6.4. Device Driver Implementation

6.4.1. Device Independent Function Call

System calls use a table to use and execute the correct driver code.

6.4.2. Driver–Kernel Interface

• Drivers are distinct from main part of kernel

• Kernel makes calls on specific functions, drivers implement them

• Drivers use kernel functions for:

  • Device allocation
  • Resource (e.g., memory) allocation
  • Scheduling
  • etc. (varies from OS to OS)

6.4.3. Reconfigurable Device Drivers

Modern systems can be reconfigured with tables holding pointers to functions. This allows drivers to be added without recompiling the Operating System kernel.