Why in embedded engineering, driver layer or library layer coding is?
I am not sure, if there is any such differentiation but i can say, in application layer you just use the functionality provided by driver layer or library layer . You juggle in application layer to implement the requirements of application. But where as in Driver layer, you need to understand the bare metal (Hardware ) and the timing, modes and etc.. and then do lot of jugglers with bits and bytes and provide the generic API to the upper layers. Both the layers have there own challenges.