build: add --without-kmodules configure flag

Which can be used to exclude kernel modules from rootfs in the image
building phase. Otherwise by default included kernel modules are copied
to the resulting rootfs image.

Signed-off-by: Dmitry Voytik <dmitry.voytik@huawei.com>

Author: Dmitry Voytik

build/Makefile.am

@@ -1,5 +1,9 @@
 all-local: initrd
 
+if WITH_KMODULES
+export INCLUDE_KMODULES=1
+endif
+
 if WITH_VBOX
 initrd-local:
 	bash ./make-initrd.sh vbox

build/make-initrd.sh

@@ -19,11 +19,14 @@ cp socat /tmp/hyperstart-rootfs/sbin/
 cp libm.so.6 /tmp/hyperstart-rootfs/lib64/
 cp mount.nfs /tmp/hyperstart-rootfs/sbin/mount.nfs4
 
-if [ "$1"x = "aarch64"x ]; then
-	echo "build hyperstart for aarch64"
-	tar -xf modules_aarch64.tar -C /tmp/hyperstart-rootfs/lib/modules
-else
-	tar -xf modules.tar -C /tmp/hyperstart-rootfs/lib/modules
+if [ "$INCLUDE_KMODULES"x == "1"x ]; then
+	if [ "$1"x = "aarch64"x ]; then
+		echo "build hyperstart for aarch64"
+		tar -xf modules_aarch64.tar -C \
+			/tmp/hyperstart-rootfs/lib/modules
+	else
+		tar -xf modules.tar -C /tmp/hyperstart-rootfs/lib/modules
+	fi
 fi
 
 # create symlinks to busybox and iptables

configure.ac

@@ -73,6 +73,14 @@ AS_IF([test "x$enable_daemon" = "xno"],[SYSTEMD_SYSTEMUNIT=no])
 AC_SUBST(SYSTEMD_SYSTEMUNIT)
 AM_CONDITIONAL(SYSTEMD, test "x${SYSTEMD_SYSTEMUNIT}" != "xno" )
 
+AC_ARG_WITH([kmodules],
+	    AS_HELP_STRING([--without-kmodules],
+			   [Do not include kernel modules in the rootfs]), [],
+			   [])
+# by default kernel modules are included
+AS_IF([test "x$with_kmodules" = "x"],[with_kmodules=yes])
+AM_CONDITIONAL([WITH_KMODULES], [test "x$with_kmodules" = "xyes"])
+
 AC_CHECK_FILE([/usr/include/linux/vm_sockets.h],
 	      [have_vsock=yes], [have_vsock=no])
 if test "x$have_vsock" == "xyes"; then
@@ -94,6 +102,7 @@ AC_MSG_RESULT([
 
 	with-vbox:	${with_vbox}
 	with-aarch64:	${with_aarch64}
+	with-kmodules:  ${with_kmodules}
 
 	vsock-support:  ${have_vsock}