disk/part: introduce get_device_and_partition

All block device related commands (scsiboot, fatload, ext2ls, etc.) have
simliar duplicated device and partition parsing and selection code. This
adds a common function to replace various implementations.

The new function has an enhancement over current versions. If no device
or partition is specified on the command line, the bootdevice env variable
will be used (scsiboot does this).
Signed-off-by: NRob Herring <rob.herring@calxeda.com>

disk/part.c

@@ -70,7 +70,7 @@ static const struct block_drvr block_drvr[] = {
 
 DECLARE_GLOBAL_DATA_PTR;
 
-block_dev_desc_t *get_dev(char* ifname, int dev)
+block_dev_desc_t *get_dev(const char *ifname, int dev)
 {
 	const struct block_drvr *drvr = block_drvr;
 	block_dev_desc_t* (*reloc_get_dev)(int dev);
@@ -97,7 +97,7 @@ block_dev_desc_t *get_dev(char* ifname, int dev)
 	return NULL;
 }
 #else
-block_dev_desc_t *get_dev(char* ifname, int dev)
+block_dev_desc_t *get_dev(const char *ifname, int dev)
 {
 	return NULL;
 }
@@ -288,6 +288,7 @@ void init_part (block_dev_desc_t * dev_desc)
 	    return;
 	}
 #endif
+	dev_desc->part_type = PART_TYPE_UNKNOWN;
 }
 
 
@@ -441,3 +442,67 @@ int get_partition_info(block_dev_desc_t *dev_desc, int part
 
 	return -1;
 }
+
+int get_device_and_partition(const char *ifname, const char *dev_str,
+			     block_dev_desc_t **dev_desc,
+			     disk_partition_t *info)
+{
+	int ret;
+	char *ep;
+	int dev;
+	block_dev_desc_t *desc;
+	int part = 0;
+	char *part_str;
+
+	if (dev_str)
+		dev = simple_strtoul(dev_str, &ep, 16);
+
+	if (!dev_str || (dev_str == ep)) {
+		dev_str = getenv("bootdevice");
+		if (dev_str)
+			dev = simple_strtoul(dev_str, &ep, 16);
+		if (!dev_str || (dev_str == ep))
+			goto err;
+	}
+
+	desc = get_dev(ifname, dev);
+	if (!desc || (desc->type == DEV_TYPE_UNKNOWN))
+		goto err;
+
+	if (desc->part_type == PART_TYPE_UNKNOWN) {
+		/* disk doesn't use partition table */
+		if (!desc->lba) {
+			printf("**Bad disk size - %s %d:0 **\n", ifname, dev);
+			return -1;
+		}
+		info->start = 0;
+		info->size = desc->lba;
+		info->blksz = desc->blksz;
+
+		*dev_desc = desc;
+		return 0;
+	}
+
+	part_str = strchr(dev_str, ':');
+	if (part_str)
+		part = (int)simple_strtoul(++part_str, NULL, 16);
+
+	ret = get_partition_info(desc, part, info);
+	if (ret) {
+		printf("** Invalid partition %d, use `dev[:part]' **\n", part);
+		return -1;
+	}
+	if (strncmp((char *)info->type, BOOT_PART_TYPE, sizeof(info->type)) != 0) {
+		printf("** Invalid partition type \"%.32s\""
+			" (expect \"" BOOT_PART_TYPE "\")\n",
+			info->type);
+		return -1;
+	}
+
+	*dev_desc = desc;
+	return part;
+
+err:
+	puts("** Invalid boot device, use `dev[:part]' **\n");
+	return -1;
+}

include/part.h

@@ -98,7 +98,7 @@ typedef struct disk_partition {
 
 /* Misc _get_dev functions */
 #ifdef CONFIG_PARTITIONS
-block_dev_desc_t* get_dev(char* ifname, int dev);
+block_dev_desc_t *get_dev(const char *ifname, int dev);
 block_dev_desc_t* ide_get_dev(int dev);
 block_dev_desc_t* sata_get_dev(int dev);
 block_dev_desc_t* scsi_get_dev(int dev);
@@ -112,8 +112,12 @@ int get_partition_info (block_dev_desc_t * dev_desc, int part, disk_partition_t
 void print_part (block_dev_desc_t *dev_desc);
 void  init_part (block_dev_desc_t *dev_desc);
 void dev_print(block_dev_desc_t *dev_desc);
+int get_device_and_partition(const char *ifname, const char *dev_str,
+			     block_dev_desc_t **dev_desc,
+			     disk_partition_t *info);
 #else
-static inline block_dev_desc_t* get_dev(char* ifname, int dev) { return NULL; }
+static inline block_dev_desc_t *get_dev(const char *ifname, int dev)
+{ return NULL; }
 static inline block_dev_desc_t* ide_get_dev(int dev) { return NULL; }
 static inline block_dev_desc_t* sata_get_dev(int dev) { return NULL; }
 static inline block_dev_desc_t* scsi_get_dev(int dev) { return NULL; }
@@ -127,6 +131,11 @@ static inline int get_partition_info (block_dev_desc_t * dev_desc, int part,
 static inline void print_part (block_dev_desc_t *dev_desc) {}
 static inline void  init_part (block_dev_desc_t *dev_desc) {}
 static inline void dev_print(block_dev_desc_t *dev_desc) {}
+static inline int get_device_and_partition(const char *ifname,
+					   const char *dev_str,
+					   block_dev_desc_t **dev_desc,
+					   disk_partition_t *info)
+{ *dev_desc = NULL; return -1; }
 #endif
 
 #ifdef CONFIG_MAC_PARTITION