./need.sh python kvm busybox

redo-ifchange "$2.initrd" memcalc.py
rm -f "$1.out" "$1.code"

# Linux only allows an initrd of size < 50% of RAM,
# so set a RAM amount based on the initrd size.
mem=$(./memcalc.py "$2.initrd")
echo "$2: kvm memory required: $mem" >&2

kvm \
	-m "$mem" \
	-kernel /boot/vmlinuz-$(uname -r) \
	-initrd "$2.initrd" \
	-append 'rdinit=/rdinit panic=1 console=ttyS0 loglevel=4' \
	-no-reboot \
	-display none \
	-chardev stdio,mux=on,id=char0 \
	-chardev file,id=char1,path="$1.out" \
	-chardev file,id=char2,path="$1.code" \
	-serial chardev:char0 \
	-serial chardev:char1 \
	-serial chardev:char2 >&2
fix_cr() {
	# serial devices use crlf (\r\n) as line
	# endings instead of just lf (\n).
	sed -e 's/\r//g'
}
rv=$(fix_cr <"$1.code")
[ -n "$rv" ] || exit 99
if [ "$rv" -eq 0 ]; then
	fix_cr <"$1.out" >$3
	echo "ok." >&2
else
	echo "kvm program returned error: $rv" >&2
fi
exit "$rv"