Can't find correct configuration

Wed Sep 6 01:38:58 PDT 2023

Yes, you are right about the situation.
My partition for UBI is 248MiB.
So, the question remains - can this 8MB be utilized?
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).
> >>>>
> >>>
> >>> .
> >>>
> >>
> >
> > .
> >
>