running out of space dd'ing JFFS2 image to /dev/mtdblock/0

[Robert P. J. Day]

On Mon, 31 Jan 2005, Artem B. Bityuckiy wrote:

> On Mon, 31 Jan 2005, Robert P. J. Day wrote:

> >   ah, excellent, but while we're on the subject of parameters, is
> > there any hope of getting some consistency in the way parameter values
> > are supplied across the world of JFFS2 and MTD?
> >
> >   to wit, with "mkfs.jffs2":
> >
> > -p, --pad[=SIZE] Pad output to SIZE bytes with 0xFF. If SIZE is
> >                         not specified, the output is padded to the
> > 			end of the final erase block
> >
> >
> >   so, apparently, you supply an *exact* byte size here (it's not
> > mentioned if you can use KiB or MiB prefixes).
> >
> >   with "--pagesize" and "--eraseblock", the help states that you *can*
> > use those prefixes.
> >
> >   if you check what you can do with the mtdram module, you get:
> >
> > $ modinfo mtdram
> > filename:
> > /lib/modules/2.6.10-1.741_FC3/kernel/drivers/mtd/devices/mtdram.ko
> > parm:           total_size:Total device size in KiB
> > parm:           erase_size:Device erase block size in KiB
> >
> >   so the values here are ... what?  strictly in KiB?  so i'd supply
> > something like
> >
> >   total_size=16384
> >
> > to specify 16M?  it's just a bit painful to jump around between the
> > various utilities and have to keep remembering what the standard is.
> >
> >   thoughts?

> My thought that if you sent patch that fixes this inconsistency it
> will be nice. :-)

first, it's necessary to define a simple standard, so what about
something like the following?  any size values in *any* of the
JFFS2-related programs shall be in one of the following formats:

  ###		(interpreted as bytes)
  ###KiB	(obvious)
  ###MiB	(obvious)

at the moment, this is not being followed.  for instance, mkfs.jffs2
has the --pad=SIZE option, where a simple number is treated as KiB.
anyway, you get idea -- it's pretty confusing.

so, do we at least have some agreement on a standard?  which would
hold across *all* programs and modules?  i'm not even going to
*consider* looking at patches to do this unless i'm convinced everyone
agrees, since changes like this will clearly force people to change
the way they do some things.  and i know how fond some people are of
*that* idea. :-)

rday