update-kernel: support for arm architecture

update-kernel.in

@@ -152,6 +152,9 @@ if [ -z "$FLAVOR" ]; then
     [ "$FLAVOR" ] || FLAVOR=vanilla
 fi
 
+[ "$ARCH" ] || ARCH=$(apk --print-arch)
+ARM=$(echo "$ARCH" | grep ^arm || :)
+
 TMPDIR=$(mktemp -d /tmp/$SCRIPT.XXXXXX)
 ROOT=$TMPDIR/root
 BOOT=$ROOT/boot
@@ -176,7 +179,7 @@ _apk() {
 	wrapper="fakeroot $opt -s $fake_env --"
     fi
 
-    $wrapper apk $cmd $QUIET_OPT -p $ROOT ${ARCH:+--arch "$ARCH"} \
+    $wrapper apk $cmd $QUIET_OPT -p $ROOT --arch "$ARCH" \
 	--keys-dir /etc/apk/keys \
 	--repositories-file /etc/apk/repositories $*
 }
@@ -193,7 +196,7 @@ _apk add --initdb --update-cache
 
 if [ "$BUILDDIR" ]; then
     mkdir -p $BOOT
-    make -C "$BUILDDIR" firmware_install install modules_install \
+    make -C "$BUILDDIR" ${ARM:+z}install firmware_install modules_install \
 	INSTALL_MOD_PATH=$ROOT INSTALL_PATH=$BOOT
 else
     if [ -z "$PACKAGES" ]; then
@@ -214,8 +217,9 @@ depmod -b $ROOT "$KVER"
 STAGING=$TMPDIR/boot
 MODLOOP=$TMPDIR/modloop
 MODIMG=modloop-$FLAVOR
+DTB_STAGING=$TMPDIR/dtbs
 
-mkdir $MODLOOP $STAGING
+mkdir $DTB_STAGING $MODLOOP $STAGING
 cp -a $ROOT/lib/modules $MODLOOP
 cp -a $ROOT/lib/firmware $MODLOOP/modules
 _exec mksquashfs $MODLOOP "$STAGING/$MODIMG" -comp xz
@@ -227,6 +231,12 @@ for file in System.map config vmlinuz; do
     cp "$BOOT/$file$KVER_FLAVOR" $STAGING
 done
 
+if [ "$ARM" ]; then
+    DTBDIR=$ROOT/usr/lib/linux-$KVER
+    [ "$BUILDDIR" ] && DTBDIR=$BUILDDIR/source/arch/arm/boot/dts
+    cp "$DTBDIR"/*.dtb $DTB_STAGING
+fi
+
 
 if [ "$MNTDIR" ]; then
     ignore_sigs
@@ -236,6 +246,12 @@ fi
 
 mv $STAGING/* "$DESTDIR"
 
+if [ "$ARM" ]; then
+    DTBDIR=$DESTDIR/dtbs
+    mkdir -p "$DTBDIR"
+    mv $DTB_STAGING/* "$DTBDIR"
+fi
+
 if [ "$MNTDIR" ]; then
     set +e
     sync