Makefiles: calculate KVER properly

When deriving the kernel version (KVER) from KDIR, the file
$(KDIR)/include/config/kernel.release should be preferred over
'make kernelversion'.

For example, the Ubuntu 3.2.0-23-generic kernel has a kernel.release
file containing '3.2.0-23-generic', but 'make kernelversion' returns
3.2.14. Since the modules are stored under /lib/modules/3.2.0-23-generic,
the value in kernel.release is the correct one to use.
    
Also:
- Evaluate KVER only once
- All depmod commands must include KVER
    
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
[bvanassche: Split long lines / removed trailing whitespace]


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5286 d57e44dd-8a1f-0410-8b47-8ef2f437770f

fcst/Makefile

@@ -26,19 +26,6 @@
 #    - install and uninstall must be made as root
 #
 
-ifndef PREFIX
-        PREFIX=/usr/local
-endif
-
-ifeq ($(KVER),)
-  ifeq ($(KDIR),)
-    KVER = $(shell uname -r)
-    KDIR := /lib/modules/$(KVER)/build
-  endif
-else
-  KDIR := /lib/modules/$(KVER)/build
-endif
-
 export PWD    := $(shell pwd)
 export CONFIG_FCST   := m
 
@@ -55,11 +42,30 @@ EXTRA_CFLAGS += -I$(SCST_INC_DIR) $(FCSTFLAGS$(BUILDMODE))
 
 MODULE_NAME = fcst
 
-INSTALL_DIR := /lib/modules/$(KVER)/extra
-
 ifneq ($(KERNELRELEASE),)
 include $(SUBDIRS)/Makefile_in-tree
 else
+######### BEGIN OUT-OF-TREE RULES #########
+
+ifndef PREFIX
+        PREFIX=/usr/local
+endif
+
+ifeq ($(KVER),)
+  ifeq ($(KDIR),)
+    KVER := $(shell uname -r)
+    KDIR := /lib/modules/$(KVER)/build
+  else
+    KVER := $(strip $(shell						\
+	cat $(KDIR)/include/config/kernel.release 2>/dev/null ||	\
+	make -s -C $(KDIR) kernelversion))
+  endif
+else
+  KDIR := /lib/modules/$(KVER)/build
+endif
+
+INSTALL_DIR := /lib/modules/$(KVER)/extra
+
 SCST_INC_DIR := $(shell if [ -e "$$PWD/../scst" ];			\
                   then echo "$$PWD/../scst/include";			\
                   else echo "$(PREFIX)/include/scst"; fi)
@@ -102,6 +108,8 @@ endif
 uninstall:
 	rm -f $(INSTALL_DIR)/$(MODULE_NAME).ko
 	-/sbin/depmod -a $(KVER)
+
+########## END OUT-OF-TREE RULES ##########
 endif
 
 clean: