Can't find correct configuration

Wed Sep 6 01:53:18 PDT 2023

在 2023/9/6 16:38, Leon Pollak 写道:
> Yes, you are right about the situation.
> My partition for UBI is 248MiB.
> So, the question remains - can this 8MB be utilized?

Yes, it can.

> Or are they already in use by UBI which sees partition size?
> 
> 
> On Wed, 6 Sept 2023 at 10:34, Zhihao Cheng <chengzhihao1 at huawei.com> wrote:
>>
>> 在 2023/9/6 15:27, Leon Pollak 写道:
>>> I work on embedded device. The rest of the NAND is used for SPL,
>>> U-Boot, U-Boot environment and kernel.
>>> What is left is 248MiB.
>>> I am not sure I can use the whole space for UBI - how will the SPL/U-Boot work?
>>
>> Do you mean UBI and uboot are put into same flash(256M)? If so, your
>> partitioning method is right.
>>
>> 8M(mtd0) - uboot
>> 248M(mtd1) - UBI
>>
>> UBI won't access mtd0.
>>
>>
>>>
>>> On Wed, 6 Sept 2023 at 10:21, Zhihao Cheng <chengzhihao1 at huawei.com> wrote:
>>>>
>>>> 在 2023/9/6 14:57, Leon Pollak 写道:
>>>>> Thousands of thanks, Zhihao Cheng!!!
>>>>> It worked exactly as you wrote.
>>>>> The only question remained is:
>>>>> My partition size is 248MiB.
>>>>> I thought that leaving 8MiB "spare' will be used just for these
>>>>> reserved PEBs, but now I understand this was incorrect.
>>>>> So, may I utilize these 8MiB back or will they still be used by UBI
>>>>> for something?
>>>>>
>>>>
>>>> I believe you have two mtd devices, 248M(mtd0 for ubi) and 8M(reserved,
>>>> won't be accessed by UBI) now. Please don't split the 256M into two mtd
>>>> devices if you only need 1 UBI device, just format the whole flash(256M)
>>>> into UBI, and UBI itself will handle its reservation without user
>>>> intervening.
>>>>
>>>>> On Wed, 6 Sept 2023 at 05:50, Zhihao Cheng <chengzhihao1 at huawei.com> wrote:
>>>>>>
>>>>>> 在 2023/9/6 10:42, Zhihao Cheng 写道:
>>>>>>> 在 2023/9/5 22:45, Leon Pollak 写道:
>>>>>>> Hi
>>>>>>>> Hello, all.
>>>>>>>> I will be very very thankful for the help to find the correct
>>>>>>>> configuration for my NAND.
>>>>>>>> I passed through a lot of mails in the lists and google and ChatGPT -
>>>>>>>> no success.
>>>>>>>> I have 256MB NAND and 248MB partition for UBIFS. I run:
>>>>>>>> mkfs.ubifs -v -r rootfs -F -m 2048 -e 126976 -c 1981 -o ./ubifs.img
>>>>>>>> ubinize -v -o rootfs.img -m 2048 -p 128KiB -s 512 -O 2048 ubinize.cfg
>>>>>>>> -----
>>>>>>>> and ubinize.cfg looks like:
>>>>>>>> [ubifs]
>>>>>>>> mode=ubi
>>>>>>>> image=./ubifs.img
>>>>>>>> vol_id=0
>>>>>>>> vol_size=240MiB
>>>>>>>> vol_type=dynamic
>>>>>>>> vol_name=ubi_rootfs
>>>>>>>> vol_alignment=1
>>>>>>>> vol_flags=autoresize
>>>>>>>> ------
>>>>>>>> Kernel configuration  was with CONFIG_MTD_UBI_BEB_LIMIT=20.
>>>>>>>> and here is the kernel log:
>>>>>>>> [    2.695659] ubi0: attaching mtd4
>>>>>>>> [    3.372343] ubi0: scanning is finished
>>>>>>>> [    3.383066] ubi0 warning: ubi_eba_init: cannot reserve enough PEBs
>>>>>>>> for bad PEB handling, reserved 4, need 40
>>>>>>>> [    3.404320] ubi0: volume 0 ("ubi_rootfs") re-sized from 1982 to
>>>>>>>> 1982 LEBs
>>>>>>>> [    3.411667] ubi0: attached mtd4 (name "FS", size 248 MiB)
>>>>>>>> [    3.417095] ubi0: PEB size: 131072 bytes (128 KiB), LEB size:
