What is the function of PA13 (BOOTFAILN) on the STM32MP15x

[RZ]

I'm working on a design with the STM32MP153 and came across the additional function of PA13 as BOOTFAILN.

I can guess what this means but I can't find any documentation on the subject. Don't know when or why this pin gets active. Or is it an input? In the reference design schematics both a LED and a switch are connected to this pin.

Thanks for any insight.

[PatrickF]

please have a look to https://wiki.st.com/stm32mpu/wiki/STM32MP15_ROM_code_overview#Debug_and_Error_messages and also 8.3.5 "Debug triggers and LEDs" of AN5031