diff options
Diffstat (limited to 'chapter06/makedev.xml')
| -rw-r--r-- | chapter06/makedev.xml | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/chapter06/makedev.xml b/chapter06/makedev.xml index 59be742ce..271ebef80 100644 --- a/chapter06/makedev.xml +++ b/chapter06/makedev.xml @@ -27,14 +27,14 @@ contains only a shell script.</para> chmod 754 /dev/make_devices</userinput></screen> <para>Device nodes are special files: things that can generate or receive data. -They usually correspond to physical pieces of hardware, and can be created by -issuing commands of the form: <command>mknod -m mode name type major +They usually correspond to physical pieces of hardware. Device nodes can be +created by issuing commands of the form: <command>mknod -m mode name type major minor</command>. In such a command, <emphasis>mode</emphasis> is the usual octal read/write/execute permissions triplet, and <emphasis>name</emphasis> is the name of the device file to be created. It may seem surprising, but the device name is actually arbitrary, except that most programs rely on devices such as <filename>/dev/null</filename> having their usual names. The remaining -three parameters tell the kernel what piece of hardware the device node +three parameters tell the kernel what device the node actually refers to. The <emphasis>type</emphasis> is a letter, either b or c, indicating whether the device is accessed in blocks (such as a hard disk) or character by character (such as the console). And <emphasis>major</emphasis> @@ -44,7 +44,7 @@ numbers for Linux can be found in the file <filename>devices.txt</filename> in the <filename class="directory">Documentation</filename> subdirectory of the kernel sources.</para> -<para>Note that the same major/minor combination are usually assigned to both a +<para>Note that the same major/minor combination is usually assigned to both a block and a character device. These are, however, completely unrelated devices that cannot be interchanged. A device is identified by the type/major/minor triple, not just the major/minor pair, so when creating a device node it is @@ -79,11 +79,11 @@ system.</para> <para>If that didn't work either, the only option left is to create a few ptyXX and ttyXX device nodes. To do this, open <filename>make_devices</filename> in your editor, go to the section "Pseudo-TTY masters" and enable as many ptyXX -devices as you think you will need (one for every active xterm, ssh connection, -telnet connection, and so on). In the immediately following section "Pseudo-TTY -slaves", enable the corresponding ttyXX devices. When you are done, rerun -<command>./make_devices</command> from inside <filename>/dev</filename> to have -it create the new devices.</para> +devices as you think you will need (every xterm, ssh connection, telnet +connection, and the like, uses one of these pseudo terminals). In the +immediately following section "Pseudo-TTY slaves", enable the corresponding +ttyXX devices. When you are done, rerun <command>./make_devices</command> from +inside <filename>/dev</filename> to have it create the new devices.</para> </sect2> |