We are currently developing FOTA for the msp430f5529 which we are using on one of our boards. This board is connected to another board which has STM32F405 on board and connected with UART.
This STM based board is connected to another hmi microprocessor by uart. We want to send the firmware file to hmi and it will be stored there. When there is an update permission from the user, this file will be transferred to stm based board by uart and this board will transfer this file to first msp430 based board without storing at all, i.e real time transfer to msp and stm32 is just an agent in this transaction.
Now,
What i am looking for is as follows-
1. We do not want to use BSL method hardware explained in SLAU319AF - MSP430 Flash Devices Bootloader (BSL) i e. We do not wish to use DTR and RTS pins but only want to use Rx and Tx.
2. We want to reset the microcontroller by software to pull the microcontroller into boot set. (Software reset)
3. If above two conditions are met, then please also give some guidance on how to achieve safety of upgradation/ update fallback if update failure of BSL and security.
Examples of the same would be really appreciated.