5.1.3. What is a Device Driver?

Definition:

• A Device Driver is a core software component of an operating system that abstracts a device and provides a well defined interface for generic core code

Characteristics:

• mechanism, not policy

• type

• "contact" with userspace or not

Kernel components a driver interacts with:

• File system (device files, file operations ...)
  • open(), read()

• Scheduler
  • schedule()

• Memory management
  • kmalloc(), ...

• Process management
  • bad example: current->state = TASK_INTERRUPTIBLE