From: Daniel Golle Subject: ubi: auto-create ubiblock device for rootfs Signed-off-by: Daniel Golle --- drivers/mtd/ubi/block.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) --- a/drivers/mtd/ubi/block.c +++ b/drivers/mtd/ubi/block.c @@ -652,6 +652,44 @@ static void __init ubiblock_create_from_ } } +#define UBIFS_NODE_MAGIC 0x06101831 +static inline int ubi_vol_is_ubifs(struct ubi_volume_desc *desc) +{ + int ret; + uint32_t magic_of, magic; + ret = ubi_read(desc, 0, (char *)&magic_of, 0, 4); + if (ret) + return 0; + magic = le32_to_cpu(magic_of); + return magic == UBIFS_NODE_MAGIC; +} + +static void __init ubiblock_create_auto_rootfs(void) +{ + int ubi_num, ret, is_ubifs; + struct ubi_volume_desc *desc; + struct ubi_volume_info vi; + + for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++) { + desc = ubi_open_volume_nm(ubi_num, "rootfs", UBI_READONLY); + if (IS_ERR(desc)) + continue; + + ubi_get_volume_info(desc, &vi); + is_ubifs = ubi_vol_is_ubifs(desc); + ubi_close_volume(desc); + if (is_ubifs) + break; + + ret = ubiblock_create(&vi); + if (ret) + pr_err("UBI error: block: can't add '%s' volume, err=%d\n", + vi.name, ret); + /* always break if we get here */ + break; + } +} + static void ubiblock_remove_all(void) { struct ubiblock *next; @@ -684,6 +722,10 @@ int __init ubiblock_init(void) */ ubiblock_create_from_param(); + /* auto-attach "rootfs" volume if existing and non-ubifs */ + if (IS_ENABLED(CONFIG_MTD_ROOTFS_ROOT_DEV)) + ubiblock_create_auto_rootfs(); + /* * Block devices are only created upon user requests, so we ignore * existing volumes.