2731 lines
104 KiB
Text
2731 lines
104 KiB
Text
<!--
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The FreeBSD Documentation Project
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$Id: chapter.sgml,v 1.12 1999-08-05 20:48:25 nik Exp $
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-->
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<chapter id="serialcomms">
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<title>Serial Communications</title>
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<sect1 id="serial">
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<title>Serial Basics</title>
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<para><emphasis>Assembled from FAQ.</emphasis></para>
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<para>This section should give you some general information about serial
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ports. If you do not find what you want here, check into the Terminal
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and Dialup sections of the handbook.</para>
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<para>The <filename>ttyd<replaceable>X</replaceable></filename> (or
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<filename>cuaa<replaceable>X</replaceable></filename>) device is the
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regular device you will want to open for your applications. When a
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process opens the device, it will have a default set of terminal I/O
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settings. You can see these settings with the command</para>
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<screen>&prompt.root; <userinput>stty -a -f /dev/ttyd1</userinput></screen>
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<para>When you change the settings to this device, the settings are in
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effect until the device is closed. When it is reopened, it goes back to
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the default set. To make changes to the default set, you can open and
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adjust the settings of the “initial state” device. For
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example, to turn on <acronym>CLOCAL</acronym> mode, 8 bits, and
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<emphasis>XON/XOFF</emphasis> flow control by default for ttyd5,
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do:</para>
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<screen>&prompt.root; <userinput>stty -f /dev/ttyid5 clocal cs8 ixon ixoff</userinput></screen>
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<para>A good place to do this is in <filename>/etc/rc.serial</filename>.
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Now, an application will have these settings by default when it opens
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<filename>ttyd5</filename>. It can still change these settings to its
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liking, though.</para>
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<para>You can also prevent certain settings from being changed by an
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application by making adjustments to the “lock state”
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device. For example, to lock the speed of <filename>ttyd5</filename> to
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57600 bps, do</para>
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<screen>&prompt.root; <userinput>stty -f /dev/ttyld5 57600</userinput></screen>
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<para>Now, an application that opens <filename>ttyd5</filename> and tries
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to change the speed of the port will be stuck with 57600 bps.</para>
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<para>Naturally, you should make the initial state and lock state devices
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writable only by <username>root</username>. The
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<filename>MAKEDEV</filename> script does <emphasis>not</emphasis> do
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this when it creates the device entries.</para>
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</sect1>
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<sect1 id="term">
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<title>Terminals</title>
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<para><emphasis>Contributed by &a.kelly; 28 July 1996</emphasis></para>
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<para>Terminals provide a convenient and low-cost way to access the power
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of your FreeBSD system when you are not at the computer's console or on
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a connected network. This section describes how to use terminals with
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FreeBSD.</para>
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<sect2 id="term-uses">
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<title>Uses and Types of Terminals</title>
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<para>The original Unix systems did not have consoles. Instead, people
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logged in and ran programs through terminals that were connected to
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the computer's serial ports. It is quite similar to using a modem and
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some terminal software to dial into a remote system to do text-only
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work.</para>
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<para>Today's PCs have consoles capable of high quality graphics, but
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the ability to establish a login session on a serial port still exists
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in nearly every Unix-style operating system today; FreeBSD is no
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exception. By using a terminal attached to a unused serial port, you
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can log in and run any text program that you would normally run on the
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console or in an <command>xterm</command> window in the X Window
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System.</para>
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<para>For the business user, you can attach many terminals to a FreeBSD
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system and place them on your employees' desktops. For a home user, a
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spare computer such as an older IBM PC or a Macintosh can be a
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terminal wired into a more powerful computer running FreeBSD. You can
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turn what might otherwise be a single-user computer into a powerful
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multiple user system.</para>
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<para>For FreeBSD, there are three kinds of terminals:</para>
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<itemizedlist>
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<listitem>
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<para><link linkend="term-dumb">Dumb terminals</link></para>
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</listitem>
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<listitem>
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<para><link linkend="term-pcs">PCs acting as terminals</link></para>
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</listitem>
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<listitem>
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<para><link linkend="term-x">X terminals</link></para>
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</listitem>
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</itemizedlist>
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<para>The remaining subsections describe each kind.</para>
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<sect3 id="term-dumb">
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<title>Dumb Terminals</title>
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<para>Dumb terminals are specialized pieces of hardware that let you
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connect to computers over serial lines. They are called
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“dumb” because they have only enough computational power
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to display, send, and receive text. You cannot run any programs on
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them. It is the computer to which you connect them that has all the
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power to run text editors, compilers, email, games, and so
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forth.</para>
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<para>There are hundreds of kinds of dumb terminals made by many
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manufacturers, including Digital Equipment Corporation's VT-100 and
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Wyse's WY-75. Just about any kind will work with FreeBSD. Some
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high-end terminals can even display graphics, but only certain
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software packages can take advantage of these advanced
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features.</para>
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<para>Dumb terminals are popular in work environments where workers do
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not need access to graphic applications such as those provided by
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the X Window System.</para>
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</sect3>
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<sect3 id="term-pcs">
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<title>PCs Acting As Terminals</title>
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<para>If a <link linkend="term-dumb">dumb terminal</link> has just
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enough ability to display, send, and receive text, then certainly
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any spare personal computer can be a dumb terminal. All you need is
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the proper cable and some <emphasis>terminal emulation</emphasis>
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software to run on the computer.</para>
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<para>Such a configuration is popular in homes. For example, if your
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spouse is busy working on your FreeBSD system's console, you can do
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some text-only work at the same time from a less powerful personal
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computer hooked up as a terminal to the FreeBSD system.</para>
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</sect3>
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<sect3 id="term-x">
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<title>X Terminals</title>
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<para>X terminals are the most sophisticated kind of terminal
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available. Instead of connecting to a serial port, they usually
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connect to a network like Ethernet. Instead of being relegated to
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text-only applications, they can display any X application.</para>
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<para>We introduce X terminals just for the sake of completeness.
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However, this chapter does <emphasis>not</emphasis> cover setup,
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configuration, or use of X terminals.</para>
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</sect3>
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</sect2>
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<sect2 id="term-cables-ports">
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<title>Cables and Ports</title>
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<para>To connect a terminal to your FreeBSD system, you need the right
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kind of cable and a serial port to which to connect it. This section
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tells you what to do. If you are already familiar with your terminal
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and the cable it requires, skip to <link
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linkend="term-config">Configuration</link>.</para>
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<sect3 id="term-cables">
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<title>Cables</title>
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<para>Because terminals use serial ports, you need to use
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serial—also known as RS-232C—cables to connect the
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terminal to the FreeBSD system.</para>
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<para>There are a couple of kinds of serial cables. Which one
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you'll use depends on the terminal you want to connect:</para>
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<itemizedlist>
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<listitem>
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<para>If you are connecting a personal computer to act as a
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terminal, use a <link linkend="term-null">null-modem</link>
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cable. A null-modem cable connects two computers or terminals
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together.</para>
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</listitem>
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<listitem>
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<para>If you have an actual terminal, your best source of
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information on what cable to use is the documentation that
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accompanied the terminal. If you do not have the documentation,
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then try a <link linkend="term-null">null-modem</link> cable.
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If that does not work, then try a <link
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linkend="term-std">standard</link> cable.</para>
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</listitem>
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</itemizedlist>
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<para>Also, the serial port on <emphasis>both</emphasis> the terminal
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and your FreeBSD system must have connectors that will fit the cable
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you are using.</para>
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<sect4 id="term-null">
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<title>Null-modem cables</title>
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<para>A null-modem cable passes some signals straight through, like
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“signal ground,” but switches other signals. For
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example, the “send data” pin on one end goes to the
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“receive data” pin on the other end.</para>
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<para>If you like making your own cables, here is a table showing a
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recommended way to construct a null-modem cable for use with
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terminals. This table shows the RS-232C signal names and the pin
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numbers on a DB-25 connector.</para>
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<informaltable frame="none">
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<tgroup cols="5">
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<thead>
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<row>
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<entry>Signal</entry>
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<entry>Pin #</entry>
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<entry></entry>
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<entry>Pin #</entry>
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<entry>Signal</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry>TxD</entry>
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<entry>2</entry>
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<entry>connects to</entry>
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<entry>3</entry>
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<entry>RxD</entry>
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</row>
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<row>
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<entry>RxD</entry>
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<entry>3</entry>
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<entry>connects to</entry>
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<entry>2</entry>
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<entry>TxD</entry>
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</row>
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<row>
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<entry>DTR</entry>
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<entry>20</entry>
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<entry>connects to</entry>
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<entry>6</entry>
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<entry>DSR</entry>
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</row>
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<row>
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<entry>DSR</entry>
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<entry>6</entry>
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<entry>connects to</entry>
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<entry>20</entry>
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<entry>DTR</entry>
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</row>
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<row>
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<entry>SG</entry>
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<entry>7</entry>
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<entry>connects to</entry>
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<entry>7</entry>
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<entry>SG</entry>
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</row>
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<row>
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<entry>DCD</entry>
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<entry>8</entry>
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<entry>connects to</entry>
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<entry>4</entry>
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<entry>RTS</entry>
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</row>
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<row>
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<entry>RTS</entry>
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<entry>4</entry>
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<entry></entry>
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<entry>5</entry>
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<entry>CTS</entry>
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</row>
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<row>
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<entry>CTS</entry>
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<entry>5</entry>
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<entry>connects to</entry>
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<entry>8</entry>
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<entry>DCD</entry>
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</row>
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</tbody>
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</tgroup>
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</informaltable>
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<note>
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<para>For DCD to RTS, connect pins 4 to 5 internally in the
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connector hood, and then to pin 8 in the remote
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hood.</para>
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</note>
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</sect4>
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<sect4 id="term-std">
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<title>Standard RS-232C Cables</title>
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<para>A standard serial cable passes all the RS-232C signals
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straight-through. That is, the “send data” pin on one
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end of the cable goes to the “send data” pin on the
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other end. This is the type of cable to connect a modem to your
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FreeBSD system, and the type of cable needed for some
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terminals.</para>
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</sect4>
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</sect3>
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<sect3 id="term-ports">
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<title>Ports</title>
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<para>Serial ports are the devices through which data is transferred
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between the FreeBSD host computer and the terminal. This section
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describes the kinds of ports that exist and how they are addressed
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in FreeBSD.</para>
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<sect4 id="term-portkinds">
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<title>Kinds of Ports</title>
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<para>Several kinds of serial ports exist. Before you purchase or
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construct a cable, you need to make sure it will fit the ports on
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your terminal and on the FreeBSD system.</para>
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<para>Most terminals will have DB25 ports. Personal computers,
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including PCs running FreeBSD, will have DB25 or DB9 ports. If you
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have a multiport serial card for your PC, you may have RJ-12 or
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RJ-45 ports.</para>
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<para>See the documentation that accompanied the hardware for
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specifications on the kind of port in use. A visual inspection of
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the port often works, too.</para>
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</sect4>
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<sect4 id="term-portnames">
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<title>Port Names</title>
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<para>In FreeBSD, you access each serial port through an entry in
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the <filename>/dev</filename> directory. There are two different
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kinds of entries:</para>
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<itemizedlist>
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<listitem>
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<para>Callin ports are named
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<filename>/dev/ttyd<replaceable>X</replaceable></filename>
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where <replaceable>X</replaceable> is the port number,
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starting from zero. Generally, you use the callin port for
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terminals. Callin ports require that the serial line assert
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the data carrier detect (DCD) signal to work.</para>
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</listitem>
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<listitem>
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<para>Callout ports are named
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<filename>/dev/cuaa<replaceable>X</replaceable></filename>.
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You usually do not use the callout port for terminals, just
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for modems. You may use the callout port if the serial cable
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or the terminal does not support the carrier detect
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signal.</para>
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</listitem>
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</itemizedlist>
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<para>See the &man.sio.4; manual page for more information.</para>
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<para>If you have connected a terminal to the first serial port
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(<devicename>COM1</devicename> in DOS parlance), then you want to
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use <filename>/dev/ttyd0</filename> to refer to the terminal. If
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it is on the second serial port (also known as
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<devicename>COM2</devicename>), it is
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<filename>/dev/ttyd1</filename>, and so forth.</para>
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<para>Note that you may have to configure your kernel to support
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each serial port, especially if you have a multiport serial card.
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See <link linkend="kernelconfig">Configuring the FreeBSD
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Kernel</link> for more information.</para>
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</sect4>
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</sect3>
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</sect2>
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<sect2 id="term-config">
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<title>Configuration</title>
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<para>This section describes what you need to configure on your FreeBSD
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system to enable a login session on a terminal. It assumes you have
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already configured your kernel to support the serial port to which the
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terminal is connected—and that you have connected it.</para>
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<para>In a nutshell, you need to tell the <command>init</command>
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process, which is responsible for process control and initialization,
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to start a <command>getty</command> process, which is responsible for
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reading a login name and starting the <command>login</command>
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program.</para>
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<para>To do so, you have to edit the <filename>/etc/ttys</filename>
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file. First, use the <command>su</command> command to become root.
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Then, make the following changes to
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<filename>/etc/ttys</filename>:</para>
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<procedure>
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<step>
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<para>Add an line to <filename>/etc/ttys</filename> for the entry in
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the <filename>/dev</filename> directory for the serial port if it
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is not already there.</para>
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</step>
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<step>
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<para>Specify that <filename>/usr/libexec/getty</filename> be run on
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the port, and specify the appropriate
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<replaceable>getty</replaceable> type from the
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<filename>/etc/gettytab</filename> file.</para>
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</step>
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<step>
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<para>Specify the default terminal type.</para>
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</step>
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<step>
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<para>Set the port to “on.”</para>
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</step>
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<step>
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<para>Specify whether the port should be
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“secure.”</para>
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</step>
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<step>
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<para>Force <command>init</command> to reread the
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<filename>/etc/ttys</filename> file.</para>
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</step>
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</procedure>
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<para>As an optional step, you may wish to create a custom
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<replaceable>getty</replaceable> type for use in step 2 by making an
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entry in <filename>/etc/gettytab</filename>. This document does
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not explain how to do so; you are encouraged to see the
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&man.gettytab.5; and the &man.getty.8; manual pages for more
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information.</para>
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<para>The remaining sections detail how to do these steps. We will use
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a running example throughout these sections to illustrate what we need
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to do. In our example, we will connect two terminals to the system: a
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Wyse-50 and a old 286 IBM PC running Procomm terminal software
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emulating a VT-100 terminal. We connect the Wyse to the second serial
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port and the 286 to the sixth serial port (a port on a multiport
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serial card).</para>
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<para>For more information on the <filename>/etc/ttys</filename>
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file, see the &man.ttys.5; manual page.</para>
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<sect3 id="term-etcttys">
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<title>Adding an Entry to <filename>/etc/ttys</filename></title>
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<para>First, you need to add an entry to the
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<filename>/etc/ttys</filename> file, unless one is already
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there.</para>
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<para>The <filename>/etc/ttys</filename> file lists all of the ports
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on your FreeBSD system where you want to allow logins. For example,
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the first virtual console <filename>ttyv0</filename> has an entry in
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this file. You can log in on the console using this entry. This
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file contains entries for the other virtual consoles, serial ports,
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and pseudo-ttys. For a hardwired terminal, just list the serial
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port's <filename>/dev</filename> entry without the
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<filename>/dev</filename> part.</para>
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<para>When you installed your FreeBSD system, the
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<filename>/etc/ttys</filename> file included entries for the first
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four serial ports: <filename>ttyd0</filename> through
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<filename>ttyd3</filename>. If you are attaching a terminal on one
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of those ports, you do not need to add an entry.</para>
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<para>In our example, we attached a Wyse-50 to the second serial port,
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<filename>ttyd1</filename>, which is already in the file. We need
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to add an entry for the 286 PC connected to the sixth serial port.
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Here is an excerpt of the <filename>/etc/ttys</filename> file after
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we add the new entry:</para>
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<programlisting>
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ttyd1 "/usr/libexec/getty std.9600" unknown off secure
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ttyd5</programlisting>
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</sect3>
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<sect3 id="term-getty">
|
|
<title>Specifying the <replaceable>getty</replaceable> Type</title>
|
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|
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<para>Next, we need to specify what program will be run to handle the
|
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logins on a terminal. For FreeBSD, the standard program to do that
|
|
is <filename>/usr/libexec/getty</filename>. It is what provides the
|
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<prompt>login:</prompt> prompt.</para>
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|
|
<para>The program <command>getty</command> takes one (optional)
|
|
parameter on its command line, the <replaceable>getty</replaceable>
|
|
type. A <replaceable>getty</replaceable> type tells about
|
|
characteristics on the terminal line, like bps rate and parity. The
|
|
<command>getty</command> program reads these characteristics from
|
|
the file <filename>/etc/gettytab</filename>.</para>
|
|
|
|
<para>The file <filename>/etc/gettytab</filename> contains lots of
|
|
entries for terminal lines both old and new. In almost all cases,
|
|
the entries that start with the text <literal>std</literal> will
|
|
work for hardwired terminals. These entries ignore parity. There is
|
|
a <literal>std</literal> entry for each bps rate from 110 to 115200.
|
|
Of course, you can add your own entries to this file. The manual
|
|
page &man.gettytab.5; provides more
|
|
information.</para>
|
|
|
|
<para>When setting the <replaceable>getty</replaceable> type in the
|
|
<filename>/etc/ttys</filename> file, make sure that the
|
|
communications settings on the terminal match.</para>
|
|
|
|
<para>For our example, the Wyse-50 uses no parity and connects at
|
|
38400 bps. The 286 PC uses no parity and connects at 19200 bps.
|
|
Here is the <filename>/etc/ttys</filename> file so far (showing just
|
|
the two terminals in which we are interested):</para>
|
|
|
|
<programlisting>
|
|
ttyd1 "/usr/libexec/getty std.38400" unknown off secure
|
|
ttyd5 "/usr/libexec/getty std.19200"</programlisting>
|
|
|
|
<para>Note that the second field—where we specify what program
|
|
to run—appears in quotes. This is important, otherwise the
|
|
type argument to <command>getty</command> might be interpreted as
|
|
the next field.</para>
|
|
</sect3>
|
|
|
|
<sect3 id="term-deftermtype">
|
|
<title>Specifying the Default Terminal Type</title>
|
|
|
|
<para>The third field in the <filename>/etc/ttys</filename> file lists
|
|
the default terminal type for the port. For dialup ports, you
|
|
typically put <literal>unknown</literal> or
|
|
<literal>dialup</literal> in this field because users may dial up
|
|
with practically any kind of terminal or software. For hardwired
|
|
terminals, the terminal type does not change, so you can put a real
|
|
terminal type in this field.</para>
|
|
|
|
<para>Users will usually use the <command>tset</command> program in
|
|
their <filename>.login</filename> or <filename>.profile</filename>
|
|
files to check the terminal type and prompt for one if necessary.
|
|
By setting a terminal type in the <filename>/etc/ttys</filename>
|
|
file, users can forego such prompting.</para>
|
|
|
|
<para>To find out what terminal types FreeBSD supports, see the
|
|
file <filename>/usr/share/misc/termcap</filename>. It lists
|
|
about 600 terminal types. You can add more if you wish. See
|
|
the &man.termcap.5; manual page for information.</para>
|
|
|
|
<para>In our example, the Wyse-50 is a Wyse-50 type of terminal
|
|
(although it can emulate others, we will leave it in Wyse-50 mode).
|
|
The 286 PC is running Procomm which will be set to emulate a VT-100.
|
|
Here are the pertinent yet unfinished entries from the
|
|
<filename>/etc/ttys</filename> file:</para>
|
|
|
|
<programlisting>
|
|
ttyd1 "/usr/libexec/getty std.38400" wy50 off secure
|
|
ttyd5 "/usr/libexec/getty std.19200" vt100</programlisting>
|
|
</sect3>
|
|
|
|
<sect3 id="term-enable">
|
|
<title>Enabling the Port</title>
|
|
|
|
<para>The next field in <filename>/etc/ttys</filename>, the fourth
|
|
field, tells whether to enable the port. Putting
|
|
<literal>on</literal> here will have the <command>init</command>
|
|
process start the program in the second field,
|
|
<command>getty</command>, which will prompt for a login. If you put
|
|
<literal>off</literal> in the fourth field, there will be no
|
|
<command>getty</command>, and hence no logins on the port.</para>
|
|
|
|
<para>So, naturally, you want an <literal>on</literal> in this field.
|
|
Here again is the <filename>/etc/ttys</filename> file. We have
|
|
turned each port <literal>on</literal>.</para>
|
|
|
|
<programlisting>
|
|
ttyd1 "/usr/libexec/getty std.38400" wy50 on secure
|
|
ttyd5 "/usr/libexec/getty std.19200" vt100 on</programlisting>
|
|
</sect3>
|
|
|
|
<sect3 id="term-secure">
|
|
<title>Specifying Secure Ports</title>
|
|
|
|
<para>We have arrived at the last field (well, almost: there is an
|
|
optional <literal>window</literal> specifier, but we will ignore
|
|
that). The last field tells whether the port is secure.</para>
|
|
|
|
<para>What does “secure” mean?</para>
|
|
|
|
<para>It means that the root account (or any account with a user ID of
|
|
0) may login on the port. Insecure ports do not allow root to
|
|
login.</para>
|
|
|
|
<para>How do you use secure and insecure ports?</para>
|
|
|
|
<para>By marking a port as insecure, the terminal to which it is
|
|
connected will not allow root to login. People who know the root
|
|
password to your FreeBSD system will first have to login using a
|
|
regular user account. To gain superuser privileges, they will then
|
|
have to use the <command>su</command> command.</para>
|
|
|
|
<para>Because of this, you will have two records to help track down
|
|
possible compromises of root privileges: both the
|
|
<command>login</command> and the <command>su</command> command make
|
|
records in the system log (and logins are also recorded in the
|
|
<filename>wtmp</filename> file).</para>
|
|
|
|
<para>By marking a port as secure, the terminal will allow root in.
|
|
People who know the root password will just login as root. You will
|
|
not have the potentially useful login and <command>su</command>
|
|
command records.</para>
|
|
|
|
<para>Which should you use?</para>
|
|
|
|
<para>Just use “insecure.” Use “insecure”
|
|
<emphasis>even</emphasis> for terminals <emphasis>not</emphasis> in
|
|
public user areas or behind locked doors. It is quite easy to login
|
|
and use <command>su</command> if you need superuser
|
|
privileges.</para>
|
|
|
|
<para>Here finally are the completed entries in the
|
|
<filename>/etc/ttys</filename> file, with comments added to describe
|
|
where the terminals are:</para>
|
|
|
|
<programlisting>
|
|
ttyd1 "/usr/libexec/getty std.38400" wy50 on insecure # Kitchen
|
|
ttyd5 "/usr/libexec/getty std.19200" vt100 on insecure # Guest bathroom</programlisting>
|
|
</sect3>
|
|
|
|
<sect3 id="term-hup">
|
|
<title>Force <command>init</command> to Reread
|
|
<filename>/etc/ttys</filename></title>
|
|
|
|
<para>When you boot FreeBSD, the first process,
|
|
<command>init</command>, will read the
|
|
<filename>/etc/ttys</filename> file and start the programs listed
|
|
for each enabled port to prompt for logins.</para>
|
|
|
|
<para>After you edit <filename>/etc/ttys</filename>, you do not want
|
|
to have to reboot your system to get <command>init</command> to see
|
|
the changes. So, <command>init</command> will reread
|
|
<filename>/etc/ttys</filename> if it receives a SIGHUP (hangup)
|
|
signal.</para>
|
|
|
|
<para>So, after you have saved your changes to
|
|
<filename>/etc/ttys</filename>, send <literal>SIGHUP</literal> to
|
|
<command>init</command> by typing:</para>
|
|
|
|
<screen>&prompt.root; <userinput>kill -HUP 1</userinput></screen>
|
|
|
|
<para>(The <command>init</command> process <emphasis>always</emphasis>
|
|
has process ID 1.)</para>
|
|
|
|
<para>If everything is set up correctly, all cables are in place, and
|
|
the terminals are powered up, you should see login prompts. Your
|
|
terminals are ready for their first logins!</para>
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2 id="term-debug">
|
|
<title>Debugging your connection</title>
|
|
|
|
<para>Even with the most meticulous attention to detail, something could
|
|
still go wrong while setting up a terminal. Here is a list of
|
|
symptoms and some suggested fixes.</para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term>No login prompt appears</term>
|
|
|
|
<listitem>
|
|
<para>Make sure the terminal is plugged in and powered up. If it
|
|
is a personal computer acting as a terminal, make sure it is
|
|
running terminal emulation software on the correct serial
|
|
port.</para>
|
|
|
|
<para>Make sure the cable is connected firmly to both the terminal
|
|
and the FreeBSD computer. Make sure it is the right kind of
|
|
cable.</para>
|
|
|
|
<para>Make sure the terminal and FreeBSD agree on the bps rate and
|
|
parity settings. If you have a video display terminal, make
|
|
sure the contrast and brightness controls are turned up. If it
|
|
is a printing terminal, make sure paper and ink are in good
|
|
supply.</para>
|
|
|
|
<para>Make sure that a <command>getty</command> process is running
|
|
and serving the terminal. Type <screen>&prompt.root;
|
|
<userinput>ps -axww|grep getty</userinput></screen> to get a
|
|
list of running <command>getty</command> processes. You should
|
|
see an entry for the terminal. For example, the display
|
|
|
|
<screen>22189 d1 Is+ 0:00.03 /usr/libexec/getty std.38400 ttyd1</screen>
|
|
|
|
shows that a <command>getty</command> is running on the second
|
|
serial port <literal>ttyd1</literal> and is using the
|
|
<literal>std.38400</literal> entry in
|
|
<filename>/etc/gettytab</filename>.</para>
|
|
|
|
<para>If no <command>getty</command> process is running, make sure
|
|
you have enabled the port in <filename>/etc/ttys</filename>.
|
|
Make sure you have run <command>kill -HUP 1</command>.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>Garbage appears instead of a login prompt</term>
|
|
|
|
<listitem>
|
|
<para>Make sure the terminal and FreeBSD agree on the bps rate and
|
|
parity settings. Check the getty processes to make sure the
|
|
correct <replaceable>getty</replaceable> type is in use. If
|
|
not, edit <filename>/etc/ttys</filename> and run <command>kill
|
|
-HUP 1</command>.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>Characters appear doubled; the password appears when
|
|
typed</term>
|
|
|
|
<listitem>
|
|
<para>Switch the terminal (or the terminal emulation software)
|
|
from “half duplex” or “local echo” to
|
|
“full duplex.”</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="dialup">
|
|
<title>Dialin Service</title>
|
|
|
|
<para><emphasis>Contributed by &a.ghelmer;.</emphasis></para>
|
|
|
|
<para>This document provides suggestions for configuring a FreeBSD system
|
|
to handle dialup modems. This document is written based on the author's
|
|
experience with FreeBSD versions 1.0, 1.1, and 1.1.5.1 (and experience
|
|
with dialup modems on other UNIX-like operating systems); however, this
|
|
document may not answer all of your questions or provide examples
|
|
specific enough to your environment. The author cannot be responsible if
|
|
you damage your system or lose data due to attempting to follow the
|
|
suggestions here.</para>
|
|
|
|
<sect2 id="dialup-prereqs">
|
|
<title>Prerequisites</title>
|
|
|
|
<para>To begin with, the author assumes you have some basic knowledge of
|
|
FreeBSD. You need to have FreeBSD installed, know how to edit files
|
|
in a UNIX-like environment, and how to look up manual pages on the
|
|
system. As discussed below, you will need certain versions of
|
|
FreeBSD, and knowledge of some terminology & modem and
|
|
cabling.</para>
|
|
|
|
<sect3>
|
|
<title>FreeBSD Version</title>
|
|
|
|
<para>First, it is assumed that you are using FreeBSD version 1.1 or
|
|
higher (including versions 2.x). FreeBSD version 1.0 included two
|
|
different serial drivers, which complicates the situation. Also,
|
|
the serial device driver (<devicename>sio</devicename>) has improved
|
|
in every release of FreeBSD, so more recent versions of FreeBSD are
|
|
assumed to have better and more efficient drivers than earlier
|
|
versions.</para>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Terminology</title>
|
|
|
|
<para>A quick rundown of terminology:</para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term>bps</term>
|
|
|
|
<listitem>
|
|
<para>Bits per Second — the rate at which data is
|
|
transmitted</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>DTE</term>
|
|
|
|
<listitem>
|
|
<para>Data Terminal Equipment — for example, your
|
|
computer</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>DCE</term>
|
|
|
|
<listitem>
|
|
<para>Data Communications Equipment — your modem</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>RS-232</term>
|
|
|
|
<listitem>
|
|
<para>EIA standard for serial communications via hardware</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
<para>If you need more information about these terms and data
|
|
communications in general, the author remembers reading that
|
|
<emphasis>The RS-232 Bible</emphasis> (anybody have an ISBN?) is a
|
|
good reference.</para>
|
|
|
|
<para>When talking about communications data rates, the author does
|
|
not use the term “baud”. Baud refers to the number of
|
|
electrical state transitions that may be made in a period of time,
|
|
while “bps” (bits per second) is the
|
|
“correct” term to use (at least it does not seem to
|
|
bother the curmudgeons quite a much).</para>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>External vs. Internal Modems</title>
|
|
|
|
<para>External modems seem to be more convenient for dialup, because
|
|
external modems often can be semi-permanently configured via
|
|
parameters stored in non-volatile RAM and they usually provide
|
|
lighted indicators that display the state of important RS-232
|
|
signals. Blinking lights impress visitors, but lights are also very
|
|
useful to see whether a modem is operating properly.</para>
|
|
|
|
<para>Internal modems usually lack non-volatile RAM, so their
|
|
configuration may be limited only to setting DIP switches. If your
|
|
internal modem has any signal indicator lights, it is probably
|
|
difficult to view the lights when the system's cover is in
|
|
place.</para>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Modems and Cables</title>
|
|
|
|
<para>A background knowledge of these items is assumed</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>You know how to connect your modem to your computer so that
|
|
the two can communicate (unless you have an internal modem,
|
|
which does not need such a cable)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>You are familiar with your modem's command set, or know
|
|
where to look up needed commands</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>You know how to configure your modem (probably via a
|
|
terminal communications program) so you can set the non-volatile
|
|
RAM parameters</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<para>The first, connecting your modem, is usually simple — most
|
|
straight-through serial cables work without any problems. You need
|
|
to have a cable with appropriate connectors (DB-25 or DB-9, male or
|
|
female) on each end, and the cable must be a DCE-to-DTE cable with
|
|
these signals wired:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>Transmitted Data (<acronym>SD</acronym>)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Received Data (<acronym>RD</acronym>)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Request to Send (<acronym>RTS</acronym>)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Clear to Send (<acronym>CTS</acronym>)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Data Set Ready (<acronym>DSR</acronym>)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Data Terminal Ready (<acronym>DTR</acronym>)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Carrier Detect (<acronym>CD</acronym>)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Signal Ground (<acronym>SG</acronym>)</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<para>FreeBSD needs the <acronym>RTS</acronym> and
|
|
<acronym>CTS</acronym> signals for flow-control at speeds above
|
|
2400bps, the <acronym>CD</acronym> signal to detect when a call has
|
|
been answered or the line has been hung up, and the
|
|
<acronym>DTR</acronym> signal to reset the modem after a session is
|
|
complete. Some cables are wired without all of the needed signals,
|
|
so if you have problems, such as a login session not going away when
|
|
the line hangs up, you may have a problem with your cable.</para>
|
|
|
|
<para>The second prerequisite depends on the modem(s) you use. If you
|
|
do not know your modem's command set by heart, you will need to have
|
|
the modem's reference book or user's guide handy. Sample commands
|
|
for USR Sportster 14,400 external modems will be given, which you
|
|
may be able to use as a reference for your own modem's
|
|
commands.</para>
|
|
|
|
<para>Lastly, you will need to know how to setup your modem so that it
|
|
will work well with FreeBSD. Like other UNIX-like operating
|
|
systems, FreeBSD uses the hardware signals to find out when a call
|
|
has been answered or a line has been hung up and to hangup and reset
|
|
the modem after a call. FreeBSD avoids sending commands to the
|
|
modem or watching for status reports from the modem. If you are
|
|
familiar with connecting modems to PC-based bulletin board systems,
|
|
this may seem awkward.</para>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Serial Interface Considerations</title>
|
|
|
|
<para>FreeBSD supports NS8250-, NS16450-, NS16550-, and NS16550A-based
|
|
EIA RS-232C (CCITT V.24) communications interfaces. The 8250 and
|
|
16450 devices have single-character buffers. The 16550 device
|
|
provides a 16-character buffer, which allows for better system
|
|
performance. (Bugs in plain 16550's prevent the use of the
|
|
16-character buffer, so use 16550A's if possible). Because
|
|
single-character-buffer devices require more work by the operating
|
|
system than the 16-character-buffer devices, 16550A-based serial
|
|
interface cards are much preferred. If the system has many active
|
|
serial ports or will have a heavy load, 16550A-based cards are
|
|
better for low-error-rate communications.</para>
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Quick Overview</title>
|
|
|
|
<para>Here is the process that FreeBSD follows to accept dialup logins.
|
|
A <command>getty</command> process, spawned by
|
|
<command>init</command>, patiently waits to open the assigned serial
|
|
port (<filename>/dev/ttyd0</filename>, for our example). The command
|
|
<command>ps ax</command> might show this:</para>
|
|
|
|
<screen> 4850 ?? I 0:00.09 /usr/libexec/getty V19200 ttyd0</screen>
|
|
|
|
<para>When a user dials the modem's line and the modems connect, the
|
|
<acronym>CD</acronym> line is asserted by the modem. The kernel
|
|
notices that carrier has been detected and completes
|
|
<command>getty</command>'s open of the port. <command>getty</command>
|
|
sends a <prompt>login:</prompt> prompt at the specified initial line
|
|
speed. <command>getty</command> watches to see if legitimate
|
|
characters are received, and, in a typical configuration, if it finds
|
|
junk (probably due to the modem's connection speed being different
|
|
than <command>getty</command>'s speed), <command>getty</command> tries
|
|
adjusting the line speeds until it receives reasonable
|
|
characters.</para>
|
|
|
|
<para>We hope <command>getty</command> finds the correct speed and the
|
|
user sees a <prompt>login:</prompt> prompt. After the user enters
|
|
his/her login name, <command>getty</command> executes
|
|
<filename>/usr/bin/login</filename>, which completes the login by
|
|
asking for the user's password and then starting the user's
|
|
shell.</para>
|
|
|
|
<para>Let's dive into the configuration...</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Kernel Configuration</title>
|
|
|
|
<para>FreeBSD kernels typically come prepared to search for four serial
|
|
ports, known in the PC-DOS world as <devicename>COM1:</devicename>,
|
|
<devicename>COM2:</devicename>, <devicename>COM3:</devicename>, and
|
|
<devicename>COM4:</devicename>. FreeBSD can presently also handle
|
|
“dumb” multiport serial interface cards, such as the Boca
|
|
Board 1008 and 2016 (please see the manual page &man.sio.4; for kernel
|
|
configuration information if you have a multiport serial card). The
|
|
default kernel only looks for the standard COM ports, though.</para>
|
|
|
|
<para>To see if your kernel recognizes any of your serial ports, watch
|
|
for messages while the kernel is booting, or use the
|
|
<command>/sbin/dmesg</command> command to replay the kernel's boot
|
|
messages. In particular, look for messages that start with the
|
|
characters <literal>sio</literal>. Hint: to view just the messages
|
|
that have the word <literal>sio</literal>, use the command:</para>
|
|
|
|
<screen>&prompt.root; <userinput>/sbin/dmesg | grep 'sio'</userinput></screen>
|
|
|
|
<para>For example, on a system with four serial ports, these are the
|
|
serial-port specific kernel boot messages:</para>
|
|
|
|
<screen>sio0 at 0x3f8-0x3ff irq 4 on isa
|
|
sio0: type 16550A
|
|
sio1 at 0x2f8-0x2ff irq 3 on isa
|
|
sio1: type 16550A
|
|
sio2 at 0x3e8-0x3ef irq 5 on isa
|
|
sio2: type 16550A
|
|
sio3 at 0x2e8-0x2ef irq 9 on isa
|
|
sio3: type 16550A</screen>
|
|
|
|
<para>If your kernel does not recognize all of your serial ports, you
|
|
will probably need to configure a custom FreeBSD kernel for your
|
|
system.</para>
|
|
|
|
<para>Please see the BSD System Manager's Manual chapter on
|
|
“Building Berkeley Kernels with Config” [the source for
|
|
which is in <filename>/usr/src/share/doc/smm</filename>] and
|
|
“FreeBSD Configuration Options” [in
|
|
<filename>/sys/conf/options</filename> and in
|
|
<filename>/sys/<replaceable>arch</replaceable>/conf/options.<replaceable>arch</replaceable></filename>,
|
|
with <emphasis>arch</emphasis> for example being
|
|
<filename>i386</filename>] for more information on configuring and
|
|
building kernels. You may have to unpack the kernel source
|
|
distribution if have not installed the system sources already
|
|
(<filename>srcdist/srcsys.??</filename> in FreeBSD 1.1,
|
|
<filename>srcdist/sys.??</filename> in FreeBSD 1.1.5.1, or the entire
|
|
source distribution in FreeBSD 2.0) to be able to configure and build
|
|
kernels.</para>
|
|
|
|
<para>Create a kernel configuration file for your system (if you have
|
|
not already) by <command>cd</command>ing to
|
|
<filename>/sys/i386/conf</filename>. Then, if you are creating a new
|
|
custom configuration file, copy the file
|
|
<filename>GENERICAH</filename> (or <filename>GENERICBT</filename>, if
|
|
you have a BusTek SCSI controller on FreeBSD 1.x) to
|
|
<filename>YOURSYS</filename>, where <filename>YOURSYS</filename> is
|
|
the name of your system, but in upper-case letters. Edit the file,
|
|
and change the device lines:</para>
|
|
|
|
<programlisting>
|
|
device sio0 at isa? port "IO_COM1" tty irq 4 vector siointr
|
|
device sio1 at isa? port "IO_COM2" tty irq 3 vector siointr
|
|
device sio2 at isa? port "IO_COM3" tty irq 5 vector siointr
|
|
device sio3 at isa? port "IO_COM4" tty irq 9 vector siointr</programlisting>
|
|
|
|
<para>You can comment-out or completely remove lines for devices you do
|
|
not have. If you have a multiport serial board, such as the Boca
|
|
Board BB2016, please see the &man.sio.4; man page for complete
|
|
information on how to write configuration lines for multiport boards.
|
|
Be careful if you are using a configuration file that was previously
|
|
used for a different version of FreeBSD because the device flags have
|
|
changed between versions.</para>
|
|
|
|
<note>
|
|
<para><literal>port "IO_COM1"</literal> is a substitution for
|
|
<literal>port 0x3f8</literal>, <literal>IO_COM2</literal> is
|
|
<literal>0x2f8</literal>, <literal>IO_COM3</literal> is
|
|
<literal>0x3e8</literal>, and <literal>IO_COM4</literal> is
|
|
<literal>0x2e8</literal>, which are fairly common port addresses for
|
|
their respective serial ports; interrupts 4, 3, 5, and 9 are fairly
|
|
common interrupt request lines. Also note that regular serial ports
|
|
<emphasis>cannot</emphasis> share interrupts on ISA-bus PCs
|
|
(multiport boards have on-board electronics that allow all the
|
|
16550A's on the board to share one or two interrupt request
|
|
lines).</para>
|
|
</note>
|
|
|
|
<para>When you are finished adjusting the kernel configuration file, use
|
|
the program <command>config</command> as documented in “Building
|
|
Berkeley Kernels with Config” and the
|
|
&man.config.8; manual page to prepare a kernel building directory,
|
|
then build, install, and test the new kernel.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Device Special Files</title>
|
|
|
|
<para>Most devices in the kernel are accessed through “device
|
|
special files”, which are located in the
|
|
<filename>/dev</filename> directory. The <devicename>sio</devicename>
|
|
devices are accessed through the
|
|
<filename>/dev/ttyd<replaceable>?</replaceable></filename> (dial-in)
|
|
and <filename>/dev/cua0<replaceable>?</replaceable></filename>
|
|
(call-out) devices. On FreeBSD version 1.1.5 and higher, there are
|
|
also initialization devices
|
|
(<filename>/dev/ttyid<replaceable>?</replaceable></filename> and
|
|
<filename>/dev/cuai0<replaceable>?</replaceable></filename>) and
|
|
locking devices
|
|
(<filename>/dev/ttyld<replaceable>?</replaceable></filename> and
|
|
<filename>/dev/cual0<replaceable>?</replaceable></filename>). The
|
|
initialization devices are used to initialize communications port
|
|
parameters each time a port is opened, such as
|
|
<literal>crtscts</literal> for modems which use
|
|
<literal>CTS/RTS</literal> signaling for flow control. The locking
|
|
devices are used to lock flags on ports to prevent users or programs
|
|
changing certain parameters; see the manual pages &man.termios.4;,
|
|
&man.sio.4;, and &man.stty.1; for
|
|
information on the terminal settings, locking & initializing
|
|
devices, and setting terminal options, respectively.</para>
|
|
|
|
<sect3>
|
|
<title>Making Device Special Files</title>
|
|
|
|
<para>A shell script called <command>MAKEDEV</command> in the
|
|
<filename>/dev</filename> directory manages the device special
|
|
files. (The manual page for &man.MAKEDEV.8; on FreeBSD 1.1.5 is
|
|
fairly bogus in its discussion of <acronym>COM</acronym> ports, so
|
|
ignore it.) To use <command>MAKEDEV</command> to make dialup device
|
|
special files for <devicename>COM1:</devicename> (port 0),
|
|
<command>cd</command> to <filename>/dev</filename> and issue the
|
|
command <command>MAKEDEV ttyd0</command>. Likewise, to make dialup
|
|
device special files for <devicename>COM2:</devicename> (port 1),
|
|
use <command>MAKEDEV ttyd1</command>.</para>
|
|
|
|
<para><command>MAKEDEV</command> not only creates the
|
|
<filename>/dev/ttyd<replaceable>?</replaceable></filename> device
|
|
special files, but also creates the
|
|
<filename>/dev/cua0<replaceable>?</replaceable></filename> (and all
|
|
of the initializing and locking special files under FreeBSD 1.1.5
|
|
and up) and removes the hardwired terminal special file
|
|
<filename>/dev/tty0<replaceable>?</replaceable></filename>, if it
|
|
exists.</para>
|
|
|
|
<para>After making new device special files, be sure to check the
|
|
permissions on the files (especially the
|
|
<filename>/dev/cua*</filename> files) to make sure that only users
|
|
who should have access to those device special files can read &
|
|
write on them — you probably do not want to allow your average
|
|
user to use your modems to dialout. The default permissions on the
|
|
<filename>/dev/cua*</filename> files should be sufficient:</para>
|
|
|
|
<screen>crw-rw---- 1 uucp dialer 28, 129 Feb 15 14:38 /dev/cua01
|
|
crw-rw---- 1 uucp dialer 28, 161 Feb 15 14:38 /dev/cuai01
|
|
crw-rw---- 1 uucp dialer 28, 193 Feb 15 14:38 /dev/cual01</screen>
|
|
|
|
<para>These permissions allow the user <username>uucp</username> and
|
|
users in the group <username>dialer</username> to use the call-out
|
|
devices.</para>
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Configuration Files</title>
|
|
|
|
<para>There are three system configuration files in the
|
|
<filename>/etc</filename> directory that you will probably need to
|
|
edit to allow dialup access to your FreeBSD system. The first,
|
|
<filename>/etc/gettytab</filename>, contains configuration information
|
|
for the <filename>/usr/libexec/getty</filename> daemon. Second,
|
|
<filename>/etc/ttys</filename> holds information that tells
|
|
<filename>/sbin/init</filename> what <filename>tty</filename> devices
|
|
should have <command>getty</command> processes running on them.
|
|
Lastly, you can place port initialization commands in the
|
|
<filename>/etc/rc.serial</filename> script if you have FreeBSD 1.1.5.1
|
|
or higher; otherwise, you can initialize ports in the
|
|
<filename>/etc/rc.local</filename> script.</para>
|
|
|
|
<para>There are two schools of thought regarding dialup modems on UNIX.
|
|
One group likes to configure their modems and system so that no matter
|
|
at what speed a remote user dials in, the local computer-to-modem
|
|
RS-232 interface runs at a locked speed. The benefit of this
|
|
configuration is that the remote user always sees a system login
|
|
prompt immediately. The downside is that the system does not know
|
|
what a user's true data rate is, so full-screen programs like Emacs
|
|
will not adjust their screen-painting methods to make their response
|
|
better for slower connections.</para>
|
|
|
|
<para>The other school configures their modems' RS-232 interface to vary
|
|
its speed based on the remote user's connection speed. For example,
|
|
V.32bis (14.4 Kbps) connections to the modem might make the modem run
|
|
its RS-232 interface at 19.2 Kbps, while 2400 bps connections make the
|
|
modem's RS-232 interface run at 2400 bps. Because
|
|
<command>getty</command> does not understand any particular modem's
|
|
connection speed reporting, <command>getty</command> gives a
|
|
<prompt>login:</prompt> message at an initial speed and watches the
|
|
characters that come back in response. If the user sees junk, it is
|
|
assumed that they know they should press the
|
|
<literal><Enter></literal> key until they see a recognizable
|
|
prompt. If the data rates do not match, <command>getty</command> sees
|
|
anything the user types as “junk”, tries going to the next
|
|
speed and gives the <prompt>login:</prompt> prompt again. This
|
|
procedure can continue ad nauseum, but normally only takes a keystroke
|
|
or two before the user sees a good prompt. Obviously, this login
|
|
sequence does not look as clean as the former
|
|
“locked-speed” method, but a user on a low-speed
|
|
connection should receive better interactive response from full-screen
|
|
programs.</para>
|
|
|
|
<para>The author will try to give balanced configuration information,
|
|
but is biased towards having the modem's data rate follow the
|
|
connection rate.</para>
|
|
|
|
<sect3>
|
|
<title><filename>/etc/gettytab</filename></title>
|
|
|
|
<para><filename>/etc/gettytab</filename> is a &man.termcap.5;-style
|
|
file of configuration information for &man.getty.8;. Please see the
|
|
&man.gettytab.5; manual page for complete information on the
|
|
format of the file and the list of capabilities.</para>
|
|
|
|
<sect4>
|
|
<title>Locked-Speed Config</title>
|
|
|
|
<para>If you are locking your modem's data communications rate at a
|
|
particular speed, you probably will not need to make any changes
|
|
to <filename>/etc/gettytab</filename>.</para>
|
|
</sect4>
|
|
|
|
<sect4>
|
|
<title>Matching-Speed Config</title>
|
|
|
|
<para>You will need to setup an entry in
|
|
<filename>/etc/gettytab</filename> to give
|
|
<command>getty</command> information about the speeds you wish to
|
|
use for your modem. If you have a 2400 bps modem, you can
|
|
probably use the existing <literal>D2400</literal> entry. This
|
|
entry already exists in the FreeBSD 1.1.5.1
|
|
<filename>gettytab</filename> file, so you do not need to add it
|
|
unless it is missing under your version of FreeBSD:</para>
|
|
|
|
<programlisting>
|
|
#
|
|
# Fast dialup terminals, 2400/1200/300 rotary (can start either way)
|
|
#
|
|
D2400|d2400|Fast-Dial-2400:\
|
|
:nx=D1200:tc=2400-baud:
|
|
3|D1200|Fast-Dial-1200:\
|
|
:nx=D300:tc=1200-baud:
|
|
5|D300|Fast-Dial-300:\
|
|
:nx=D2400:tc=300-baud:</programlisting>
|
|
|
|
<para>If you have a higher speed modem, you will probably need to
|
|
add an entry in <filename>/etc/gettytab</filename>; here is an
|
|
entry you could use for a 14.4 Kbps modem with a top interface
|
|
speed of 19.2 Kbps:</para>
|
|
|
|
<programlisting>
|
|
#
|
|
# Additions for a V.32bis Modem
|
|
#
|
|
um|V300|High Speed Modem at 300,8-bit:\
|
|
:nx=V19200:tc=std.300:
|
|
un|V1200|High Speed Modem at 1200,8-bit:\
|
|
:nx=V300:tc=std.1200:
|
|
uo|V2400|High Speed Modem at 2400,8-bit:\
|
|
:nx=V1200:tc=std.2400:
|
|
up|V9600|High Speed Modem at 9600,8-bit:\
|
|
:nx=V2400:tc=std.9600:
|
|
uq|V19200|High Speed Modem at 19200,8-bit:\
|
|
:nx=V9600:tc=std.19200:</programlisting>
|
|
|
|
<para>On FreeBSD 1.1.5 and later, this will result in 8-bit, no
|
|
parity connections. Under FreeBSD 1.1, add
|
|
<literal>:np:</literal> parameters to the
|
|
<literal>std.<replaceable>xxx</replaceable></literal> entries at
|
|
the top of the file for 8 bits, no parity; otherwise, the default
|
|
is 7 bits, even parity.</para>
|
|
|
|
<para>The example above starts the communications rate at 19.2 Kbps
|
|
(for a V.32bis connection), then cycles through 9600 bps (for
|
|
V.32), 2400 bps, 1200 bps, 300 bps, and back to 19.2 Kbps.
|
|
Communications rate cycling is implemented with the
|
|
<literal>nx=</literal> (“next table”) capability.
|
|
Each of the lines uses a <literal>tc=</literal> (“table
|
|
continuation”) entry to pick up the rest of the
|
|
“standard” settings for a particular data rate.</para>
|
|
|
|
<para>If you have a 28.8 Kbps modem and/or you want to take
|
|
advantage of compression on a 14.4 Kbps modem, you need to use a
|
|
higher communications rate than 19.2 Kbps. Here is an example of
|
|
a <filename>gettytab</filename> entry starting a 57.6 Kbps:</para>
|
|
|
|
<programlisting>
|
|
#
|
|
# Additions for a V.32bis or V.34 Modem
|
|
# Starting at 57.6 Kbps
|
|
#
|
|
vm|VH300|Very High Speed Modem at 300,8-bit:\
|
|
:nx=VH57600:tc=std.300:
|
|
vn|VH1200|Very High Speed Modem at 1200,8-bit:\
|
|
:nx=VH300:tc=std.1200:
|
|
vo|VH2400|Very High Speed Modem at 2400,8-bit:\
|
|
:nx=VH1200:tc=std.2400:
|
|
vp|VH9600|Very High Speed Modem at 9600,8-bit:\
|
|
:nx=VH2400:tc=std.9600:
|
|
vq|VH57600|Very High Speed Modem at 57600,8-bit:\
|
|
:nx=VH9600:tc=std.57600:</programlisting>
|
|
|
|
<para>If you have a slow CPU or a heavily loaded system and you do
|
|
not have 16550A-based serial ports, you may receive sio
|
|
“silo” errors at 57.6 Kbps.</para>
|
|
</sect4>
|
|
</sect3>
|
|
|
|
<sect3 id="dialup-ttys">
|
|
<title><filename>/etc/ttys</filename></title>
|
|
|
|
<para><filename>/etc/ttys</filename> is the list of
|
|
<filename>ttys</filename> for <command>init</command> to monitor.
