在arm板子中用：
ubiattach -m 25 -b 3 /dev/ubi_ctrl创建出/dev/ubi3_0
然后在用ubiblock --create /dev/ubi3_0去创建/dev/ubiblock3_0
一直报下面错误：
ubiblock: error!: UBI block is not present in the system
ubiblock: error!: cannot create block device
error 38 (Function not implemented)
```c
dmesg log：
ubi3: attaching mtd25
ubi3: scanning is finished
ubi3 warning: print_rsvd_warning: cannot reserve enough PEBs for bad PEB handling, reserved 12, need 40
ubi3: attached mtd25 (name "oemfs_b", size 42 MiB)
ubi3: PEB size: 262144 bytes (256 KiB), LEB size: 253952 bytes
ubi3: min./max. I/O unit sizes: 4096/4096, sub-page size 4096
ubi3: VID header offset: 4096 (aligned 4096), data offset: 8192
ubi3: good PEBs: 169, bad PEBs: 0, corrupted PEBs: 0
ubi3: user volume: 1, internal volumes: 1, max. volumes count: 128
ubi3: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 1360627509
ubi3: available PEBs: 0, total reserved PEBs: 169, PEBs reserved for bad PEB handling: 12
ubi3: background thread "ubi_bgt3d" started, PID 320
然后执行上述操作，就会报错。
内核配置defconfig中也将CONFIG_MTD_UBI_BLOCK相关的打开了，但是一直报错，可以指点一下，到底是那出现的问题吗？