[bf8c11f] | 1 | <?xml version="1.0" encoding="ISO-8859-1"?> |
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| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" |
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| 3 | "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [ |
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| 4 | <!ENTITY % general-entities SYSTEM "../../general.ent"> |
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| 5 | %general-entities; |
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| 6 | ]> |
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| 7 | |
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| 8 | <sect1 id="ch-chroot-kernfs"> |
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| 9 | <?dbhtml filename="kernfs.html"?> |
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| 10 | |
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| 11 | <title>Mounting Virtual Kernel File Systems</title> |
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| 12 | |
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[0d80be2] | 13 | <xi:include xmlns:xi="http://www.w3.org/2003/XInclude" |
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| 14 | href="../../boot/common/devices.xml" |
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| 15 | xpointer="xpointer(//*[@os='a'])"/> |
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[bf8c11f] | 16 | |
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| 17 | <para>Various file systems exported by the kernel are used to communicate |
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| 18 | to and from the kernel itself. These file systems are virtual in that no |
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| 19 | disk space is used for them. The content of the file systems resides in |
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| 20 | memory.</para> |
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| 21 | |
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| 22 | <para>Begin by creating directories onto which the file systems will |
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| 23 | be mounted:</para> |
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| 24 | |
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[8545aa19] | 25 | <screen><userinput>mkdir -pv $LFS/{dev,proc,sys}</userinput></screen> |
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[bf8c11f] | 26 | |
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| 27 | <para>Now mount the file systems:</para> |
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| 28 | |
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[dd9906e] | 29 | <screen><userinput>mount -vt proc proc $LFS/proc |
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[dca40f5] | 30 | mount -vt sysfs sysfs $LFS/sys</userinput></screen> |
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[bf8c11f] | 31 | |
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[b71fa50] | 32 | <para>Remember that if for any reason you stop working on the CLFS system |
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[bf8c11f] | 33 | and start again later, it is important to check that these file systems |
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| 34 | are mounted again before entering the chroot environment.</para> |
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| 35 | |
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[ed3238a] | 36 | <para>Two device nodes, /dev/console and /dev/null, are required to be |
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| 37 | present on the filesystem. These are needed by the kernel even before |
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| 38 | starting Udev early in the boot process, so we create them here:</para> |
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[bf8c11f] | 39 | |
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[ed3238a] | 40 | <screen><userinput>mknod -m 600 $LFS/dev/console c 5 1 |
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| 41 | mknod -m 666 $LFS/dev/null c 1 3</userinput></screen> |
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| 42 | |
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| 43 | <para>Once the system is complete and booting, the rest of our device |
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| 44 | nodes are created by the Udev package. Since this package is not |
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| 45 | available to us right now, we must take other steps to provide device |
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[b71fa50] | 46 | nodes under on the CLFS filesystem. We will use the <quote>bind</quote> |
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[ed3238a] | 47 | option in the mount command to make our host system's /dev structure |
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[b71fa50] | 48 | appear in the new CLFS filesystem:</para> |
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[ed3238a] | 49 | |
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| 50 | <screen><userinput>/tools/bin/mount -o bind /dev $LFS/dev</userinput></screen> |
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| 51 | |
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| 52 | <para>Additional file systems will soon be mounted from within the chroot |
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| 53 | environment. To keep the host up to date, perform a <quote>fake mount</quote> |
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| 54 | for each of these now:</para> |
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| 55 | |
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| 56 | <screen><userinput>mount -f -vt tmpfs tmpfs $LFS/dev/shm |
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[dd9906e] | 57 | mount -f -vt devpts -o gid=10,mode=620 devpts $LFS/dev/pts</userinput></screen> |
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[bf8c11f] | 58 | |
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| 59 | </sect1> |
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