|
|
<filename>/etc/ttys</filename> also provides security information to
|
|
<command>login</command> (user <username>root</username> may only
|
|
login on ttys marked <literal>secure</literal>). See the manual
|
|
page for
|
|
&man.ttys.5; for more information.</para>
|
|
|
|
<para>You will need to either modify existing lines in
|
|
<filename>/etc/ttys</filename> or add new lines to make
|
|
<command>init</command> run <command>getty</command> processes
|
|
automatically on your new dialup ports. The general format of the
|
|
line will be the same, whether you are using a locked-speed or
|
|
matching-speed configuration:</para>
|
|
|
|
<programlisting>
|
|
ttyd0 "/usr/libexec/getty xxx" dialup on</programlisting>
|
|
|
|
<para>The first item in the above line is the device special file for
|
|
this entry — <literal>ttyd0</literal> means
|
|
<filename>/dev/ttyd0</filename> is the file that this
|
|
<command>getty</command> will be watching. The second item,
|
|
<literal>"/usr/libexec/getty
|
|
<replaceable>xxx</replaceable>"</literal>
|
|
(<replaceable>xxx</replaceable> will be replaced by the initial
|
|
<filename>gettytab</filename> capability) is the process
|
|
<command>init</command> will run on the device. The third item,
|
|
<literal>dialup</literal>, is the default terminal type. The fourth
|
|
parameter, <literal>on</literal>, indicates to
|
|
<command>init</command> that the line is operational. There can be
|
|
a fifth parameter, <literal>secure</literal>, but it should only be
|
|
used for terminals which are physically secure (such as the system
|
|
console).</para>
|
|
|
|
<para>The default terminal type (<literal>dialup</literal> in the
|
|
example above) may depend on local preferences.
|
|
<literal>dialup</literal> is the traditional default terminal type
|
|
on dialup lines so that users may customize their login scripts to
|
|
notice when the terminal is <literal>dialup</literal> and
|
|
automatically adjust their terminal type. However, the author finds
|
|
it easier at his site to specify <literal>vt102</literal> as the
|
|
default terminal type, since the users just use VT102 emulation on
|
|
their remote systems.</para>
|
|
|
|
<para>After you have made changes to <filename>/etc/ttys</filename>,
|
|
you may send the <command>init</command> process a
|
|
<acronym>HUP</acronym> signal to re-read the file. You can use the
|
|
command <screen>&prompt.root; <userinput>kill -1
|
|
1</userinput></screen> to send the signal. If this is your
|
|
first time setting up the system, though, you may want to wait until
|
|
your modem(s) are properly configured and connected before signaling
|
|
<command>init</command>.</para>
|
|
|
|
<sect4>
|
|
<title>Locked-Speed Config</title>
|
|
|
|
<para>For a locked-speed configuration, your
|
|
<filename>ttys</filename> entry needs to have a fixed-speed entry
|
|
provided to <command>getty</command>. For a modem whose port
|
|
speed is locked at 19.2 Kbps, the <filename>ttys</filename> entry
|
|
might look like this:</para>
|
|
|
|
<programlisting>
|
|
ttyd0 "/usr/libexec/getty std.19200" dialup on</programlisting>
|
|
|
|
<para>If your modem is locked at a different data rate, substitute
|
|
the appropriate name for the
|
|
<literal>std.<replaceable>speed</replaceable></literal> entry for
|
|
<literal>std.19200</literal> from
|
|
<filename>/etc/gettytab</filename> for your modem's data
|
|
rate.</para>
|
|
</sect4>
|
|
|
|
<sect4>
|
|
<title>Matching-Speed Config</title>
|
|
|
|
<para>In a matching-speed configuration, your
|
|
<filename>ttys</filename> entry needs to reference the appropriate
|
|
beginning “auto-baud” (sic) entry in
|
|
<filename>/etc/gettytab</filename>. For example, if you added the
|
|
above suggested entry for a matching-speed modem that starts at
|
|
19.2 Kbps (the <filename>gettytab</filename> entry containing the
|
|
<literal>V19200</literal> starting point), your
|
|
<filename>ttys</filename> entry might look like this:</para>
|
|
|
|
<programlisting>
|
|
ttyd0 "/usr/libexec/getty V19200" dialup on</programlisting>
|
|
</sect4>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title><filename>/etc/rc.serial</filename> or
|
|
<filename>/etc/rc.local</filename></title>
|
|
|
|
<para>High-speed modems, like V.32, V.32bis, and V.34 modems, need to
|
|
use hardware (<filename>RTS/CTS</filename>) flow control. You can
|
|
add <command>stty</command> commands to
|
|
<filename>/etc/rc.serial</filename> on FreeBSD 1.1.5.1 and up, or
|
|
<filename>/etc/rc.local</filename> on FreeBSD 1.1, to set the
|
|
hardware flow control flag in the FreeBSD kernel for the modem
|
|
ports.</para>
|
|
|
|
<para>For example, on a sample FreeBSD 1.1.5.1 system,
|
|
<filename>/etc/rc.serial</filename> reads:</para>
|
|
|
|
<programlisting>
|
|
#!/bin/sh
|
|
#
|
|
# Serial port initial configuration
|
|
|
|
stty -f /dev/ttyid1 crtscts
|
|
stty -f /dev/cuai01 crtscts</programlisting>
|
|
|
|
<para>This sets the <literal>termios</literal> flag
|
|
<literal>crtscts</literal> on serial port #1's
|
|
(<devicename>COM2:</devicename>) dialin and dialout initialization
|
|
devices.</para>
|
|
|
|
<para>On an old FreeBSD 1.1 system, these entries were added to
|
|
<filename>/etc/rc.local</filename> to set the
|
|
<literal>crtscts</literal> flag on the devices:</para>
|
|
|
|
<programlisting>
|
|
# Set serial ports to use RTS/CTS flow control
|
|
stty -f /dev/ttyd0 crtscts
|
|
stty -f /dev/ttyd1 crtscts
|
|
stty -f /dev/ttyd2 crtscts
|
|
stty -f /dev/ttyd3 crtscts</programlisting>
|
|
|
|
<para>Since there is no initialization device special file on FreeBSD
|
|
1.1, one has to just set the flags on the sole device special file
|
|
and hope the flags are not cleared by a miscreant.</para>
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Modem Settings</title>
|
|
|
|
<para>If you have a modem whose parameters may be permanently set in
|
|
non-volatile RAM, you will need to use a terminal program (such as
|
|
Telix under PC-DOS or <command>tip</command> under FreeBSD) to set the
|
|
parameters. Connect to the modem using the same communications speed
|
|
as the initial speed <command>getty</command> will use and configure
|
|
the modem's non-volatile RAM to match these requirements:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para><acronym>CD</acronym> asserted when connected</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para><acronym>DTR</acronym> asserted for operation; dropping DTR
|
|
hangs up line & resets modem</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para><acronym>CTS</acronym> transmitted data flow control</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Disable <acronym>XON/XOFF</acronym> flow control</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para><acronym>RTS</acronym> received data flow control</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Quiet mode (no result codes)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>No command echo</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<para>Please read the documentation for your modem to find out what
|
|
commands and/or DIP switch settings you need to give it.</para>
|
|
|
|
<para>For example, to set the above parameters on a USRobotics
|
|
Sportster 14,400 external modem, one could give these commands to
|
|
the modem:</para>
|
|
|
|
<programlisting>
|
|
ATZ
|
|
AT&C1&D2&H1&I0&R2&W</programlisting>
|
|
|
|
<para>You might also want to take this opportunity to adjust other
|
|
settings in the modem, such as whether it will use V.42bis and/or MNP5
|
|
compression.</para>
|
|
|
|
<para>The USR Sportster 14,400 external modem also has some DIP switches
|
|
that need to be set; for other modems, perhaps you can use these
|
|
settings as an example:</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>Switch 1: UP — DTR Normal</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Switch 2: Do not care (Verbal Result Codes/Numeric Result
|
|
Codes)</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Switch 3: UP — Suppress Result Codes</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Switch 4: DOWN — No echo, offline commands</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Switch 5: UP — Auto Answer</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Switch 6: UP — Carrier Detect Normal</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Switch 7: UP — Load NVRAM Defaults</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Switch 8: Do not care (Smart Mode/Dumb Mode)</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<para>Result codes should be disabled/suppressed for dialup modems to
|
|
avoid problems that can occur if <command>getty</command> mistakenly
|
|
gives a <prompt>login:</prompt> prompt to a modem that is in command
|
|
mode and the modem echoes the command or returns a result code. I
|
|
have heard this sequence can result in a extended, silly conversation
|
|
between <command>getty</command> and the modem.</para>
|
|
|
|
<sect3>
|
|
<title>Locked-speed Config</title>
|
|
|
|
<para>For a locked-speed configuration, you will need to configure the
|
|
modem to maintain a constant modem-to-computer data rate independent
|
|
of the communications rate. On a USR Sportster 14,400 external
|
|
modem, these commands will lock the modem-to-computer data rate at
|
|
the speed used to issue the commands:</para>
|
|
|
|
<programlisting>
|
|
ATZ
|
|
AT&B1&W</programlisting>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Matching-speed Config</title>
|
|
|
|
<para>For a variable-speed configuration, you will need to configure
|
|
your modem to adjust its serial port data rate to match the incoming
|
|
call rate. On a USR Sportster 14,400 external modem, these commands
|
|
will lock the modem's error-corrected data rate to the speed used to
|
|
issue the commands, but allow the serial port rate to vary for
|
|
non-error-corrected connections:</para>
|
|
|
|
<programlisting>
|
|
ATZ
|
|
AT&B2&W</programlisting>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Checking the Modem's Configuration</title>
|
|
|
|
<para>Most high-speed modems provide commands to view the modem's
|
|
current operating parameters in a somewhat human-readable fashion.
