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| author | Ezequiel Garcia <ezequiel.garcia@free-electrons.com> | 2014-02-25 13:25:22 -0300 |
|---|---|---|
| committer | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2014-02-28 16:29:48 +0200 |
| commit | 9d54c8a33eec78289b1b3f6e10874719c27ce0a7 (patch) | |
| tree | ba34d64d9dcc1b923f0556da5678ab854b4c529d /drivers/mtd/ubi/Kconfig | |
| parent | 5547fec74a566e1f5e00a937b9a367f7c6a94a8b (diff) | |
UBI: R/O block driver on top of UBI volumes
This commit introduces read-only block device emulation on top of UBI volumes.
Given UBI takes care of wear leveling and bad block management it's possible
to add a thin layer to enable block device access to UBI volumes.
This allows to use a block-oriented filesystem on a flash device.
The UBI block devices are meant to be used in conjunction with any
regular, block-oriented file system (e.g. ext4), although it's primarily
targeted at read-only file systems, such as squashfs.
Block devices are created upon user request through new ioctls:
UBI_IOCVOLATTBLK to attach and UBI_IOCVOLDETBLK to detach.
Also, a new UBI module parameter is added 'ubi.block'. This parameter is
needed in order to attach a block device on boot-up time, allowing to
mount the rootfs on a ubiblock device.
For instance, you could have these kernel parameters:
ubi.mtd=5 ubi.block=0,0 root=/dev/ubiblock0_0
Or, if you compile ubi as a module:
$ modprobe ubi mtd=/dev/mtd5 block=/dev/ubi0_0
Artem: amend commentaries and massage the patch a little bit.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Diffstat (limited to 'drivers/mtd/ubi/Kconfig')
| -rw-r--r-- | drivers/mtd/ubi/Kconfig | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig index 36663af56d89..783fb186d876 100644 --- a/drivers/mtd/ubi/Kconfig +++ b/drivers/mtd/ubi/Kconfig @@ -87,4 +87,19 @@ config MTD_UBI_GLUEBI work on top of UBI. Do not enable this unless you use legacy software. +config MTD_UBI_BLOCK + bool "Read-only block devices on top of UBI volumes" + default n + help + This option enables read-only UBI block devices support. UBI block + devices will be layered on top of UBI volumes, which means that the + UBI driver will transparently handle things like bad eraseblocks and + bit-flips. You can put any block-oriented file system on top of UBI + volumes in read-only mode (e.g., ext4), but it is probably most + practical for read-only file systems, like squashfs. + + When selected, this feature will be built in the UBI driver. + + If in doubt, say "N". + endif # MTD_UBI |