Embedded Developer

 Monocypher is an open-source BSD licensed project that has great data encryption and decryption capability for embedded systems. Here is a short simple engineer view on how to make it work. Sequence diagram In the image is a sequence diagram that described how to securely exchange data works in one way from server to client.

Pretty much all that is needed to enable RDP (read protection) is to enable level 1 of the protection by writing values between 0xAA - 0xCC to a specific register.   If you are using the STM32 HAL library you can check my integration as part of the function  FlashAdapter_setReadProtection  and function  ActivateProtection . After enabling RDP level 1 the whole flash will be read-protected. Once you decide to disable it the whole flash will be wiped out and no one will be able to read your binary. This is now part of the IMBootlaoder code. Once when you enable RDP protection all code is protected. The cool thing you can still update your firmware code by using the IMFlahser application, without disabling RDP .  You can ignore PCROP (Proprietary code readout protection). It is a cool feature that SMT32 also has, but I'll cover this in some future posts. 

Ascent AeroSystems , Wilmington, MA    

 IMBootloader now has support for STM32F7 MCUs.  It was tested and developed at Pixhawk 4 board. Board has STM32F765II MCU.  Check the code here: https://github.com/IMProject/IMBootloader

IMBootloader  is now supporting STM32H7xx microcontrollers. Development is done with  Mateksys H743-SLIM . IMBootlaoder has an IMLedBlink example for this board.   

Since almost every Embedded project needs a bootloader and application for flashing firmware, I've decided to open-source my solution. The idea is to have a universal bootloader for all microcontrollers and a single flasher application. Another idea is to have a flashing application that can run on all operating systems. This is where I open-sourced  IMBootloader ,  IMFlahser  together with the  IMLedBlink  example.  Let shortly explain them. IMBootloader Adapter functions For anyone who wants to port this bootloader, it needs to do it through adapter functions. The source file of adapter functions is here:  firmware_update_adapter.c Magic key IMBootlaoder is running at interrupt events from USB. In the beginning, it will check if firmware exists by checking the special part of flash and it will looking for the magic key. If the magic key exists bootloader will jump to the firmware. It is to keep booting time short as possible. If the magic key is not written bootloader will listen

An image with setup needed to debug S32K from NXP. Pretty much similar to STM32 MCUs but these " Other options " where you add " r g q " are important. Don't know what they do but without it, you will not be able to do proper inline debugging.