| From: Daniel Golle <daniel@makrotopia.org> |
| Subject: ubi: auto-attach mtd device named "ubi" or "data" on boot |
| |
| Signed-off-by: Daniel Golle <daniel@makrotopia.org> |
| --- |
| drivers/mtd/ubi/build.c | 36 ++++++++++++++++++++++++++++++++++++ |
| 1 file changed, 36 insertions(+) |
| |
| --- a/drivers/mtd/ubi/build.c |
| +++ b/drivers/mtd/ubi/build.c |
| @@ -1177,6 +1177,73 @@ static struct mtd_info * __init open_mtd |
| return mtd; |
| } |
| |
| +/* |
| + * This function tries attaching mtd partitions named either "ubi" or "data" |
| + * during boot. |
| + */ |
| +static void __init ubi_auto_attach(void) |
| +{ |
| + int err; |
| + struct mtd_info *mtd; |
| + loff_t offset = 0; |
| + size_t len; |
| + char magic[4]; |
| + |
| + /* try attaching mtd device named "ubi" or "data" */ |
| + mtd = open_mtd_device("ubi"); |
| + if (IS_ERR(mtd)) |
| + mtd = open_mtd_device("data"); |
| + |
| + if (IS_ERR(mtd)) |
| + return; |
| + |
| + /* get the first not bad block */ |
| + if (mtd_can_have_bb(mtd)) |
| + while (mtd_block_isbad(mtd, offset)) { |
| + offset += mtd->erasesize; |
| + |
| + if (offset > mtd->size) { |
| + pr_err("UBI error: Failed to find a non-bad " |
| + "block on mtd%d\n", mtd->index); |
| + goto cleanup; |
| + } |
| + } |
| + |
| + /* check if the read from flash was successful */ |
| + err = mtd_read(mtd, offset, 4, &len, (void *) magic); |
| + if ((err && !mtd_is_bitflip(err)) || len != 4) { |
| + pr_err("UBI error: unable to read from mtd%d\n", mtd->index); |
| + goto cleanup; |
| + } |
| + |
| + /* check for a valid ubi magic */ |
| + if (strncmp(magic, "UBI#", 4)) { |
| + pr_err("UBI error: no valid UBI magic found inside mtd%d\n", mtd->index); |
| + goto cleanup; |
| + } |
| + |
| + /* don't auto-add media types where UBI doesn't makes sense */ |
| + if (mtd->type != MTD_NANDFLASH && |
| + mtd->type != MTD_NORFLASH && |
| + mtd->type != MTD_DATAFLASH && |
| + mtd->type != MTD_MLCNANDFLASH) |
| + goto cleanup; |
| + |
| + mutex_lock(&ubi_devices_mutex); |
| + pr_notice("UBI: auto-attach mtd%d\n", mtd->index); |
| + err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO, 0, 0); |
| + mutex_unlock(&ubi_devices_mutex); |
| + if (err < 0) { |
| + pr_err("UBI error: cannot attach mtd%d\n", mtd->index); |
| + goto cleanup; |
| + } |
| + |
| + return; |
| + |
| +cleanup: |
| + put_mtd_device(mtd); |
| +} |
| + |
| static int __init ubi_init(void) |
| { |
| int err, i, k; |
| @@ -1260,6 +1327,12 @@ static int __init ubi_init(void) |
| } |
| } |
| |
| + /* auto-attach mtd devices only if built-in to the kernel and no ubi.mtd |
| + * parameter was given */ |
| + if (IS_ENABLED(CONFIG_MTD_ROOTFS_ROOT_DEV) && |
| + !ubi_is_module() && !mtd_devs) |
| + ubi_auto_attach(); |
| + |
| err = ubiblock_init(); |
| if (err) { |
| pr_err("UBI error: block: cannot initialize, error %d\n", err); |