Changeset 38

Timestamp:

Nov 5, 2010, 7:13:11 PM (15 years ago)

Author:

markus

Message:

changes for drive geometry mapping

Location:

trunk/src/os2ahci

Files:

• ata.c (modified) (3 diffs)
• ata.h (modified) (2 diffs)

trunk/src/os2ahci/ata.c

@@ -431 +431 @@
   u16 *id_buf = add_workspace(iorb)->buf;
 
-  /* Fill-in geometry information; os2ahci has been designed for devices
-   * adhering to the ATA spec v8 or later, thus the real geometry doesn't
-   * really matter (it's actually marked "obsolete" in the ATA 8 specs).
-   * In order to maintain compatibitily to the BIOS and partition tables,
-   * we'll use the same algorithm as used by typical PC BIOS versions:
+  /* Fill-in geometry information; the ATA-8 spec declares the geometry
+   * fields in the ATA ID buffer as obsolete but it's still the best
+   * guess in most cases. If the information stored in the geometry
+   * fields is apparently incorrect, we'll use the algorithm typically
+   * used by SCSI adapters and modern PC BIOS releases:
    *
    *  - 512 bytes per sector
@@ -459 +459 @@
    */
   memset(geometry, 0x00, geometry_len);
+  geometry->BytesPerSector  = 512;
 
   /* extract total number of sectors */
   if (id_buf[ATA_ID_CFS_ENABLE_2] & 0x40) {
     /* 48-bit LBA supported */
-    if (id_buf[ATA_ID_LBA_CAPACITY_2 + 2] != 0) {
+    if (ATA_CAPACITY48_H(id_buf) != 0) {
       /* more than 32 bits for number of sectors */
       dprintf("warning: limiting disk %d.%d.%d to 2TB\n",
@@ -470 +471 @@
       geometry->TotalSectors = 0xffffffffUL;
     } else {
-      geometry->TotalSectors = *((u32 *) (id_buf + ATA_ID_LBA_CAPACITY_2));
+      geometry->TotalSectors = ATA_CAPACITY48_L(id_buf);
     }
   } else {
     /* 28-bit LBA */
-    geometry->TotalSectors = *((u32 *) (id_buf + ATA_ID_LBA_CAPACITY)) &
-                             0x0fffffffUL;
-  }
-
-  geometry->BytesPerSector  = 512;
-  geometry->NumHeads        = 255;
-  geometry->SectorsPerTrack = 63;
-  geometry->TotalCylinders  = geometry->TotalSectors /
-                               ((u32) geometry->NumHeads *
-                                (u32) geometry->SectorsPerTrack);
+    geometry->TotalSectors = ATA_CAPACITY(id_buf) & 0x0fffffffUL;
+  }
+
+  /* see whether the "current" (read: BIOS-supplied) geometry looks OK */
+  if (CUR_HEADS(id_buf) > 0 && CUR_CYLS(id_buf) > 0 &&
+      CUR_SECTORS(id_buf) > 0 &&
+      CUR_CAPACITY(id_buf) == CUR_HEADS(id_buf) *
+                              CUR_CYLS(id_buf) *
+                              CUR_SECTORS(id_buf)) {
+    /* use BIOS-supplied values for geometry */
+    geometry->NumHeads        = CUR_HEADS(id_buf);
+    geometry->SectorsPerTrack = CUR_SECTORS(id_buf);
+    geometry->TotalCylinders  = CUR_CYLS(id_buf);
+
+  } else if (ATA_HEADS(id_buf) > 0 && ATA_CYLS(id_buf) > 0 &&
+             ATA_SECTORS(id_buf) > 0) {
+    /* use ATA-supplied values for geometry */
+    geometry->NumHeads        = ATA_HEADS(id_buf);
+    geometry->SectorsPerTrack = ATA_SECTORS(id_buf);
+    geometry->TotalCylinders  = ATA_CYLS(id_buf);
+
+  } else {
+    /* construct values based on typical [SCSI] BIOS algorithms */
+    geometry->NumHeads        = 255;
+    geometry->SectorsPerTrack = 63;
+    geometry->TotalCylinders  = geometry->TotalSectors /
+                                 ((u32) geometry->NumHeads *
+                                  (u32) geometry->SectorsPerTrack);
+  }
+
+  if (debug > 1) {
+    printf("geometry information:\n");
+    printf("  heads:     %d\n", (u16) geometry->NumHeads);
+    printf("  sectors:   %d\n", (u16) geometry->SectorsPerTrack);
+    printf("  cylinders: %d\n", (u16) geometry->TotalCylinders);
+    printf("  capacity:  %ldMB\n", (u32) (geometry->TotalSectors / 2048));
+  }
 
   /* tell interrupt handler that this IORB is complete */

trunk/src/os2ahci/ata.h

@@ -21 +21 @@
 
 /* -------------------------- macros and constants ------------------------- */
+
+/******************************************************************************
+ * Macros to access geometry values in the ATA ID buffer
+ */
+#define ATA_CYLS(id_buf)            *((u32 *) (id_buf + ATA_ID_CYLS))
+#define ATA_HEADS(id_buf)           *((u32 *) (id_buf + ATA_ID_HEADS))
+#define ATA_SECTORS(id_buf)         *((u32 *) (id_buf + ATA_ID_SECTORS))
+#define ATA_CAPACITY(id_buf)        *((u32 *) (id_buf + ATA_ID_LBA_CAPACITY))
+
+#define ATA_CAPACITY48_L(id_buf)    *((u32 *) (id_buf + ATA_ID_LBA_CAPACITY_2))
+#define ATA_CAPACITY48_H(id_buf)    *((u32 *) (id_buf + ATA_ID_LBA_CAPACITY_2 + 2))
+
+#define CUR_CYLS(id_buf)            *((u32 *) (id_buf + ATA_ID_CUR_CYLS))
+#define CUR_HEADS(id_buf)           *((u32 *) (id_buf + ATA_ID_CUR_HEADS))
+#define CUR_SECTORS(id_buf)         *((u32 *) (id_buf + ATA_ID_CUR_SECTORS))
+#define CUR_CAPACITY(id_buf)        *((u32 *) (id_buf + ATA_ID_CUR_CAPACITY))
+
 
 /******************************************************************************
@@ -50 +67 @@
 #define ATA_ID_CUR_HEADS        55
 #define ATA_ID_CUR_SECTORS      56
+#define ATA_ID_CUR_CAPACITY     57
 #define ATA_ID_MULTSECT         59
 #define ATA_ID_LBA_CAPACITY     60