|
|
On the USR Sportster 14,400 external modems, the command
|
|
<command>ATI5</command> displays the settings that are stored in the
|
|
non-volatile RAM. To see the true operating parameters of the modem
|
|
(as influenced by the USR's DIP switch settings), use the commands
|
|
<command>ATZ</command> and then <command>ATI4</command>.</para>
|
|
|
|
<para>If you have a different brand of modem, check your modem's
|
|
manual to see how to double-check your modem's configuration
|
|
parameters.</para>
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Troubleshooting</title>
|
|
|
|
<para>Here are a few steps you can follow to check out the dialup modem
|
|
on your system.</para>
|
|
|
|
<sect3>
|
|
<title>Checking out the FreeBSD system</title>
|
|
|
|
<para>Hook up your modem to your FreeBSD system, boot the system, and,
|
|
if your modem has status indication lights, watch to see whether the
|
|
modem's <acronym>DTR</acronym> indicator lights when the
|
|
<prompt>login:</prompt> prompt appears on the system's console
|
|
— if it lights up, that should mean that FreeBSD has started a
|
|
<command>getty</command> process on the appropriate communications
|
|
port and is waiting for the modem to accept a call.</para>
|
|
|
|
<para>If the <acronym>DTR</acronym> indicator doesn't light, login to
|
|
the FreeBSD system through the console and issue a <command>ps
|
|
ax</command> to see if FreeBSD is trying to run a
|
|
<command>getty</command> process on the correct port. You should see
|
|
a lines like this among the processes displayed:</para>
|
|
|
|
<screen> 114 ?? I 0:00.10 /usr/libexec/getty V19200 ttyd0
|
|
115 ?? I 0:00.10 /usr/libexec/getty V19200 ttyd1</screen>
|
|
|
|
<para>If you see something different, like this:</para>
|
|
|
|
<screen> 114 d0 I 0:00.10 /usr/libexec/getty V19200 ttyd0</screen>
|
|
|
|
<para>and the modem has not accepted a call yet, this means that
|
|
<command>getty</command> has completed its open on the
|
|
communications port. This could indicate a problem with the cabling
|
|
or a mis-configured modem, because <command>getty</command> should
|
|
not be able to open the communications port until
|
|
<acronym>CD</acronym> (carrier detect) has been asserted by the
|
|
modem.</para>
|
|
|
|
<para>If you do not see any <command>getty</command> processes waiting
|
|
to open the desired
|
|
<filename>ttyd<replaceable>?</replaceable></filename> port,
|
|
double-check your entries in <filename>/etc/ttys</filename> to see
|
|
if there are any mistakes there. Also, check the log file
|
|
<filename>/var/log/messages</filename> to see if there are any log
|
|
messages from <command>init</command> or <command>getty</command>
|
|
regarding any problems. If there are any messages, triple-check the
|
|
configuration files <filename>/etc/ttys</filename> and
|
|
<filename>/etc/gettytab</filename>, as well as the appropriate
|
|
device special files <filename>/dev/ttyd?</filename>, for any
|
|
mistakes, missing entries, or missing device special files.</para>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Try Dialing In</title>
|
|
|
|
<para>Try dialing into the system; be sure to use 8 bits, no parity, 1
|
|
stop bit on the remote system. If you do not get a prompt right
|
|
away, or get garbage, try pressing <literal><Enter></literal>
|
|
about once per second. If you still do not see a
|
|
<prompt>login:</prompt> prompt after a while, try sending a
|
|
<command>BREAK</command>. If you are using a high-speed modem to do
|
|
the dialing, try dialing again after locking the dialing modem's
|
|
interface speed (via <command>AT&B1</command> on a USR
|
|
Sportster, for example).</para>
|
|
|
|
<para>If you still cannot get a <prompt>login:</prompt> prompt, check
|
|
<filename>/etc/gettytab</filename> again and double-check
|
|
that</para>
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>The initial capability name specified in
|
|
<filename>/etc/ttys</filename> for the line matches a name of a
|
|
capability in <filename>/etc/gettytab</filename></para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Each <literal>nx=</literal> entry matches another
|
|
<filename>gettytab</filename> capability name</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>Each <literal>tc=</literal> entry matches another
|
|
<filename>gettytab</filename> capability name</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<para>If you dial but the modem on the FreeBSD system will not answer,
|
|
make sure that the modem is configured to answer the phone when
|
|
<acronym>DTR</acronym> is asserted. If the modem seems to be
|
|
configured correctly, verify that the <acronym>DTR</acronym> line is
|
|
asserted by checking the modem's indicator lights (if it has
|
|
any).</para>
|
|
|
|
<para>If you have gone over everything several times and it still does
|
|
not work, take a break and come back to it later. If it still does
|
|
not work, perhaps you can send an electronic mail message to the
|
|
&a.questions;describing your modem and your problem, and the good
|
|
folks on the list will try to help.</para>
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Acknowledgments</title>
|
|
|
|
<para>Thanks to these people for comments and advice:</para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term>&a.kelly;</term>
|
|
|
|
<listitem>
|
|
<para>for a number of good suggestions</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="dialout">
|
|
<title>Dialout Service</title>
|
|
|
|
<para><emphasis>Information integrated from FAQ.</emphasis></para>
|
|
|
|
<para>The following are tips to getting your host to be able to connect
|
|
over the modem to another computer. This is appropriate for
|
|
establishing a terminal session with a remote host.</para>
|
|
|
|
<para>This is useful to log onto a BBS.</para>
|
|
|
|
<para>This kind of connection can be extremely helpful to get a file on
|
|
the Internet if you have problems with PPP. If you need to ftp
|
|
something and PPP is broken, use the terminal session to ftp it. Then
|
|
use zmodem to transfer it to your machine.</para>
|
|
|
|
<sect2>
|
|
<title>Why cannot I run <command>tip</command> or
|
|
<command>cu</command>?</title>
|
|
|
|
<para>On your system, the programs <command>tip</command> and
|
|
<command>cu</command> are probably executable only by
|
|
<username>uucp</username> and group <username>dialer</username>. You
|
|
can use the group <username>dialer</username> to control who has
|
|
access to your modem or remote systems. Just add yourself to group
|
|
dialer.</para>
|
|
|
|
<para>Alternatively, you can let everyone on your system run
|
|
<command>tip</command> and <command>cu</command> by typing:</para>
|
|
|
|
<screen>&prompt.root; <userinput>chmod 4511 /usr/bin/tip</userinput></screen>
|
|
|
|
<para>You do not have to run this command for <command>cu</command>,
|
|
since <command>cu</command> is just a hard link to
|
|
<command>tip</command>.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>My stock Hayes modem is not supported, what can I do?</title>
|
|
|
|
<para>Actually, the man page for <command>tip</command> is out of date.
|
|
There is a generic Hayes dialer already built in. Just use
|
|
<literal>at=hayes</literal> in your <filename>/etc/remote</filename>
|
|
file.</para>
|
|
|
|
<para>The Hayes driver is not smart enough to recognize some of the
|
|
advanced features of newer modems—messages like
|
|
<literal>BUSY</literal>, <literal>NO DIALTONE</literal>, or
|
|
<literal>CONNECT 115200</literal> will just confuse it. You should
|
|
turn those messages off when you use <command>tip</command> (using
|
|
<command>ATX0&W</command>).</para>
|
|
|
|
<para>Also, the dial timeout for <command>tip</command> is 60 seconds.
|
|
Your modem should use something less, or else tip will think there is
|
|
a communication problem. Try <command>ATS7=45&W</command>.</para>
|
|
|
|
<para>Actually, as shipped <command>tip</command> does not yet support
|
|
it fully. The solution is to edit the file
|
|
<filename>tipconf.h</filename> in the directory
|
|
<filename>/usr/src/usr.bin/tip/tip</filename> Obviously you need the
|
|
source distribution to do this.</para>
|
|
|
|
<para>Edit the line <literal>#define HAYES 0</literal> to
|
|
<literal>#define HAYES 1</literal>. Then <command>make</command> and
|
|
<command>make install</command>. Everything works nicely after
|
|
that.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="direct-at">
|
|
<title>How am I expected to enter these AT commands?</title>
|
|
|
|
<para>Make what is called a “direct” entry in your
|
|
<filename>/etc/remote</filename> file. For example, if your modem is
|
|
hooked up to the first serial port, <filename>/dev/cuaa0</filename>,
|
|
then put in the following line:</para>
|
|
|
|
<programlisting>
|
|
cuaa0:dv=/dev/cuaa0:br#19200:pa=none</programlisting>
|
|
|
|
<para>Use the highest bps rate your modem supports in the br capability.
|
|
Then, type <command>tip cuaa0</command> and you will be connected to
|
|
your modem.</para>
|
|
|
|
<para>If there is no <filename>/dev/cuaa0</filename> on your system, do
|
|
this:</para>
|
|
|
|
<screen>&prompt.root; <userinput>cd /dev</userinput>
|
|
&prompt.root; <userinput>MAKEDEV cuaa0</userinput></screen>
|
|
|
|
<para>Or use cu as root with the following command:</para>
|
|
|
|
<screen>&prompt.root; <userinput>cu -l<replaceable>line</replaceable> -s<replaceable>speed</replaceable></userinput></screen>
|
|
|
|
<para><replaceable>line</replaceable> is the serial port
|
|
(e.g.<filename>/dev/cuaa0</filename>) and
|
|
<replaceable>speed</replaceable> is the speed
|
|
(e.g.<literal>57600</literal>). When you are done entering the AT
|
|
commands hit <command>~.</command> to exit.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>The <literal>@</literal> sign for the pn capability does not
|
|
work!</title>
|
|
|
|
<para>The <literal>@</literal> sign in the phone number capability tells
|
|
tip to look in <filename>/etc/phones</filename> for a phone number.
|
|
But the <literal>@</literal> sign is also a special character in
|
|
capability files like <filename>/etc/remote</filename>. Escape it
|
|
with a backslash:</para>
|
|
|
|
<programlisting>
|
|
pn=\@</programlisting>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>How can I dial a phone number on the command line?</title>
|
|
|
|
<para>Put what is called a “generic” entry in your
|
|
<filename>/etc/remote</filename> file. For example:</para>
|
|
|
|
<programlisting>
|
|
tip115200|Dial any phone number at 115200 bps:\
|
|
:dv=/dev/cuaa0:br#115200:at=hayes:pa=none:du:
|
|
tip57600|Dial any phone number at 57600 bps:\
|
|
:dv=/dev/cuaa0:br#57600:at=hayes:pa=none:du:</programlisting>
|
|
|
|
<para>Then you can things like:</para>
|
|
|
|
<screen>&prompt.root; <userinput>tip -115200 5551234</userinput></screen>
|
|
|
|
<para>If you prefer <command>cu</command> over <command>tip</command>,
|
|
use a generic cu entry:</para>
|
|
|
|
<programlisting>
|
|
cu115200|Use cu to dial any number at 115200bps:\
|
|
:dv=/dev/cuaa1:br#57600:at=hayes:pa=none:du:</programlisting>
|
|
|
|
<para>and type:</para>
|
|
|
|
<screen>&prompt.root; <userinput>cu 5551234 -s 115200</userinput></screen>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Do I have to type in the bps rate every time I do that?</title>
|
|
|
|
<para>Put in an entry for <literal>tip1200</literal> or
|
|
<literal>cu1200</literal>, but go ahead and use whatever bps rate is
|
|
appropriate with the br capability. <command>tip</command> thinks a
|
|
good default is 1200 bps which is why it looks for a
|
|
<literal>tip1200</literal> entry. You do not have to use 1200 bps,
|
|
though.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>I access a number of hosts through a terminal server.</title>
|
|
|
|
<para>Rather than waiting until you are connected and typing
|
|
<command>CONNECT <host></command> each time, use tip's
|
|
<literal>cm</literal> capability. For example, these entries in
|
|
<filename>/etc/remote</filename>:</para>
|
|
|
|
<programlisting>
|
|
pain|pain.deep13.com|Forrester's machine:\
|
|
:cm=CONNECT pain\n:tc=deep13:
|
|
muffin|muffin.deep13.com|Frank's machine:\
|
|
:cm=CONNECT muffin\n:tc=deep13:
|
|
deep13:Gizmonics Institute terminal server:\
|
|
:dv=/dev/cua02:br#38400:at=hayes:du:pa=none:pn=5551234:</programlisting>
|
|
|
|
<para>will let you type <command>tip pain</command> or <command>tip
|
|
muffin</command> to connect to the hosts pain or muffin; and
|
|
<command>tip deep13</command> to get to the terminal server.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Can tip try more than one line for each site?</title>
|
|
|
|
<para>This is often a problem where a university has several modem lines
|
|
and several thousand students trying to use them...</para>
|
|
|
|
<para>Make an entry for your university in
|
|
<filename>/etc/remote</filename> and use <literal>@</literal> for the
|
|
<literal>pn</literal> capability:</para>
|
|
|
|
<programlisting>
|
|
big-university:\
|
|
:pn=\@:tc=dialout
|
|
dialout:\
|
|
:dv=/dev/cuaa3:br#9600:at=courier:du:pa=none:</programlisting>
|
|
|
|
<para>Then, list the phone numbers for the university in
|
|
<filename>/etc/phones</filename>:</para>
|
|
|
|
<programlisting>
|
|
big-university 5551111
|
|
big-university 5551112
|
|
big-university 5551113
|
|
big-university 5551114</programlisting>
|
|
|
|
<para><command>tip</command> will try each one in the listed order, then
|
|
give up. If you want to keep retrying, run <command>tip</command> in
|
|
a while loop.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Why do I have to hit CTRL+P twice to send CTRL+P once?</title>
|
|
|
|
<para>CTRL+P is the default “force” character, used to tell
|
|
<command>tip</command> that the next character is literal data. You
|
|
can set the force character to any other character with the
|
|
<command>~s</command> escape, which means “set a
|
|
variable.”</para>
|
|
|
|
<para>Type
|
|
<command>~sforce=<replaceable>single-char</replaceable></command>
|
|
followed by a newline. <replaceable>single-char</replaceable> is any
|
|
single character. If you leave out
|
|
<replaceable>single-char</replaceable>, then the force character is
|
|
the nul character, which you can get by typing CTRL+2 or CTRL+SPACE.
|
|
A pretty good value for <replaceable>single-char</replaceable> is
|
|
SHIFT+CTRL+6, which I have seen only used on some terminal
|
|
servers.</para>
|
|
|
|
<para>You can have the force character be whatever you want by
|
|
specifying the following in your <filename>$HOME/.tiprc</filename>
|
|
file:</para>
|
|
|
|
<programlisting>
|
|
force=<single-char></programlisting>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Suddenly everything I type is in UPPER CASE??</title>
|
|
|
|
<para>You must have pressed CTRL+A, <command>tip</command>'s
|
|
“raise character,” specially designed for people with
|
|
broken caps-lock keys. Use <command>~s</command> as above and set the
|
|
variable <literal>raisechar</literal> to something reasonable. In
|
|
fact, you can set it to the same as the force character, if you never
|
|
expect to use either of these features.</para>
|
|
|
|
<para>Here is a sample .tiprc file perfect for Emacs users who need to
|
|
type CTRL+2 and CTRL+A a lot:</para>
|
|
|
|
<programlisting>
|
|
force=^^
|
|
raisechar=^^</programlisting>
|
|
|
|
<para>The ^^ is SHIFT+CTRL+6.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>How can I do file transfers with <command>tip</command>?</title>
|
|
|
|
<para>If you are talking to another UNIX system, you can send and
|
|
receive files with <command>~p</command> (put) and
|
|
<command>~t</command> (take). These commands run
|
|
<command>cat</command> and <command>echo</command> on the remote
|
|
system to accept and send files. The syntax is:</para>
|
|
|
|
<cmdsynopsis>
|
|
<command>~p</command>
|
|
<arg choice="plain">local-file</arg>
|
|
<arg choice="opt">remote-file</arg>
|
|
</cmdsynopsis>
|
|
|
|
<cmdsynopsis>
|
|
<command>~t</command>
|
|
<arg choice="plain">remote-file</arg>
|
|
<arg choice="opt">local-file</arg>
|
|
</cmdsynopsis>
|
|
|
|
<para>There is no error checking, so you probably should use another
|
|
protocol, like zmodem.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>How can I run zmodem with <command>tip</command>?</title>
|
|
|
|
<para>To receive files, start the sending program on the remote end.
