amiga partition table support.

[yaboot.git] / second / partition.c

diff --git a/second/partition.c b/second/partition.c
index c8663497927b04dc851a190fb5c3ae518be0a3b9..e3ab4c58855d7adfbfc48fe17366dc063fbe667f 100644 (file)
--- a/second/partition.c
+++ b/second/partition.c
@@ -1,6 +1,8 @@
 /*
  *  partition.c - partition table support
  *
+ *  Copyright (C) 2004 Sven Luther
+ *
  *  Copyright (C) 2001, 2002 Ethan Benson
  *
  *  Copyright (C) 1999 Benjamin Herrenschmidt
@@ -31,6 +33,7 @@
 #include "stdlib.h"
 #include "mac-part.h"
 #include "fdisk-part.h"
+#include "amiga-part.h"
 #include "partition.h"
 #include "prom.h"
 #include "string.h"
@@ -213,6 +216,110 @@ identify_iso_fs(ihandle device, unsigned int *iso_root_block)
      return 0;
 }
 
+/* 
+ * Detects and read amiga partition tables.
+ */
+
+static int
+_amiga_checksum (unsigned int blk_size)
+{
+       unsigned int sum;
+       int i, end;
+       unsigned int *amiga_block = (unsigned int *) block_buffer;
+
+       sum = amiga_block[0];
+       end = amiga_block[AMIGA_LENGTH];
+
+       if (end > blk_size) end = blk_size;
+
+       for (i = 1; i < end; i++) sum += amiga_block[i];
+
+       return sum;
+}
+
+static int
+_amiga_find_rdb (const char *dev_name, prom_handle disk, unsigned int prom_blksize)
+{
+       int i;
+       unsigned int *amiga_block = (unsigned int *) block_buffer;
+
+       for (i = 0; i<AMIGA_RDB_MAX; i++) {
+               if (i != 0) {
+                       if (prom_readblocks(disk, i, 1, block_buffer) != 1) {
+                               prom_printf("Can't read boot block %d\n", i);
+                               break;
+                       }       
+               }
+               if ((amiga_block[AMIGA_ID] == AMIGA_ID_RDB) && (_amiga_checksum (prom_blksize) == 0))
+                       return 1;
+       }
+       /* Amiga partition table not found, let's reread block 0 */
+       if (prom_readblocks(disk, 0, 1, block_buffer) != 1) {
+               prom_printf("Can't read boot blocks\n");
+               return 0; /* TODO: something bad happened, should fail more verbosely */
+       }       
+       return 0;
+}
+
+static void
+partition_amiga_lookup( const char *dev_name, prom_handle disk,
+                        unsigned int prom_blksize, struct partition_t** list )
+{
+       int partition, part;
+       unsigned int blockspercyl;
+       unsigned int *amiga_block = (unsigned int *) block_buffer;
+       unsigned int *used = NULL;
+       unsigned int possible;
+       int checksum;
+       int i;
+
+       blockspercyl = amiga_block[AMIGA_SECT] * amiga_block[AMIGA_HEADS];
+       possible = amiga_block[AMIGA_RDBLIMIT]/32 +1;
+
+       used = (unsigned int *) malloc (sizeof (unsigned int) * (possible + 1));
+
+       for (i=0; i < possible; i++) used[i] = 0;
+
+
+       for (part = amiga_block[AMIGA_PARTITIONS], partition = 0;
+               part != AMIGA_END;
+               part = amiga_block[AMIGA_PART_NEXT], partition++)
+       {
+               if (prom_readblocks(disk, part, 1, block_buffer) != 1) {
+                       prom_printf("Can't read partition block %d\n", part);
+                       break;
+               }       
+               checksum = _amiga_checksum (prom_blksize);
+               if ((amiga_block[AMIGA_ID] == AMIGA_ID_PART) &&
+                       (checksum == 0) &&
+                       ((used[part/32] & (0x1 << (part % 32))) == 0))
+               {
+                       used[part/32] |= (0x1 << (part % 32));
+               } else {
+                       prom_printf("Amiga partition table corrupted at block %d\n", part);
+                       if (amiga_block[AMIGA_ID] != AMIGA_ID_PART)
+                               prom_printf ("block type is not partition but %08x\n", amiga_block[AMIGA_ID]);
+                       if (checksum != 0)
+                               prom_printf ("block checsum is bad : %d\n", checksum);
+                       if ((used[part/32] & (0x1 << (part % 32))) != 0)
+                               prom_printf ("partition table is looping, block %d already traveled\n", part);
+                       break;
+               }
+
+              /* We use the partition block size from the partition table.
+               * The filesystem implmentations are responsible for mapping
+               * to their own fs blocksize */
+              add_new_partition(
+                   list, /* partition list */
+                   partition, /* partition number */
+                   "Linux", /* type */
+                   '\0', /* name */
+                   blockspercyl * amiga_block[AMIGA_PART_LOWCYL], /* start */
+                   blockspercyl * (amiga_block[AMIGA_PART_HIGHCYL] - amiga_block[AMIGA_PART_LOWCYL] + 1), /* size */
+                   prom_blksize );
+       }
+}
+
 struct partition_t*
 partitions_lookup(const char *device)
 {
@@ -260,6 +367,9 @@ partitions_lookup(const char *device)
                            0,
                            prom_blksize);
          prom_printf("ISO9660 disk\n");
+     } else if (_amiga_find_rdb(device, disk, prom_blksize) != -1) {
+         /* amiga partition format */
+         partition_amiga_lookup(device, disk, prom_blksize, &list);
      } else {
          prom_printf("No supported partition table detected\n");
          goto bail;