#!/bin/bash

prefix=/usr/local
kernelsourcedir=
kerneldir=/lib/modules/$(uname -r)/build
cc=gcc
ld=ld
objcopy=objcopy
ar=ar
want_module=1
qemu_cflags=
qemu_ldflags=
kvm_trace=
qemu_opts=()
cross_prefix=
arch=`uname -m`
target_exec=
# don't use uname if kerneldir is set
no_uname=
depmod_version=
if [ -z "TMPDIR" ] ; then
    TMPDIR=.
fi

usage() {
    cat <<-EOF
	Usage: $0 [options]

	Options include:
	    --arch=ARCH            architecture to compile for ($arch)
	    --cross-prefix=PREFIX  prefix for cross compile
	    --prefix=PREFIX        where to install things ($prefix)
	    --with-patched-kernel  don't use external module
	    --with-kvm-trace       Enable kvm_trace
	    --kerneldir=DIR        kernel build directory ($kerneldir)
	    --qemu-cflags=CFLAGS   CFLAGS to add to qemu configuration
	    --qemu-ldflags=LDFLAGS LDFLAGS to add to qemu configuration

	Any additional option is given to qemu's configure verbatim; including:

EOF
    cd qemu
    ./configure --help | egrep "enable-|disable-" \
	| grep -v user | grep -v system | grep -v kqemu | grep -v kvm \
	| sed -e "s/^  /    /g" \
	| sed -e"s/  enable/enable/g" | sed -e "s/  disable/disable/g"
    exit 1
}

while [[ "$1" = -* ]]; do
    opt="$1"; shift
    arg=
    hasarg=
    if [[ "$opt" = *=* ]]; then
	arg="${opt#*=}"
	opt="${opt%%=*}"
	hasarg=1
    fi
    case "$opt" in
	--prefix)
	    prefix="$arg"
	    ;;
	--kerneldir)
	    kerneldir="$arg"
            no_uname=1
	    ;;
	--with-patched-kernel)
	    want_module=
	    ;;
	--with-kvm-trace)
	    kvm_trace=y
	    ;;
	--qemu-cflags)
	    qemu_cflags="$arg"
	    ;;
	--qemu-ldflags)
	    qemu_ldflags="$arg"
	    ;;
	--arch)
	    arch="$arg"
	    ;;
	--cross-prefix)
	    cross_prefix="$arg"
            ;;
	--help)
	    usage
	    ;;
	*)
	    qemu_opts=("${qemu_opts[@]}" "$opt${hasarg:+=$arg}")
	    ;;
    esac
done


#set kenel directory
libkvm_kerneldir=$(readlink -f kernel)

case $arch in
    i?86*|x86_64*)
        arch=${arch/#i?86/i386}
        target_exec="x86_64-softmmu"
        qemu_cflags="$qemu_cflags -DCONFIG_X86"
        ;;
    ia64*)
        target_exec="ia64-softmmu"
        ;;
    powerpc*)
        target_exec="ppcemb-softmmu"
        qemu_cflags="$qemu_cflags -I $PWD/libfdt"
        qemu_ldflags="$qemu_ldflags -L $PWD/libfdt"
        ;;
esac

processor=${arch#*-}
arch=${arch%%-*}

# see if we have split build and source directories
if [ -d "$kerneldir/include2" ]; then
    kernelsourcedir=${kerneldir%/*}/source
fi

if [ -n "$no_uname" ]; then
    if [ -e "$kerneldir/.kernelrelease" ]; then
        depmod_version=`cat "$kerneldir/.kernelrelease"`

    elif [ -e "$kerneldir/include/config/kernel.release" ]; then
            depmod_version=`cat "$kerneldir/include/config/kernel.release"`
    elif [ -e "$kerneldir/.config" ]; then
	depmod_version=$(awk '/Linux kernel version:/ { print $NF }'
			 "$kerneldir/.config")
    else
        echo
        echo "Error: kernelversion not found"
        echo "Please make sure your kernel is configured"
        echo
        exit 1
    fi
fi

#configure user dir
(cd user; ./configure --prefix="$prefix" --kerneldir="$libkvm_kerneldir" \
          --arch="$arch" --processor="$processor" \
          ${cross_prefix:+"--cross-prefix=$cross_prefix"})

#configure qemu
(cd qemu; ./configure --target-list=$target_exec \
    --disable-kqemu \
    --extra-cflags="-I $PWD/../libkvm $qemu_cflags" \
    --extra-ldflags="-L $PWD/../libkvm $qemu_ldflags" \
    --kerneldir="$libkvm_kerneldir" \
    --prefix="$prefix" \
    ${cross_prefix:+"--cross-prefix=$cross_prefix"} \
    ${cross_prefix:+"--cpu=$arch"} "${qemu_opts[@]}"
) || usage


cat <<EOF > config.mak
ARCH=$arch
PROCESSOR=$processor
PREFIX=$prefix
KERNELDIR=$kerneldir
KERNELSOURCEDIR=$kernelsourcedir
LIBKVM_KERNELDIR=$libkvm_kerneldir
WANT_MODULE=$want_module
CROSS_COMPILE=$cross_prefix
CC=$cross_prefix$cc
LD=$cross_prefix$ld
OBJCOPY=$cross_prefix$objcopy
AR=$cross_prefix$ar
DEPMOD_VERSION=$depmod_version
EOF

cat <<EOF > kernel/config.kbuild
EXT_CONFIG_KVM_TRACE=$kvm_trace
EOF