AnsweredAssumed Answered

STM32L021 Jump to Bootloader issue

Question asked by Steve Krattiger on Sep 29, 2017
Latest reply on Oct 20, 2017 by Steve Krattiger

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.

 

Thanks!

 

- SteveK

Outcomes