tools/livecd-iso-to-pxeboot.sh

   1 #!/bin/bash
   2 # Convert a live CD iso so that it can be booted over the network
   3 # using PXELINUX.
   4 # Copyright 2008 Red Hat, Inc.
   5 # Written by Richard W.M. Jones <rjones@redhat.com>
   6 # Based on a script by Jeremy Katz <katzj@redhat.com>
   7 # Based on original work by Chris Lalancette <clalance@redhat.com>
   8 #
   9 # This program is free software; you can redistribute it and/or modify
  10 # it under the terms of the GNU General Public License as published by
  11 # the Free Software Foundation; version 2 of the License.
  12 #
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU Library General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program; if not, write to the Free Software
  20 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21
  22 export PATH=/sbin:/usr/sbin:$PATH
  23
  24 usage() {
  25     echo "Usage: livecd-iso-to-pxeboot <isopath>"
  26     exit 1
  27 }
  28
  29 cleanup() {
  30     [ -d "$CDMNT" ] && umount $CDMNT && rmdir $CDMNT
  31 }
  32
  33 exitclean() {
  34     echo "Cleaning up to exit..."
  35     cleanup
  36     exit 1
  37 }
  38
  39 if [ $(id -u) != 0 ]; then
  40     echo "You need to be root to run this script."
  41     exit 1
  42 fi
  43
  44 # Check pxelinux.0 exists.
  45 if [ ! -f /usr/lib/syslinux/pxelinux.0 ]; then
  46     echo "Warning: /usr/lib/syslinux/pxelinux.0 not found."
  47     echo "Make sure syslinux or pxelinux is installed on this system."
  48 fi
  49
  50 while [ $# -gt 1 ]; do
  51     case "$1" in
  52         *) usage ;;
  53     esac
  54     shift
  55 done
  56
  57 ISO="$1"
  58
  59 if [ -z "$ISO" -o ! -e "$ISO" ]; then
  60     usage
  61 fi
  62
  63 if [ -d tftpboot ]; then
  64     echo "Subdirectory tftpboot exists already.  I won't overwrite it."
  65     echo "Delete the subdirectory before running."
  66     exit 1
  67 fi
  68
  69 mkdir tftpboot
  70
  71 # Mount the ISO.
  72 # FIXME: would be better if we had better mountpoints
  73 CDMNT=$(mktemp -d /media/cdtmp.XXXXXX)
  74 mount -o loop "$ISO" $CDMNT || exitclean
  75
  76 trap exitclean SIGINT SIGTERM
  77
  78 # Does it look like an ISO?
  79 if [ ! -d $CDMNT/isolinux -o ! -f $CDMNT/isolinux/initrd0.img ]; then
  80     echo "The ISO image doesn't look like a LiveCD ISO image to me."
  81     exitclean
  82 fi
  83
  84 # Create a cpio archive of just the ISO and append it to the
  85 # initrd image.  The Linux kernel will do the right thing,
  86 # aggregating both cpio archives (initrd + ISO) into a single
  87 # filesystem.
  88 ISOBASENAME=`basename "$ISO"`
  89 ISODIRNAME=`dirname "$ISO"`
  90 ( cd "$ISODIRNAME" && echo "$ISOBASENAME" | cpio -H newc --quiet -o ) |
  91   gzip -9 |
  92   cat $CDMNT/isolinux/initrd0.img - > tftpboot/initrd0.img
  93
  94 # Kernel image.
  95 cp $CDMNT/isolinux/vmlinuz0 tftpboot/vmlinuz0
  96
  97 # pxelinux bootloader.
  98 if [ -f /usr/lib/syslinux/pxelinux.0 ]; then
  99     cp /usr/lib/syslinux/pxelinux.0 tftpboot
 100 else
 101     echo "Warning: You need to add pxelinux.0 to tftpboot/ subdirectory"
 102 fi
 103
 104 # pxelinux configuration.
 105 mkdir tftpboot/pxelinux.cfg
 106 cat > tftpboot/pxelinux.cfg/default <<EOF
 107 DEFAULT pxeboot
 108 TIMEOUT 20
 109 PROMPT 0
 110 LABEL pxeboot
 111         KERNEL vmlinuz0
 112         APPEND initrd=initrd0.img root=/$ISOBASENAME rootfstype=iso9660 rootflags=loop
 113 ONERROR LOCALBOOT 0
 114 EOF
 115
 116 # All done, clean up.
 117 umount $CDMNT
 118 rmdir $CDMNT
 119
 120 echo "Your pxeboot image is complete."
 121 echo
 122 echo "Copy tftpboot/ subdirectory to /tftpboot or a subdirectory of /tftpboot."
 123 echo "Set up your DHCP, TFTP and PXE server to serve /tftpboot/.../pxeboot.0"
 124 echo
 125 echo "Note: The initrd image contains the whole CD ISO and is consequently"
 126 echo "very large.  You will notice when pxebooting that initrd can take a"
 127 echo "long time to download.  This is normal behaviour."
 128
 129 exit 0