error!: "/dev/ubi0" is not a character device ?!?

[Arno Steffen]

2010/8/6 twebb <taliaferro62 at gmail.com>:
>>
>> cat /proc/devices give me back, that  (252 ubi8) is a character device.
>> But looking above, in /dev it is listed as block device !?!
>>
>> For me creating entries are not transparent, this happend with
>> ubiattach. No idea how to force ubiattach to write ubi8 in the
>> devicelist as character device.
>> Best regards
>> Arno
>>
>
> Have you gotten anywhere on this problem?  I have looked and have not
> found the udev rules anywhere.
>
> Thanks,
> twebb
>

Sorry for delay, have been out of office.
Haven't found neither /etc/udev nor /lib/udev on my embedded system.
udev is not mention in dmesg | grep udev
But after creating /etc/udev/rules/10-udev.rules I could see this in
 cat /dev/udev/rules.d/10-udev.rules
As I don't have any idea what rule I have to write in I left it blank.
So no success with this method

Other way like in : free-electrons.com/doc/training/embedded-linux/slides.pdf

cat /sys/class/ubi/ubi0/dev
252:0
rm /dev/ubi0
mknod /dev/ubi0 c 252 0
ll /dev/ubi*
crw-r--r--    1 root     root     252,   0 Jan  1 00:04 /dev/ubi0
crw-rw----    1 root     root      10,  63 Jan  1 00:00 /dev/ubi_ctrl

-> looks good so far. But finally I am screwed:

ubimkvol /dev/ubi0 -N test -m
Set volume size to 9805824UBI error: ubi_io_write: error -5 while
writing 512 bytes to PEB 81:512, written 0 bytes

UBI warning: ubi_eba_write_leb: failed to write VID header to LEB
2147479551:0, PEB 81
UBI: run torture test for PEB 81
UBI: try another PEB
UBI error: ubi_io_write: error -5 while writing 512 bytes to PEB
0:512, written 0 bytes
UBI warning: ubi_eba_write_leb: failed to write VID header to LEB
2147479551:0, PEB 0
UBI: try another PEB
UBI error: ubi_io_write: error -5 while writing 512 bytes to PEB
80:512, written 0 bytes
UBI warning: ubi_eba_write_leb: failed to write VID header to LEB
2147479551:0, PEB 80
UBI: try another PEB
UBI error: ubi_io_write: error -5 while writing 512 bytes to PEB
79:512, written 0 bytes
UBI warning: ubi_eba_write_leb: failed to write VID header to LEB
2147479551:0, PEB 79
UBI warning: ubi_ro_mode: switch to read-only mode
UBI error: ubi_io_write: read-only mode
UBI error: ubi_create_volume: cannot create volume 0, error -30
ubimkvol: error!: cannot UBI creUBI error: erase_worker: failed to
erase PEB 81, error -30
ate volume
          error 30 (UBI error: do_work: work failed with error code -30
Read-only file system)
[root at ViUBI error: ubi_thread: ubi_bgt0d: work failed with error code -30
sor:/]#