linux/Documentation/ABI/testing/sysfs-class-mtd
Kevin Cernekee 19fe7f1a00 Documentation: add MTD sysfs docs
Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-29 15:13:04 +01:00

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What: /sys/class/mtd/
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
The mtd/ class subdirectory belongs to the MTD subsystem
(MTD core).
What: /sys/class/mtd/mtdX/
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
The /sys/class/mtd/mtd{0,1,2,3,...} directories correspond
to each /dev/mtdX character device. These may represent
physical/simulated flash devices, partitions on a flash
device, or concatenated flash devices. They exist regardless
of whether CONFIG_MTD_CHAR is actually enabled.
What: /sys/class/mtd/mtdXro/
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
These directories provide the corresponding read-only device
nodes for /sys/class/mtd/mtdX/ . They are only created
(for the benefit of udev) if CONFIG_MTD_CHAR is enabled.
What: /sys/class/mtd/mtdX/dev
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
Major and minor numbers of the character device corresponding
to this MTD device (in <major>:<minor> format). This is the
read-write device so <minor> will be even.
What: /sys/class/mtd/mtdXro/dev
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
Major and minor numbers of the character device corresponding
to the read-only variant of thie MTD device (in
<major>:<minor> format). In this case <minor> will be odd.
What: /sys/class/mtd/mtdX/erasesize
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
"Major" erase size for the device. If numeraseregions is
zero, this is the eraseblock size for the entire device.
Otherwise, the MEMGETREGIONCOUNT/MEMGETREGIONINFO ioctls
can be used to determine the actual eraseblock layout.
What: /sys/class/mtd/mtdX/flags
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
A hexadecimal value representing the device flags, ORed
together:
0x0400: MTD_WRITEABLE - device is writable
0x0800: MTD_BIT_WRITEABLE - single bits can be flipped
0x1000: MTD_NO_ERASE - no erase necessary
0x2000: MTD_POWERUP_LOCK - always locked after reset
What: /sys/class/mtd/mtdX/name
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
A human-readable ASCII name for the device or partition.
This will match the name in /proc/mtd .
What: /sys/class/mtd/mtdX/numeraseregions
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
For devices that have variable eraseblock sizes, this
provides the total number of erase regions. Otherwise,
it will read back as zero.
What: /sys/class/mtd/mtdX/oobsize
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
Number of OOB bytes per page.
What: /sys/class/mtd/mtdX/size
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
Total size of the device/partition, in bytes.
What: /sys/class/mtd/mtdX/type
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
One of the following ASCII strings, representing the device
type:
absent, ram, rom, nor, nand, dataflash, ubi, unknown
What: /sys/class/mtd/mtdX/writesize
Date: April 2009
KernelVersion: 2.6.29
Contact: linux-mtd@lists.infradead.org
Description:
Minimal writable flash unit size. This will always be
a positive integer.
In the case of NOR flash it is 1 (even though individual
bits can be cleared).
In the case of NAND flash it is one NAND page (or a
half page, or a quarter page).
In the case of ECC NOR, it is the ECC block size.