#!/bin/bash

USAGE="Usage: $0 [OPTION]...
-h --help            Display this help dialog.
-c --check           Enable memcheck leak detection. Requires -d gdb.
-d --debug <arg>     Run with debugging support. 'gdb' will start gdb
                     and 'qemu' will start the qemu monitor.
-n --new-disk        Use a fresh copy of the hard disk image.
"

# XXX hardcoding these temporarily -- should be read from the makefiles
KERN_DIR=kernel
ISO_IMAGE=weenix.iso
SYMBOLS=kernel.bin
GDB_COMM_INIT=commands.gdb
GDB_PREINIT=preinit.gdb
GDB_INIT=init.gdb
GDB_MEMCHECK=memcheck.gdb
GDBCOMM=gdb-commands

cd $(dirname $0)

dbgmode="run"
newdisk=
memcheck=
while (( "$#" )); do
	case "$1" in
		-h|--help) echo "$USAGE" >&2 ; exit 0 ;;
		-c|--check) memcheck=1 ; shift ;;
		-n|--new-disk) newdisk=1 ; shift ;;
		-d|--debug) dbgmode="$2" ; shift 2 ;;
		--) shift ;;
		*) echo "Argument error." >&2 ; exit 2 ;;
	esac
done

QEMU=qemu-system-x86_64

#if ! which $QEMU; then
	#echo "Unable to find qemu." >&2
	#exit 2
#fi
# QEMU=qemu/build/x86_64-softmmu/qemu-system-x86_64

QEMU_FLAGS="-k en-us -boot order=dca -device isa-debug-exit "
QEMU_FLAGS+="-drive format=raw,file=disk0.img "
QEMU_FLAGS+="-smp 4 -vga std -machine q35 "
#QEMU_FLAGS+="-chardev null,id=char0 "
#QEMU_FLAGS+="-device pci-serial,chardev=char0,id=d1 "


MEMCHECK_INIT=
if [[ -n "$memcheck" ]]
then
    case $dbgmode in
        gdb)
            MEMCHECK_INIT="-x $GDB_MEMCHECK"
            ;;
        *)
            echo "memcheck is only supported with -d gdb" >&2
            exit 2
            ;;
    esac
fi
if [[ -n "$newdisk" || ! ( -f disk0.img ) ]]; then
	cp -f user/disk0.img disk0.img
fi

MEMORY=1024

case $dbgmode in
	run)
		$QEMU $QEMU_FLAGS -m "$MEMORY" -cdrom "$KERN_DIR/$ISO_IMAGE" -serial stdio
		;;
	gdb)
		# We recommend using GDB 8.1 or higher
		# This path is used by default to ensure department machine compatibility
		GDB=gdb
		GDB_PORT=1234
		GDB_TERM=xterm

		if ! which $GDB; then
			echo "Unable to find gdb." >&2
			exit 2
		fi

		GDB_FLAGS="-x $GDB_PREINIT -s $KERN_DIR/$SYMBOLS -x $GDB_COMM_INIT $MEMCHECK_INIT -x $GDB_INIT"
		rm -f "$GDB_COMM_INIT"
		cat "$KERN_DIR/$GDBCOMM" | grep -E ".(gdb|py)$" | while read file
		do
			echo "source $file" >> "$GDB_COMM_INIT"
		done

		#$QEMU $QEMU_FLAGS -m "$MEMORY" -cdrom "$KERN_DIR/$ISO_IMAGE" -s -S -daemonize &
		xterm -e $QEMU $QEMU_FLAGS -m "$MEMORY" -cdrom "$KERN_DIR/$ISO_IMAGE"  -serial stdio -s -S &
		$GDB $GDB_FLAGS
		;;
	gdb-only)
		# We recommend using GDB 8.1 or higher
		# This path is used by default to ensure department machine compatibility
		GDB=gdb
		GDB_PORT=1234
		GDB_TERM=xterm


		if ! which $GDB; then
			echo "Unable to find gdb." >&2
			exit 2
		fi

		GDB_FLAGS="-x $GDB_PREINIT -s $KERN_DIR/$SYMBOLS -x $GDB_COMM_INIT $MEMCHECK_INIT -x $GDB_INIT"
		rm -f "$GDB_COMM_INIT"
		cat "$KERN_DIR/$GDBCOMM" | grep -E ".(gdb|py)$" | while read file
		do
			echo "source $file" >> "$GDB_COMM_INIT"
		done

		$QEMU $QEMU_FLAGS -m "$MEMORY" -cdrom "$KERN_DIR/$ISO_IMAGE" -s -S -daemonize &
		$GDB $GDB_FLAGS
		;;
	qemu)
		$QEMU $QEMU_FLAGS -m "$MEMORY" -cdrom "$KERN_DIR/$ISO_IMAGE" -monitor stdio
		;;
	*)
		echo "'$dbgmode' is an unknown debug mode." >&2
		echo "Valid modes: gdb" >&2
		echo "$USAGE" >&2
		exit 1
		;;
esac