Hi all,
I don't understand why you want or need to use those chain loaded u-boot blobs?
The vendor u-boot bootloaders can boot mainline Linux perfectly without them. So they are not needed.
All it takes are some simple modifications of some of the Armbian u-boot scripts.
Just copy the attached files to the fat partition of the Armbian image after burning the image to a USB disk.
Edit armbianEnv.txt for the right DTB (so not in extlinux.conf) and you can boot the newer Armbian images without u-boot.ext.
I tested it with the Armbian_23.8.1_Aml-s9xx-box_bookworm_current_6.1.50_minimal.img.xz image on the following SOC's:
S905x (GXL)
S912 (GXM)
S905x2 (G12A)
S922X (G12B)
S905X3 (SM1)
assumption: you have vendor u-boot (the one that came with the box) running on eMMC. If you don't, you can just restore the stock Android image with Amlogic USB Burning tool.
All needed files and a more detailed description is on github