add a script for updating the kernel

Add a script for easily updating a kernel to a newer release, while
refreshing the patches, ensuring they still apply (and optionally also
ensure they build).

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

diff --git a/update_kernel.sh b/update_kernel.sh
new file mode 100755 (executable)
index 0000000..061e6e7
--- /dev/null
+++ b/update_kernel.sh
@@ -0,0 +1,161 @@
+#!/bin/sh
+#
+# update_kernel.sh: (c) 2017 Jonas Gorski <jonas.gorski@gmail.com>
+# Licensed under the terms of the GNU GPL License version 2
+
+BUILD=0
+BUILD_ARGS=
+VERBOSE=w
+TEST=0
+UPDATE=0
+
+KERNEL=
+PATCHVER=
+
+while [ $# > 0 ]; do
+       case $1 in
+               -b|--build)
+                       BUILD=1
+                       shift
+                       BUILD_ARGS=$1
+                       ;;
+               -q|--quiet)
+                       VERBOSE=
+                       ;;
+               -t|--test)
+                       TEST=1
+                       ;;
+               -u|--update)
+                       UPDATE=1
+                       ;;
+               -v|--verbose)
+                       VERBOSE=ws
+                       ;;
+               [1-9]*)
+                       if [ -z "$KERNEL" ]; then
+                               KERNEL=$1
+                       elif [ -z "$PATCHVER" ]; then
+                               PATCHVER=$1
+                       else
+                               exit 1
+                       fi
+                       ;;
+               *)
+                       break
+                       ;;
+
+       esac
+
+       shift
+done
+
+if [ -z "$KERNEL" ]; then
+       echo "usage: $0 [<options>...] <patchver> [<version>]"
+       echo "example: $0 3.18 3.18.30"
+       echo "If <version> is not given, it will try to find out the latest from kernel.org"
+       echo ""
+       echo "valid options:"
+       echo "-b|--build <args> also do a test build with <args> as extra arguments (e.g. -j 3)"
+       echo "-q|--quiet        less output"
+       echo "-t|--test         don't do anything, just print what it would do"
+       echo "-u|--update       update include/kernel-version.mk after a successful run"
+       echo "-v|--verbose      more output (pass V=ws to all commands)"
+       exit 1
+fi
+
+if [ -z "$PATCHVER" ]; then
+       if [ -n "$(which curl)" ]; then
+               DL_CMD="curl -s "
+       fi
+
+       if [ -n "$(which wget)" ]; then
+               DL_CMD="wget -O - -q "
+       fi
+
+       if [ -z "$DL_CMD" ]; then
+               echo "Failed to find a suitable download program. Please install either curl or wget." >&2
+               exit 1
+       fi
+
+       # https://www.kernel.org/feeds/kdist.xml
+       # $(curl -s https://www.kernel.org/feeds/kdist.xml | sed -ne 's|^.*"html_url": "\(.*/commit/.*\)",|\1.patch|p')
+       # curl -s "https://www.kernel.org/feeds/kdist.xml"
+       CURR_VERS=$($DL_CMD "https://www.kernel.org/feeds/kdist.xml" | sed -ne 's|^.*title>\([1-9][^\w]*\): .*|\1|p')
+
+       for ver in $CURR_VERS; do
+               case $ver in
+                       "$KERNEL"*)
+                               PATCHVER=$ver
+                               ;;
+               esac
+
+               if [ -n "$PATCHVER" ]; then
+                       break
+               fi
+       done
+
+       if [ -z "$PATCHVER" ]; then
+               echo "Failed to find the latest release on kernel.org, please specify the release manually" >&2
+               exit 1
+       fi
+fi
+
+echo "Refreshing Kernel $KERNEL to release $PATCHVER ..."
+
+targets=$(ls -b target/linux)
+
+if [ "$TEST" -eq 1 ]; then
+       CMD="echo"
+fi
+
+for target in $targets; do
+       if [ "$target" = "generic" -o -f "$target" ]; then
+               continue
+       fi
+
+       grep -q "broken" target/linux/$target/Makefile && { \
+               echo "Skipping $target (broken)"
+               continue
+       }
+
+       if [ -e tmp/${target}_${PATCHVER}_done ]; then
+               continue
+       fi
+
+       grep -q "${PATCHVER}" target/linux/$target/Makefile || \
+       [ -f target/linux/$target/config-${KERNEL} ] || \
+       [ -d target/linux/$target/patches-${KERNEL} ] && {
+               echo "refreshing $target ..."
+               $CMD echo "CONFIG_TARGET_$target=y" > .config || exit 1
+               $CMD echo "CONFIG_ALL_KMODS=y" >> .config || exit 1
+               $CMD make defconfig KERNEL_PATCHVER=${KERNEL} || exit 1
+               if [ ! -f tmp/${target}_${PATCHVER}_refreshed ]; then
+                       $CMD make target/linux/refresh V=$VERBOSE KERNEL_PATCHVER=${KERNEL} LINUX_VERSION=${PATCHVER} LINUX_KERNEL_HASH=skip || exit 1
+                       $CMD make target/linux/prepare V=$VERBOSE KERNEL_PATCHVER=${KERNEL} LINUX_VERSION=${PATCHVER} || exit 1
+                       $CMD touch tmp/${target}_${PATCHVER}_refreshed
+               fi
+               if [ "$BUILD" = "1" ]; then
+                       echo "building $target ... "
+                       $CMD make V=$VERBOSE KERNEL_PATCHVER=${KERNEL} LINUX_VERSION=${PATCHVER} $BUILD_ARGS || exit 1
+               fi
+               $CMD make target/linux/clean
+               $CMD touch tmp/${target}_${PATCHVER}_done
+       } || {
+               echo "skipping $target (no support for $KERNEL)"
+       }
+done
+
+if [ "$UPDATE" -eq 1 ]; then
+       NEWVER=${PATCHVER#$KERNEL}
+       if [ "$TEST" -eq 1 ]; then
+               echo ./staging_dir/host/bin/mkhash sha256 dl/linux-$PATCHVER.tar.xz
+       fi
+
+       if [ -f dl/linux-$PATCHVER.tar.xz ]; then
+               CHECKSUM=$(./staging_dir/host/bin/mkhash sha256 dl/linux-$PATCHVER.tar.xz)
+       fi
+
+       $CMD sed -i include/kernel-version.mk \
+               -e "s|LINUX_VERSION-${KERNEL} =.*|LINUX_VERSION-${KERNEL} = ${NEWVER}|" \
+               -e "s|LINUX_KERNEL_HASH-${KERNEL}.*|LINUX_KERNEL_HASH-${PATCHVER} = ${CHECKSUM}|"
+fi