Jumping to ST ROM Bootloader from user flash on STM32L073

[Dhanyakumar Hosamane]

Posted on July 22, 2017 at 13:03

Hi

STM32L073RZ supports dual bank mechanism. Dual-bank boot capability allowing to boot either from Bank 1 or Bank 2 at startup based on BOOT pins. However, I need to jump to system boot loader from user flash using simple address based mechanism to allow the user to upgrade new code on to flash memory.

Configuration

BOOT0 pin tied to 0

Using BANK 1 flash memory

Issue

On jumping to system memory from BANK 1 Flash, control (PC) returns to BANK1 flash start address as code BANK1 code is not valid. But I wanted to control to stay in system bootloader to upgrade flash memory

Is there any way to jump to system boot loader from BANK1 user flash?

#stm32l073 #stm32lo #dual-bank #system-bootloader #bootloader-rom

[Uwe Bonnes]

Posted on November 23, 2017 at 14:33

What does the reference manual tell about that situation?

[Prasanna Rawke]

Posted on November 24, 2017 at 06:59

Looking at the

https://community.st.com/servlet/JiveServlet/showImage/2-163506-19288/Capture.JPG

from one of the comments above, I have made a truth table of BOOT0 state, Validity of Bank1 code and validity of Bank2 code. I have come to the conclusion that code from Bank2 will be executed if it is valid regardless of BOOT0 state. Code from Bank1 will be executed only if there is no code in Bank2.