GPT: read partition table from device into a data structure
authorAlison Chaiken <alison@peloton-tech.com>
Tue, 4 Jul 2017 18:18:50 +0000 (11:18 -0700)
committerTom Rini <trini@konsulko.com>
Sat, 5 Aug 2017 00:34:04 +0000 (20:34 -0400)
Make the partition table available for modification by reading it from
the user-specified device into a linked list.   Provide an accessor
function for command-line testing.

Signed-off-by: Alison Chaiken <alison@peloton-tech.com>
[trini: Make this depend on CMD_GPT_RENAME, as it is the user of this
code]
Signed-off-by: Tom Rini <trini@konsulko.com>
cmd/gpt.c
include/part.h

index 65fb80b..9c920fa 100644 (file)
--- a/cmd/gpt.c
+++ b/cmd/gpt.c
@@ -19,6 +19,9 @@
 #include <linux/ctype.h>
 #include <div64.h>
 #include <memalign.h>
+#include <linux/compat.h>
+
+static LIST_HEAD(disk_partitions);
 
 /**
  * extract_env(): Expand env name from string format '&{env_name}'
@@ -151,6 +154,122 @@ static bool found_key(const char *str, const char *key)
        return result;
 }
 
+#ifdef CONFIG_CMD_GPT_RENAME
+static void del_gpt_info(void)
+{
+       struct list_head *pos = &disk_partitions;
+       struct disk_part *curr;
+       while (!list_empty(pos)) {
+               curr = list_entry(pos->next, struct disk_part, list);
+               list_del(pos->next);
+               free(curr);
+       }
+}
+
+static struct disk_part *allocate_disk_part(disk_partition_t *info, int partnum)
+{
+       struct disk_part *newpart;
+       newpart = malloc(sizeof(*newpart));
+       if (!newpart)
+               return ERR_PTR(-ENOMEM);
+       memset(newpart, '\0', sizeof(newpart));
+
+       newpart->gpt_part_info.start = info->start;
+       newpart->gpt_part_info.size = info->size;
+       newpart->gpt_part_info.blksz = info->blksz;
+       strncpy((char *)newpart->gpt_part_info.name, (const char *)info->name,
+               PART_NAME_LEN);
+       newpart->gpt_part_info.name[PART_NAME_LEN - 1] = '\0';
+       strncpy((char *)newpart->gpt_part_info.type, (const char *)info->type,
+               PART_TYPE_LEN);
+       newpart->gpt_part_info.type[PART_TYPE_LEN - 1] = '\0';
+       newpart->gpt_part_info.bootable = info->bootable;
+#ifdef CONFIG_PARTITION_UUIDS
+       strncpy(newpart->gpt_part_info.uuid, (const char *)info->uuid,
+               UUID_STR_LEN);
+       /* UUID_STR_LEN is correct, as uuid[]'s length is UUID_STR_LEN+1 chars */
+       newpart->gpt_part_info.uuid[UUID_STR_LEN] = '\0';
+#endif
+       newpart->partnum = partnum;
+
+       return newpart;
+}
+
+static void print_gpt_info(void)
+{
+       struct list_head *pos;
+       struct disk_part *curr;
+
+       list_for_each(pos, &disk_partitions) {
+               curr = list_entry(pos, struct disk_part, list);
+               printf("Partition %d:\n", curr->partnum);
+               printf("1st block %x, size %x\n", (unsigned)curr->gpt_part_info.start,
+                      (unsigned)curr->gpt_part_info.size);
+               printf("Block size %lu, name %s\n", curr->gpt_part_info.blksz,
+                      curr->gpt_part_info.name);
+               printf("Type %s, bootable %d\n", curr->gpt_part_info.type,
+                      curr->gpt_part_info.bootable);
+#ifdef CONFIG_PARTITION_UUIDS
+               printf("UUID %s\n", curr->gpt_part_info.uuid);
+#endif
+               printf("\n");
+       }
+}
+
+/*
+ * read partition info into disk_partitions list where
+ * it can be printed or modified
+ */
+static int get_gpt_info(struct blk_desc *dev_desc)
+{
+       /* start partition numbering at 1, as U-Boot does */
+       int valid_parts = 0, p, ret;
+       disk_partition_t info;
+       struct disk_part *new_disk_part;
+
+       if (disk_partitions.next == NULL)
+               INIT_LIST_HEAD(&disk_partitions);
+
+       for (p = 1; p <= MAX_SEARCH_PARTITIONS; p++) {
+               ret = part_get_info(dev_desc, p, &info);
+               if (ret)
+                       continue;
+
+               /* Add 1 here because counter is zero-based but p1 is
+                  the first partition */
+               new_disk_part = allocate_disk_part(&info, valid_parts+1);
+               if (IS_ERR(new_disk_part))
+                       goto out;
+
+               list_add_tail(&new_disk_part->list, &disk_partitions);
+               valid_parts++;
+       }
+       if (valid_parts == 0) {
+               printf("** No valid partitions found **\n");
+               goto out;
+       }
+       return valid_parts;
+ out:
+       if (valid_parts >= 1)
+               del_gpt_info();
+       return -ENODEV;
+}
+
+/* a wrapper to test get_gpt_info */
+static int do_get_gpt_info(struct blk_desc *dev_desc)
+{
+       int ret;
+
+       ret = get_gpt_info(dev_desc);
+       if (ret > 0) {
+               print_gpt_info();
+               del_gpt_info();
+               return 0;
+       }
+       return ret;
+}
+#endif
+
 /**
  * set_gpt_info(): Fill partition information from string
  *             function allocates memory, remember to free!
@@ -455,6 +574,10 @@ static int do_gpt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
                printf("Verify GPT: ");
        } else if (strcmp(argv[1], "guid") == 0) {
                ret = do_disk_guid(blk_dev_desc, argv[4]);
+#ifdef CONFIG_CMD_GPT_RENAME
+       } else if (strcmp(argv[1], "read") == 0) {
+               ret = do_get_gpt_info(blk_dev_desc);
+#endif
        } else {
                return CMD_RET_USAGE;
        }
@@ -477,6 +600,8 @@ U_BOOT_CMD(gpt, CONFIG_SYS_MAXARGS, 1, do_gpt,
        " Example usage:\n"
        " gpt write mmc 0 $partitions\n"
        " gpt verify mmc 0 $partitions\n"
+       " read <interface> <dev>\n"
+       "    - read GPT into a data structure for manipulation\n"
        " guid <interface> <dev>\n"
        "    - print disk GUID\n"
        " guid <interface> <dev> <varname>\n"
index c41aa6a..0cd803a 100644 (file)
@@ -10,6 +10,7 @@
 #include <blk.h>
 #include <ide.h>
 #include <uuid.h>
+#include <linux/list.h>
 
 struct block_drvr {
        char *name;
@@ -69,6 +70,12 @@ typedef struct disk_partition {
 #endif
 } disk_partition_t;
 
+struct disk_part {
+       int partnum;
+       disk_partition_t gpt_part_info;
+       struct list_head list;
+};
+
 /* Misc _get_dev functions */
 #ifdef CONFIG_PARTITIONS
 /**