gpt: Support for new "gpt" command

New command - "gpt" is supported. It restores the GPT partition table.
It looks into the given environment variable for partitions definition.
It can be enabled at target configuration file with CONFIG_CMD_GPT.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Piotr Wilczek <p.wilczek@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

common/Makefile

@@ -198,6 +198,7 @@ COBJS-$(CONFIG_MODEM_SUPPORT) += modem.o
 COBJS-$(CONFIG_UPDATE_TFTP) += update.o
 COBJS-$(CONFIG_USB_KEYBOARD) += usb_kbd.o
 COBJS-$(CONFIG_CMD_DFU) += cmd_dfu.o
+COBJS-$(CONFIG_CMD_GPT) += cmd_gpt.o
 endif
 
 ifdef CONFIG_SPL_BUILD

common/cmd_gpt.c

@@ -0,0 +1,333 @@
+/*
+ * cmd_gpt.c -- GPT (GUID Partition Table) handling command
+ *
+ * Copyright (C) 2012 Samsung Electronics
+ * author: Lukasz Majewski <l.majewski@samsung.com>
+ * author: Piotr Wilczek <p.wilczek@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <command.h>
+#include <mmc.h>
+#include <part_efi.h>
+#include <exports.h>
+#include <linux/ctype.h>
+
+#ifndef CONFIG_PARTITION_UUIDS
+#error CONFIG_PARTITION_UUIDS must be enabled for CONFIG_CMD_GPT to be enabled
+#endif
+
+/**
+ * extract_env(): Expand env name from string format '&{env_name}'
+ *                and return pointer to the env (if the env is set)
+ *
+ * @param str - pointer to string
+ * @param env - pointer to pointer to extracted env
+ *
+ * @return - zero on successful expand and env is set
+ */
+static char extract_env(const char *str, char **env)
+{
+	char *e, *s;
+
+	if (!str || strlen(str) < 4)
+		return -1;
+
+	if ((strncmp(str, "${", 2) == 0) && (str[strlen(str) - 1] == '}')) {
+		s = strdup(str);
+		if (s == NULL)
+			return -1;
+		memset(s + strlen(s) - 1, '\0', 1);
+		memmove(s, s + 2, strlen(s) - 1);
+		e = getenv(s);
+		free(s);
+		if (e == NULL) {
+			printf("Environmental '%s' not set\n", str);
+			return -1; /* env not set */
+		}
+		*env = e;
+		return 0;
+	}
+
+	return -1;
+}
+
+/**
+ * extract_val(): Extract value from a key=value pair list (comma separated).
+ *                Only value for the given key is returend.
+ *                Function allocates memory for the value, remember to free!
+ *
+ * @param str - pointer to string with key=values pairs
+ * @param key - pointer to the key to search for
+ *
+ * @return - pointer to allocated string with the value
+ */
+static char *extract_val(const char *str, const char *key)
+{
+	char *v, *k;
+	char *s, *strcopy;
+	char *new = NULL;
+
+	strcopy = strdup(str);
+	if (strcopy == NULL)
+		return NULL;
+
+	s = strcopy;
+	while (s) {
+		v = strsep(&s, ",");
+		if (!v)
+			break;
+		k = strsep(&v, "=");
+		if (!k)
+			break;
+		if  (strcmp(k, key) == 0) {
+			new = strdup(v);
+			break;
+		}
+	}
+
+	free(strcopy);
+
+	return new;
+}
+
+/**
+ * set_gpt_info(): Fill partition information from string
+ *		function allocates memory, remember to free!
+ *
+ * @param dev_desc - pointer block device descriptor
+ * @param str_part - pointer to string with partition information
+ * @param str_disk_guid - pointer to pointer to allocated string with disk guid
+ * @param partitions - pointer to pointer to allocated partitions array
+ * @param parts_count - number of partitions
+ *
+ * @return - zero on success, otherwise error
+ *
+ */
+static int set_gpt_info(block_dev_desc_t *dev_desc,
+			const char *str_part,
+			char **str_disk_guid,
+			disk_partition_t **partitions,
+			u8 *parts_count)
+{
+	char *tok, *str, *s;
+	int i;
+	char *val, *p;
+	int p_count;
+	disk_partition_t *parts;
+	int errno = 0;
+
+	debug("%s: MMC lba num: 0x%x %d\n", __func__,
+	      (unsigned int)dev_desc->lba, (unsigned int)dev_desc->lba);
+
+	if (str_part == NULL)
+		return -1;
+
+	str = strdup(str_part);
+
+	/* extract disk guid */
+	s = str;
+	tok = strsep(&s, ";");
+	val = extract_val(tok, "uuid_disk");
+	if (!val) {
+		free(str);
