Messages in this thread | | | Date | Tue, 17 Sep 2002 11:22:10 -0700 (PDT) | From | "Randy.Dunlap" <> | Subject | Re: Problems accessing USB Mass Storage |
| |
On Tue, 17 Sep 2002, Jonathan Corbet wrote:
| Don't know if this is helpful or not, but, based on my messing around with | SmartMedia USB stuff... | | SmartMedia cards are weird in that they have a (seemingly) random amount of | waste space at the beginning of the card. Your 8MB card, in particular, | has nothing of interest in the first 25 sectors. Some cards have a | reasonable partition table in the first sector, and some don't. Modern | Windows systems (and cameras, of course) seem to be able to access the | filesystem on the card without needing to see a partition table. | | A little while I posted a Lexar SmartMedia driver patch which hacked around | this by substituting a fake partition table when the first sector was read. | I'm not sure it's the right solution, though. A better way, perhaps, is a | little user-space program which writes the appropriate partition table | depending on the card capacity. Note that fdisk doesn't (easily) work for | this purpose, since it wants partitions to start on cylinder boundaries. | | You might try just using dd to copy your card to disk with an offset of 25 | sectors, and see of you can mount the resulting image. | | Then again, the interface to some SmartMedia readers is vastly more | complicated, as the sddr09 driver shows.
This is a bit like what we (JE, David Brownell, and I) saw at the USB plugfest in 1999. We had a camera device that we couldn't mount as a filesystem, but we could dd it. When we did that and studied the dd-ed file, we could see a FAT filesystem beginning after the first <N> blocks (but more than 25 sectors IIRC -- more like after 50-100 KB, or maybe even more).
-- ~Randy "Linux is not a research project. Never was, never will be." -- Linus, 2002-09-02
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |