Bootloader with Backup Feature

Version : 2.0

This version brings a major overhaul of the bootloader application in both the micro as well as pc tool.

Concept:

STM32F411CEUx has the application loaded at 0x08020000.

In the design so far, we are overwriting the FLASH where the current firmware is already working. So during the entire process, if there is any breakage in firmware upgrade process, we may losse the running firmware also.

To avoid such situation, I have proposed the design to backup the firmware to PC as binary file and then proceed with firmware update.
This will ensure that there is atleast the backup of running firmware and can be restored using the same procedure if upgrade fails.

Challenge:

In order to backup running firmware, we need to know the end address of the application as it may not occupy entire 128KBytes and to optimize, we need to really copy only the REAL firmware and exlude the NULLS.

In Order to achieve this, during deployment of firmware, the size is stored in Sector 2 (configured in Bootloader) at address 0x08008000
So during second deployment of application, we are checking this location for the size of running firmware and backing up to #PC.