#Sets up a common disk image that is used for building the VM disk or
#installing to USB

#See: http://wiki.osdev.org/Loopback_Device
#See: http://superuser.com/questions/130955/how-to-install-grub-into-an-img-file

echo "######## MOSS beginning setup for release . . ."

export remake_disk=0
export remake_fs=0
export remake_grub=0

#Note: on changing these, change also the Bochs configuration files.
export CYLINDERS=100
export HEADS=16
export SECTORS_PER_TRACK=63
export SECTOR_SIZE=512

if [ $remake_disk -eq 1 ]
then

#Make HDD image
echo "######## Making HDD file . . ."
dd if=/dev/zero of=build/moss-disk.bin bs=$((HEADS*SECTORS_PER_TRACK*SECTOR_SIZE)) count=$CYLINDERS

#Make partition on disk file (re-enable as necessary)
echo "######## Making partition thereon . . ."
cat <<EOF | fdisk -u -C$((CYLINDERS)) -S$((SECTORS_PER_TRACK)) -H$((HEADS)) build/moss-disk.bin
o
n
p



a
1
p
w
EOF

fi


echo "######## Filling disk . . ."
#This next section actually puts a file system and GrUB on the disk.  It took a lot of work to get to work
#since GrUB apparently wasn't intended (or at least tested sufficiently) to do this.  A lot is based on
#http://www.slideshare.net/sukhdotin/installing-grub-on-virtual-hard-disk-images-5094625, but I found
#http://www.omninerd.com/articles/Installing_GRUB_on_a_Hard_Disk_Image_File, which should be just about
#the same.

#Also, this section puts the kernel and all of the needed files on the disk.

#Mount the disk image in a loop device
sudo losetup /dev/loop0 build/moss-disk.bin

#Make the disk image's partitions into devices
sudo kpartx -v -a /dev/loop0
#Make a file system on first partition
#   Note: source also explains how to set up FAT32
if [ $remake_fs -eq 1 ]
then
echo "######## Making a filesystem . . ."
sudo mke2fs /dev/mapper/loop0p1
#Note: may have to unmount loops, restart, and then remount loops here.  See http://forum.osdev.org/viewtopic.php?f=1&t=26907
else
echo "######## NOT making a filesystem."
fi
#Mount the first partition
sudo mount -t ext2 /dev/mapper/loop0p1 /mnt
#Set up first partition's /boot directory
echo "######## Copying over GrUB files . . ."
sudo mkdir -p /mnt/boot/grub
#I tried.  I really did, to use grub-install.  It just kept failing:
#   http://forum.osdev.org/viewtopic.php?f=1&t=26907
#   http://ebroder.net/2009/08/04/installing-grub-onto-a-disk-image/
#   http://superuser.com/questions/619571/installing-grub-legacy-on-virtual-disk
#At the suggestion of http://www.slideshare.net/sukhdotin/installing-grub-on-virtual-hard-disk-images-5094625,
#just copy the needed files over.
sudo cp source/grub/stage1 /mnt/boot/grub/stage1
sudo cp source/grub/stage2 /mnt/boot/grub/stage2
sudo cp source/grub/e2fs_stage1_5 /mnt/boot/grub/e2fs_stage1_5
#Copy the kernel over and the facility to boot it
echo "######## Copying over kernel files . . ."
sudo cp build/MOSS.bin /mnt/boot/MOSS.bin
sudo cp source/grub/menu.lst /mnt/boot/grub/menu.lst
#Unmount the first partition
sudo umount /dev/mapper/loop0p1
#Unmake the first partition as a device
sudo kpartx -d /dev/loop0

#Setup GrUB device map.  I've done this before, but never passing /dev/null in . . .
if [ $remake_grub -eq 1 ]
then
echo "######## Setting up GrUB . . ."
grub --device-map=/dev/null <<EOF
device (hd0) build/moss-disk.bin
geometry (hd0) $((CYLINDERS)) $((HEADS)) $((SECTORS_PER_TRACK))
root (hd0,0)
setup (hd0)
quit
EOF
else
echo "######## NOT setting up GrUB."
fi

#Unmount the disk image
sudo losetup -d /dev/loop0

echo "######## Preparation for release complete!"