Security is a major issue nowadays for the embedded systems community. Untrustworthy authorities may use a wide range of attacks in order to retrieve critical information. This paper introduces ARMHEx, a practical solution targeting DIFT (Dynamic Information Flow Tracking) on ARM-based SoCs (e.g. Xilinx Zynq). Current DIFT implementations suffer from two major drawbacks. First, recovering required information for DIFT is generally based on software instrumentation leading to high time overheads. ARMHEx takes profit of ARM CoreSight debug components and static analysis to drastically reduce instrumentation time overhead (up to 90% compared to existing works). Then, security of the DIFT hardware extension itself is not considered in related works. In this work, we tackle this issue by proposing a solution based on ARM Trustzone.