disk: get_device_and_partition() "auto" partition and cleanup
[oweals/u-boot.git] / disk / part.c
index ed6bbe29bc878bc0073b32e8bd5a007c106748ff..0dd4b0f0c63a2a0ce118ffc21de383b5fd1f325e 100644 (file)
@@ -24,6 +24,7 @@
 #include <common.h>
 #include <command.h>
 #include <ide.h>
+#include <malloc.h>
 #include <part.h>
 
 #undef PART_DEBUG
@@ -465,66 +466,176 @@ int get_device(const char *ifname, const char *dev_str,
        return dev;
 }
 
-int get_device_and_partition(const char *ifname, const char *dev_str,
+#define PART_UNSPECIFIED -2
+#define PART_AUTO -1
+#define MAX_SEARCH_PARTITIONS 16
+int get_device_and_partition(const char *ifname, const char *dev_part_str,
                             block_dev_desc_t **dev_desc,
-                            disk_partition_t *info)
+                            disk_partition_t *info, int allow_whole_dev)
 {
-       int ret;
-       char *ep;
+       int ret = -1;
+       const char *part_str;
+       char *dup_str = NULL;
+       const char *dev_str;
        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;
+       char *ep;
+       int p;
+       int part;
+       disk_partition_t tmpinfo;
+
+       /* If no dev_part_str, use bootdevice environment variable */
+       if (!dev_part_str)
+               dev_part_str = getenv("bootdevice");
+
+       /* If still no dev_part_str, it's an error */
+       if (!dev_part_str) {
+               printf("** No device specified **\n");
+               goto cleanup;
+       }
+
+       /* Separate device and partition ID specification */
+       part_str = strchr(dev_part_str, ':');
+       if (part_str) {
+               dup_str = strdup(dev_part_str);
+               dup_str[part_str - dev_part_str] = 0;
+               dev_str = dup_str;
+               part_str++;
+       } else {
+               dev_str = dev_part_str;
        }
 
-       desc = get_dev(ifname, dev);
-       if (!desc || (desc->type == DEV_TYPE_UNKNOWN))
-               goto err;
+       /* Look up the device */
+       dev = get_device(ifname, dev_str, dev_desc);
+       if (dev < 0)
+               goto cleanup;
+
+       /* Convert partition ID string to number */
+       if (!part_str || !*part_str) {
+               part = PART_UNSPECIFIED;
+       } else if (!strcmp(part_str, "auto")) {
+               part = PART_AUTO;
+       } else {
+               /* Something specified -> use exactly that */
+               part = (int)simple_strtoul(part_str, &ep, 16);
+               /*
+                * Less than whole string converted,
+                * or request for whole device, but caller requires partition.
+                */
+               if (*ep || (part == 0 && !allow_whole_dev)) {
+                       printf("** Bad partition specification %s %s **\n",
+                           ifname, dev_part_str);
+                       goto cleanup;
+               }
+       }
+
+       /*
+        * No partition table on device,
+        * or user requested partition 0 (entire device).
+        */
+       if (((*dev_desc)->part_type == PART_TYPE_UNKNOWN) ||
+           (part == 0)) {
+               if (!(*dev_desc)->lba) {
+                       printf("** Bad device size - %s %s **\n", ifname,
+                              dev_str);
+                       goto cleanup;
+               }
 
-       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;
+               /*
+                * If user specified a partition ID other than 0,
+                * or the calling command only accepts partitions,
+                * it's an error.
+                */
+               if ((part > 0) || (!allow_whole_dev)) {
+                       printf("** No partition table - %s %s **\n", ifname,
+                              dev_str);
+                       goto cleanup;
                }
+
                info->start = 0;
-               info->size = desc->lba;
-               info->blksz = desc->blksz;
+               info->size = (*dev_desc)->lba;
+               info->blksz = (*dev_desc)->blksz;
+               info->bootable = 0;
+#ifdef CONFIG_PARTITION_UUIDS
+               info->uuid[0] = 0;
+#endif
 
-               *dev_desc = desc;
-               return 0;
+               ret = 0;
+               goto cleanup;
        }
 
-       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;
+       /*
+        * Now there's known to be a partition table,
+        * not specifying a partition means to pick partition 1.
+        */
+       if (part == PART_UNSPECIFIED)
+               part = 1;
+
+       /*
+        * If user didn't specify a partition number, or did specify something
+        * other than "auto", use that partition number directly.
+        */
+       if (part != PART_AUTO) {
+               ret = get_partition_info(*dev_desc, part, info);
+               if (ret) {
+                       printf("** Invalid partition %d **\n", part);
+                       goto cleanup;
+               }
+       } else {
+               /*
+                * Find the first bootable partition.
+                * If none are bootable, fall back to the first valid partition.
+                */
+               part = 0;
+               for (p = 1; p <= MAX_SEARCH_PARTITIONS; p++) {
+                       ret = get_partition_info(*dev_desc, p, info);
+                       if (ret)
+                               continue;
+
+                       /*
+                        * First valid partition, or new better partition?
+                        * If so, save partition ID.
+                        */
+                       if (!part || info->bootable)
+                               part = p;
+
+                       /* Best possible partition? Stop searching. */
+                       if (info->bootable)
+                               break;
+
+                       /*
+                        * We now need to search further for best possible.
+                        * If we what we just queried was the best so far,
+                        * save the info since we over-write it next loop.
+                        */
+                       if (part == p)
+                               tmpinfo = *info;
+               }
+               /* If we found any acceptable partition */
+               if (part) {
+                       /*
+                        * If we searched all possible partition IDs,
+                        * return the first valid partition we found.
+                        */
+                       if (p == MAX_SEARCH_PARTITIONS + 1)
+                               *info = tmpinfo;
+                       ret = 0;
+               } else {
+                       printf("** No valid partitions found **\n");
+                       goto cleanup;
+               }
        }
        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;
+               ret  = -1;
+               goto cleanup;
        }
 
-       *dev_desc = desc;
-       return part;
+       ret = part;
+       goto cleanup;
 
-err:
-       puts("** Invalid boot device, use `dev[:part]' **\n");
-       return -1;
+cleanup:
+       free(dup_str);
+       return ret;
 }