Big thanks to Balbes, perfect work!
I own a MXQ PRO max. This box looks like SCISHION AI ONE / RX4B. (rk3328, 4gb ram, 32gb emmc, 100mbit lan, 2.4ghz wlan, bt)
Goal: Use box as thin client (vnc, rdp,...) using armbian/ubuntu desktop istalled on emmc.
With Balbes newest image and jeanrhrum hints (https://forum.armbian.com/topic/8082-armbian-for-tv-box-rk3328/?do=findComment&comment=68975) i am able to make the box boot armbian from sd card. (SD card booting is not reliable. In many cases the box ignores the sd and boots Android. After a number of restarts the box boots from sd to Bionic desktop. I did not find the root cause, but i suspect the problem be around psu / sd card / timing. As soon as sd boot is detected, armbian boots and works very reliable)
/boot/extlinux/extlinux.conf
LABEL Armbian
LINUX /Image
INITRD /uInitrd
FDT /dtb/rockchip/rk3328-box.dtb
APPEND root=LABEL=ROOTFS rootflags=data=writeback rw console=uart8250,mmio32,0xff130000 console=tty0 no_console_suspend consoleblank=0 fsck.fix=yes fsck.repair=yes net.ifnames=0
Using this dtb: lan and spdif work well, i did not go into details with bt, wifi.
I find:
armbian@rk3328:~$ ls /dev/mmc*
/dev/mmcblk0 /dev/mmcblk0p2 /dev/mmcblk2boot0 /dev/mmcblk2rpmb
/dev/mmcblk0p1 /dev/mmcblk2 /dev/mmcblk2boot1
armbian@rk3328:~$
I was able to backup emmc (/dev/mmcblk2) to an external usb disk drive using dd. I could not use the ddbr script (sd card too small, forced into zip mode even though plenty of space on external drive)
Now, I would like to extract the device tree from android image to optimize for bt, wifi and possibly access the 7-segment display of the box.
How can I get access to androids device tree file? Could I mount /dev/mmcblk2boot<x> somehow?
Any hints on this? Best,
Markus