUBLE_STEPPING;
     SET_BDA(floppy_media_state[floppyid], fms);
+    dprintf(1, "floppy_media_sense finish %d data_rate=%x fms=%x stype=%x\n"
+            , floppyid, data_rate, fms, stype);
 
     return DISK_RET_SUCCESS;
 }
@@ -428,6 +432,7 @@ check_recal_drive(struct drive_s *drive_gf)
         && (GET_BDA(floppy_media_state[floppyid]) & FMS_MEDIA_DRIVE_ESTABLISHED))
         // Media is known.
         return DISK_RET_SUCCESS;
+    dprintf(1, "check_recal_drive %d\n", floppyid);
 
     // Recalibrate drive.
     int ret = floppy_drive_recal(floppyid);
@@ -658,7 +663,7 @@ handle_0e(void)
 {
     if (! CONFIG_FLOPPY)
         return;
-    debug_isr(DEBUG_ISR_0e);
+    debug_isr(1);
 
     // diskette interrupt has occurred
     u8 frs = GET_BDA(floppy_recalibration_status);