Isolated Partitioning of Firmware Improves IoT Device Security

There are two methods for improving IoT device security: secure partitioning and secure coding. The latter seems to have gained favor, not only for cloud software, but also for IoT device firmware. This may be because there has not been an effective firmware partitioning solution for microcontroller-based devices using memory protection units (MPUs). We are …

Using MpuPacker to Minimize Waste

The Cortex-M v7 MPU requires regions to be a power of two in size and aligned to their size. This can waste a lot of memory if they aren’t ordered efficiently. We developed our MpuPacker utility to help with this by optimizing the ordering and also recommending regions that can be reduced in size or …

MPU Debugging with smxAware

smxAware was enhanced with new features to help debug issues related to the Memory Protection Unit in SecureSMX systems. These are covered here. The IAR debugger displays the MPU registers like this: RNR can be manually patched to the slot number to view, which then shows the RBAR and RASR values for that slot. A …

Improving IoT Device Security

I just read a very good article, Supply Chain Security Guidance, by the staff at Finite State, Inc. This article brings home the massive impact upon embedded devices that President Biden’s Executive Order on Improving the Nation’s Cybersecurity will have. I think it is clear from this article that very few existing connected devices are …

MPU Extension

In any real project using a secure RTOS with a Memory Protection Unit (MPU), you are likely to run out of MPU slots for at least some tasks. One group of culprits is peripheral drivers, which tend to require multiple IO regions. If you have only one region to give to your task, you may …