I can only tell you my understanding about this. There are many causes of System Reset. If it is caused by powering up the device, power supply "BrownOut", or software generated "BrownOut Reset", it is called a BOR (BrownOut Reset). Aside from BOR, there are many other causes of System Reset. This include nRST input, Watchdog Timeout, Watchdog Password violation, Flash controller password key violation, other kinds of software generated Reset, etc. What happens after these two kinds of System Reset are very different. For none-BOR System Reset, the contends of the System Reset Vector (@ 0xFFFE) will be loaded into the PC. This is probably what you are used to. For BOR System Reset, however, the address of a mysterious BootROM will be loaded into the PC instead. The code there will do some mysterious set-up including calling a routine inside the protected area of Flash memory (if it exists). After that, depends on what was returned, it will either jump to the location pointed @0xFFFE, or the BSL starting point. The TI factory programmed protected area of Flash is such that if the BSL entry sequence was detected, the BootROM will be directed to jump to the BSL starting point. And if not, the BootROM will be directed to jump to the @0xFFFE. To do what you want, you need simply change that to always jump to BSL starting point. Please verify that what I said are correct before you try to do it.
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