How about writing embedded linux for master's thesis?
Yes, embedded linux can write many things, such as hardware design, Uboot, kernel, applications, algorithms and so on. If you can make an object by yourself and run the basic functions, the paper will basically pass. If there are some innovative algorithms and innovative designs, it will give you extra points and help you improve your ability. Of course, it is unrealistic for you to master it as a student. Embedded things come step by step, and they are improved by constantly doing projects.