Changeset 78729 in vbox for trunk/src/VBox/Devices/PC/BIOS

Timestamp:

May 24, 2019 1:27:36 PM (6 years ago)

Author:

vboxsync

Message:

BIOS: After ATA reset, first wait for drive not busy, then read other registers.

File:

• trunk/src/VBox/Devices/PC/BIOS/ata.c (modified) (3 diffs)

trunk/src/VBox/Devices/PC/BIOS/ata.c

@@ -1 +1 @@
 /* $Id$ */
 /** @file
- * PC BIOS - ???
+ * PC BIOS - ATA disk support.
  */
 
@@ -177 +177 @@
     outb(iobase2+ATA_CB_DC, ATA_CB_DC_HD15 | ATA_CB_DC_NIEN);
 
+    // 8.2.1 (h) -- wait for not BSY
+    max=0xffff; /* The ATA specification says that the drive may be busy for up to 30 seconds. */
+    while(--max>0) {
+        uint8_t status = inb(iobase1+ATA_CB_STAT);
+        if ((status & ATA_CB_STAT_BSY) == 0)
+            break;
+        pdelay=0xffff;
+        while (--pdelay>0) {
+            /* nothing */
+        }
+    }
+
     if (bios_dsk->devices[device].type != DSK_TYPE_NONE) {
         // 8.2.1 (g) -- check for sc==sn==0x01
@@ -185 +197 @@
 
         if ( (sc==0x01) && (sn==0x01) ) {
-            // 8.2.1 (h) -- wait for not BSY
-            max=0xffff; /* The ATA specification says that the drive may be busy for up to 30 seconds. */
+            // 8.2.1 (i) -- wait for DRDY
+            max = 0x10; /* Speed up for virtual drives. Disks are immediately ready, CDs never */
             while(--max>0) {
                 uint8_t status = inb(iobase1+ATA_CB_STAT);
-                if ((status & ATA_CB_STAT_BSY) == 0)
+                if ((status & ATA_CB_STAT_RDY) != 0)
                     break;
-                pdelay=0xffff;
-                while (--pdelay>0) {
-                    /* nothing */
-                }
-            }
-        }
-    }
-
-    // 8.2.1 (i) -- wait for DRDY
-    max = 0x10; /* Speed up for virtual drives. Disks are immediately ready, CDs never */
-    while(--max>0) {
-        uint8_t status = inb(iobase1+ATA_CB_STAT);
-        if ((status & ATA_CB_STAT_RDY) != 0)
-            break;
+            }
+        }
     }