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 "$ISO" ]; then
  60     usage
  61 fi
  62
  63 if [ -d tftpboot ]; then
  64     echo "Subdirectory tftpboot exists already.  I won't overwrite it."
  65     echo "Delete the subdirectory before running."
  66     exit 1
  67 fi
  68
  69 # Mount the ISO.
  70 # FIXME: would be better if we had better mountpoints
  71 CDMNT=$(mktemp -d /media/cdtmp.XXXXXX)
  72 mount -o loop "$ISO" $CDMNT || exitclean
  73
  74 trap exitclean SIGINT SIGTERM
  75
  76 # Does it look like an ISO?
  77 if [[ ( ! -d $CDMNT/isolinux ) || ( ! -f $CDMNT/isolinux/initrd0.img && ! -f $CDMNT/isolinux/initrd.img  ) ]]; then
  78     echo "The ISO image doesn't look like a LiveCD ISO image to me."
  79     exitclean
  80 fi
  81
  82 if [[ -f $CDMNT/isolinux/initrd0.img ]]; then
  83     INITRD=initrd0.img
  84     VMLINUZ=vmlinuz0
  85 else
  86     INITRD=initrd.img
  87     VMLINUZ=vmlinuz
  88 fi
  89
  90 mkdir tftpboot
  91
  92 # Create a cpio archive of just the ISO and append it to the
  93 # initrd image.  The Linux kernel will do the right thing,
  94 # aggregating both cpio archives (initrd + ISO) into a single
  95 # filesystem.
  96 ISOBASENAME=`basename "$ISO"`
  97 ISODIRNAME=`dirname "$ISO"`
  98 ( cd "$ISODIRNAME" && echo "$ISOBASENAME" | cpio -H newc --quiet -L -o ) |
  99   gzip -9 |
 100   cat $CDMNT/isolinux/$INITRD - > tftpboot/$INITRD
 101
 102 # Kernel image.
 103 cp $CDMNT/isolinux/$VMLINUZ tftpboot/$VMLINUZ
 104
 105 # pxelinux bootloader.
 106 if [ -f /usr/share/syslinux/pxelinux.0 ]; then
 107     cp /usr/share/syslinux/pxelinux.0 tftpboot
 108 elif [ -f /usr/lib/syslinux/pxelinux.0 ]; then
 109     cp /usr/lib/syslinux/pxelinux.0 tftpboot
 110 else
 111     echo "Warning: You need to add pxelinux.0 to tftpboot/ subdirectory"
 112 fi
 113
 114 # Get boot append line from original cd image.
 115 if [ -f $CDMNT/isolinux/isolinux.cfg ]; then
 116     APPEND=$(grep -m1 append $CDMNT/isolinux/isolinux.cfg | sed -e "s#CDLABEL=[^ ]*#/$ISOBASENAME#" -e "s/ *append *//")
 117 fi
 118
 119 # pxelinux configuration.
 120 mkdir tftpboot/pxelinux.cfg
 121 cat > tftpboot/pxelinux.cfg/default <<EOF
 122 DEFAULT pxeboot
 123 TIMEOUT 20
 124 PROMPT 0
 125 LABEL pxeboot
 126         KERNEL $VMLINUZ
 127         APPEND rootflags=loop $APPEND
 128 ONERROR LOCALBOOT 0
 129 EOF
 130
 131 # All done, clean up.
 132 umount $CDMNT
 133 rmdir $CDMNT
 134
 135 echo "Your pxeboot image is complete."
 136 echo
 137 echo "Copy tftpboot/ subdirectory to /tftpboot or a subdirectory of /tftpboot."
 138 echo "Set up your DHCP, TFTP and PXE server to serve /tftpboot/.../pxeboot.0"
 139 echo
 140 echo "Note: The initrd image contains the whole CD ISO and is consequently"
 141 echo "very large.  You will notice when pxebooting that initrd can take a"
 142 echo "long time to download.  This is normal behaviour."
 143
 144 exit 0