[BUG v1.4.6] `mtdinfo -u' confused by some RAM MTD devices (with a "bad" erasesize?)
brian.foster at maxim-ic.com
Fri Mar 16 09:39:29 EDT 2012
I was showing a colleague the ‘mtdinfo -u’ option,
and noticed some rather amusing output when querying
a RAM-type MTD device. This is mtd-utils v1.4.6 with
a v2.6.36 kernel and our own driver for the device:
# mtdinfo --version
# mtdinfo -u /dev/mtd1
Eraseblock size: 1 bytes
Amount of eraseblocks: 16384 (16384 bytes, 16.0 KiB)
Minimum input/output unit size: 1 byte
Sub-page size: 1 byte
Character device major/minor: 90:2
Bad blocks are allowed: false
Device is writable: true
Default UBI VID header offset: 64
Default UBI data offset: 128
Default UBI LEB size: -127 bytes
Maximum UBI volumes count: 128
A “default UBI LEB size” of “-1 bytes” ?!
● I have not investigated any further.
● I haven't tried a later version of mtd-utils.
● I cannot rule the possibility of a bork in our
driver (which is for special-purpose embedded
NVRAM on our chip, and really is only 16KiB).
● I haven't tried the generic mtdram driver, but
know its erasesize is always a multiple of 1KiB.
And I seriously doubt we'd ever try to use UBI or
UBIFS with this specialist 16KiB embedded NVRAM!
Principal MTS, Software | La Ciotat, France
Maxim Integrated Products | Web: http://www.maxim-ic.com/
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