#!/bin/sh

debianrelease=jessie
debianarch=amd64

nameserver=8.8.8.8

cidr2mask ()
{
   # Number of args to shift, 255..255, first non-255 byte, zeroes
   set -- $(( 5 - ($1 / 8) )) 255 255 255 255 $(( (255 << (8 - ($1 % 8))) & 255 )) 0 0 0
   [ $1 -gt 1 ] && shift $1 || shift
   echo ${1-0}.${2-0}.${3-0}.${4-0}
}

ip=$(ip route get 1 | awk '{print $NF;exit}')
gateway=$(ip route get 1 | awk '{print $3;exit}')
default_if=$(ip route list | awk '/^default/ {print $5}')
cidr=$(ip -o -f inet addr show $default_if | awk '{print $4}')
netmask=$(cidr2mask "${cidr##*/}")

echo "Detected network configuration:" 1>&2
echo "IP:       $ip" 1>&2
echo "Gateway:  $gateway" 1>&2
echo "Netmask:  $netmask" 1>&2

if mountpoint /boot > /dev/null 2>&1
then
    ipxepath="/ipxe.lkrn"
else
    ipxepath="/boot/ipxe.lkrn"
fi

if ! test -f "/boot/ipxe.lkrn"
then
    wget http://boot.ipxe.org/ipxe.lkrn -O /boot/ipxe.lkrn
fi

cat <<EOF
menuentry "Install from internet mirror: Arch Linux latest x86_64" {
    linux16 ${ipxepath} set net0/ip $ip \&\& set net0/netmask $netmask \&\& set net0/gateway $gateway \&\& set dns $nameserver \&\& ifopen net0 \&\& initrd http://mirror.nl.leaseweb.net/archlinux/iso/latest/arch/boot/x86_64/archiso.img \&\& chain http://mirror.nl.leaseweb.net/archlinux/iso/latest/arch/boot/x86_64/vmlinuz archiso_http_srv=http://mirror.nl.leaseweb.net/archlinux/iso/latest/ archisobasedir=arch checksum=y ip=${ip}::${gateway}:${netmask}::eth0
}

menuentry "Install from internet mirror: Debian ${debianrelease} amd64" {
    linux16 ${ipxepath} set net0/ip $ip \&\& set net0/netmask $netmask \&\& set net0/gateway $gateway \&\& set dns $nameserver \&\& ifopen net0 \&\& initrd http://ftp2.de.debian.org/debian/dists/${debianrelease}/main/installer-${debianarch}/current/images/netboot/debian-installer/${debianarch}/initrd.gz \&\& chain http://ftp2.de.debian.org/debian/dists/${debianrelease}/main/installer-${debianarch}/current/images/netboot/debian-installer/${debianarch}/linux netcfg/choose_interface=\\\$\{net0/mac\}
}

menuentry "Install from internet mirror: FreeBSD 11 amd64" {
    linux16 ${ipxepath} set net0/ip $ip \&\& set net0/netmask $netmask \&\& set net0/gateway $gateway \&\& set dns $nameserver \&\& ifopen net0 \&\& initrd http://mfsbsd.vx.sk/files/images/11/mfsbsd-11.0-RELEASE-amd64.img \&\& chain http://boot.rackspace.com/memdisk harddisk raw
}
EOF