I am trying to understand the firmware update code for STM32 Microcontrollers. Came across this example code from STM32 for their IAP over UART repository (link)[https://github.com/eziya/STM32F4_HAL_IAP_UART/blob/master/STM32F4_HAL_IAP_UART/Src/main.c#L112C3-L112C75]. I understand the high level view of what the code does as shown below: