Configuring HP-UX For Peripherals

288 AppendixC

Major and Minor Numbers

Creating Device Special Files using mknod

To create device special ﬁles for any driver other than those listed on the

insf and mksf manpages, use mknod.

Step 1. Change directory to /dev.

Step 2. Determine the major number by invoking the lsdev command.

Step 3. Construct a minor numberfor the device by using the bit assignments for

the device driver. For HP devices, the bit assignments are found in tables

earlier in this Appendix. For custom device drivers, consult

documentation supplied with the driver.

Step 4. Create the device special ﬁles for the device using the following syntax:

/usr/sbin/mknod <file_name> b|c <major#> <minor#>

• Name the ﬁle something easily associated with the device.

• Use b for block device special ﬁle or c for character device special ﬁle.

• Make ﬁles for both block and character if driver supports both.

• Use the block or character major number reported by lsdev.

• Use the minor number constructed from the bit assignment tables.

For example, the scope device driver has block and character major

numbers of 65 and 234 respectively. Its minor number of 0x026000 is

constructed like instr0 (see Table C-7, “Bit Assignments for

Miscellaneous Devices.”) Bits 8 through 15 encode 2 as the card instance

of the interface card and bits 16 through 19 encode 6 as the instrument

address.

/usr/sbin/mknod /dev/scope b 65 0x026000

/usr/sbin/mknod /dev/c_scope c 234 0x026000

Step 5. Verify the conﬁguration by invoking ioscan with the -fun or fkn option.

If created properly, the new device special ﬁles will be displayed with the

conﬁgured device.