#!/bin/bash
#
# InitRD.sh.txt
# -------------
#
# Original Files
# --------------
#	http://Linux-Boot.net/Boot/FD
#	http://document.eidologic.de/Documentation/Making_boot_disk.html
#
#	http://www.linux.org/docs/ldp/howto/Bootdisk-HOWTO/buildroot.html
# 	http://www.tldp.org/HOWTO/Encrypted-Root-Filesystem-HOWTO/setup-boot-device.html
#
#	http://penguinppc.org/embedded/howto/root-filesystem.html
#	http://linuxdoc.org/HOWTO/mini/Loopback-Root-FS.html 
#
#
# 08-Mar-05 amo Date-of-Birth
# 10-Mar-05 amo Added LoopSize for how big "/" has to be to hold the initrd
#
#
#
NM="InitRD.sh.txt"
#
#
# Run the command and show status
# -------------------------------
function doecho()
{
  cmd=$1
  #
  echo "$cmd"
  $cmd
  #
  if [ $? != 0 ];
  then
    echo "#"
    echo "# ERROR: FAILED: $cmd "
    echo "#"
    #
    exit 1
    #
  fi
  #
} # doecho
#
#
# Create a file ... /etc/fstab, /etc/inittab, /etc/lilo.conf
# -------------
function CreateFile()
{
  fil=$1
  lin="$2"
  #
  echo "#" > $fil
  echo "$lin" >> $fil
  echo "#" >> $fil
  #
} # createfile
#
#
# ===========================================================
#
# minimum rootFS that runs in /dev/ram
#
#
CreateRootFS()
{
  #
  Src=`pwd`
  #
  DLoop="/tmp/loop.initrd"
  MLoop="/mnt/loop"
  #
  umount $MLoop
  #
  # Size of the RootFS ( /dev/loop ) - it will be "/"
  # -----------------
  #oopSize="8192"
  #oopSize="16384"
  LoopSize="32768"
  #
  doecho "dd if=/dev/zero of=$DLoop count=$LoopSize bs=1024"
  doecho "mke2fs -q -j $DLoop"
  #
  doecho "mount -o rw,loop $DLoop $MLoop"
  #
  doecho "cd $MLoop"
  echo "#"
  #
  #
  doecho "mkdir boot bin dev etc initrd lib mnt proc root sbin tmp usr var"
  chmod 1777 tmp
  #
  RootFS="$Src/RootFS.txt"
  #
  if [ ! -f "$RootFS" ];
  then
    echo "#"
    echo "# ERROR: Missing Contents of initrd=$RootFS"
    echo "#"
    #
    exit 1
    #
  fi
  #
  DevLibBin=` grep -iv ^# $RootFS `
  #
  # echo "$DevLibBin.."
  #
  echo "tar cf - $DevLibBin | ( cd $MLoop ; tar xvfp - ) "
        tar cf - $DevLibBin | ( cd $MLoop ; tar xvfp - )
  #
  # remove the prev copy
  rm -f $DLoop.gz ; sleep 2
  #
  echo "#"
  echo "sync ; gzip -9 $DLoop"
  gzip -9 $DLoop
  echo "#"
  echo "#"
  #
  cd 
  umount $MLoop
  #
} # CreateRootFS
#
#
#
# ===========================================================
#
echo "#"
echo "# Create a minimum RootFS "
echo "#"
#
CreateRootFS
#
#
# End of file