Always check the pinned thread on this forum: Single Armbian image for RK + AML + AW (aarch64 ARMv8)
These instructions are in that post:
1. Take for example this desktop.img from Sep. 24: Armbian_20.09_Arm-64_focal_current_5.8.10_desktop.img.xz I've had really good results with 20.09 ubuntu focal & debian bullseye images.
2. now burn it to a usb with the program https://www.balena.io/etcher/
After it's done you're going to see 2 Partitions appear - you want to open the one says /BOOT.
3. Create your u-boot: Find this file: "u-boot-s905x2-s922" Copy and paste it with a new name of "u-boot.ext". It in fact works for s905x3 too.
4. Now inside /BOOT/dtb/amlogic these are your "Device Tree Binaries". Kernel uses it to detect all your hardware. The Trial and error part is finding the right one that makes your hardware work.
Scroll to the bottom you'll see 'meson-sm1-sei610.dtb' rforcen is talking about Normally you have to copy & past .dtb files into this directory. But for now try that one!
5. Configure your 'extlinux.conf'. Edit /extlinux/extlinux.conf and comment out or delete every line for other boards. Near the end you want to uncomment FDT & APPEND for '# aml s9xxx' put in your dtb file from step 4.
I have a very minimalist one looks like this:
# aml s9xxx
APPEND root=LABEL=ROOTFS rootflags=data=writeback rw console=ttyAML0,115200n8 console=tty0 no_console_suspend consoleblank=0 fsck.fix=yes fsck.repair=yes net.ifnames=0
Now All you have to is try to use a 'toothpick' to make it boot from external media! Search Google see if your box has a "Hidden" recovery button inside the Audio Jack? most do, but some have it more visibly outside. Press it with power unplugged. When you plug it in, keep holding it down until after you see your device's Logo. I hold it about 6 sec after that. When you release it, the logo will go dark, and it's going into Armbian's boot process. Now it will reboot several times while it sets things up. Give it few minutes and you should have a running Armbian!
If this fails: try dtb files from earlier in this thread. I found almotra's list very helpful! And try different images, try a server only image instead.
Note: Only run from external media. Do NOT try to install to eMMC yet! it will brick your device. Take a backup with `ddbr`