DisplayPort serial protocol not working on linux boards

Hi,

I’m using the DisplayPort option with DJI Goggles and Caddx Vista + WTF.OS in another vehicles using Matek F765 and Pixhawk6X with

SERIALX_PROTOCOL=42
SERIALX_BAUD=115200
OSD_TYPE=5

But trying the same on a linux - beaglebone + bbbmini cape I didnt have anything in the OSD.
Setting up to use DJI Custom OSD - SERIALX_PROTOCOL = 33 and OSD_TYPE=3 - everything is working fine.

Any clue of what is happening ? There is anything missing in the linux board definition before compiling ?
I put some debug messages in the init and probe in the AP_OSD_MSP_DisplayPort.cpp and I can see both init and probe is working, but I can’t have anything on the goggles.
I addedd a HAL_WITH_MSP_DISPLAYPORT define in the under AP_HAL/boards/linux.h and even with that, I can’t have anything in the goggles. Connecting the Air Unit to a Matek I can have the OSD working, so I believe there is something missing in the linux version.

Thanks