lfs-book-zh_CN/chapter06/makedev-exp.sgml

<sect2>
<title>Command explanations</title>

<para>
<userinput>sed "s/# 9/9/" MAKEDEV &gt;/dev/MAKEDEV:</userinput> By
default the Makedev script only creates the hda1-hda8 and hdb1-hdb8
devices. By replacing "# 9" by "9"'s in the MAKEDEV script, it will
create hda1-hda20, hdb1-hdb20 and possible others (like hdc and hdd)
</para>

<para>
<userinput>chmod 754 /dev/MAKEDEV:</userinput> This sets the permissions
of the MAKEDEV script to mode 754 which makes it executable only for
owner and group and readable by everybody.
</para>

</sect2>