OpenWrt/LEDE Project

  • Status Closed
  • Percent Complete
  • Task Type Bug Report
  • Category Base system
  • Assigned To No-one
  • Operating System All
  • Severity Low
  • Priority Very Low
  • Reported Version openwrt-19.07
  • Due in Version Undecided
  • Due Date Undecided
  • Private
Attached to Project: OpenWrt/LEDE Project
Opened by Kai Schug - 17.03.2020
Last edited by Petr Štetiar - 25.04.2020

FS#2907 - kernel panic WNDAP660 / apm821xx

similar error like  FS#1516  device with NAND bad block here at 0×00480000 kernel panic after flashing 19.07.2

2nd device without a NAND bad block works without problem

<\n>[ 12.941706] UBI error: no valid UBI magic found inside mtd4<\r>
<\n>[ 13.008591] hctosys: unable to open rtc device (rtc0)<\r>
<\n>[ 13.069865] VFS: Cannot open root device “ubiblock0_0” or unknown-block(0,0): error -6<\r>
<\n>[ 13.164830] Please append a correct “root=” boot option; here are the available partitions:<\r>
<\n>[ 13.265012] 1f00 1024 mtdblock0 <\r>
<\n>[ 13.265014] (driver?)<\r>
<\n>[ 13.343332] 1f01 64 mtdblock1 <\r>
<\n>[ 13.343333] (driver?)<\r>
<\n>[ 13.421660] 1f02 27392 mtdblock2 <\r>
<\n>[ 13.421661] (driver?)<\r>
<\n>[ 13.499988] 1f03 4032 mtdblock3 <\r>
<\n>[ 13.499989] (driver?)<\r>
<\n>[ 13.578316] 1f04 23360 mtdblock4 <\r>
<\n>[ 13.578317] (driver?)<\r>
<\n>[ 13.656645] 1f05 64 mtdblock5 <\r>
<\n>[ 13.656646] (driver?)<\r>
<\n>[ 13.734972] 1f06 4096 mtdblock6 <\r>
<\n>[ 13.734974] (driver?)<\r>
<\n>[ 13.813301] 1f07 128 mtdblock7 <\r>
<\n>[ 13.813303] (driver?)<\r>
<\n>[ 13.891630] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)<\r>


Closed by  Petr ┼átetiar
25.04.2020 12:38
Reason for closing:  Won't fix
Additional comments about closing:  

HW issue.

Project Manager
Christian Lamparter commented on 21.03.2020 10:29


yeah this is a common problem with bad blocks. From what I remember, this is caused by the different bad-block mitigations between u-boot and the linux kernel. What you could try (apart from replacing the nand chip): follow the "boot initramfs" instructions on the bad device and get to the openwrt root shell.

from there: Upload the openwrt's sysupgrade.bin image to the router to /tmp/
use mtd erase on the "ubi" partition (should be mtd4, but check with /proc/mtd) just to be sure (actually this would be optional) and then initialize the mtd with ubiformat /dev/mtd4 and use sysupgrade -n /tmp/sysupgrade.bin and let it reboot.

(Basically, these are the same instructions from the installation process from different routers that didn't have UBI and use initramfs for the installation. You can find more of
the same if you browse through the git commit history)

Kai Schug commented on 22.03.2020 05:04

solution like proposed by mk24 in a similar case: different block size for WNDAP !


Available keyboard shortcuts


Task Details

Task Editing