#!/bin/sh

TOPDIR=`pwd`

# mkdir -p /mnt/loop1 /mnt/loop2

# we need to set aside a few loop devices. I chose (in reverse order of their appearance)
# -- loop1 for the boot image
# -- loop2 for the RAM disk image
# since the loop1 choice is reflected in the lilo.loopfix file, 
# you should not change that (or you need to change the file).
# I had used loop0 first, but I found that this is used by the Samba daemon.
# Also, I assume that the mount points are /mnt/loop{1,2}.
# In principle we could do with one, but it comes in handy to be able to
# leave one mounted, so I took two different ones. 

# Assume that everything to be loaded into memory with the
# RAM disk image (initrd) is is in the roottree directory. 

echo "Creating the Initial RAM disk image.... "

# first find out how much space we need. 
ISIZE=`du -s -k  roottree/ | awk '{print $1}'`

# add 2 Meg for extra   
ISIZE=`expr $ISIZE + 2048`
echo "Initial RAM disk contents will be $ISIZE KB"

# delete the existing RAM disk image, if there is one
rm -f root

# dd if=/dev/zero of=$TOPDIR/root bs=1k count=$ISIZE

# umount /mnt/loop2  2>/dev/null >/dev/null
# losetup -d /dev/loop2 2>/dev/null >/dev/null

# # associate it with /dev/loop2
# losetup /dev/loop2 $TOPDIR/root

# # make an ext2 filesystem on it. Set reserve to 0
# mke2fs -q -m 0 /dev/loop2 $ISIZE
# if [ $? != 0 ] ; then
#   echo "Build failed."
#   exit 1
# fi

# # we mount it...
# mount /dev/loop2 /mnt/loop2 

# # ... and delete the lost+found directory 
# rm -rf /mnt/loop2/lost+found 

# # then we copy the contents of our roottree to this filesystem
# cp -dpR roottree/* /mnt/loop2/
# if [ $? != 0 ] ; then
#   echo "RAM disk build failed."
#   exit 1
# fi

# # and unmount and divorce /dev/loop2
# umount /mnt/loop2
# losetup -d /dev/loop2 

(cd roottree; find . | cpio --quiet -c -o) >root

echo "Building initial RAM disk done"

# Now we have the image of the RAM disk in $TOPDIR/loopfiles/root. We
# compress this one and write the compressed image to the boot tree:

echo "Compressing the RAM disk image.... "

# delete any existing one
rm -f cdtree/boot/isolinux/initrd.img

# and gzip our RAM disk image and put it in the right place.
# gzip -9 -c root >cdtree/boot/isolinux/initrd.img
gzip -9 < root >cdtree/boot/isolinux/initrd.img
if [ $? != 0 ] ; then
  echo "Build failed"
  exit 1
fi

rdsize=`expr $ISIZE \* 1024`
echo "Ramdisk size is $rdsize"

echo "Making isolinux.cfg"
cat >cdtree/boot/isolinux/isolinux.cfg <<END_OF_DATA
default linux
prompt 1
display boot.msg
timeout 300
F1 boot.msg
F2 options.msg
F3 general.msg
F4 kernel.msg
label linux
  kernel vmlinuz
  append ramdisk_size=$rdsize initrd=initrd.img
label memtest86
  kernel memtest
  append -
END_OF_DATA

# we are done with the RAM disk image, delete it
rm -f root

echo "Initial RAM disk initrd.img is built."