fix issues if kernel config is changed after the compile has started

SVN-Revision: 4570

openwrt/include/kernel-build.mk

@@ -94,10 +94,11 @@ $(KERNEL_IPKG):
 	fi
 	$(IPKG_BUILD) $(KERNEL_IDIR) $(KERNEL_BUILD_DIR)
 
-$(TOPDIR)/.kernel.mk:
-	echo "BOARD:=$(BOARD)" > $@
-	echo "LINUX_VERSION:=$(LINUX_VERSION)" >> $@
-	echo "LINUX_RELEASE:=$(LINUX_RELEASE)" >> $@
+$(TOPDIR)/.kernel.mk: $(TOPDIR)/target/linux/$(BOARD)-$(KERNEL)/Makefile
+	echo "CONFIG_BOARD:=$(BOARD)" > $@
+	echo "CONFIG_KERNEL:=$(KERNEL)" >> $@
+	echo "CONFIG_LINUX_VERSION:=$(LINUX_VERSION)" >> $@
+	echo "CONFIG_LINUX_RELEASE:=$(LINUX_RELEASE)" >> $@
 
 pkg-install: FORCE
 	@for pkg in $(INSTALL_TARGETS); do \

openwrt/include/kernel.mk

@@ -9,15 +9,25 @@ ifeq ($(DUMP),1)
   BOARD:=<BOARD>
   LINUX_VERSION:=<LINUX_VERSION>
 else
--include $(TOPDIR)/.kernel.mk
 
-ifneq (,$(findstring 2.4.,$(LINUX_VERSION)))
-KERNEL:=2.4
-LINUX_KMOD_SUFFIX=o
+  include $(TOPDIR)/.kernel.mk
+  include $(INCLUDE_DIR)/target.mk
+
+  # check to see if .kernel.mk matches target.mk
+  ifeq ($(CONFIG_BOARD)-$(CONFIG_KERNEL),$(BOARD)-$(KERNEL))
+     LINUX_VERSION:=$(CONFIG_LINUX_VERSION)
+     RELEASE:=$(CONFIG_RELEASE)
+  else
+  # oops, old .kernel.config; rebuild it (hiding the misleading errors this produces)
+    $(warning rebuilding .kernel.mk)
+    $(TOPDIR)/.kernel.mk: FORCE
+	@$(MAKE) -C $(TOPDIR)/target/linux/$(BOARD)-$(KERNEL) $@ &>/dev/null
   endif
-ifneq (,$(findstring 2.6.,$(LINUX_VERSION)))
-KERNEL:=2.6
+
+  ifeq ($(KERNEL),2.6)
     LINUX_KMOD_SUFFIX=ko
+  else
+    LINUX_KMOD_SUFFIX=o
   endif
 
   LINUX_KARCH:=$(shell echo $(ARCH) | sed -e 's/i[3-9]86/i386/' \