#!/bin/bash

# Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
# Date: 2009-10-08
# License: GPL v3+

set -e

# depends on grub2

# specify the first argument as the new installer image:

output="$1"

# optionally specify the second argument as a preseed file:

preseed="$2"

SUITE=${SUITE:-stable}
ARCH=${ARCH:-amd64}
DISTRO=${DISTRO:-debian}

if [ -z "$output" ] ; then
    printf "you must specify a file name for the image to be built" >&2
    exit 1
fi

if [ -e "$output" ] ; then
    printf "file '%s' already exists" "$output" >&2
    exit 1
fi

preseed_args=''
if [ "$preseed" ] ; then
    if ! [ -r "$preseed" ] ; then
        printf "could not read preseed file '%s'\n" "$preseed" >&2
        exit 1
    fi
fi

WORKDIR=$(mktemp -d)

cleanup() {
    rm -rf "$WORKDIR"
}

trap cleanup EXIT

case "$DISTRO" in
    debian)
        BASEPATH="http://ftp.nl.debian.org/debian/dists/$SUITE/main/installer-$ARCH/current/images/netboot/debian-installer/$ARCH"
        ;;
    ubuntu)
        BASEPATH="http://archive.ubuntu.com/ubuntu/dists/$SUITE/main/installer-$ARCH/current/images/netboot/ubuntu-installer/$ARCH"
        ;;
esac

KERNEL=linux
INITRAMFS=initrd.gz
BOOTINSTRUCTIONS="
  linux /$KERNEL verbose -- console=ttyS0,115200n8 
  initrd /$INITRAMFS
"

case "$ARCH" in
    kfreebsd-*)
        # FIXME: this discards the requested SUITE, and just pulls the
        # latest d-i, because dkg is lazy
        SUITE=sid
        KERNEL=kfreebsd.gz
        BASEPATH="http://d-i.debian.org/daily-images/$ARCH/daily/monolithic/"
        BOOTINSTRUCTIONS='
  # this set came from mini.iso
  kfreebsd /kfreebsd.gz
  kfreebsd_module /initrd.gz type=mfs_root
  set kFreeBSD.vfs.root.mountfrom=ufs:/dev/md0
  set kFreeBSD.hw.ata.ata_dma=0	# needed for qemu hard disk # TODO: delete
  set kFreeBSD.hw.ata.atapi_dma=0	# needed for qemu cd # TODO: 1

  # this set came from http://jdc.parodius.com/freebsd/pxeboot_serial_install_7.html
  set kFreeBSD.comconsole_speed="115200"
  set kFreeBSD.console="comconsole"
'
esac

( cd "$WORKDIR" && wget "$BASEPATH"/{$KERNEL,$INITRAMFS} )

if [ "$preseed" ]; then
    unpackdir=$(mktemp -d)
    cp "$preseed" "$unpackdir/preseed.cfg"
    ( cd "$unpackdir" && fakeroot bash -c "gzip -d < '$WORKDIR/$INITRAMFS' | cpio --extract ; find . | cpio --create -H newc | gzip" ) > "$WORKDIR/$INITRAMFS.new"
    mv "$WORKDIR/$INITRAMFS.new" "$WORKDIR/$INITRAMFS"
fi

mkdir -p "$WORKDIR/boot/grub"


cat > "$WORKDIR/boot/grub/grub.cfg" <<EOF
serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1
terminal_output serial
terminal_input serial

menuentry "$SUITE d-i $ARCH (created $(date -R))" {
$BOOTINSTRUCTIONS
}
EOF

absoutput="$(pwd)/$output"

## no longer using genisoimage with grub2:
# genisoimage -R -input-charset utf-8 -b boot/grub/stage2_eltorito -no-emul-boot --boot-load-size 4 -boot-info-table "$WORKDIR"

(cd "$WORKDIR" && grub-mkrescue --output="$absoutput" .)