|
|
Then, type <command>~C rz</command> to begin receiving them
|
|
locally.</para>
|
|
|
|
<para>To send files, start the receiving program on the remote end.
|
|
Then, type <command>~C sz <replaceable>files</replaceable></command>
|
|
to send them to the remote system.</para>
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1>
|
|
<title>Setting Up the Serial Console</title>
|
|
|
|
<para><emphasis>&a.yokota; and &a.wpaul:</emphasis></para>
|
|
|
|
<para><emphasis>The text is heavily based on
|
|
<filename>/sys/i386/boot/biosboot/README.serial</filename> written by
|
|
&a.wpaul;.</emphasis></para>
|
|
|
|
<sect2 id="serialconsole-intro">
|
|
<title>Introduction</title>
|
|
|
|
<para>The FreeBSD/i386 operating system can boot on a system with only
|
|
a dumb terminal on a serial port as a console. Such a configuration
|
|
should be useful for two classes of people; system administrators who
|
|
wish to install FreeBSD on a dedicated file/compute/terminal server
|
|
machines that have no keyboard or monitor attached, and developers who
|
|
want to debug the kernel or device drivers.</para>
|
|
|
|
<para>Starting from version 3.1, FreeBSD/i386 employs a three stage
|
|
bootstrap. The first two stages are in the boot block code which is
|
|
stored at the beginning of the FreeBSD slice on the boot disk. The
|
|
boot block will then load and run the boot loader
|
|
(<filename>/boot/loader</filename>) as the third stage code. (See
|
|
&man.boot.8; and &man.loader.8; for more details on the boot
|
|
process.)</para>
|
|
|
|
<para>In order to set up the serial console you must configure the boot
|
|
block code, the boot loader code and the kernel.</para>
|
|
|
|
<para>In FreeBSD version 3.0, the boot loader does not exist and there
|
|
are only two stages in the bootstrap; the boot blocks directly load
|
|
the kernel into memory. If you are using FreeBSD 3.0, then you should
|
|
disregard any reference to the boot loader in this section. You can
|
|
still use the serial port as a console.</para>
|
|
|
|
<para>FreeBSD versions 2.X are quite different from 3.X, in that the
|
|
serial port driver, &man.sio.4;, must be configured in a different
|
|
way. This chapter will not describe the settings for version 2.X
|
|
systems. If you are using these older versions of FreeBSD, please
|
|
consult <filename>/sys/i386/boot/biosboot/README.serial</filename>
|
|
instead.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="serialconsole-howto">
|
|
<title>6 Steps to Set up the Serial Console</title>
|
|
|
|
<procedure>
|
|
<step>
|
|
<para>Prepare a serial cable.</para>
|
|
|
|
<para>You will need either a null-modem cable or a standard serial
|
|
cable and a null-modem adapter. See <xref linkend="term"> for
|
|
a discussion on serial cables.</para>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Unplug your keyboard.</para>
|
|
|
|
<para>Most PC systems probe for the keyboard during the Power-On
|
|
Self-Test (POST) and will generate an error if the keyboard is not
|
|
detected. Some machines complain loudly about the lack of a
|
|
keyboard and will not continue to boot until it is plugged
|
|
in.</para>
|
|
|
|
<para>If your computer complains about the error, but boots anyway,
|
|
then you do not have to do anything special. (One machine with a
|
|
Phoenix BIOS that I have here merely says <errorname>Keyboard
|
|
failed</errorname> then continues to boot normally.)</para>
|
|
|
|
<para>If your computer refuses to boot without a keyboard attached
|
|
then you will have to configure the BIOS so that it ignores this
|
|
error (if it can). Consult your motherboard's manual for details
|
|
on how to do this.</para>
|
|
|
|
<tip>
|
|
<para>Setting the keyboard to “Not installed” in the
|
|
BIOS setup does <emphasis>not</emphasis> mean that you will not
|
|
be able to use your keyboard. All this does is tell the BIOS
|
|
not to probe for a keyboard at power-on so that it will not
|
|
complain if the keyboard is not plugged in. You can leave the
|
|
keyboard plugged in even with this flag set to “Not
|
|
installed” and the keyboard will still work.</para>
|
|
</tip>
|
|
|
|
<note>
|
|
<para>If your system has a PS/2 mouse, chances are very good that
|
|
you may have to unplug your mouse as well as your keyboard.
|
|
This is because PS/2 mice share some hardware with the keyboard,
|
|
and leaving the mouse plugged in can fool the keyboard probe
|
|
into thinking the keyboard is still there. It is said that a
|
|
Gateway 2000 Pentium 90Mhz system with an AMI BIOS that behaves
|
|
this way. In general this is not a problem since the mouse is
|
|
not much good without the keyboard anyway.</para>
|
|
</note>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Plug a dumb terminal into <devicename>COM1:</devicename>
|
|
(<devicename>sio0</devicename>).</para>
|
|
|
|
<para>If you do not have a dumb terminal, you can use an old PC/XT
|
|
with a modem program, or the serial port on another UNIX box. If
|
|
you do not have a <devicename>COM1:</devicename>
|
|
(<devicename>sio0</devicename>), get one. At this time, there is
|
|
no way to select a port other than <devicename>COM1:</devicename>
|
|
for the boot blocks without recompiling the boot blocks. If you
|
|
are already using <devicename>COM1:</devicename> for another
|
|
device, you will have to temporarily remove that device and
|
|
install a new boot block and kernel once you get FreeBSD up and
|
|
running. (It is assumed that <devicename>COM1:</devicename> will
|
|
be available on a file/compute/terminal server anyway; if you
|
|
really need <devicename>COM1:</devicename> for something else
|
|
(and you can not switch that something else to
|
|
<devicename>COM2:</devicename> (<devicename>sio1</devicename>)),
|
|
then you probably should not even be bothering with all this in
|
|
the first place.)</para>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Make sure the configuration file of your kernel has
|
|
appropriate flags set for <devicename>COM1:</devicename>
|
|
(<devicename>sio0</devicename>).</para>
|
|
|
|
<para>Relevant flags are:</para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><literal>0x10</literal></term>
|
|
|
|
<listitem>
|
|
<para>Enables console support for this unit. The other
|
|
console flags are ignored unless this is set. Currently, at
|
|
most one unit can have console support; the first one (in
|
|
config file order) with this flag set is preferred. This
|
|
option alone will not make the serial port the console. Set
|
|
the following flag or use the <option>-h</option> option
|
|
described below, together with this flag.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><literal>0x20</literal></term>
|
|
|
|
<listitem>
|
|
<para>Forces this unit to be the console (unless there is
|
|
another higher priority console), regardless of the
|
|
<option>-h</option> option discussed below. This flag
|
|
replaces the <literal>COMCONSOLE</literal> option in FreeBSD
|
|
versions 2.X. The flag <literal>0x20</literal> must be used
|
|
together with the <option>0x10</option> flag.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><literal>0x40</literal></term>
|
|
|
|
<listitem>
|
|
<para>Reserves this unit (in conjunction with
|
|
<literal>0x10</literal>) and makes the unit unavailable for
|
|
normal access. You should not set this flag to the serial
|
|
port unit which you want to use as the serial console. The
|
|
only use of this flag is to designate the unit for kernel
|
|
remote debugging. See <xref linkend="kerneldebug"> for more
|
|
information on remote debugging.</para>
|
|
|
|
<note>
|
|
<para>In FreeBSD 4.0-CURRENT or later the semantics of the
|
|
flag <literal>0x40</literal> are slightly different and
|
|
there is another flag to specify a serial port for remote
|
|
debugging.</para>
|
|
</note>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
<para>Example:</para>
|
|
|
|
<programlisting>
|
|
device sio0 at isa? port "IO_COM1" tty flags 0x10 irq 4</programlisting>
|
|
|
|
<para>See &man.sio.4; for more details.</para>
|
|
|
|
<para>If the flags were not set, you need to run UserConfig (on a
|
|
different console) or recompile the kernel.</para>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Create <filename>boot.config</filename> in the root directory
|
|
of the <literal>a</literal> partition on the boot drive.</para>
|
|
|
|
<para>This file will instruct the boot block code how you would like
|
|
to boot the system. In order to activate the serial console, you
|
|
need one or more of the following options—if you want
|
|
multiple options, include them all on the same line:</para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><option>-h</option></term>
|
|
|
|
<listitem>
|
|
<para>Toggles internal and serial consoles. You can use this
|
|
to switch console devices. For instance, if you boot from
|
|
the internal (video) console, you can use
|
|
<option>-h</option> to direct the boot loader and the kernel
|
|
to use the serial port as its console device. Alternatively,
|
|
if you boot from the serial port, you can use the
|
|
<option>-h</option> to tell the boot loader and the kernel
|
|
to use the video display as the console instead.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><option>-D</option></term>
|
|
|
|
<listitem>
|
|
<para>Toggles single and dual console configurations. In the
|
|
single configuration the console will be either the internal
|
|
console (video display) or the serial port, depending on the
|
|
state of the <option>-h</option> option above. In the dual
|
|
console configuration, both the video display and the
|
|
serial port will become the console at the same time,
|
|
regardless of the state of the <option>-h</option> option.
