Add the functionality to create an (empty) GPT from scratch. The

code is directly copied from migrate.c. The intend is to express
migrate in terms of create and add. The functionality to add
partitions is not yet there.

4 files changed, 199 insertions, 2 deletions

diff --git a/sbin/gpt/Makefile b/sbin/gpt/Makefile
index 6500d1f..e6d76cb 100644
--- a/sbin/gpt/Makefile
+++ b/sbin/gpt/Makefile
@@ -1,7 +1,7 @@
 # $FreeBSD$
 
 PROG=	gpt
-SRCS=	destroy.c gpt.c map.c migrate.c recover.c show.c
+SRCS=	create.c destroy.c gpt.c map.c migrate.c recover.c show.c
 WARNS=	4
 NOMAN=	not yet
 
diff --git a/sbin/gpt/create.c b/sbin/gpt/create.c
new file mode 100644
index 0000000..a82970d
--- /dev/null
+++ b/sbin/gpt/create.c
@@ -0,0 +1,196 @@
+/*
+ * Copyright (c) 2002 Marcel Moolenaar
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+#include <sys/uuid.h>
+#include <sys/gpt.h>
+
+#include <err.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "map.h"
+#include "gpt.h"
+
+int primary_only;
+
+static void
+usage_create(void)
+{
+
+	fprintf(stderr,
+	    "usage: %s [-p] device ...\n", getprogname());
+	exit(1);
+}
+
+static void
+create(int fd)
+{
+	off_t blocks, last;
+	map_t *gpt, *tpg;
+	map_t *tbl, *lbt;
+	map_t *map;
+	struct gpt_hdr *hdr;
+	struct gpt_ent *ent;
+	unsigned int i;
+
+	if (map_find(MAP_TYPE_PRI_GPT_HDR) != NULL ||
+	    map_find(MAP_TYPE_SEC_GPT_HDR) != NULL) {
+		warnx("%s: error: device already contains a GPT", device_name);
+		return;
+	}
+
+	/* Get the amount of free space after the MBR */
+	blocks = map_unused(1LL, 0LL);
+	if (blocks == 0LL) {
+		warnx("%s: error: no room for the GPT header", device_name);
+		return;
+	}
+
+	/* Don't create more than parts entries. */
+	if ((uint64_t)(blocks - 1) * secsz > parts * sizeof(struct gpt_ent)) {
+		blocks = (parts * sizeof(struct gpt_ent)) / secsz;
+		if ((parts * sizeof(struct gpt_ent)) % secsz)
+			blocks++;
+		blocks++;		/* Don't forget the header itself */
+	}
+
+	last = mediasz / secsz - 1LL;
+
+	/* Never cross the median of the device. */
+	if ((blocks + 1LL) > ((last + 1LL) >> 1))
+		blocks = ((last + 1LL) >> 1) - 1LL;
+
+	/*
+	 * Get the amount of free space at the end of the device and
+	 * calculate the size for the GPT structures.
+	 */
+	map = map_last();
+	if (map->map_type != MAP_TYPE_UNUSED) {
+		warnx("%s: error: no room for the backup header", device_name);
+		return;
+	}
+
+	if (map->map_size < blocks)
+		blocks = map->map_size;
+	if (blocks == 1LL) {
+		warnx("%s: error: no room for the GPT table", device_name);
+		return;
+	}
+
+	blocks--;		/* Number of blocks in the GPT table. */
+	gpt = map_add(1LL, 1LL, MAP_TYPE_PRI_GPT_HDR, calloc(1, secsz));
+	tbl = map_add(2LL, blocks, MAP_TYPE_PRI_GPT_TBL,
+	    calloc(blocks, secsz));
+	if (gpt == NULL || tbl == NULL)
