Configuring HP-UX For Peripherals

270 AppendixC
Major and Minor Numbers
Understanding how the Kernel Associates Drivers to Device
Understanding how the Kernel Associates
Drivers to Device
The kernel communicates with the hardware by associating the driver
name with a hardware address. The kernel identifies the drivers it needs
from the /stand/system file and finds them using the files in the
/usr/conf/master.d directory.
All standard HP-UX interface and device drivers shipped are located in
the library /usr/conf/lib/libhp-ux.a.
The kernel recognizes interface and device drivers (and by extension,
peripheral devices) by major and minor numbers encoded into the device
special files.
Figure C-1 Device Special Files Contain Major and Minor Numbers
Each device driver in the system is assigned a major number, which the
kernel uses to locate the driver routine to service an I/O request.
The driver uses the minor number to locate the specific device and for
information regarding how to handle data.
Major Numbers
The major number is an index for the device driver into one of two kernel