make mrproper: This will ensure that the kernel tree is absolutely clean. yes "" | make config: 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. make dep: 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. ln -s ../src/linux/include/linux and ln -s ../src/linux/include/asm: 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 <linux/errno.h>. 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.