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>Linux Kernel Modules Installation HOWTO</TH
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CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="KERNEL"
>4. Recompiling the Kernel for Modules</A
></H1
><P
> The kernel can be reconfigured to use modules for everything other than
the file system mounted as root (in most cases, this is the ext2 file
system).
</P
><P
> However, there are certain items that appear to be difficult to set up
properly as modules, so I would recommend the following be compiled into
the kernel:
</P
><P
></P
><UL
><LI
><P
> Ethernet hardware drivers.
</P
></LI
><LI
><P
> SCSI CD-ROM drivers.
</P
></LI
></UL
><P
> On the other hand, there are certain driver combinations that
<EM
>ONLY</EM
> work as modules, especially combinations
of two or more of the following group:
</P
><P
></P
><UL
><LI
><P
> A Parallel Printer,
</P
></LI
><LI
><P
> A Parallel Port drive, such as the <EM
>IOMEGA</EM
> ZipDrive or
JazzDrive, or the <EM
>BackPack</EM
> CD-ROM drive, and
</P
></LI
><LI
><P
> The <EM
>PLIP</EM
> Daemon.
</P
></LI
></UL
><P
> You will need to decide what you are compiling into the kernel, and
what as modules, but should take the above points into consideration. The
actual choices are made during the compilation, by the second of the
following sequence of instructions:
</P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
>cd /usr/src/linux
make menuconfig
make dep clean modules modules_install zImage
</PRE
></FONT
></TD
></TR
></TABLE
><P
> Having done that, the module dependencies need to be mapped out. This
is done with the following command:
</P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
>depmod -a
</PRE
></FONT
></TD
></TR
></TABLE
><P
> The new kernel now needs to be inserted in the boot chain. I am
assuming the reader is using <SPAN
CLASS="APPLICATION"
>LILO</SPAN
> for this purpose, since this is the only
loader I have any experience with.
</P
><P
> I recommend that one does NOT automatically insert the newly compiled
kernel as the default Linux kernel since if it should fail, it is then
extremely difficult to recover one's Linux setup without doing a complete
reinstallation, which is not to be recommended. For this reason, I have
the following entry in my <TT
CLASS="FILENAME"
>/etc/lilo.conf</TT
> file:
</P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
>image=/usr/src/linux/arch/i386/boot/zImage
label=new
alias=n
read-only
vga=ask
optional
</PRE
></FONT
></TD
></TR
></TABLE
><P
> This entry says that there is an OPTIONAL boot option (which will be
ignored if the image in question does not exist) which boots the file
<TT
CLASS="FILENAME"
>/boot/newlinux</TT
> if selected, and allows one to select
the video mode it is to be booted in.
</P
><P
> Assuming the existence of the above entry in <TT
CLASS="FILENAME"
>/etc/lilo.conf</TT
>
the revised kernel is already correctly located at the end of compilation, and
it can be installed via the following command:
</P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
>lilo
</PRE
></FONT
></TD
></TR
></TABLE
><P
> Having done that, the reader needs to follow the further steps relevant
to their selected distribution, as follows:
</P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="REDHAT"
>5.1. Configuring Debian or RedHat for Modules</A
></H2
><P
> Prior to carrying out the steps listed here, the steps listed in
<SPAN
CLASS="QUOTE"
>"<A
HREF="kernel.html"
><I
>Recompiling the Kernel for Modules</I
></A
>"</SPAN
>
are assumed to have been carried out.
</P
><P
> The Debian and RedHat distributions have identical boot procedures, so
also have identical procedures for configuring modules into them.
</P
><P
></P
><OL
TYPE="1"
><LI
><P
> Having logged in as root, use your favourite text editor to create
a new file called <TT
CLASS="FILENAME"
>/etc/rc.d/init.d/modules.init</TT
>
with the following contents therein:
</P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
># Modules initialisation.