>>>>>>>> 126976 bytes
>>>>>>>> [    3.424006] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page
>>>>>>>> size 512
>>>>>>>> [    3.430740] ubi0: VID header offset: 2048 (aligned 2048), data
>>>>>>>> offset: 4096
>>>>>>>> [    3.437734] ubi0: good PEBs: 1990, bad PEBs: 0, corrupted PEBs: 0
>>>>>>>> [    3.443860] ubi0: user volume: 1, internal volumes: 1, max. volumes
>>>>>>>> count: 128
>>>>>>>> [    3.451117] ubi0: max/mean erase counter: 1/0, WL threshold: 4096,
>>>>>>>> image sequence number: 1590570073
>>>>>>>> [    3.460295] ubi0: available PEBs: 0, total reserved PEBs: 1990,
>>>>>>>> PEBs reserved for bad PEB handling: 4
>>>>>>>> [    3.469575] ubi0: background thread "ubi_bgt0d" started, PID 131
>>>>>>>> [    4.648718] UBIFS (ubi0:0): background thread "ubifs_bgt0_0"
>>>>>>>> started, PID 136
>>>>>>>> [    4.676640] UBIFS (ubi0:0): start fixing up free space
>>>>>>>> [   10.250099] UBIFS (ubi0:0): free space fixup complete
>>>>>>>> [   10.269046] UBIFS (ubi0:0): UBIFS: mounted UBI device 0, volume 0,
>>>>>>>> name "ubi_rootfs"
>>>>>>>> [   10.276830] UBIFS (ubi0:0): LEB size: 126976 bytes (124 KiB),
>>>>>>>> min./max. I/O unit sizes: 2048 bytes/2048 bytes
>>>>>>>> [   10.286794] UBIFS (ubi0:0): FS size: 250142720 bytes (238 MiB, 1970
>>>>>>>> LEBs), journal size 9023488 bytes (8 MiB, 72 LEBs)
>>>>>>>> [   10.297540] UBIFS (ubi0:0): reserved for root: 0 bytes (0 KiB)
>>>>>>>> [   10.303406] UBIFS (ubi0:0): media format: w4/r0 (latest is w5/r0),
>>>>>>>> UUID A14D586A-32E2-45D7-A07E-BDC472FDF31D, small LPT model
>>>>>>>>
>>>>>>>> My question is: why does this warning about reserved 4, needed 40
>>>>>>>> appear? How can I solve this?
>>>>>>>>
>>>>>>>
>>>>>>> Solution: Modify ubinize.cfg,  vol_size=240MiB -> vol_size=235MiB
>>>>>>>
>>>>>>> Why does this warning about reserved 4, needed 40 appear?
>>>>>>> The count of bad PEBs reserved by UBI is: total_pebs(nand chip) *
>>>>>>> CONFIG_MTD_UBI_BEB_LIMIT/1024 = 2048 *  20 / 1024 = 40
>>>>>>> When fastmap is not enabled, the count of internal PEBs reserved by UBI
>>>>>>> is: UBI_LAYOUT_VOLUME_EBS[2] + WL_RESERVED_PEBS[1] +
>>>>>>> EBA_RESERVED_PEBS[1] = 4
>>>>>>>
>>>>>>> Total PEBs for UBI is 1990(good PEBs: 1990), the max count of user
>>>>>>> volume PEBs is 1990 - 40 - 4 = 1946
>>>>>>>
>>>>>>> In ubinize.cfg, vol_size=240MiB, the count of user volume PEBs is(see
>>>>>>> ubinize.c in mtduitls): vi_size + (leb_size - 1) / leb_size
>>>>>>> vi_size = 240M = 240 * 1024 * 1024
>>>>>>> leb_size = 128K - 2K(ec) - 2K(vid) = 124 * 1024
>>>>>>> result = 1982
>>>>>>>
>>>>>>> So there are 1990 - 1982 - 4 = 4 PEBs reserved for bad PEB handling,
>>>>>>> which is less than 40.
>>>>>>>
>>>>>>> When we set  vol_size=235MiB, the count of user volume PEBs is: (235 *
>>>>>>> 1024 * 1024 + 124 * 1024 - 1) / (124 * 1024) = 1941
>>>>>>> 1990 - 4 - 40 = 1946, finally maybe there is message from kernel like
>>>>>>> "("ubi_rootfs") re-sized from 1941 to 1946 LEBs".
>>>>>>
>>>>>> Acutally, the 'vol_size' in ubinize.cfg means the size of data on
>>>>>> volume(exclude vid/ec), not the size of volume(include vid/ec).
>>>>>>
>>>>>
>>>>> .
>>>>>
>>>>
>>>
>>> .
>>>
>>
> 
> .
> 