Stm32mp1xxx uart4 U-Boot stop boot routine when the Stlink not connected

[MWoło.2]

Hi,

I have a small problem during stm32mp1xxx bring up. The Uart4 is debug console and is connected to stlink v2.1 on virtual serial. The problem is that this stlink makes all the time interrupt U-Boot and stack in it (stlink not connected to USB). To go system father I need to connect stlink to USB and type 'boot'.

I tried to add

CONFIG_BOOTDELAY=-2
CONFIG_SILENT_CONSOLE=y
CONFIG_SYS_DEVICE_NULLDEV=y
CONFIG_SILENT_CONSOLE_UPDATE_ON_SET=y
CONFIG_SILENT_U_BOOT_ONLY=y

but without success.

In the hardware, I added pull up resistors

To prove my theory I make a shortcut on resistor R58 and the system boot-up all the time.

How to correctly resolve this problem

Thanks in advanced

BR Michal

[PatrickF]

Hi @Michał Wołowik​ ,

Similar behavior has been seen on some rather old ST-Link FW versions (V2J33M25 if I remember).

Please update to latest FW : https://www.st.com/en/development-tools/stsw-link007.html

Regards

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[MWoło.2]

Perfect answer as always ;)

Thanks, Patrick, of course working after upgrading to the latest.

BR Michal