UBI support

[Sascha Hauer]

Hi Baruch,

On Thu, Jul 08, 2010 at 12:19:25PM +0300, Baruch Siach wrote:
> Hi Sascha,
> 
> On Mon, Jul 05, 2010 at 03:16:23PM +0200, Sascha Hauer wrote:
> > The following series prepares and implements UBI for barebox. Here is a log
> > while playing with UBI:
> 
> I've tested this on our i.MX25 board. Here's what I get:
> 
> barebox:/ ubiattach /dev/nand0.rootfs
> UBI: attaching mtd0 to ubi0
> UBI: physical eraseblock size:   131072 bytes (128 KiB)
> UBI: logical eraseblock size:    129024 bytes
> UBI: smallest flash I/O unit:    2048
> UBI: sub-page size:              512
> UBI: VID header offset:          512 (aligned 512)
> UBI: data offset:                2048
> UBI: empty MTD device detected
> UBI: create volume table (copy #1)
> UBI error: ubi_scan_get_free_peb: no eraseblocks found
> failed to attach: error 28

I just tested it on an i.MX35 board which should have the same Nand
Controller as the i.MX25. I have never seen Nand devices with a subpage
size smaller than the I/O unit size (sub-page size: 512), so I would
start looking there.
I don't know how this subpage size is handled. It may well be that this
is a bug in the Nand driver and not UBI.
You could also go through 'git log drivers/mtd/ubi' in the kernel to see
if there's something relevant. Unfortunately I don't know from which
kernel version the U-Boot UBI code was derived from.

Sascha


> 
> The kernel is able to attach the same device as follows:
> 
> UBI: attaching mtd3 to ubi0
> UBI: physical eraseblock size:   131072 bytes (128 KiB)
> UBI: logical eraseblock size:    129024 bytes
> UBI: smallest flash I/O unit:    2048
> UBI: sub-page size:              512
> UBI: VID header offset:          512 (aligned 512)
> UBI: data offset:                2048
> UBI: attached mtd3 to ubi0
> UBI: MTD device name:            "rootfs"
> UBI: MTD device size:            122 MiB
> UBI: number of good PEBs:        975
> UBI: number of bad PEBs:         1
> UBI: max. allowed volumes:       128
> UBI: wear-leveling threshold:    4096
> UBI: number of internal volumes: 1
> UBI: number of user volumes:     1
> UBI: available PEBs:             0
> UBI: total number of reserved PEBs: 975
> UBI: number of PEBs reserved for bad PEB handling: 9
> UBI: max/mean erase counter: 1/0
> UBI: image sequence number: 1519924105
> UBI: background thread "ubi_bgt0d" started, PID 852
> 
> Where should I look to diagnose this?
> 
> baruch
> 
> -- 
>                                                      ~. .~   Tk Open Systems
> =}------------------------------------------------ooO--U--Ooo------------{=
>    - baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
> 

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