I have created a new ubifs.img by cross-compiling the source code. By following instructions from https://github.com/IMGCreator/openwrt/README.md I have flashed the NAND firmware1 partition with the new ubifs.img and set boot_paratiotion parameter to 1. However, during boot I get the following error
VFS: Cannot open root device “ubi0:rootfs” or unknown-block(0,0): error -19.
We’re looking into what may have gone wrong, but it could be one of many different things. Could you please try following the instructions for flashing NAND from within OpenWrt (from the same document)? That page has been updated recently so be sure to refresh it if you have left it open. If you flash the partition from there and it still does not work, it points to it being a problem with the image itself rather than the NAND flash mechanism.