1130b656e5
This will make a number of things easier in the future, as well as (finally!) avoiding the Id-smashing problem which has plagued developers for so long. Boy, I'm glad we're not using sup anymore. This update would have been insane otherwise.
65 lines
2.5 KiB
Plaintext
65 lines
2.5 KiB
Plaintext
<!-- This is an SGML document in the linuxdoc DTD of the Tutorial for
|
|
Configuring a FreeBSD for Dialup Services by Guy Helmer.
|
|
$FreeBSD$
|
|
|
|
The FreeBSD Documentation Project
|
|
|
|
<!DOCTYPE linuxdoc PUBLIC "-//FreeBSD//DTD linuxdoc//EN">
|
|
|
|
<linuxdoc>
|
|
<article>
|
|
<title> Serial Basics
|
|
<author> FAQ
|
|
<date> 24 Nov 1996, (c) 1996
|
|
|
|
<abstract> This section outlines some of the basics to get your serial ports working. This is really just a stepping stone into the section on PPP or Dialout if you are interested in modems.
|
|
</abstract>
|
|
|
|
<toc>
|
|
-->
|
|
|
|
<sect><heading>Serial Basics<label id="serial"></heading>
|
|
|
|
<p><em>Assembled from FAQ.</em>
|
|
|
|
This section should give you some general information about serial ports. If you do not find what you want here, check into the Terminal and Dialup sections of the handbook.
|
|
|
|
|
|
<p>
|
|
The <tt/ttydX/ (or <tt/cuaaX/) device is the regular device
|
|
you will want to open for your applications. When a process opens
|
|
the device, it will have a default set of terminal I/O settings.
|
|
You can see these settings with the command
|
|
<verb>
|
|
stty -a -f /dev/ttyd1
|
|
</verb>
|
|
|
|
When you change the settings to this device, the settings are in
|
|
effect until the device is closed. When it is reopened, it goes
|
|
back to the default set. To make changes to the default set, you
|
|
can open and adjust the settings of the ``initial state'' device.
|
|
For example, to turn on <tt/CLOCAL/ mode, 8 bits, and
|
|
<tt>XON/XOFF</tt> flow control by default for ttyd5, do:
|
|
<verb>
|
|
stty -f /dev/ttyid5 clocal cs8 ixon ixoff
|
|
</verb>
|
|
|
|
A good place to do this is in <tt>/etc/rc.serial</tt>. Now, an
|
|
application will have these settings by default when it opens
|
|
<tt/ttyd5/. It can still change these settings to its liking,
|
|
though.
|
|
|
|
You can also prevent certain settings from being changed by an
|
|
application by making adjustments to the ``lock state'' device.
|
|
For example, to lock the speed of <tt/ttyd5/ to 57600 bps, do
|
|
<verb>
|
|
stty -f /dev/ttyld5 57600
|
|
</verb>
|
|
|
|
Now, an application that opens <tt/ttyd5/ and tries to change the
|
|
speed of the port will be stuck with 57600 bps.
|
|
|
|
Naturally, you should make the initial state and lock state
|
|
devices writable only by <tt/root/. The <tt/MAKEDEV/ script does
|
|
<bf/NOT/ do this when it creates the device entries.
|