I know normally openwrt has no default root password but somehow it's asking me a real root password. I mean not the blank password.
I downloaded the file twice and verified its sha256sum. I even tried formatting my microsd card more than once. But it still asks for password on first boot, so I can't login to LuCi or connect via ssh.
No such problem on 19.07.7 btw. I guess only for 21.02 RC2.
The password file most likely is on the second parition that is formatted with ext2 (my guess haven't used openwrt on the Pi) and OS X stupidly can not read ext2 natively. Suggest to fireup virtualbox with a Linux OS that will allow you to read it.
Or you can connect SD Card reader to the Pi when you boot from another SD card to check this card from the Pi.
I think you are right guys. I guess my microsd card is "dirty" from previous uses somehow. Exactly like as you said. I should clean it before retry.
So how can I do that on ubuntu? Like this one? I'm not sure how to do that. sudo dd if=zero of=/dev/mmcblk