From 84bcac3e0d7a113e52d22b866d1a844be02fbc04 Mon Sep 17 00:00:00 2001 From: fgerlits Date: Fri, 2 Mar 2007 12:37:36 +0000 Subject: [PATCH] a HOWTO for creating a live CD --- campcaster/doc/index.html | 2 + campcaster/doc/liveCdHowto.html | 292 ++++++++++++++++++++++++++++++++ 2 files changed, 294 insertions(+) create mode 100644 campcaster/doc/liveCdHowto.html diff --git a/campcaster/doc/index.html b/campcaster/doc/index.html index 212a140d3..139c7e3a0 100644 --- a/campcaster/doc/index.html +++ b/campcaster/doc/index.html @@ -44,6 +44,8 @@ environment
  • release process
  • localizing LS Studio
  • definitions of shared station/user preferences
    • +
  • HOWTO create a repository CD
    • +
  • HOWTO create a live CD

    • Generated documentation

    diff --git a/campcaster/doc/liveCdHowto.html b/campcaster/doc/liveCdHowto.html new file mode 100644 index 000000000..5803c5533 --- /dev/null +++ b/campcaster/doc/liveCdHowto.html @@ -0,0 +1,292 @@ + + + + + Campcaster live CD creation process documentation + + + +

    Preface

    +This document is part of the Campcaster +project, Copyright © 2004 Media +Development Loan Fund, under the GNU GPL.
    + + + +

    Scope

    +This document describes the process of creating a custom Ubuntu live CD +with the Campcaster packages added. + + +

    Acknowledgement

    + +The following HOWTO has been copied from Alberto Turelli's HOWTO at +http://www.atworkonline.it/~bibe/ubuntu/custom-livecd.htm, with some modifications. + + +

    Introduction

    +

    +A live CD is a bootable CD with a complete Linux system on it. A live CD +which contains the Campcaster packages can be used to demo Campcaster +without having to install anything on the hard drive. +

    + +

    +It can also be used to create a new, complete Ubuntu system on the hard drive, +with Campcaster automatically installed on it. +

    + +The live CD creation process consists of the following steps:
    +
      +
    1. Copy the live CD
      2. +
    2. Free some space
      3. +
    3. Mount the compressed filesystem
      4. +
    4. Create an image for the modified filesystem
      5. +
    5. Copy the compressed filesystem
      6. +
    6. Chroot to, and tweak the system
      7. +
    7. Finish the modified filesystem
      8. +
    8. Build the modified compressed filesystem
      9. +
    9. Create the new live CD
      10. +
    + + +

    Notes

    + +

    +The live CD produced with this HOWTO (as of revision 3055) has the following issues: +

    + + + + +

    The steps in detail

    + +

    1. Copy the live CD

    +Export a shell variable (say, WORK) pointing to a working directory somewhere on your disk (say, ~/mylivecd), so you can use this page as a copy-and-paste howto. +
    +$ export WORK=~/mylivecd
+$ mkdir -p $WORK
+
    + +Mount a (K)Ubuntu Linux Live CD +
    +$ mount -t iso9660 /dev/hdc /cdrom
+
    +or the ISO image: +
    +$ sudo mount -t iso9660 -o loop /path/to/dapper-live-i386.iso /cdrom
+
    + +Then copy the content of the disk into a new directory, set the write permission on the new directory's content, and unmount the Live CD (or the ISO image): +
    +$ cd $WORK
+$ mkdir ubuntu-livecd
+$ cp -a /cdrom/. ubuntu-livecd
+$ chmod -R u+w ubuntu-livecd
+$ sudo umount /cdrom
+
    +The directory contains about 690 MB. +You need a copy, because it will be modified. + + +

    2. Free some space

    +The copy of the Live CD has various subdirectories. +I removed one of them, containing some Windows applications. +
    +$ rm -rf $WORK/ubuntu-livecd/programs
+
    +The Live CD works fine without these programs. +That saves about 30 MB. + + +

    3. Mount the compressed filesystem

    + +

    +The visible content of the Live CD is mainly used for booting. +(K)Ubuntu Linux itself is contained in a compressed filesystem image in $WORK/ubuntu-livecd/casper/filesystem.squashfs. +

    + +

    +To decompress and read this file, you need the squashfs module (installed by default on Ubuntu Dapper), and the squashfs-tools package. +

    + +

    +Finally loopback mount the compressed filesystem on a new mount point, say $WORK/old: + +

    +$ mkdir $WORK/old
+$ sudo mount -t squashfs -o loop,ro $WORK/ubuntu-livecd/casper/filesystem.squashfs $WORK/old
+
    + +Have a look at $WORK/old. +You should see the root of the (K)Ubuntu filesystem. +

