Debugging using Pixhawk Debug Adapter Mini and ST-Link V2

I have a Pixhawk4 and I’m trying to modify the bootloader code for debugging by adding the debug messages. But I am not able to get any. I used hal.console->printf() which gives linker error in the bootloader but gives other messages after boot to the console (Linux minicom).
I tried uprintf() too which in the code support.cpp says for usb debugging but still no output…It mentions about a macro to be defined
#define BOOTLOADER_DEBUG SD1”
But since I couldn’t find any debug port like that in the hwdef.h or hwdef_bl.h files i guess this too won’t work.
I saw about this Pixhawk Debug Adapter Mini and ST-Link V2 could be helpful for debugging but not sure how to console it to the usb port.
Can someone please suggest me how to enable the debug port and debug through this USB port.
(If not in Pixhawk4, CubeOrangePlus is also appreciated).
Thanks