#!/bin/sh -e
#
# Update Linux kernel headers QEMU requires from a specified kernel tree.
#
# Copyright (C) 2011 Siemens AG
#
# Authors:
#  Jan Kiszka        <jan.kiszka@siemens.com>
#
# This work is licensed under the terms of the GNU GPL version 2.
# See the COPYING file in the top-level directory.

tmpdir=`mktemp -d`
linux="$1"
output="$2"

if [ -z "$linux" ] || ! [ -d "$linux" ]; then
    cat << EOF
usage: update-kernel-headers.sh LINUX_PATH [OUTPUT_PATH]

LINUX_PATH      Linux kernel directory to obtain the headers from
OUTPUT_PATH     output directory, usually the qemu source tree (default: $PWD)
EOF
    exit 1
fi

if [ -z "$output" ]; then
    output="$PWD"
fi

cp_virtio() {
    from=$1
    to=$2
    virtio=$(find "$from" -name '*virtio*h' -o -name "input.h" -o -name "pci_regs.h")
    if [ "$virtio" ]; then
        rm -rf "$to"
        mkdir -p "$to"
        for f in $virtio; do
            if
                grep '#include' "$f" | grep -v -e 'linux/virtio' \
                                             -e 'linux/types' \
                                             -e 'linux/if_ether' \
                                             -e 'sys/' \
                                             > /dev/null
            then
                echo "Unexpected #include in input file $f".
                exit 2
            fi

            header=$(basename "$f");
            sed -e 's/__u\([0-9][0-9]*\)/uint\1_t/g' \
                -e 's/__s\([0-9][0-9]*\)/int\1_t/g' \
                -e 's/__le\([0-9][0-9]*\)/uint\1_t/g' \
                -e 's/__be\([0-9][0-9]*\)/uint\1_t/g' \
                -e 's/<linux\/\([^>]*\)>/"standard-headers\/linux\/\1"/' \
                -e 's/__bitwise__//' \
                -e 's/__attribute__((packed))/QEMU_PACKED/' \
                -e 's/__inline__/inline/' \
                -e '/sys\/ioctl.h/d' \
                -e 's/SW_MAX/SW_MAX_/' \
                "$f" > "$to/$header";
        done
    fi
}

# This will pick up non-directories too (eg "Kconfig") but we will
# ignore them in the next loop.
ARCHLIST=$(cd "$linux/arch" && echo *)

for arch in $ARCHLIST; do
    # Discard anything which isn't a KVM-supporting architecture
    if ! [ -e "$linux/arch/$arch/include/asm/kvm.h" ] &&
        ! [ -e "$linux/arch/$arch/include/uapi/asm/kvm.h" ] ; then
        continue
    fi

    # Blacklist architectures which have KVM headers but are actually dead
    if [ "$arch" = "ia64" ]; then
        continue
    fi

    make -C "$linux" INSTALL_HDR_PATH="$tmpdir" SRCARCH=$arch headers_install

    rm -rf "$output/linux-headers/asm-$arch"
    mkdir -p "$output/linux-headers/asm-$arch"
    for header in kvm.h kvm_para.h; do
        cp "$tmpdir/include/asm/$header" "$output/linux-headers/asm-$arch"
    done
    if [ $arch = x86 ]; then
        cp "$tmpdir/include/asm/hyperv.h" "$output/linux-headers/asm-x86"
    fi
    if [ $arch = powerpc ]; then
        cp "$tmpdir/include/asm/epapr_hcalls.h" "$output/linux-headers/asm-powerpc/"
    fi

    cp_virtio "$tmpdir/include/asm" "$output/include/standard-headers/asm-$arch"
done

rm -rf "$output/linux-headers/linux"
mkdir -p "$output/linux-headers/linux"
for header in kvm.h kvm_para.h vfio.h vhost.h \
              psci.h; do
    cp "$tmpdir/include/linux/$header" "$output/linux-headers/linux"
done
rm -rf "$output/linux-headers/asm-generic"
mkdir -p "$output/linux-headers/asm-generic"
for header in kvm_para.h; do
    cp "$tmpdir/include/asm-generic/$header" "$output/linux-headers/asm-generic"
done
if [ -L "$linux/source" ]; then
    cp "$linux/source/COPYING" "$output/linux-headers"
else
    cp "$linux/COPYING" "$output/linux-headers"
fi

cat <<EOF >$output/linux-headers/linux/virtio_config.h
#include "standard-headers/linux/virtio_config.h"
EOF
cat <<EOF >$output/linux-headers/linux/virtio_ring.h
#include "standard-headers/linux/virtio_ring.h"
EOF

cp_virtio "$tmpdir/include/linux/" "$output/include/standard-headers/linux"

cat <<EOF >$output/include/standard-headers/linux/types.h
#include <stdint.h>
#include "qemu/compiler.h"
EOF
cat <<EOF >$output/include/standard-headers/linux/if_ether.h
#define ETH_ALEN    6
EOF

rm -rf "$tmpdir"