Add easier way to use DKMS

Makefile.dkms

@@ -0,0 +1,24 @@
+modname := bbswitch
+DKMS := dkms
+modver := $(shell awk -F'"' '/MODULE_VERSION/{print $$2}' < bbswitch.c)
+
+# directory in which generated files are stored
+DKMS_DEST := /usr/src/$(modname)-$(modver)
+
+all: install
+
+src_install:
+	mkdir -p '$(DKMS_DEST)'
+	cp Makefile bbswitch.c '$(DKMS_DEST)'
+	sed 's/#MODULE_VERSION#/$(modver)/' dkms/dkms.conf > '$(DKMS_DEST)/dkms.conf'
+
+build: src_install
+	$(DKMS) build 'bbswitch/$(modver)'
+
+install: build
+	$(DKMS) install 'bbswitch/$(modver)'
+
+uninstall:
+	$(DKMS) remove bbswitch/$(modver) --all
+
+.PHONY: all src_install build install uninstall

README.md

@@ -38,10 +38,16 @@ information.
 DKMS support
 ------------
 
-Change `#MODULE_VERSION#` to the current version of bbswitch. Copy the
-Makefile, C source and dkms.conf file to `/usr/src/bbswitch-VERSION/` (replace
-VERSION with the current version of bbswitch which has been inserted for
-`#MODULE_VERSION#`.
+If you have DKMS installed, you can install bbswitch in such a way that it
+survives kernel upgrades. It is recommended to remove older versions of bbswitch
+by running `dkms remove bbswitch/OLDVERSION --all` as root. To install the new
+version, simply run:
+
+    # make -f Makefile.dkms
+
+To uninstall it, run:
+
+    # make -f Makefile.dkms uninstall
 
 Usage
 -----