Appendix
Using/dev Entries
APPENDIX A
On the workstation is a directory called /dev. This directory
contains a host of devices. Some devices are pseudo devices
called] pseudo fry's. A pseudo try device is a process that acts
like a serial device, such as a terminal, There can be up to
255 of these. Each connection to the PortMaster requires a
pseudo try device, In addition, other Sun software programs
use pseudo tty devices. These include; workstation shelltool
windows, Rlogin, rsh or other network processes.
First, to use a device, the operating system has to have
support for that device. The second thing you need to access
a device is an entry in /der which is the name of that device,
The name entry in /der cross references to a major device
number and a minor device number. The major device
number is used for a single type of device in the operating
system, Psuedo ttys use the major device number 20 on Sun
Workstations. Then each of the devices which acts like a
pseudo tty is assigned a minor device number For example,
tile entry, /dev/ttyp0(b is the first pseudo-try entry in /dev.
Tile device 'name' is ttyp0. If the command:
Is -I /dev/ttyp0
is performed, the following entry would be displayed:
crw-rw-rw- 1 root 20. 0 Sep 2 08:20 /dev/ttyp0
This indicates that /dev/ttyp0 has major device number 20 (a
pseudo try) and minor device 0 (the first minor device
number).
TO use the default /der devices, simply use the path and name
of the device, for example:
A-I
/dev/ttypO
The port types Device and TwoWay require a device name,
which is found in the /der directory. The generic Sun
Workstation operating system has support for 48 pseudo
devices. To go beyond the 48 devices, you must modify your
UNIX kernel.
Refer to the Sun Installation documentation for more complete
descriptions of these steps. In the System and Network
Administration Guide, see the Re-configuring the System
Kernel chapter. In the generic configuration file, in the
/sysl<arch>/conf directory (where <arch> is the machine
architecture - sun3, sun4, sun4c), there is a line dealing with
pseudo-try devices. This line sets the default number of
pseudo-tty devices to 48:
pseudo-device pry #psuedo-tty's, also Beedod for SunVlew
Change the entry from 'pry' to 'pry64' and you will set tile
number of pseudo-tty devices to 64, Append any number you
wish, up to 255 to the 'pty' entry. No number defaults to 48
devices. You will then need to re-build your kernel, as
described in the Sun documentation.
The last step is to make entries in /dev to match the operating system support. The first 64 are created using a program called MAKEDEV. During a standard SunOS installation the first 48 device entries will be automatically created. They are:
/dev/ttyp0 - /dev/ttypf /dev/ttyq0 - /dev/ttyqf /dev/ttyr0 - /dev/ttyrf
An additional 16 may be created using MAKEDEV which is
located in tile /der directory. Use the command:
MAKEDEV pty3
and /dev/ttys0 - /dev/ttysf will be created.
To create entries above 64 devices, use PMDEV which is
located in the /usr/portmaster directory. This command takes
the form:
PMDEV pty[4. 5, 6.7.8.9]
Each time you use PMDEV. 32 devices are added to the /der
directory. For example, the command:
PMDEV pty4
would create an additional 32 devices:
/dex/tty)40 /dev/tly5F
Repeat PMDEV up to pty9 to create a total of 255 entries in
/dev.
There is a utility included~ with the PortMaster software called
]Sty. This program lists only the pseudo-tty devices that are
in /dev, sorted in numerical order. It is a quick way to check on what pseudo-try devices you have in your /der directory.
This program resides in the /usr/portmaster directory. Simply
use the command:
Istty