Alrighty, so I got the UART working and came across something very similar to what you did.
When booting the image, I get this:
Scanning bootdev 'mmc@fe2b0000.bootdev':
1 script ready mmc 1 mmc@fe2b0000.bootdev.part /boot/boot.scr
** Booting bootflow 'mmc@fe2b0000.bootdev.part_1' with script
303 bytes read in 4 ms (73.2 KiB/s)
31076864 bytes read in 2604 ms (11.4 MiB/s)
13151992 bytes read in 1140 ms (11 MiB/s)
Failed to load '/boot/dtb/rockchip/rk3566-orangepi-3b-v2.1.dtb'
libfdt fdt_check_header(): FDT_ERR_BADMAGIC
So I’m guessing that your board is a v1.1 and mine is a v2.1 and it has detected the difference. But since the only dtb available has neither a v1.1 nor a v2.1 in the filename, it can’t find one to load.
I tried the steps you suggested, but that hit a snag:
=> load mmc 0 ${kernel_addr_r} /vmlinux z-6.10.6-edge-rockchip64
Card did not respond to voltage select! : -110
** Bad device specification mmc 0 **
Couldn't find partition mmc 0
Can't set block device
=>
No matter, my laptop is a Linux box (Zorin OS) with an SD Card slot so I just moved the SD Card over to my laptop, changed into the directory on the SD Card with the DTBs and did a:
sudo cp rk3566-orangepi-3b.dtb rk3566-orangepi-3b-v2.1.dtb
Ejected the SDCard, popped it in the OrangePi and tried again.
The good news:
It now booted up and I got output on my HDMI monitor
The bad news:
It looks like the rk3566-orangepi-3b.dtb is the one for the v1.1 board and so I’ve got all the same bugs that folks were reporting before. When the NIC didn’t grab a DHCP address I manually set the sync rate to 100M and was able to get an IP, but yeah this DTB is not the right one.
I did an additional test where I grabbed the rk3566-orangepi3b-v2.2.dtb from my working armbian/debian SDCard and copied it over. Despite both being debian bookworm it didn’t take. I didn’t get the missing file error, but instead it just freezes when it hits “loading kernel”.
So it looks like whatever fix @MichaIng did in this thread (Ethernet not working in the new version of Orange Pi 3B - #28 by MichaIng) or got rolled back or something.
On the bright side, if we can get his attention we now have someone with a v1.1 board and someone with a v2.1 board, both with UART cables… so we can do some troubleshooting to help iron out any issues!