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@@ -1,8 +1,9 @@
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-<sect1 id="ch-system-MAKEDEV" xreflabel="Makedev">
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-<title>Creating devices with Makedev-&makedev-version;</title>
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-<?dbhtml filename="makedev.html" dir="chapter06"?>
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+<sect1 id="ch-system-MAKEDEV" xreflabel="Make_devices">
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+<title>Creating devices with Make_devices-&makedev-version;</title>
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+<?dbhtml filename="makedevices.html" dir="chapter06"?>
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-<para>The MAKEDEV package contains a script for making device nodes.</para>
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+<para>The Make_devices package contains a script for creating device
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+nodes.</para>
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<screen>&buildtime; &makedev-time;
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&diskspace; &makedev-compsize;</screen>
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@@ -15,62 +16,79 @@
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<sect2>
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<title>Making devices</title>
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-<para>Note that unpacking the <filename>MAKEDEV-&makedev-version;.bz2</filename>
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-file doesn't create a directory for you to <command>cd</command> into, as
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-the file contains only a shell script.</para>
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+<para>Note that unpacking the
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+<filename>make_devices-&makedev-version;.bz2</filename> file doesn't
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+create a directory for you to <command>cd</command> into, as the file
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+contains only a shell script.</para>
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+
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+<para>Install the <filename>make_devices</filename> script:</para>
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+
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+<screen><userinput>bzcat make_devices-&makedev-version;.bz2 > /dev/make_devices
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+chmod 754 /dev/make_devices</userinput></screen>
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+
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+<para>Device nodes are special files: things that can generate or receive data.
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+They usually correspond to physical pieces of hardware, and can be created by
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+issuing commands of the form: <command>mknod -m mode name type major
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+minor</command>. In such a command, <emphasis>mode</emphasis> is the usual
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+octal read/write/execute permissions triplet, and <emphasis>name</emphasis> is
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+the name of the device file to be created. It may seem surprising, but the
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+device name is actually arbitrary, except that most programs rely on devices
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+such as <filename>/dev/null</filename> having their usual names. The remaining
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+three parameters tell the kernel what piece of hardware the device node
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+actually refers to. The <emphasis>type</emphasis> is a letter, either b or c,
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+indicating whether the device is accessed in blocks (such as a hard disk) or
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+character by character (such as the console). And <emphasis>major</emphasis>
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+and <emphasis>minor</emphasis> are numbers, together forming a code that
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+identifies the device to the kernel. A list of the currently assigned device
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+numbers for Linux can be found in the file <filename>devices.txt</filename> in
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+the <filename class="directory">Documentation</filename> subdirectory of the
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+kernel sources.</para>
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+
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+<para>Note that the same major/minor combination are usually assigned to both a
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+block and a character device. These are, however, completely unrelated devices
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+that cannot be interchanged. A device is identified by the type/major/minor
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+triple, not just the major/minor pair, so when creating a device node it is
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+important to choose the correct <emphasis>type</emphasis> of device.</para>
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+
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+<para>Because looking up the type/major/minor triples and using
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+<command>mknod</command> manually is tedious and error-prone, the
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+<filename>make_devices</filename> script has been created. It contains a whole
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+series of <command>mknod</command> commands, one for each device, complete with
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+recommended name, permissions and group assignment. It has been set up so that
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+only a minimal set of commonly used devices is enabled and the other lines are
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+commented out. You should open <filename>make_devices</filename> in an editor
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+and customize it to your needs. This takes some time, but is very simple. When
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+you are satisfied, run the script to create the device files:</para>
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-<para>Install the <command>MAKEDEV</command> script:</para>
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-
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-<screen><userinput>bzcat MAKEDEV-&makedev-version;.bz2 > /dev/MAKEDEV
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-chmod 754 /dev/MAKEDEV</userinput></screen>
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+<screen><userinput>cd /dev
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+./make_devices</userinput></screen>
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-<para>Run the script to create the device files:</para>
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+<para>(The FHS states that there should be a <filename>MAKEDEV</filename>
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+script present in the <filename class="directory">/dev</filename> directory.
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+But the FHS is mistaken: it should not dictate anything about files, and limit
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+itself to directories.)</para>
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-<screen><userinput>cd /dev
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-./MAKEDEV -v generic-nopty</userinput></screen>
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-
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-<para>The meaning of the arguments:</para>
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-
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-<itemizedlist>
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-<listitem><para><userinput>-v</userinput>: This tells the script to run in
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-verbose mode.</para></listitem>
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-
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-<listitem><para><userinput>generic-nopty</userinput>: This instructs
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-<command>MAKEDEV</command> to create a generic selection of commonly used
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-device special files, except for the ptyXX and ttyXX range of files. We don't
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-need those files because we are going to use Unix98 PTYs via the
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-<emphasis>devpts</emphasis> file system.</para></listitem>
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-</itemizedlist>
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-
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-<para>If it turns out that some special device <filename>zzz</filename> that
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-you need is missing, try running <userinput>./MAKEDEV -v zzz</userinput>.
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-Alternatively, you may create devices via the <command>mknod</command>
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-program. Please refer to its man and info pages if you need more
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-information.</para>
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-
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-<para>If you wish your system to be FHS-compliant, then the
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-<filename>MAKEDEV</filename> script has to remain present in the
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-<filename class="directory">/dev</filename> directory. This way it is always
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-available for making extra device nodes.</para>
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-
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-<para>Additionally, if you were unable to mount the devpts file system earlier
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-in <xref linkend="ch-system-proc"/>, now is the time to try the alternatives. If
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-your kernel supports the devfs file system, run the following command to mount
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+<para>If you had success with mounting the devpts file system earlier in <xref
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+linkend="ch-system-proc"/>, you can continue with the next section. If you were
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+unable to mount devpts, now is the time to try the alternatives. If your kernel
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+supports the devfs file system, run the following command to mount
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devfs:</para>
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<screen><userinput>mount -t devfs devfs /dev</userinput></screen>
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<para>This will mount the devfs file system over the top of the new static
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-<filename>/dev</filename> structure. This poses no problems, as the device nodes
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-created are still present, they are just hidden by the new devfs
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-file system.</para>
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-
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-<para>If this still doesn't work, the only option left is to use the MAKEDEV
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-script to create the ptyXX and ttyXX range of files that would otherwise not be
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-needed. Ensure you are still in the <filename>/dev</filename> directory then run
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-<userinput>./MAKEDEV -v pty</userinput>. The downside of this is, we are
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-creating an extra 512 device special files which will not be needed when we
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-finally boot into the finished LFS system.</para>
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+<filename>/dev</filename> structure. This poses no problems, as the device
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+nodes created are still present, they are just hidden by the new devfs file
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+system.</para>
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+
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+<para>If that didn't work either, the only option left is to create a few ptyXX
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+and ttyXX device nodes. To do this, open <filename>make_devices</filename> in
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+your editor, go to the section "Pseudo-TTY masters" and enable as many ptyXX
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+devices as you think you will need (one for every active xterm, ssh connection,
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+telnet connection, and so on). In the immediately following section "Pseudo-TTY
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+slaves", enable the corresponding ttyXX devices. When you are done, rerun
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+<command>./make_devices</command> from inside <filename>/dev</filename> to have
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+it create the new devices.</para>
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</sect2>
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Alex Gronenwoud