Keeps booting from EMMC

Hi all,

Recently a 2 GB version of the Radxa Zero arrived.
I have flashed an uSD card and put it in the Zero, to boot it.
However, it keeps booting android 9, which is probably installed on the EMMC.
How can I remove this version?
How can I replace it with other software?

Thanks in advance,


I tried holding the usb boot button for a while, but now the system doesn’t boot anymore.
It only shows the s905Y2 logo…

I’d guess the distro image you’re trying to use is not detected via the u-boot bootscripts so it falls-thru back to Android. You can exorcise vendor u-boot from eMMC with:

echo 0 > /sys/block/mmcblk1boot1/force_ro
echo 0 > /sys/block/mmcblk1boot0/force_ro
dd if=/dev/zero of=/dev/mmcblk1 bs=1m count=10

If the distro image has it’s own u-boot then it should now boot from SD (as we just erased the first 10MB of emmc). If you need vanilla u-boot you can use which is 2021.07 with some patches to support the zero.

If the goal is to make something work with the vendor u-boot you’ll need to share UART output so people can see where things go wrong.

1 Like

thanks for your reply!

How can I read the UART output, is it on the gpio pins?

And my OS is Windows, is there a way to put that piece of code to there? In other words; how and where do i put that piece of code into?

My ‘goal’ is to put linux on it (such as the Manjaro image) and write / edit a script such as Copypi;
so that I can backup anything. A Radxa Zero with usb-c to usb 3.0 dongle and some LED’s connected to show the completion of backups to a different medium.


See for the UART connection. If you want to put Manjaro on the board I’d erase vendor u-boot (use mine) and it should find their bootscript without any problems. If you need a dtb file there is one in which should work with Linux 5.12+

If you sudo dd if=u-boot.bin of=/dev/sdx bs=512 seek=1 from the chewit mentioned then if a sd card is in it will boot from sd or not boot from emmc.

Just download from and install fastboot on a linux machine and sudo pip3 install pyamlboot

or its the but as chewit said all the info is in the 1st document