FreeBSD Device Drivers

Tying Everything Together

You now know enough to write your first Newbus driver. Example 7-1 is a simple Newbus driver (based on code written by Murray Stokely) for a fictitious PCI device.

Note

Take a quick look at this code and try to discern some of its structure. If you don’t understand all of it, don’t worry; an explanation follows.

Example 7-1. foo_pci.c

#include <sys/param.h>
  #include <sys/module.h>
  #include <sys/kernel.h>
  #include <sys/systm.h>

  #include <sys/conf.h>
  #include <sys/uio.h>
  #include <sys/bus.h>

  #include <dev/pci/pcireg.h>
  #include <dev/pci/pcivar.h>

 struct foo_pci_softc {
         device_t        device;
         struct cdev *cdev; }; static d_open_t foo_pci_open; ...