partx: add mac partition table support

Signed-off-by: Davidlohr Bueso <dave@gnu.org>

diff --git a/partx/mac.c b/partx/mac.c
new file mode 100644 (file)
index 0000000..ed4ed9b
--- /dev/null
+++ b/partx/mac.c
@@ -0,0 +1,74 @@
+/*
+ * Lifted from kpartx's mac.c
+ *
+ * Integrated to partx (utils-linux-ng)
+ *       Davidlohr Bueso <dave@gnu.org>
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+
+#include "bitops.h"
+#include "partx.h"
+
+#define MAC_PARTITION_MAGIC     0x504d
+#define MAC_DRIVER_MAGIC        0x4552
+
+struct mac_partition {
+        uint16_t  signature;      /* expected to be MAC_PARTITION_MAGIC */
+        uint16_t  res1;
+        uint32_t  map_count;      /* # blocks in partition map */
+        uint32_t  start_block;    /* absolute starting block # of partition */
+        uint32_t  block_count;    /* number of blocks in partition */
+        /* there is more stuff after this that we don't need */
+};
+
+/* Driver descriptor structure, in block 0 */
+struct mac_driver_desc {
+        uint16_t  signature;      /* expected to be MAC_DRIVER_MAGIC */
+        uint16_t  block_size;
+        uint32_t  block_count;
+};
+
+int
+read_mac_pt(int fd, struct slice all, struct slice *sp, int ns) {
+       struct mac_driver_desc *md;
+        struct mac_partition *part;
+       unsigned secsize;
+       char *data;
+       int blk, blocks_in_map;
+        int n = 0;
+
+       md = (struct mac_driver_desc *) getblock(fd, 0);
+       if (md == NULL)
+               return -1;
+
+       if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC)
+               return -1;
+
+       secsize = be16_to_cpu(md->block_size);
+       data = getblock(fd, secsize/512);
+       if (!data)
+               return -1;
+       part = (struct mac_partition *) (data + secsize%512);
+
+       if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
+               return -1;
+
+       blocks_in_map = be32_to_cpu(part->map_count);
+       for (blk = 1; blk <= blocks_in_map && blk <= ns; ++blk, ++n) {
+               int pos = blk * secsize;
+               data = getblock(fd, pos/512);
+               if (!data)
+                       return -1;
+
+               part = (struct mac_partition *) (data + pos%512);
+               if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
+                       break;
+
+               sp[n].start = be32_to_cpu(part->start_block) * (secsize/512);
+               sp[n].size = be32_to_cpu(part->block_count) * (secsize/512);
+       }
+       return n;
+}