We've been using the mfgtool kernel (mostly because of CONFIG_FSL_UTP) along with imx_usb_loader and utp_com for some time now. It does the job but I recently noticed that support seems to be missing in more recent kernels (i.e.: linux-imx-5.4).
I was wondering how to get something similar but with recent kernels? Some seem to be using imx_usb_loader along with fastboot. Others use UUU.
Any suggestions? Ideally I would be able to boot a kernel, send commands and also files.