Implementation of System Calls
In the implementation of system calls, not only the kernel source code that provides the required functions is relevant but also the way in which the functions are invoked. Functions are not called in the same way as normal C functions because the boundary between user and kernel mode is crossed. This raises various problems that are handled by platform-specific assembly language code. This code establishes a processor-independent state as quickly as possible to enable system calls to be implemented independently of the underlying architecture. How parameters are passed between userspace and kernel space must also be considered.
Continue reading here: Implementation of Handler Functions
Was this article helpful?