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Jum to Bootloader from application without PIN.



I am developing a bootloader, I would like to flash the STM32 using another MCU using USART.

My question is, If it possible to enter into bootloader mode without using external pins? I would like to enter just by software, is that possible?

I see that all the bootloader activation patterns include PIN state. is there any other way to do it without pin?




Chief II

I mean yes. On some MCUs with detect fw required erase 0 sector before jump.

But when you develop own bootloader , this is based on your code... no problem.

For system bootloader read AN2606

Uwe Bonnes
Principal II

As start, e,g, check for warm reboot or some magic in RAM and go to the system bootloader or the application else.

It's probably desirable to provide for a NRST, BOOT0 connection, along with the UART, to allow you significant control over the process.

You can write your OWN loader code to interact with another MCU, and update, completely independently of the ROM based System Loader. In many cases that will be simpler and more secure.

Ultimately the MCU can call and execute whatever code you direct it at.

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