o Newer EFI implementations require that a GPT is preceeded by

   a PMBR. Make sure the create command creates a PMBR as well
   (if not already present).
o  When parsing the MBR, explicitly check for a PMBR and create
   a PMBR map node if one is found.
o  When parsing the MBR, recurse to handle extended partitions.
   This allows us to flatten nested MBRs when migrating to a
   GPT.
o  Have the migrate command bail out if it encounters a partition
   it doesn't know how to migrate. This avoids data loss.
o  Change the output of the show command so that the UUIDs of the
   GPT partitions fit on the same line.
o  Show when partitions are extended partitions and add the PMBR
   type.

Approved by: re (blanket)

1 files changed, 35 insertions, 0 deletions

diff --git a/sbin/gpt/create.c b/sbin/gpt/create.c
index ec2b121..e9ac8ce 100644
--- a/sbin/gpt/create.c
+++ b/sbin/gpt/create.c
@@ -58,6 +58,7 @@ create(int fd)
 	map_t *gpt, *tpg;
 	map_t *tbl, *lbt;
 	map_t *map;
+	struct mbr *mbr;
 	struct gpt_hdr *hdr;
 	struct gpt_ent *ent;
 	unsigned int i;
@@ -67,6 +68,40 @@ create(int fd)
 		warnx("%s: error: device already contains a GPT", device_name);
 		return;
 	}
+	if (map_find(MAP_TYPE_MBR) != NULL) {
+		warnx("%s: error: device contains a MBR", device_name);
+		return;
+	}
+
+	/*
+	 * Create PMBR.
+	 */
+	if (map_find(MAP_TYPE_PMBR) == NULL) {
+		if (map_free(0LL, 1LL) == 0) {
+			warnx("%s: error: no room for the PMBR", device_name);
+			return;
+		}
+		mbr = gpt_read(fd, 0LL, 1);
+		bzero(mbr, sizeof(*mbr));
+		mbr->mbr_sig = MBR_SIG;
+		mbr->mbr_part[0].part_shd = 0xff;
+		mbr->mbr_part[0].part_ssect = 0xff;
+		mbr->mbr_part[0].part_scyl = 0xff;
+		mbr->mbr_part[0].part_typ = 0xee;
+		mbr->mbr_part[0].part_ehd = 0xff;
+		mbr->mbr_part[0].part_esect = 0xff;
+		mbr->mbr_part[0].part_ecyl = 0xff;
+		mbr->mbr_part[0].part_start_lo = 1;
+		if (mediasz > 0xffffffff) {
+			mbr->mbr_part[0].part_size_lo = 0xffff;
+			mbr->mbr_part[0].part_size_hi = 0xffff;
+		} else {
+			mbr->mbr_part[0].part_size_lo = mediasz & 0xffff;
+			mbr->mbr_part[0].part_size_hi = mediasz >> 16;
+		}
+		map = map_add(0LL, 1LL, MAP_TYPE_PMBR, mbr);
+		gpt_write(fd, map);
+	}
 
 	/* Get the amount of free space after the MBR */
 	blocks = map_free(1LL, 0LL);