Cubietruck upgrading issue

Sorry can't ssh into it because it's not booting up after I erased the previous configurations/packages with "firstboot" command and re-flashed the sd card with the new 18.06.2 image. Any idea why it's not booting?

Do you need some help to connect the console? I don't see any other way to find out what is wrong.

Any help is appreciated. I tried to connect a monitor to the HDMI port as well as the VGA port, a USB keyboard. The HDMI showed a message said "Press Enter to activate this console", but the USB keyboard looks not recognized by OpenWrt. It can still boot up the old 18.06.1 image after the "firstboot" command, but it will not boot the 18.06.2 image.

So you have an operational 18.06.1?
It works but you cannot upgrade to 18.06.2?

Yes that's right.

Can you try with the regular sysupgrade method?

There is no sysupgrade image for downloading.

Did you open the link?

sysupgrade works out of the box, using (at least) the ext4-sdcard.img.gz files.

I see some models have 4 different images for downloading, two of them are sysupgrade images. But for Cubietruck there is no sysupagrade image. Only 2 images for flashing. Tried to use the flashing image in sysupgrade but it's never successful. It stayed in the upgrading page forever. After 4 hours I rebooted the Cubietruck but it couldn't boot up. Has OpenWrt tested how to upgrade the Cubietruck board?

I presume you used sun7i-a20-cubietruck-ext4-sdcard.img.gz and verified the sha256sum before flashing.
What does the console show?

That's the image I used. The console just showed "Do not power off your router. Upgrading..." and stays there forever.

And the sha256sum was correct?

After you reboot what do you see on the serial console?

sha256 sum is correct. I used the web admin page. Not ssh or serial console.

When you upload the image for upgrade in Luci it shows the sha256sum before flashing. Did you verify it before hitting the flash button?

For now you can try to reflash the SD card or connect the serial console and see what is going on in there.

Did you flash the GZ file, or did you extract the IMG from the file and flash the IMG?

sha256 sum is verified. After using the "firstboot" command, reflashed 18.06.2 image but it didn't boot up. I used the img file for flashing, gz file for sysupgrade. both not working.

Also tried a brand new SD card to flash the 18.06.2 img file but still not booting up. Looks like the openwrt remembered something which can't be erased with the "firstboot" command.