Ask mostly about Linux and your experience with Board Support Packages (BSPs).
Also, look into C concepts, as the C language is used most for BSPs.
Interview questions will depend on your past project experience.
How is the probe function invoked?
Etc.
The following metrics were computed from 1 interview experience for the Qualcomm BSP Engineer role in India.
Qualcomm's interview process for their BSP Engineer roles in India is incredibly easy as the vast majority of engineers get an offer after going through it.
Candidates reported having very good feelings for Qualcomm's BSP Engineer interview process in India.