Hi.
I am looking for some info relating to the factory bootloader in the STM32WL33.
In a nutshell, I dont need it nor want it. My application will require a custom bootloader that will read program from EEPROM over SPI.
I have discovered from a previous post that to protect the chip from external programming, one can disable the SWD pins in the registers.
However looking closer, the factory bootloader is still accessible by pulling up PA10 (BOOT0). This means that using openly available tools someone could reprogram my device. Not something anyone wants im sure!
So i have been looking for a way to disable it or delete it. Of which i appear to have failed to do. So i looked for some other reasonable measure.
The only piece of info i can find useful to me, is that the bootloader has a secure boot element to it, in that a Key can be entered into a OTP area.
Validation of the key is then required in order to program the flash and even to run the loaded application on POR.
The kicker....These OTP areas, according to the bootloader documentation, can only be programmed from inside the bootloader. The one i dont want to use...
In this case, im not being awkward, I just find it unnecessary to be forced to use a feature that only adds potential issues. Not just that but the pins that the bootloader uses for UART are being used by other features.
Can anyone shed any further light on the secure boot feature on whether the OTP areas can be programmed by a custom bootloader.
Also, is the code for the factory bootloader open source?? If it is, is there a link?
Many thanks
Many thanks
