Hey everyone,
i solved the problem with the hard fault by referring to this Post.
I switched the domain in the imx cortex m ATF(ARM TRUSTED FIRMWARE) source to Domain 1 ( D1R | D1W ) →
RDC_PDAPn(RDC_PDAP_UART2, D1R | D1W)
This all together is included inside the imx-boot file, which can be replaced in order to modify the toradex easy installer compatible images. This process is well documented in chapter: Building U-Boot
Build U-Boot and Linux Kernel from Source Code
cheers
Nikolai Fichtner