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/share/syslinux/pxelinux.0 -a ! -f /usr/lib/syslinux/pxelinux.0 ]; then
  46     echo "Warning: 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 -L -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/share/syslinux/pxelinux.0 ]; then
  99     cp /usr/share/syslinux/pxelinux.0 tftpboot
 100 elif [ -f /usr/lib/syslinux/pxelinux.0 ]; then
 101     cp /usr/lib/syslinux/pxelinux.0 tftpboot
 102 else
 103     echo "Warning: You need to add pxelinux.0 to tftpboot/ subdirectory"
 104 fi
 105
 106 # Get boot append line from original cd image.
 107 if [ -f $CDMNT/isolinux/isolinux.cfg ]; then
 108     APPEND=$(grep -m1 append $CDMNT/isolinux/isolinux.cfg | sed -e "s#CDLABEL=[^ ]*#/$ISOBASENAME#" -e "s/ *append *//")
 109 fi
 110
 111 # pxelinux configuration.
 112 mkdir tftpboot/pxelinux.cfg
 113 cat > tftpboot/pxelinux.cfg/default <<EOF
 114 DEFAULT pxeboot
 115 TIMEOUT 20
 116 PROMPT 0
 117 LABEL pxeboot
 118         KERNEL vmlinuz0
 119         APPEND rootflags=loop $APPEND
 120 ONERROR LOCALBOOT 0
 121 EOF
 122
 123 # All done, clean up.
 124 umount $CDMNT
 125 rmdir $CDMNT
 126
 127 echo "Your pxeboot image is complete."
 128 echo
 129 echo "Copy tftpboot/ subdirectory to /tftpboot or a subdirectory of /tftpboot."
 130 echo "Set up your DHCP, TFTP and PXE server to serve /tftpboot/.../pxeboot.0"
 131 echo
 132 echo "Note: The initrd image contains the whole CD ISO and is consequently"
 133 echo "very large.  You will notice when pxebooting that initrd can take a"
 134 echo "long time to download.  This is normal behaviour."
 135
 136 exit 0