Rock64 Debian 11 (Bullseye) install problem

[as365n4]

If you used the Debian Installer, you won't have U-Boot installed. Because the Installer is generic for all supported Boards, they do not install board specific U-Boot.
You have to install U-Boot in order to get Debian working.
Two options, either build U-Boot on device after Installer has finished and flash the SD-Card with U-Boot or use the files Debian provides:

/usr/lib/u-boot/rock64-rk3328/u-boot.bin
/usr/lib/u-boot/rock64-rk3328/idbloader.img

they are part of the package "u-boot-rockchip".

Hi,
I'm stuck just in this place. Can you help me to make my debian SD card bootable? I'm newbie and dont konw how to proceed with  two options you suggest.
Thanks in avance

a bit late but hope it will help others who searched for a solution...

As pointed out above the Debian Installer is kind of broken as it does not install u-boot and also does not partition the target correctly.
There are several options build your own image as decribed here
Or use an image from a different Distro and partition the target and install u-boot and then use the Debian Installer without reformating the drive, as others suggested.

Myself as I had no luck with the Debian Installer, I always build my own image if I have to flash a Rock64 or H64B.
Also worth a note, the Debian Installer offers a shell which one could access and do comand line work, but the included BusyBox has a very limited amount of comands available.

With regards to partitioning the first 32767 sectors of the SD-Card or eMMC-Module are reserved for u-boot on any Rockchip based Board!
Your partitions need to start after or on sector 32768, otherwise you will end up with a brocken partition as the u-boot flash does not care about your partitions and may overwrite your data if you used any sector before 32767.