* commands/search.c (options): Add --fs_uuid option.
(search_fs_uuid): New function.
(grub_cmd_search): Fix --set argument passing.
Use search_fs_uuid() when requested via --fs_uuid.
(grub_search_init): Update help message.
* fs/ext2.c (struct grub_ext2_sblock): Rename `unique_id' to `uuid'
and redeclare it as an array of 16-bit words.
(grub_ext2_uuid): New function.
(grub_ext2_fs): Reference grub_ext2_uuid() in `uuid' struct member.
* include/grub/fs.h (struct grub_fs): Add `uuid' struct member.
* util/update-grub.in (GRUB_DEVICE_UUID, GRUB_DEVICE_BOOT)
(GRUB_DEVICE_BOOT_UUID): New variables.
(GRUB_DRIVE. GRUB_DRIVE_BOOT. GRUB_DRIVE_BOOT_GRUB): Remove.
* util/grub.d/00_header.in: Set root using `search --fs_uuid' command
whenever possible.
* util/grub.d/10_hurd.in: Avoid explicit use of root drive. Instead,
just assume `root' variable has the right value.
* util/grub.d/10_linux.in: Likewise.
* util/grub-probe.c (probe): Probe for filesystem UUID when requested
via PRINT_FS_UUID.
(main): Recognise `-t fs_uuid' argument.