OpenWrt 21.02.2 image and NAND change to squashfs+ubifs

Hi all,

An OpenWrt 21.02.2 image is now available.

μVirt has also been updated, see the images directory here.

NAND root filesystem change
In this version, we have changed the NAND version to use a SquashFS overlay for / instead of directly using ubifs. This means you will be able to ‘restore to factory defaults’ (aka firstboot), and it should be more robust to power cuts and other interruptions.

We would like to do something similar (including A/B booting) for disk based OpenWrt installs but that is far down the priority list at the moment.

This requires a change in the bootargs for OpenWrt NAND:

root=/dev/ram0 earlycon ubi.mtd=ubi${openwrt_active_sys}


root=/dev/ubiblock0_1 earlycon ubi.mtd=ubi${openwrt_active_sys}

I recommend NAND users make a backup of their configuration and then install firmware v0.8.10, which includes this build of OpenWrt.
(This release is specifically to implement the NAND change, everyone else can remain on v0.8.9)

Alternatively, you can update your U-Boot environment:

setenv bootcmd_openwrt_nand 'ubi part ubi${openwrt_active_sys} && ubi read $load_addr kernel && setenv bootargs "console=ttyS0,115200 root=/dev/ubiblock0_1 earlycon ubi.mtd=ubi${openwrt_active_sys}" && mtd read dpl 0x80100000 && fsl_mc apply DPL 0x80100000 && bootm $load_addr#ten64'

(The single quotes / ' are important, otherwise U-Boot will immediately evaluate ${openwrt_active_sys} to its current value)

Upstream status
For those interested, I opened a pull request to add EFI support to OpenWrt’s armvirt (which will likely be renamed to genericarm or similar after this). Hopefully it will be a part of OpenWrt 22.x.

(This pull does not contain NAND support or some very specific features such as DPAA2 passthrough, but otherwise it is functionally the same as the arm64/efi images we have been publishing)


I have just installed the firmware plus NAND OpenWrt image, did the successful settings recovery from commandline, no hiccups.

This version gives me much faster 4G speeds (Quectel EM06), so worth the effort.

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