Add update-vermagic make target

Makefile

@@ -103,6 +103,13 @@ manifest: FORCE
 	mkdir -p $(GLUON_IMAGEDIR)/sysupgrade
 	mv $(GLUON_BUILDDIR)/$(GLUON_BRANCH).manifest.tmp $(GLUON_IMAGEDIR)/sysupgrade/$(GLUON_BRANCH).manifest
 
+update-vermagic: FORCE
+	@$(CheckExternal)
+	+($(foreach GLUON_TARGET,$(GLUON_TARGETS), \
+		$(GLUONMAKE_EARLY) maybe-prepare-target GLUON_TARGET='$(GLUON_TARGET)' V=s$(OPENWRT_VERBOSE) && \
+		$(GLUONMAKE) update-vermagic GLUON_TARGET='$(GLUON_TARGET)' V=s$(OPENWRT_VERBOSE) && \
+	) :)
+
 dirclean : FORCE
 	for dir in build_dir dl staging_dir tmp; do \
 		rm -rf $(GLUON_ORIGOPENWRTDIR)/$$dir; \
@@ -364,9 +371,7 @@ package_install: FORCE
 	if [ ! -x $(TARGET_DIR)/bin/opkg ]; then rm -rf $(TARGET_DIR)/usr/lib/opkg; fi
 
 
-ifeq ($(GLUON_OPKG_CONFIG),1)
 include $(INCLUDE_DIR)/version.mk
-endif
 
 opkg_config: FORCE
 	cp $(GLUON_OPENWRTDIR)/package/system/opkg/files/opkg.conf $(TARGET_DIR)/etc/opkg.conf
@@ -382,7 +387,7 @@ image: FORCE
 	cp -r $(BOARD_KDIR) $(PROFILE_KDIR)
 
 	+$(GLUONMAKE) package_install
-	+$(GLUONMAKE) opkg_config GLUON_OPKG_CONFIG=1
+	+$(GLUONMAKE) opkg_config
 
 	$(call Image/mkfs/prepare)
 	$(_SINGLE)$(NO_TRACE_MAKE) -C $(TOPDIR)/target/linux/$(BOARD)/image install TARGET_BUILD=1 IMG_PREFIX=gluon \
@@ -418,7 +423,15 @@ manifest: FORCE
 		) : \
 	) >> $(GLUON_BUILDDIR)/$(GLUON_BRANCH).manifest.tmp
 
+update-vermagic: FORCE
+	mkdir -p '$(BOARD_BUILDDIR)'
+	echo '$(DEFAULT_OPKG_REPO)' > '$(BOARD_BUILDDIR)/default_opkg_repo'
+	$(VERSION_SED) '$(BOARD_BUILDDIR)/default_opkg_repo'
+	wget -q -O- "$$(cat '$(BOARD_BUILDDIR)/default_opkg_repo')/base/Packages.gz" \
+		| gzip -d \
+		| awk '/Depends: kernel / { match($$3,/[[:xdigit:]]{32}/,m); print m[0]; exit }' \
+		> $(GLUONDIR)/targets/$(GLUON_TARGET)/vermagic
 
-.PHONY: all images prepare clean gluon-tools manifest
+.PHONY: all images prepare clean gluon-tools manifest update-vermagic
 
 endif

docs/dev/hardware.rst

@@ -84,8 +84,9 @@ The file ``config`` can be used to add additional, target-specific options to th
 
 The files ``vermagic`` must have the correct content so kernel modules from the upstream repositories
 can be installed without dependency issues. The OpenWrt version a Gluon release is based on is defined by the upstream package repo URL in ``include/gluon.mk``
-(in the variable ``CONFIG_VERSION_REPO``); at the time this documentation was written, this was ``barrier_breaker/14.07``; whenever
+(in the variable ``DEFAULT_OPKG_REPO``); at the time this documentation was written, this was ``barrier_breaker/14.07``; whenever
-the package repo is updated, all ``vermagic`` files must be updated as well.
+the package repo is updated, all ``vermagic`` files must be updated as well. The command ``make update-vermagic`` can be used to get the correct
+vermagic, or update the values when ``DEFAULT_OPKG_REPO`` has changed.
 
 The content is a hash which is part of the version number of the kernel package. So in the case of ``ar71xx-generic`` on
 ``barrier_breaker``, we look for the kernel package in the directory ``https://downloads.openwrt.org/barrier_breaker/14.07/ar71xx/generic/packages/base/``.

include/gluon.mk

@@ -35,7 +35,9 @@ export GLUON_LANGS
 ifeq ($(OPENWRT_BUILD),1)
 ifeq ($(GLUON_TOOLS),1)
 
-CONFIG_VERSION_REPO := $(shell $(GLUONDIR)/scripts/site.sh opkg_repo || echo http://downloads.openwrt.org/chaos_calmer/15.05-rc2/%S/packages)
+DEFAULT_OPKG_REPO := http://downloads.openwrt.org/chaos_calmer/15.05-rc2/%S/packages
+
+CONFIG_VERSION_REPO := $(shell $(GLUONDIR)/scripts/site.sh opkg_repo || echo '$(DEFAULT_OPKG_REPO)')
 export CONFIG_VERSION_REPO
 
 GLUON_SITE_CODE := $(shell $(GLUONDIR)/scripts/site.sh site_code)