|
|
However, that the dual console configuration takes effect
|
|
only during the boot block is running. Once the boot loader
|
|
gets control, the console specified by the
|
|
<option>-h</option> option becomes the only console.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><option>-P</option></term>
|
|
|
|
<listitem>
|
|
<para>Makes the boot block probe the keyboard. If no keyboard
|
|
is found, the <option>-D</option> and <option>-h</option>
|
|
options are automatically set.</para>
|
|
|
|
<note>
|
|
<para>Due to space constraints in the current version of the
|
|
boot blocks, the <option>-P</option> option is capable of
|
|
detecting extended keyboards only. Keyboards with less
|
|
than 101 keys (and without F11 and F12 keys) may not be
|
|
detected. Keyboards on some laptop computers may not be
|
|
properly found because of this limitation. If this is to
|
|
be the case with your system, you have to abandon using
|
|
the <option>-P</option> option. Unfortunately there is no
|
|
workaround for this problem.</para>
|
|
</note>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
<para>Use either the <option>-P</option> option to select the
|
|
console automatically, or the <option>-h</option> option to
|
|
activate the serial console.</para>
|
|
|
|
<para>You may include other options described in &man.boot.8; as
|
|
well.</para>
|
|
|
|
<para>The options, except for <option>-P</option>, will be passed to
|
|
the boot loader (<filename>/boot/loader</filename>). The boot
|
|
loader will determine which of the internal video or the serial
|
|
port should become the console by examining the state of the
|
|
<option>-h</option> option alone. This means that if you specify
|
|
the <option>-D</option> option but not the <option>-h</option>
|
|
option in <filename>/boot.config</filename>, you can use the
|
|
serial port as the console only during the boot block; the boot
|
|
loader will use the internal video display as the console.</para>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Boot the machine.</para>
|
|
|
|
<para>When you start your FreeBSD box, the boot blocks will echo the
|
|
contents of <filename>/boot.config</filename> to the console. For
|
|
example;</para>
|
|
|
|
<screen>/boot.config: -P
|
|
Keyboard: no</screen>
|
|
|
|
<para>The second line appears only if you put <option>-P</option> in
|
|
<filename>/boot.config</filename> and indicates presence/absence
|
|
of the keyboard. These messages go to either serial or internal
|
|
console, or both, depending on the option in
|
|
<filename>/boot.config</filename>.</para>
|
|
|
|
<informaltable frame="none">
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry>Options</entry>
|
|
<entry>Message goes to</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry>none</entry>
|
|
<entry>internal console</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-h</option></entry>
|
|
<entry>serial console</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-D</option></entry>
|
|
<entry>serial and internal consoles</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-Dh</option></entry>
|
|
<entry>serial and internal consoles</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-P</option>, keyboard present</entry>
|
|
<entry>internal console</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-P</option>, keyboard absent</entry>
|
|
<entry>serial console</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
|
|
<para>After the above messages, there will be a small pause before
|
|
the boot blocks continue loading the boot loader and before any
|
|
further messages printed to the console. Under normal
|
|
circumstances, you do not need to interrupt the boot blocks, but
|
|
you may want to do so in order to make sure things are set up
|
|
correctly.</para>
|
|
|
|
<para>Hit any key, other than Enter/Return, at the console to
|
|
interrupt the boot process. The boot blocks will then prompt you
|
|
for further action. You should now see something like:</para>
|
|
|
|
<screen>>> FreeBSD/i386 BOOT
|
|
Default: 0:wd(0,a)/boot/loader
|
|
boot:</screen>
|
|
|
|
<para>Verify the above message appears on either the serial or
|
|
internal console or both, according to the options you put in
|
|
<filename>/boot.config</filename>. If the message appears in the
|
|
correct console, hit Enter/Return to continue the boot
|
|
process.</para>
|
|
|
|
<para>If you want the serial console but you do not see the prompt
|
|
on the serial terminal, something is wrong with your settings. In
|
|
the meantime, you enter <option>-h</option> and hit Enter/Return
|
|
(if possible) to tell the boot block (and then the boot loader and
|
|
the kernel) to choose the serial port for the console. Once the
|
|
system is up, go back and check what went wrong.</para>
|
|
</step>
|
|
</procedure>
|
|
|
|
<para>After the boot loader is loaded and you are in the third stage of
|
|
the boot process you can still switch between the internal console and
|
|
the serial console by setting appropriate environment variables in the
|
|
boot loader. See <xref linkend="serialconsole-loader">.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="serialconsole-summary">
|
|
<title>Summary</title>
|
|
|
|
<para>Here is the summary of various settings discussed in this section
|
|
and the console eventually selected.</para>
|
|
|
|
<sect3>
|
|
<title>Case 1: You set the flags to 0x10 for sio0</title>
|
|
|
|
<programlisting>device sio0 at isa? port "IO_COM1" tty flags 0x10 irq 4</programlisting>
|
|
|
|
<informaltable frame="none">
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Options in /boot.config</entry>
|
|
<entry>Console during boot blocks</entry>
|
|
<entry>Console during boot loader</entry>
|
|
<entry>Console in kernel</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry>nothing</entry>
|
|
<entry>internal</entry>
|
|
<entry>internal</entry>
|
|
<entry>internal</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-h</option></entry>
|
|
<entry>serial</entry>
|
|
<entry>serial</entry>
|
|
<entry>serial</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-D</option></entry>
|
|
<entry>serial and internal</entry>
|
|
<entry>internal</entry>
|
|
<entry>internal</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-Dh</option></entry>
|
|
<entry>serial and internal</entry>
|
|
<entry>serial</entry>
|
|
<entry>serial</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-P</option>, keyboard present</entry>
|
|
<entry>internal</entry>
|
|
<entry>internal</entry>
|
|
<entry>internal</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-P</option>, keyboard absent</entry>
|
|
<entry>serial and internal</entry>
|
|
<entry>serial</entry>
|
|
<entry>serial</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Case 2: You set the flags to 0x30 for sio0</title>
|
|
|
|
<programlisting>device sio0 at isa? port "IO_COM1" tty flags 0x30 irq 4</programlisting>
|
|
|
|
<informaltable frame="none">
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Options in /boot.config</entry>
|
|
<entry>Console during boot blocks</entry>
|
|
<entry>Console during boot loader</entry>
|
|
<entry>Console in kernel</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry>nothing</entry>
|
|
<entry>internal</entry>
|
|
<entry>internal</entry>
|
|
<entry>serial</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-h</option></entry>
|
|
<entry>serial</entry>
|
|
<entry>serial</entry>
|
|
<entry>serial</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-D</option></entry>
|
|
<entry>serial and internal</entry>
|
|
<entry>internal</entry>
|
|
<entry>serial</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-Dh</option></entry>
|
|
<entry>serial and internal</entry>
|
|
<entry>serial</entry>
|
|
<entry>serial</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-P</option>, keyboard present</entry>
|
|
<entry>internal</entry>
|
|
<entry>internal</entry>
|
|
<entry>serial</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><option>-P</option>, keyboard absent</entry>
|
|
<entry>serial and internal</entry>
|
|
<entry>serial</entry>
|
|
<entry>serial</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2 id="serialconsole-tips">
|
|
<title>Tips for the Serial Console</title>
|
|
|
|
<sect3>
|
|
<title>Setting A Faster Serial Port Speed</title>
|
|
|
|
<para>By default the serial port settings are set to 9600 baud, 8
|
|
bits, no parity, 1 stop bit. If you wish to change the speed, you
|
|
need to recompile at least the boot blocks. Add the following line
|
|
to <filename>/etc/make.conf</filename> and compile new boot
|
|
blocks:</para>
|
|
|
|
<programlisting>BOOT_COMCONSOLE_SPEED=19200</programlisting>
|
|
|
|
<para>If the serial console is configured in some other way than by
|
|
booting with <option>-h</option>, or if the serial console used by
|
|
the kernel is different from the one used by the boot blocks, then
|
|
you must also add the following option to the kernel configuration
|
|
file and compile a new kernel:</para>
|
|
|
|
<programlisting>options CONSPEED=19200</programlisting>
|
|
</sect3>
|
|
|
|
<sect3 id="serialconsole-com2">
|
|
<title>Using Serial Port Other Than <devicename>sio0</devicename> For
|
|
The Console</title>
|
|
|
|
<para>Using a port other than <devicename>sio0</devicename> as the
|
|
console requires some recompiling. If you want to use another
|
|
serial port for whatever reasons, recompile the boot blocks, the
|
|
boot loader and the kernel as follows.</para>
|
|
|
|
<procedure>
|
|
<step>
|
|
<para>Get the kernel source.</para>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Edit <filename>/etc/make.conf</filename> and set
|
|
<literal>BOOT_COMCONSOLE_PORT</literal> to the address of the
|
|
port you want to use (0x3F8, 0x2F8, 0x3E8 or 0x2E8). Only
|
|
<devicename>sio0</devicename> through
|
|
<devicename>sio3</devicename> (<devicename>COM1:</devicename>
|
|
through <devicename>COM4:</devicename>) can be used; multiport
|
|
serial cards will not work. No interrupt setting is
|
|
needed.</para>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Create a custom kernel configuration file and add
|
|
appropriate flags for the serial port you want to use. For
|
|
example, if you want to make <devicename>sio1</devicename>
|
|
(<devicename>COM2:</devicename>) the console:</para>
|
|
|
|
<programlisting>device sio1 at isa? port "IO_COM2" tty flags 0x10 irq 3</programlisting>
|
|
|
|
<para>or</para>
|
|
|
|
<programlisting>device sio1 at isa? port "IO_COM2" tty flags 0x30 irq 3</programlisting>
|
|
|
|
<para>The console flags for the other serial ports should not be
|
|
set.</para>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Recompile and install the boot blocks:</para>
|
|
|
|
<screen>&prompt.root; <userinput>cd /sys/boot/i386/boot2</userinput>
|
|
&prompt.root; <userinput>make</userinput>
|
|
&prompt.root; <userinput>make install</userinput></screen>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Recompile and install the boot loader:</para>
|
|
|
|
<screen>&prompt.root; <userinput>cd /sys/boot/i386/loader</userinput>
|
|
&prompt.root; <userinput>make</userinput>
|
|
&prompt.root; <userinput>make install</userinput></screen>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Rebuild and install the kernel.</para>
|
|
</step>
|
|
|
|
<step>
|
|
<para>Write the boot blocks to the boot disk with
|
|
&man.disklabel.8; and boot from the new kernel.</para>
|
|
</step>
|
|
</procedure>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Entering the DDB Debugger from the Serial Line</title>
|
|
|
|
<para>If you wish to drop into the kernel debugger from the serial
|
|
console (useful for remote diagnostics, but also dangerous if you
|
|
generate a spurious BREAK on the serial port!) then you should
|
|
compile your kernel with the following options:</para>
|
|
|
|
<programlisting>options BREAK_TO_DEBUGGER
|
|
options DDB</programlisting>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Getting a Login Prompt on the Serial Console</title>
|
|
|
|
<para>While this is not required, you may wish to get a
|
|
<emphasis>login</emphasis> prompt over the serial line, now that you
|
|
can see boot messages and can enter the kernel debugging session
|
|
through the serial console. Here is how to do it.</para>
|
|
|
|
<para>Open the file <filename>/etc/ttys</filename> with an editor
|
|
and locate the lines:</para>
|
|
|
|
<programlisting>ttyd0 "/usr/libexec/getty std.9600" unknown off secure
|
|
ttyd1 "/usr/libexec/getty std.9600" unknown off secure
|
|
ttyd2 "/usr/libexec/getty std.9600" unknown off secure
|
|
ttyd3 "/usr/libexec/getty std.9600" unknown off secure</programlisting>
|
|
|
|
<para><literal>ttyd0</literal> through <literal>ttyd3</literal>
|
|
corresponds to <devicename>COM1</devicename> through
|
|
<devicename>COM4</devicename>. Change <literal>off</literal> to
|
|
<literal>on</literal> for the desired port. If you have changed the
|
|
speed of the serial port, you need to change
|
|
<literal>std.9600</literal> to match the current setting, e.g.
|
|
<literal>std.19200</literal>.</para>
|
|
|
|
<para>You may also want to change the terminal type from
|
|
<literal>unknown</literal> to the actual type of your serial
|
|
terminal.</para>
|
|
|
|
<para>After editing the file, you must <command>kill -HUP 1</command>
|
|
to make this change take effect.</para>
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2 id="serialconsole-loader">
|
|
<title>Changing Console from the Boot Loader</title>
|
|
|
|
<para>Previous sections described how to set up the serial console by
|
|
tweaking the boot block. This section shows that you can specify the
|
|
console by entering some commands and environment variables in the
|
|
boot loader. As the boot loader is invoked as the third stage of the
|
|
boot process, after the boot block, the settings in the boot loader
|
|
will override the settings in the boot block.</para>
|
|
|
|
<sect3>
|
|
<title>Setting Up the Serial Console</title>
|
|
|
|
<para>You can easily specify the boot loader and the kernel to use the
|
|
serial console by writing just one line in
|
|
<filename>/boot/loader.rc</filename>:</para>
|
|
|
|
<programlisting>set console=comconsole</programlisting>
|
|
|
|
<para>This will take effect regardless of the settings in the boot
|
|
block discussed in the previous section.</para>
|
|
|
|
<para>You had better put the above line as the first line of
|
|
<filename>/boot/loader.rc</filename> so as to see boot messages on
|
|
the serial console as early as possible.</para>
|
|
|
|
<para>Likewise, you can specify the internal console as:</para>
|
|
|
|
<programlisting>set console=vidconsole</programlisting>
|
|
|
|
<para>If you do not set the boot loader environment variable
|
|
<envar>console</envar>, the boot loader, and subsequently the
|
|
kernel, will use whichever console indicated by the
|
|
<option>-h</option> option in the boot block.</para>
|
|
|
|
<para>In versions 3.2 or later, you may specify the console in
|
|
<filename>/boot/loader.conf.local</filename> or
|
|
<filename>/boot/loader.conf</filename>, rather than in
|
|
<filename>/boot/loader.rc</filename>. In this method your
|
|
<filename>/boot/loader.rc</filename> should look like:</para>
|
|
|
|
<programlisting>include /boot/loader.4th
|
|
start</programlisting>
|
|
|
|
<para>Then, create <filename>/boot/loader.conf.local</filename> and
|
|
put the following line there.</para>
|
|
|
|
<programlisting>console=comconsole</programlisting>
|
|
|
|
<para>or</para>
|
|
|
|
<programlisting>console=vidconsole</programlisting>
|
|
|
|
<para>See &man.loader.conf.5; for more information.</para>
|
|
|
|
<note>
|
|
<para>At the moment, the boot loader has no option equivalent to the
|
|
<option>-P</option> option in the boot block, and there is no
|
|
provision to automatically select the internal console and the
|
|
serial console based on the presence of the keyboard.</para>
|
|
</note>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Using Serial Port Other than <devicename>sio0</devicename> for
|
|
the Console</title>
|
|
|
|
<para>You need to recompile the boot loader to use a serial port other
|
|
than <devicename>sio0</devicename> for the serial console. Follow the
|
|
procedure described in <xref linkend="serialconsole-com2">.</para>
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2 id="serialconsole-caveats">
|
|
<title>Caveats</title>
|
|
|
|
<para>The idea here is to allow people to set up dedicated servers that
|
|
require no graphics hardware or attached keyboards. Unfortunately,
|
|
while (most?) every system will let you boot without a keyboard, there
|
|
are quite a few that will not let you boot without a graphics adapter.
|
|
Machines with AMI BIOSes can be configured to boot with no graphics
|
|
adapter installed simply by changing the `graphics adapter' setting in
|
|
the CMOS configuration to `Not installed.'</para>
|
|
|
|
<para>However, many machines do not support this option and will refuse
|
|
to boot if you have no display hardware in the system. With these
|
|
machines, you'll have to leave some kind of graphics card plugged in,
|
|
(even if it's just a junky mono board) although you will not have to
|
|
attach a monitor into it. You might also try installing an AMI
|
|
BIOS.</para>
|
|
</sect2>
|
|
</sect1>
|
|
</chapter>
|
|
|
|
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|
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