[SeaBIOS] [coreboot] Patch number 4 for floppy in SeaBIOS

[Kevin O'Connor]

On Sat, Dec 07, 2013 at 11:05:17AM +0100, Gelip wrote:
> My floppy is OK. I tested it in this mobo with vendor BIOS and also in other PC and working good. After apply incremental patch still Disk I/O error:

Looks like the seabios cyl/head/sector code was totally broken.  QEMU
was able to cope, but real hardware would not.  Can you try the patch
below (against a clean repo)?

-Kevin


diff --git a/src/hw/floppy.c b/src/hw/floppy.c
index d43b489..8779078 100644
--- a/src/hw/floppy.c
+++ b/src/hw/floppy.c
@@ -274,38 +274,30 @@ 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)
 {
     // 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);
+    // Turn on motor of selected drive, DMA & int enabled, normal operation
+    outb((floppyid ? 0x20 : 0x10) | 0x0c | floppyid, PORT_FD_DOR);
+
+    if (!(origdor & 0x04)) {
+        // Controller was just enabled - wait for irq.
+        int ret = floppy_wait_irq();
         if (ret)
             return ret;
-    }
 
-    // Turn on motor of selected drive, DMA & int enabled, normal operation
-    dor = (floppyid ? 0x20 : 0x10) | 0x0c | floppyid;
-    outb(dor, PORT_FD_DOR);
+        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;
+    }
 
     return DISK_RET_SUCCESS;
 }
@@ -324,12 +316,24 @@ 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;
 
-    // send Recalibrate command (2 bytes) to controller
+    // send a Specify command to controller
     struct floppy_pio_s pio;
+    pio.cmdlen = 3;
+    pio.resplen = 0;
+    pio.waitirq = 0;
+    pio.data[0] = 0x03;  // 07: Recalibrate
+    pio.data[1] = GET_GLOBAL(diskette_param_table2.dbt.specify1);
+    pio.data[2] = GET_GLOBAL(diskette_param_table2.dbt.specify2);
+    ret = floppy_pio(&pio);
+    if (ret)
+        return ret;
+
+    // send Recalibrate command (2 bytes) to controller
     pio.cmdlen = 2;
     pio.resplen = 0;
     pio.waitirq = 1;
@@ -356,6 +360,8 @@ 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 +389,7 @@ 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 +423,8 @@ 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 +437,7 @@ 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);
@@ -496,11 +506,10 @@ static struct chs_s
 lba2chs(struct disk_op_s *op)
 {
     struct chs_s res = { };
-    u32 lba = op->lba;
 
-    u32 tmp = lba + 1;
+    u32 tmp = op->lba;
     u16 nls = GET_GLOBALFLAT(op->drive_gf->lchs.sector);
-    res.sector = tmp % nls;
+    res.sector = (tmp % nls) + 1;
 
     tmp /= nls;
     u16 nlh = GET_GLOBALFLAT(op->drive_gf->lchs.head);