%general-entities; ]> Preparing Virtual Kernel File Systems /dev/* Applications running in user space utilize various file systems exported by the kernel to communicate with the kernel itself. These file systems are virtual: no disk space is used for them. The content of the file systems resides in memory. These file systems must be mounted in the $LFS directory tree so the applications can find them in the chroot environment. Begin by creating directories on which the file systems will be mounted: mkdir -pv $LFS/{dev,proc,sys,run} Mounting and Populating /dev During a normal boot, the kernel automatically mounts the devtmpfs filesystem on the /dev directory; the devices are created dynamically on that virtual filesystem when they are first detected or accessed. Device creation is generally done during the boot process by the kernel and the udev program. Since the new system does not yet include udev and has not yet been booted, it is necessary to mount and populate the /dev directory manually. This is accomplished by bind mounting the host system's /dev directory. A bind mount is a special type of mount that allows you to create a mirror of a directory or mount point at some other location. Use the following command to do this: mount -v --bind /dev $LFS/dev Mounting Virtual Kernel File Systems Now mount the remaining virtual kernel filesystems: mount -v --bind /dev/pts $LFS/dev/pts mount -vt proc proc $LFS/proc mount -vt sysfs sysfs $LFS/sys mount -vt tmpfs tmpfs $LFS/run In some host systems, /dev/shm is a symbolic link to /run/shm. The /run tmpfs was mounted above so in this case only a directory needs to be created. In other host systems /dev/shm is a mount point for a tmpfs. In that case the mount of /dev above will only create /dev/shm as a directory in the chroot environment. In this situation we must explicitly mount a tmpfs: if [ -h $LFS/dev/shm ]; then mkdir -pv $LFS/$(readlink $LFS/dev/shm) else mount -t tmpfs -o nosuid,nodev tmpfs $LFS/dev/shm fi