OESF Portables Forum

Everything Else => Sharp Zaurus => Model Specific Forums => Distros, Development, and Model Specific Forums => Archived Forums => Cxx0 Hardware => Topic started by: Luke-Jr2 on August 08, 2004, 10:40:49 pm

Title: I/O errors
Post by: Luke-Jr2 on August 08, 2004, 10:40:49 pm

I recently began looking into finally installing OpenZaurus/Opie on my C760... First, however, I want to back it up...
dd-ing to my PC via netcat shows a ton of:
 . . . dd: /dev/mtd3: Input/output error
In the kernel log, there's lots of:
 . . . sharp_sl_nand_read_ecc: Failed ECC read, page 0x0002ffe0
Via the service menu, there's a flash tester... it suggests 1 byte is bad.

The errors begin around when there is 37 MB saved on my PC and continue until about ... well, it doesn't stop... =p

Is this semi-normal (like bad pixels) and likely to have been there when I got it? Will the Z workaround the bad area and continue to function with just a bit less flash space?
Will installing another ROM (C860 or OZ) be risking making my Z unusable as a result?
On a side topic, am I even backing up the proper device (mtd0-3) or should I be looking elsewhere to get an entire backup?

Thanks

Title: I/O errors
Post by: waalkman on August 10, 2004, 10:37:57 pm

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...The errors begin around when there is 37 MB saved on my PC and continue until about ... well, it doesn't stop... =p

I imagine it looked pretty bad  


It's normal to encounter bad bytes on a flash card, in fact the manufacturer expects them. However, dd doesn't  

I suggest that you try something other than dd.

Quote

Is this semi-normal (like bad pixels) and likely to have been there when I got it? Will the Z workaround the bad area and continue to function with just a bit less flash space?

Yes this entirely normal and is to be expected. And I think that the driver for the card does the error checking and the mapping of bad bytes (as opposed to being done in hardware).

Quote

Will installing another ROM (C860 or OZ) be risking making my Z unusable as a result?

Nope. Not because of that anyways. But be careful as to what you write into these areas. That could easily make it a shiny new paperweight. I would be scared to death of trying to write back what I dd'ed out.

So if you are talking about writing what you dd'ed out back in, then I certainly wouldn't. But I like the intent of your idea, it would be nice to have a utility to make a mirror image of the Z so that you could try out a new ROM without having to rebuild the entire thing from scratch (anybody know of a utility that does this?).

Quote

On a side topic, am I even backing up the proper device (mtd0-3) or should I be looking elsewhere to get an entire backup?

I suppose that would get just about all of it. Anybody else know?


A little light reading:

http://www.linux-mtd.infradead.org/ (http://www.linux-mtd.infradead.org/)


John

Title: I/O errors
Post by: ThC on August 11, 2004, 09:19:43 am

Quote

it would be nice to have a utility to make a mirror image of the Z so that you could try out a new ROM without having to rebuild the entire thing from scratch (anybody know of a utility that does this?).

Sharp did include such a tool in their maintenance (on+D+M) menu ... known as NAND backup and restore

Title: I/O errors
Post by: waalkman on August 12, 2004, 04:20:03 am

Quote

Sharp did include such a tool in their maintenance (on+D+M) menu ... known as NAND backup and restore

Just call me chicken but I put the service menu in the "There be dragons" catagory.

(But you are absolutely right, shame on me  )


John