+		return;
+
+	hdr = gpt->map_data;
+	memcpy(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig));
+	hdr->hdr_revision = GPT_HDR_REVISION;
+	/*
+	 * XXX struct gpt_hdr is not a multiple of 8 bytes in size and thus
+	 * contains padding we must not include in the size.
+	 */
+	hdr->hdr_size = offsetof(struct gpt_hdr, padding);
+	hdr->hdr_lba_self = gpt->map_start;
+	hdr->hdr_lba_alt = last;
+	hdr->hdr_lba_start = tbl->map_start + blocks;
+	hdr->hdr_lba_end = last - blocks - 1LL;
+	uuidgen(&hdr->hdr_uuid, 1);
+	hdr->hdr_lba_table = tbl->map_start;
+	hdr->hdr_entries = (blocks * secsz) / sizeof(struct gpt_ent);
+	if (hdr->hdr_entries > parts)
+		hdr->hdr_entries = parts;
+	hdr->hdr_entsz = sizeof(struct gpt_ent);
+
+	ent = tbl->map_data;
+	for (i = 0; i < hdr->hdr_entries; i++)
+		uuidgen(&ent[i].ent_uuid, 1);
+
+	hdr->hdr_crc_table = crc32(ent, hdr->hdr_entries * hdr->hdr_entsz);
+	hdr->hdr_crc_self = crc32(hdr, hdr->hdr_size);
+
+	gpt_write(fd, gpt);
+	gpt_write(fd, tbl);
+
+	/*
+	 * Create backup GPT if the user didn't suppress it.
+	 */
+	if (!primary_only) {
+		tpg = map_add(last, 1LL, MAP_TYPE_SEC_GPT_HDR,
+		    calloc(1, secsz));
+		lbt = map_add(last - blocks, blocks, MAP_TYPE_SEC_GPT_TBL,
+		    tbl->map_data);
+		memcpy(tpg->map_data, gpt->map_data, secsz);
+		hdr = tpg->map_data;
+		hdr->hdr_lba_self = tpg->map_start;
+		hdr->hdr_lba_alt = gpt->map_start;
+		hdr->hdr_lba_table = lbt->map_start;
+		hdr->hdr_crc_self = 0;		/* Don't ever forget this! */
+		hdr->hdr_crc_self = crc32(hdr, hdr->hdr_size);
+		gpt_write(fd, lbt);
+		gpt_write(fd, tpg);
+	}
+}
+
+int
+cmd_create(int argc, char *argv[])
+{
+	int ch, fd;
+
+	while ((ch = getopt(argc, argv, "p")) != -1) {
+		switch(ch) {
+		case 'p':
+			primary_only = 1;
+			break;
+		default:
+			usage_create();
+		}
+	}
+
+	if (argc == optind)
+		usage_create();
+
+	while (optind < argc) {
+		fd = gpt_open(argv[optind++]);
+		if (fd == -1) {
+			warn("unable to open device '%s'", device_name);
+			continue;
+		}
+
+		create(fd);
+
+		gpt_close(fd);
+	}
+
+	return (0);
+}
diff --git a/sbin/gpt/gpt.c b/sbin/gpt/gpt.c
index 409ee72..e3f1365 100644
--- a/sbin/gpt/gpt.c
+++ b/sbin/gpt/gpt.c
@@ -385,7 +385,7 @@ static struct {
 	const char *name;
 } cmdsw[] = {
 	{ NULL, "add" },
-	{ NULL, "create" },
+	{ cmd_create, "create" },
 	{ NULL, "delete" },
 	{ cmd_destroy, "destroy" },
 	{ NULL, "help" },
diff --git a/sbin/gpt/gpt.h b/sbin/gpt/gpt.h
index d6d0b71..268abe1 100644
--- a/sbin/gpt/gpt.h
+++ b/sbin/gpt/gpt.h
@@ -62,6 +62,7 @@ void*	gpt_read(int, off_t, size_t);
 int	gpt_write(int, map_t *);
 void	unicode16(short *, const wchar_t *, size_t);
 
+int	cmd_create(int, char *[]);
 int	cmd_destroy(int, char *[]);
 int	cmd_migrate(int, char *[]);
 int	cmd_recover(int, char *[]);