Linux & embedded

Operating systems being an optional subject for electronics student in India in some universities.Very few have a knowledge on operating system,let alone Linux.
Text books seem to talking about everything else other the use of linux in embedded systems.One can consider text books to learn the APIs or system calls of linux well.The below link posted will give you a idea about what all you would come across while starting to learn Linux.
http://www.embedded.com/electronics-blogs/open-mike/4420567/Learning-Linux-for-embedded-systems