Do not build firmware on buildds

There is no mipsel cross-compiler packaged for Debian, so building
the firmware on arbitrary build machines is not possible.

So let packagers build firmware when generating the source package.
The built firmware is kept in the debian/ directory and then
copied verbatim to <staging directory>/usr/share/xburst-tools
at the appropriate time.

The commands to prepare the firmware are in a script named
debian/autogen.sh, which could be taught to do other things (such as
generate a changelog) later.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

usbboot/debian/rules

@@ -6,12 +6,22 @@ build clean install binary-arch binary-indep binary:
 	+dh --parallel $(opt_no_act) $@
 
 override_dh_auto_clean:
+	test -e debian/xburst_stage1.bin || { \
+		echo >&2 see debian/README.source; \
+		exit 1; \
+	}
 	dh_auto_clean
 	sh debian/clean.sh
 
-override_dh_auto_configure:
-	AUTOMAKE="automake --foreign" autoreconf -is
-	dh_auto_configure -- $(opt_optimize) $(opt_quiet) LDFLAGS=-Wl,-z,defs
+override_dh_auto_configure: configure
+	dh_auto_configure -- $(opt_optimize) $(opt_quiet) \
+		--disable-firmware  LDFLAGS=-Wl,-z,defs
+
+override_dh_auto_install:
+	dh_auto_install
+	: install firmware from source package
+	dh_install debian/xburst_stage1.bin usr/share/xburst-tools/
+	dh_install debian/xburst_stage2.bin usr/share/xburst-tools/
 
 opt_optimize = CFLAGS="-g -O2"
 opt_no_act =
@@ -29,3 +39,11 @@ ifneq (,$(filter quiet,$(DEB_BUILD_OPTIONS)))
     opt_quiet = --quiet
     MAKEFLAGS += --quiet
 endif
+
+configure: configure.ac
+	AUTOMAKE="automake --foreign" autoreconf -is
+
+firmware: configure
+	./configure --enable-firmware
+	$(MAKE) -C src ../xburst_stage1/xburst_stage1.bin \
+		../xburst_stage2/xburst_stage2.bin