Greetings
I am attempting to port LEDE/OpenWRT to a new device; the TRENDnet TEW-827DRU, which is a IPQ806X-based (AP148) system. It has a NAND flash for storage with a UBI (kernel + squashfs + ubifs).
When my system attempts to attach the UBI, I see the following error from linux:
[ 3.781181] ubi0: attaching mtd11 [ 3.835224] UBI: EOF marker found, PEBs from 40 will be erased [ 3.835384] ubi0: scanning is finished [ 3.840040] ubi0 error: ubi_read_volume_table: the layout volume was not found [ 3.844072] ubi0 error: ubi_attach_mtd_dev: failed to attach mtd11, error -22 [ 3.850897] UBI error: cannot attach mtd11
I took this to google and it turns out that Ram Chandra Jangir here had noted the same issue a few months back, and then I got lucky and saw his patches yesterday:
https://patchwork.ozlabs.org/patch/657285/ https://patchwork.ozlabs.org/patch/624733/
I emailed Ram and he sent me his boot log and it looks identical to mine, so I think it's the same issue. (thx again Ram!)
I tried re-flashing my UBI and tftpbooting my kernel before u-boot could ever get a chance to mangle it, and now I get much further, though I'm still not able to mount my rootfs for unknown reasons:
[ 3.772502] ubi0: attaching mtd11 [ 3.826477] UBI: EOF marker found, PEBs from 40 will be erased [ 3.826638] ubi0: scanning is finished [ 3.872936] ubi0: volume 2 ("rootfs_data") re-sized from 9 to 430 LEBs [ 3.873734] ubi0: attached mtd11 (name "rootfs", size 64 MiB) [ 3.878347] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [ 3.884234] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [ 3.890936] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096 [ 3.897849] ubi0: good PEBs: 512, bad PEBs: 0, corrupted PEBs: 0 [ 3.904627] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128 [ 3.910815] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 2142265782 [ 3.917902] ubi0: available PEBs: 0, total reserved PEBs: 512, PEBs reserved for bad PEB handling: 40 [ 3.927275] ubi0: background thread "ubi_bgt0d" started, PID 54 [ 3.937007] block ubiblock0_1: created from ubi0:1(rootfs) [ 3.942096] hctosys: unable to open rtc device (rtc0) [ 3.956528] VFS: Cannot open root device "ubi0:rootfs" or unknown-block(31,11): error -2 [ 3.956556] Please append a correct "root=" boot option; here are the available partitions:
Any advice on this? Any background information that I can read up on? My google searches have not come up with much. Ram knew about this, but I don't know if it's otherwise a known issue.
The process works fine on the OEM system, so I assume this is some ubinize format change which is incompatible with the older u-boot. Or, the newer kernel code doesn't know how to deal with the UBI once the older u-boot has mangled/attached it.
Seems like a backwards incompatibility issue.
Just to be clear, my kernel is inside the UBI, so u-boot must attach the UBI and read the volume to boot.
Rebuilding and replacing my u-boot is probably not possible for now, though I do have the OEM source. My device has a jtag, but I have not tested it and that's out of my league.
Additional info below:
--
My u-boot version: U-Boot 2012.07 [Standard IPQ806X.LN,r40331]
The old OEM ubinize is 1.2 from mtd-utils-1.4.5.
The old OEM kernel is 3.4.103. New kernel is 4.4.15.
LEDE built from commit 21f460a5dbef5e3ec59e2032b5b113fe045b475f
The new LEDE ubinize version is 1.5.2. The ubinize command (via LEDE's ubinize-image.sh script) to build my image was (paths truncated for readability):
ubinize-image.sh --kernel .../TEW827DRU-uImage .../root.squashfs .../lede-ipq806x-TEW827DRU-squashfs-factory.bin.tmp -p 128KiB -m 2048 -E 5
Notably the new LEDE ubinize command uses "-E 5" whereas the old OEM does not, but I don't think that's related.
The ubinize.ini file looked like:
[kernel] mode=ubi vol_id=0 vol_type=dynamic vol_name=kernel image=/.../TEW827DRU-uImage [rootfs] mode=ubi vol_id=1 vol_type=dynamic vol_name=rootfs image=/.../root.squashfs [rootfs_data] mode=ubi vol_id=2 vol_type=dynamic vol_name=rootfs_data vol_size=1MiB vol_flags=autoresize