Security in embedded systems is a major concern for several years. Untrustworthy authorities use a wide range of both hardware and software attacks. This paper introduces ARMHEx, a practical solution targeting DIFT (Dynamic Information Flow Tracking) implementations on ARM-based SoCs. DIFT is a solution that consists in tracking the dissemination of data inside the system and permit to ensure some security properties. Existing DIFT solutions are either hardly portable to SoCs or bring unsuitable time overheads. ARMHEx overcomes both issues using modern debugging CPU features, along with a coprocessor implemented in FPGA logic. This work demonstrates how ARMHEx performs DIFT with negligible communication costs opening interesting perspectives in the context of reconfigurability and hardware-en- hanced security for multiprocessor architectures.