contrib/initrd/mkinitrd-net

   1 #!/bin/sh
   2 #
   3 # $Id$
   4 # initrd builder for network booting
   5
   6 # Utility function to determine whether or not a filesystem is usable for
   7 # loopback mounts.  Lifted verbatim from Erik Troan's mkinitrd script.
   8 #
   9 is_good_fs() {
  10     local parttype= tmpname=
  11     local dir=$1
  12     [[ -d $dir ]] || return 1
  13     [[ -w $dir ]] || return 1
  14     [[ $dir == */ ]] && dir=${dir%/}
  15     parttype=$(awk "{if (\$2 == \""$dir"\") print \$3 }" /proc/mounts)
  16
  17     while tmpname=${dir%/*} && [[ -z $parttype ]];do
  18         [[ -z $tmpname ]] && tmpname=/
  19         parttype=$(awk "{if (\$2 == \""$tmpname"\") print \$3 }" /proc/mounts)
  20         dir=$tmpname
  21     done
  22
  23     case $parttype in
  24         nfs|tmpfs) return 1;;
  25         *) return 0;
  26     esac
  27 }
  28
  29 # Find a suitable temporary directory (i.e. not tmpfs or nfs)
  30 if is_good_fs $TMPDIR; then
  31   tmpdir=$TMPDIR
  32 elif is_good_fs /tmp; then
  33   tmpdir=/tmp
  34 elif is_good_fs /var/tmp; then
  35   tmpdir=/var/tmp
  36 elif is_good_fs /root/tmp; then
  37   tmpdir=/root/tmp
  38 else
  39   echo "Cannot use a tmp directory" >&2
  40   exit 1
  41 fi
  42
  43 # Default settings (some can be overridden by command-line options)
  44 include_modules=include-modules
  45 initrd_skel=/usr/lib/mkinitrd-net/initrd-skel
  46 kernel_ver=`uname -r`
  47 use_sudo=y
  48 keep=n
  49 output_dir=/var/lib/tftpboot
  50 make_link=y
  51 quiet=
  52
  53 # No need to use sudo if we are root
  54 if [ $UID -eq 0 ]; then
  55   use_sudo=n
  56 fi
  57
  58 USAGE="Usage: $0 [-k|--kernel <kernel_ver>] [-n|--nolink] [-q|--quiet] [-l|--local] [--nosudo] [--keep] [--help] module_list ..."
  59
  60 # Parse command-line options
  61 while [ $# -gt 0 ]; do
  62   case "$1" in
  63     -l|--local)
  64                 shift
  65                 use_local=y ;;
  66     -k|--kernel)
  67                 shift
  68                 kernel_ver=$1
  69                 shift ;;
  70     --nosudo)   shift ; use_sudo=n ;;
  71     --keep)     shift ; keep=y ;;
  72     --n|--nolink)
  73                 shift ; make_link=n ;;
  74     -q|--quiet) shift ; quiet=-q ;;
  75     --help)     shift ; do_help=y ;;
  76     --)         shift ; break ;;
  77     -*)         echo "${0}: ${1}: invalid option" >&2
  78                 echo $USAGE >& 2
  79                 exit 2 ;;
  80     *)          break ;;
  81   esac
  82 done
  83
  84 # Build list of requested modules
  85 modules="$*"
  86 requested_modules="$modules"
  87 modules="$modules nfs" # Always require nfs for nfs mount
  88 modules="$modules af_packet" # Always require af_packet for udhcpc
  89
  90 # --help => Print help message
  91 if [ "$do_help" == "y" ]; then
  92   echo $USAGE
  93   echo "  -k, --kernel   Specify kernel version"
  94   echo "  -n, --nolink   Do not create a matching symbolic link"
  95   echo "  -l, --local    Run locally from CVS (for developers only)"
  96   echo "  --nosudo       Do not use sudo (i.e. must run as root instead)"
  97   echo "  --keep         Keep temporary files instead of deleting them"
  98   exit 0;
  99 fi
 100
 101 # --local => we are running directly from CVS, rather than
 102 # from an installed copy, so use local files and directories
 103 if [ "$use_local" == "y" ]; then
 104   include_modules=./include-modules
 105   initrd_skel=initrd-skel
 106   output_dir=tftpboot
 107 fi
 108
 109 # If use_sudo is set, check that sudo exists
 110 sudo=/usr/bin/sudo
 111 if [ "$use_sudo" == "y" ]; then
 112   if [ ! -x $sudo ]; then
 113     use_sudo=n
 114     echo "WARNING: --nosudo not specified but $sudo not found"
 115   fi
 116 fi
 117 if [ "$use_sudo" == "n" ]; then
 118   sudo=
 119 fi
 120
 121 # Create temporary working files
 122 initrd=`mktemp -d ${tmpdir}/initrd.XXXXXX`
 123 initrdimg=`mktemp ${tmpdir}/initrd.img.XXXXXX`
 124 initrdmnt=`mktemp -d ${tmpdir}/initrd.mnt.XXXXXX`
 125
 126 # Copy skeleton into temporary area
 127 cp -a $initrd_skel/* $initrd/
 128 mkdir -p $initrd/lib/modules/$kernel_ver
 129 $include_modules $quiet -k $kernel_ver -d $initrd/lib/modules/$kernel_ver $modules > $initrd/bin/insert-modules || exit 1
 130 chmod 755 $initrd/bin/insert-modules
 131
 132 # Create empty ext2fs image file
 133 dd if=/dev/zero bs=1k of=$initrdimg count=$((`du -sk $initrd | cut -f1` * 7 / 6)) 2> /dev/null
 134 /sbin/mke2fs -q -F $initrdimg 2> /dev/null
 135
 136 # Mount image file, copy files on, create /dev entries, display free space, umount
 137 $sudo mount -o loop $initrdimg $initrdmnt
 138 cp -a $initrd/* $initrdmnt/
 139 $sudo mknod $initrdmnt/dev/console c 5 1
 140 $sudo mknod $initrdmnt/dev/null c 1 3
 141 $sudo mknod $initrdmnt/dev/ram b 1 1
 142 $sudo mknod $initrdmnt/dev/systty c 4 0
 143 for i in 1 2 3 4; do $sudo mknod $initrdmnt/dev/tty$i c 4 $i; done
 144 if [ "$quiet" == "n" ]; then
 145   df -h $initrdmnt
 146 fi
 147 $sudo umount $initrdmnt
 148
 149 # Create output file
 150 initrd_suffix=`echo $requested_modules | tr " " .`
 151 gzip -9 -n -c $initrdimg > $output_dir/initrd-$initrd_suffix.$kernel_ver.img
 152
 153 # Create symlink
 154 if [ "$make_link" == "y" ]; then
 155   link=$output_dir/initrd-$initrd_suffix.img
 156   [ -L $link ] && rm -f $link
 157   ln -s initrd-$initrd_suffix.$kernel_ver.img $link
 158 fi
 159
 160 # Remove temporary files
 161 if [ "$keep" == "n" ]; then
 162   rm -rf $initrd
 163   rm -f $initrdimg
 164   rmdir $initrdmnt
 165 fi