+		return -2;
+	}
+	if (extract_env(val, &p))
+		p = val;
+	*str_disk_guid = strdup(p);
+	free(val);
+
+	if (strlen(s) == 0)
+		return -3;
+
+	i = strlen(s) - 1;
+	if (s[i] == ';')
+		s[i] = '\0';
+
+	/* calculate expected number of partitions */
+	p_count = 1;
+	p = s;
+	while (*p) {
+		if (*p++ == ';')
+			p_count++;
+	}
+
+	/* allocate memory for partitions */
+	parts = calloc(sizeof(disk_partition_t), p_count);
+
+	/* retrive partions data from string */
+	for (i = 0; i < p_count; i++) {
+		tok = strsep(&s, ";");
+
+		if (tok == NULL)
+			break;
+
+		/* uuid */
+		val = extract_val(tok, "uuid");
+		if (!val) { /* 'uuid' is mandatory */
+			errno = -4;
+			goto err;
+		}
+		if (extract_env(val, &p))
+			p = val;
+		if (strlen(p) >= sizeof(parts[i].uuid)) {
+			printf("Wrong uuid format for partition %d\n", i);
+			errno = -4;
+			goto err;
+		}
+		strcpy((char *)parts[i].uuid, p);
+		free(val);
+
+		/* name */
+		val = extract_val(tok, "name");
+		if (!val) { /* name is mandatory */
+			errno = -4;
+			goto err;
+		}
+		if (extract_env(val, &p))
+			p = val;
+		if (strlen(p) >= sizeof(parts[i].name)) {
+			errno = -4;
+			goto err;
+		}
+		strcpy((char *)parts[i].name, p);
+		free(val);
+
+		/* size */
+		val = extract_val(tok, "size");
+		if (!val) { /* 'size' is mandatory */
+			errno = -4;
+			goto err;
+		}
+		if (extract_env(val, &p))
+			p = val;
+		parts[i].size = ustrtoul(p, &p, 0);
+		parts[i].size /= dev_desc->blksz;
+		free(val);
+
+		/* start address */
+		val = extract_val(tok, "start");
+		if (val) { /* start address is optional */
+			if (extract_env(val, &p))
+				p = val;
+			parts[i].start = ustrtoul(p, &p, 0);
+			parts[i].start /= dev_desc->blksz;
+			free(val);
+		}
+	}
+
+	*parts_count = p_count;
+	*partitions = parts;
+	free(str);
+
+	return 0;
+err:
+	free(str);
+	free(*str_disk_guid);
+	free(parts);
+
+	return errno;
+}
+
+static int gpt_mmc_default(int dev, const char *str_part)
+{
+	int ret;
+	char *str_disk_guid;
+	u8 part_count = 0;
+	disk_partition_t *partitions = NULL;
+
+	struct mmc *mmc = find_mmc_device(dev);
+
+	if (mmc == NULL) {
+		printf("%s: mmc dev %d NOT available\n", __func__, dev);
+		return CMD_RET_FAILURE;
+	}
+
+	if (!str_part)
+		return -1;
+
+	/* fill partitions */
+	ret = set_gpt_info(&mmc->block_dev, str_part,
+			&str_disk_guid, &partitions, &part_count);
+	if (ret) {
+		if (ret == -1)
+			printf("No partition list provided\n");
+		if (ret == -2)
+			printf("Missing disk guid\n");
+		if ((ret == -3) || (ret == -4))
+			printf("Partition list incomplete\n");
+		return -1;
+	}
+
+	/* save partitions layout to disk */
+	gpt_restore(&mmc->block_dev, str_disk_guid, partitions, part_count);
+	free(str_disk_guid);
+	free(partitions);
+
+	return 0;
+}
+
+/**
+ * do_gpt(): Perform GPT operations
+ *
+ * @param cmdtp - command name
+ * @param flag
+ * @param argc
+ * @param argv
+ *
+ * @return zero on success; otherwise error
+ */
+static int do_gpt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	int ret = CMD_RET_SUCCESS;
+	int dev = 0;
+	char *pstr;
+
+	if (argc < 5)
+		return CMD_RET_USAGE;
+
+	/* command: 'write' */
+	if ((strcmp(argv[1], "write") == 0) && (argc == 5)) {
+		/* device: 'mmc' */
+		if (strcmp(argv[2], "mmc") == 0) {
+			/* check if 'dev' is a number */
+			for (pstr = argv[3]; *pstr != '\0'; pstr++)
+				if (!isdigit(*pstr)) {
+					printf("'%s' is not a number\n",
+						argv[3]);
+					return CMD_RET_USAGE;
+				}
+			dev = (int)simple_strtoul(argv[3], NULL, 10);
+			/* write to mmc */
+			if (gpt_mmc_default(dev, argv[4]))
+				return CMD_RET_FAILURE;
+		}
+	} else {
+		return CMD_RET_USAGE;
+	}
+	return ret;
+}
+
+U_BOOT_CMD(gpt, CONFIG_SYS_MAXARGS, 1, do_gpt,
+	"GUID Partition Table",
+	"<command> <interface> <dev> <partions_list>\n"
+	" - GUID partition table restoration\n"
+	" Restore GPT information on a device connected\n"
+	" to interface\n"
+);