Which FreeBSD image file should be used in conjunction with idbloader.img and u-boot.itb ?

Hello to everyone.

I was going to build a custom u-boot for my project (I want to use the
Radxa 3W for building a FreeBSD based smartphone) and look at what I see in
the ports tree…

sysutils/u-boot-radxa-zero3
<http://www.freshports.org/sysutils/u-boot-radxa-zero3>


So for u-boot I tried :


pkg install -y u-boot-radxa-zero3



> Then ` cd /usr/local/share/u-boot/u-boot-radxa-zero3`



> Then ` cat README`



> dd if=idbloader.img of=/dev/daX seek=64 bs=512 conv=sync dd if=u-boot.itb
> of=/dev/daX seek=16384 bs=512 conv=sync


So,I tried to “burn” the bootloaders file inside the official FreeBSD image
for the RockPro64,doing something like this :


# dd if=idbloader.img of=FreeBSD-14.2-RELEASE-arm64-aarch64-ROCKPRO64.img
> seek=64 bs=512 conv=sync,notrunc # dd if=u-boot.itb
> of=FreeBSD-14.2-RELEASE-arm64-aarch64-ROCKPRO64.img seek=16384 bs=512
> conv=sync,notrunc # dd if=FreeBSD-14.2-RELEASE-arm64-aarch64-ROCKPRO64.img
> | pv | dd of=/dev/sdh


My goal is to be able to have the HDMI working on the 720x720 screen that
I’ve bought :


https://it.aliexpress.com/item/1005008099495351.html


to be able to use it as a component in the phone that I’m trying to create.


If I "dd" those files to the RockPro image file,the screen remains black.

I cannot boot a rockpro64 image
(FreeBSD-14.2-RELEASE-arm64-aarch64-ROCKPRO64.img
/ rk3399) on a rk356x based board, they are way different.

So,I want to ask you which image file should I use to install those
bootloader files.

Thanks.
-- 
Mario.