About 6 months ago, I wrote a serial GUI under Windows to upgrade firmware on an STM32L052 via the UART2 port, where the firmware does a JumpToBootloader() to get things started. This took a lot of work and troubleshooting to perfect, but I know my way around the bootloader now. (or so I thought...)
I'm now porting that code to an STM32L021, and it just doesn't behave the same way. I see the code jump to the bootloader at 0x1FF00000, I can single step through, see it clear out SRAM, do a couple compares, then the bootloader jumps back to the main code. Location 0x1FF00236 is final compare and branch that jumps back (resets) to main code.
I haven't decrypted what it's checking, but was wondering if the C or Assembly source is available for the bootloader in the STM32L021?
Or, if anyone has a workaround on the L021, that would sure help.