So I managed to extract .dtb files from uboot.img using this extract-dtb tool.
Later on, on a PC running Ubuntu 22.04 LTS I used "device tree compile" to decompile thos dtb files into dts files.
I followed this article trying to use those DTS files to get the correct hardware informatin and/or drivers, but the /boot folder in the flashed SD card is empty. Probably, as the article says, dtb overlay is not activated in this image.
