core/pkg-kernel-module: ensure linux supports modules

When a package wants to build a kernel module, we should ensure that the
kernel does support modules.

This patch does it automatically for packages using the kernel-module
infrastructure.

Packages that do not use it will have to set it manually (to be done in
a followup patch).

Suggested-by: Peter Korsgaard <jacmet@uclibc.org>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Peter Korsgaard <jacmet@uclibc.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Noé Rubinstein <noe.rubinstein@gmail.com>
Cc: Jan Viktorin <viktorin@rehivetech.com>
Cc: Gustavo Zacarias <gustavo@zacarias.com.ar>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

linux/linux.mk

@@ -175,6 +175,8 @@ LINUX_KCONFIG_EDITORS = menuconfig xconfig gconfig nconfig
 LINUX_KCONFIG_OPTS = $(LINUX_MAKE_FLAGS)
 
 define LINUX_KCONFIG_FIXUP_CMDS
+	$(if $(LINUX_NEEDS_MODULES),
+		$(call KCONFIG_ENABLE_OPT,CONFIG_MODULES,$(@D)/.config))
 	$(if $(BR2_arm)$(BR2_armeb),
 		$(call KCONFIG_ENABLE_OPT,CONFIG_AEABI,$(@D)/.config))
 	$(if $(BR2_TARGET_ROOTFS_CPIO),

package/pkg-kernel-module.mk

@@ -44,6 +44,11 @@
 
 define inner-kernel-module
 
+# If the package is enabled, ensure the kernel will support modules
+ifeq ($$(BR2_PACKAGE_$(2)),y)
+LINUX_NEEDS_MODULES = y
+endif
+
 # The kernel must be built first.
 $(2)_DEPENDENCIES += linux