lfs-book/chapter05/kernel-exp.xml

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

<para>
<userinput>make mrproper:</userinput> This will ensure that the kernel
tree is absolutely clean.
</para>

<para>
<userinput>yes "" | make config:</userinput> This runs make config and
answers with the default answer to every question the config script asks 
the user (it does this by simply doing the equivalent of hitting the
Enter key, thus accepting the default Y and N answers to the questions). 
We're not configuring the real kernel here, we just need to have some sort 
of configure file created so that we can run make dep next that will 
create a few files in $LFS/usr/src/linux/include/linux, like version.h, 
among others, that we will need to compile Glibc and other packages later 
in chroot.
</para>

<para>
<userinput>make dep:</userinput> make dep checks dependencies and sets
up the dependencies file. We don't really care about the dependency
checks, but what we do care about is that make dep creates those
aforementioned files in $LFS/usr/src/linux/include/linux we will be
needing later on.
</para>

<para>
<userinput>ln -s ../src/linux/include/linux</userinput> and
<userinput>ln -s ../src/linux/include/asm:</userinput> These
commands create the linux and asm symlinks in the $LFS/usr/include
directory that point to the proper directories in the Linux source tree.
Packages that need kernel headers include them with lines like #include
&lt;linux/errno.h&gt;. These paths are relative to the /usr/include
directory so the /usr/include/linux link points to the directory
containing the Linux kernel header files. The same goes for the asm
symlink.
</para>

</sect2>