[3f8be484] | 1 | <?xml version="1.0" encoding="ISO-8859-1"?> |
---|
[aa18ac0] | 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" |
---|
| 3 | "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ |
---|
[3f8be484] | 4 | <!ENTITY % general-entities SYSTEM "../../general.ent"> |
---|
| 5 | %general-entities; |
---|
| 6 | ]> |
---|
| 7 | |
---|
| 8 | <sect1 id="ch-chroot-kernfs"> |
---|
| 9 | <?dbhtml filename="kernfs.html"?> |
---|
| 10 | |
---|
| 11 | <title>Mounting Virtual Kernel File Systems</title> |
---|
| 12 | |
---|
[d2ecc65] | 13 | <note os="a"> |
---|
| 14 | <para>The commands in the remainder of the book should be run as |
---|
| 15 | the <systemitem class="username">root</systemitem> user. Check |
---|
| 16 | that ${CLFS} is set in the |
---|
| 17 | <systemitem class="username">root</systemitem> user’s environment |
---|
| 18 | before proceeding.</para> |
---|
| 19 | </note> |
---|
[3f8be484] | 20 | |
---|
| 21 | <para>Various file systems exported by the kernel are used to communicate |
---|
| 22 | to and from the kernel itself. These file systems are virtual in that no |
---|
| 23 | disk space is used for them. The content of the file systems resides in |
---|
| 24 | memory.</para> |
---|
| 25 | |
---|
| 26 | <para>Begin by creating directories onto which the file systems will |
---|
| 27 | be mounted:</para> |
---|
| 28 | |
---|
[799de33] | 29 | <screen><userinput>mkdir -pv ${CLFS}/{dev,proc,run,sys}</userinput></screen> |
---|
[3f8be484] | 30 | |
---|
[1d396c4] | 31 | <para>Two device nodes, <filename class="devicefile">/dev/console</filename> |
---|
| 32 | and <filename class="devicefile">/dev/null</filename>, are required to be |
---|
[799de33] | 33 | present on the file system. These are needed by the kernel even before |
---|
[1d396c4] | 34 | starting Udev early in the boot process, so we create them here:</para> |
---|
[3f8be484] | 35 | |
---|
[040521bc] | 36 | <screen><userinput>mknod -m 600 ${CLFS}/dev/console c 5 1 |
---|
| 37 | mknod -m 666 ${CLFS}/dev/null c 1 3</userinput></screen> |
---|
[27e1607] | 38 | |
---|
| 39 | <para>Once the system is complete and booting, the rest of our device |
---|
[1d396c4] | 40 | nodes will be created by the kernel's |
---|
| 41 | <systemitem class="filesystem">devtmpfs</systemitem> file system. For now |
---|
| 42 | though, we will just use the <quote>bind</quote> option in the mount command |
---|
[799de33] | 43 | to make our host system's <filename class="directory">/dev</filename> structure appear in the new CLFS file system:</para> |
---|
[27e1607] | 44 | |
---|
[040521bc] | 45 | <screen><userinput>mount -v -o bind /dev ${CLFS}/dev</userinput></screen> |
---|
[27e1607] | 46 | |
---|
[799de33] | 47 | <para>Now mount the remaining file systems:</para> |
---|
| 48 | |
---|
| 49 | <screen><userinput>mount -vt devpts -o gid=&gid-tty;,mode=620 devpts ${CLFS}/dev/pts |
---|
| 50 | mount -vt proc proc ${CLFS}/proc |
---|
| 51 | mount -vt tmpfs tmpfs ${CLFS}/run |
---|
| 52 | mount -vt sysfs sysfs ${CLFS}/sys</userinput></screen> |
---|
| 53 | |
---|
| 54 | <para>On some host systems, <filename class="directory">/dev/shm</filename> |
---|
| 55 | is a symbolic link to <filename class="directory">/run/shm</filename>. |
---|
| 56 | If it is, create a directory in <filename class="directory">/run</filename>:</para> |
---|
| 57 | |
---|
| 58 | <screen><userinput>[ -h ${CLFS}/dev/shm ] && mkdir -pv ${CLFS}/$(readlink ${CLFS}/dev/shm)</userinput></screen> |
---|
| 59 | |
---|
| 60 | <para>Remember that if for any reason you stop working on the CLFS system |
---|
| 61 | and start again later, it is important to check that these file systems |
---|
| 62 | are mounted again before entering the chroot environment.</para> |
---|
[3f8be484] | 63 | |
---|
| 64 | </sect1> |
---|