#
# Start up the module auto-loading daemon.
/sbin/kerneld
# Mount all currently unmounted auto-mounted partitions.
/sbin/mount -a
</PRE
></FONT
></TD
></TR
></TABLE
></LI
><LI
><P
> Having created the above file, perform the following steps whilst
logged on as root:
</P
><TABLE
BORDER="0"
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
>cd /etc/rc.d
chmod 755 init.d/*
cd rc3.d
ln -s ../init.d/modules.init 05modules.init
</PRE
></FONT
></TD
></TR
></TABLE
></LI
></OL
><P
> The system can now be rebooted, and on doing so, it will be found that
modules are fully implemented
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="SLACKWARE"
>5.2. Configuring Slackware for Modules</A
></H2
><P
> Prior to carrying out the steps listed here, the steps listed in
<SPAN
CLASS="QUOTE"
>"<A
HREF="kernel.html"
><I
>Recompiling the Kernel for Modules</I
></A
>"</SPAN
>
are assumed to have been carried out.
</P
><P
> The file <TT
CLASS="FILENAME"
>/etc/rc.d/rc.M</TT
> needs to be edited as follows:
</P
><P
></P
><OL
TYPE="1"
><LI
><P
> Around line 18, there is a section reading as follows:
</P
><TABLE
BORDER="0"
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
># Screen blanks after 15 minutes idle time.
/bin/setterm -blank 15
</PRE
></FONT
></TD
></TR
></TABLE
><P
> Immediately after this, insert the following paragraph, with the usual
blank lines either side of it:
</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="90%"
><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
># Load the kernel module auto-loader.
/sbin/kerneld
</PRE
></FONT
></TD
></TR
></TABLE
></LI
><LI
><P
> About 12 lines further down is the following:
</P
><TABLE
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WIDTH="90%"
><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
># if there is no /etc/HOSTNAME, fall back on this default:
</PRE
></FONT
></TD
></TR
></TABLE
><P
> Immediately prior to this, insert the following paragraph, again with the
usual blank lines either side of it:
</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="90%"
><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
># Mount remaining unmounted auto-mount drives.
/sbin/mount -a
</PRE
></FONT
></TD
></TR
></TABLE
></LI
></OL
><P
> When those changes have been made, save the file.
</P
><P
> No further modifications are required for Slackware.
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="OTHERDIST"
>5.3. Configuring Other Distributions for Modules</A
></H2
><P
> Prior to carrying out the steps listed here, the steps listed in
<SPAN
CLASS="QUOTE"
>"<A
HREF="kernel.html"
><I
>Recompiling the Kernel for Modules</I
></A
>"</SPAN
>
are assumed to have been carried out.
</P
><P
> The precise procedure for other distributions has not been ascertained,
but is probably one of the above. To determine which one, display a
directory of the contents of the <TT
CLASS="FILENAME"
>/etc/rc.d</TT
> directory,
as follows:
</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="PROGRAMLISTING"
>cd /etc/rc.d
ls -l *.d rc.*
</PRE
></FONT
></TD
></TR
></TABLE
><P
> From this resulting display, you can select one of the following three
options:
</P
><P
></P
><OL
TYPE="1"
><LI
><P
> If this list includes a directory named <TT
CLASS="FILENAME"
>init.d</TT
> and some
directories with names matching <TT
CLASS="FILENAME"
>rc?.d</TT
> where the
question mark is replaced by single digits, and does <EM
>NOT</EM
>
include a file with the name <TT
CLASS="FILENAME"
>rc.M</TT
>, that distribution can
be configured for modules by following the procedure listed under the title
<SPAN
CLASS="QUOTE"
>"<A
HREF="kernel.html#REDHAT"
><I
>Configuring Debian or RedHat for Modules</I
></A
>"</SPAN
>.
</P
></LI
><LI
><P
> If this list does not include a directory named <TT
CLASS="FILENAME"
>init.d</TT
> but
includes a file named <TT
CLASS="FILENAME"
>rc.M</TT
> then that distribution can
be configured for modules by following the procedure listed under the title
<SPAN
CLASS="QUOTE"
>"<A
HREF="kernel.html#SLACKWARE"
><I
>Configuring Slackware for Modules</I
></A
>"</SPAN
>.
</P
></LI
><LI
><P
> If this list matches neither of the above criteria, then the
distribution has a boot script not covered by this HowTo. In that case,
you are invited to contact the author of this document for advice.
</P
></LI
></OL
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