    + + +

    4. Create an image for the modified compressed filesystem

    + +This requires abount 2.5 GB of disk space. Make an empty file of 2.5 GB size: +
    +$ sudo dd if=/dev/zero of=$WORK/ubuntu-fs.ext2 bs=1M count=2500
+
    +Format the file with an Ext2 filesystem: + +
    +$ sudo mke2fs $WORK/ubuntu-fs.ext2
+
    +mke2fs will warn you that ubuntu-fs.ext2 a not a real device. +This is ok, proceed. + +
    +Now loopback mount the freshly formatted filesystem on a new mount point, say $WORK/new: +
    +$ mkdir $WORK/new
+$ sudo mount -o loop $WORK/ubuntu-fs.ext2 $WORK/new
+
    + + +

    5. Copy the compressed filesystem

    + +To modify the (K)Ubuntu filesystem, we need to decompress and copy it: +
    +$ sudo cp -a $WORK/old/. $WORK/new
+
    + +We can umount $WORK/old now, because we have copies of all the data we need: +
    +$ sudo umount $WORK/old
+
    + + +

    6. Chroot to, and tweak the system

    + +

    +Now it's time to fine-tune the system to your needs, chrooting into the new system and using the standard Debian/Ubuntu tools. +

    + +

    +First, prepare the /proc filesystem and create the /etc/resolv.conf and /etc/hosts files in the copied filesystem. Then stop some services to make sure their ports are available in the chrooted system. Finally, chroot into you live CD environment: +

    +$ sudo mount -t proc -o bind /proc $WORK/new/proc
+$ sudo cp /etc/resolv.conf /etc/hosts $WORK/new/etc/
+$ sudo /etc/init.d/campcaster-scheduler stop
+$ sudo /etc/init.d/postgresql-8.1 stop
+$ sudo /etc/init.d/apache2 stop
+$ sudo chroot $WORK/new /bin/bash
+
    +

    + +

    +Now you are at the root of the (K)Ubuntu filesystem. +Tweak the system as you like: +

    +# vi /etc/apt/sources.list   # (Enable the universe and campware repositories.)
+# apt-get update
+# apt-get install campcaster-studio
+# apt-get clean
+# vim /opt/campcaster/etc/campcaster-scheduler.xml  # (Change the sound
+# vim /opt/campcaster/etc/campcaster-studio.xml     # devices to "default".)
+
    +

    + +

    +Stop the services started by the package installer, and leave the (K)Ubuntu filesystem: +

    +# /etc/init.d/campcaster-scheduler stop
+# /etc/init.d/postgresql-8.1 stop
+# /etc/init.d/apache2 stop
+# exit
+$ sudo umount $WORK/new/proc
+$ sudo rm $WORK/new/etc/resolv.conf $WORK/new/etc/hosts
+
    + +You are back at your own system. +

    + + +

    7. Finish the modified filesystem

    + +First, update the manifest file to reflect the modified packages: +
    +$ sudo chroot $WORK/new dpkg-query -W --showformat='${Package} ${Version}\n' \
+    > $WORK/ubuntu-livecd/casper/filesystem.manifest
+
    + +Next, clear the free disk space. +Even if some Debian packages were removed, the unused space on the modified filesystem still holds the content. +Fill all free space on the modified filesystem with zeroes (this will eventually fail with "no space left"), then remove the zero file: +
    +$ sudo dd if=/dev/zero of=$WORK/new/dummyfile
+$ sudo rm $WORK/new/dummyfile
+
    + +Now, all unused data blocks are filled with zeroes and compress to almost nothing. + + +

    8. Build the modified compressed filesystem

    + +Re-generate the modified filesystem: +
    +$ sudo rm $WORK/ubuntu-livecd/casper/filesystem.squashfs
+$ cd $WORK/new
+$ sudo mksquashfs . $WORK/ubuntu-livecd/casper/filesystem.squashfs
+
    +This is the most time-consuming step. + +Umount $WORK/new now, we are done: +
    +$ cd $WORK
+$ sudo umount $WORK/new
+
    + + +

    9. Create the new live CD

    + +On the Live-CD there is a MD5 hash. +Adjust it to the modified content of the CD: +
    +$ cd $WORK/ubuntu-livecd
+$ sudo find . -type f -print0 |xargs -0 md5sum |sudo tee md5sum.txt
+
    + +Now build the ISO image file, ubuntu-new.iso: +
    +$ cd $WORK
+$ sudo mkisofs \
+    -o Ubuntu+Campcaster.iso \
+    -b isolinux/isolinux.bin \
+    -c isolinux/boot.cat \
+    -no-emul-boot \
+    -boot-load-size 4 \
+    -boot-info-table \
+    -r \
+    -V "Ubuntu+Campcaster Live CD" \
+    -cache-inodes  \
+    -J \
+    -l \
+    ubuntu-livecd
+
    + +

    +Burn Ubuntu+Campcaster.iso to a disk and you are done! +

    + +

    +For testing, a virtual PC like qemu is great. +

    + +
    + +