test

Writing Device Drivers

Memory Mapping Overview

The steps that a driver must take to export device or kernel memory are as follows:

  1. Set the D_DEVMAP flag in the cb_flag flag of the cb_ops(9S) structure.

  2. Define a devmap(9E) driver entry point and optional segmap(9E) entry point to export the mapping.

  3. Use devmap_devmem_setup(9F) to set up user mappings to a device. To set up user mappings to kernel memory, use devmap_umem_setup(9F).