kbuild: Fixup deb-pkg target to generate separate firmware deb

The below is a simplistic fix for "make deb-pkg"; it splits the
firmware out to a linux-firmware-image package and adds an
(unversioned) Suggests to the linux package for this firmware.
Signed-Off-By: Jonathan McDowell <noodles@earth.li>
Acked-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/package/builddeb

@@ -15,15 +15,18 @@ set -e
 version=$KERNELRELEASE
 revision=`cat .version`
 tmpdir="$objtree/debian/tmp"
+fwdir="$objtree/debian/fwtmp"
 packagename=linux-$version
+fwpackagename=linux-firmware-image
 
 if [ "$ARCH" == "um" ] ; then
 	packagename=user-mode-linux-$version
 fi
 
 # Setup the directory structure
-rm -rf "$tmpdir"
+rm -rf "$tmpdir" "$fwdir"
 mkdir -p "$tmpdir/DEBIAN" "$tmpdir/lib" "$tmpdir/boot"
+mkdir -p "$fwdir/DEBIAN" "$fwdir/lib"
 if [ "$ARCH" == "um" ] ; then
 	mkdir -p "$tmpdir/usr/lib/uml/modules/$version" "$tmpdir/usr/share/doc/$packagename" "$tmpdir/usr/bin"
 fi
@@ -107,6 +110,7 @@ Standards-Version: 3.6.1
 
 Package: $packagename
 Provides: kernel-image-$version, linux-image-$version
+Suggests: $fwpackagename
 Architecture: any
 Description: Linux kernel, version $version
  This package contains the Linux kernel, modules and corresponding other
@@ -118,8 +122,24 @@ fi
 chown -R root:root "$tmpdir"
 chmod -R go-w "$tmpdir"
 
+# Do we have firmware? Move it out of the way and build it into a package.
+if [ -e "$tmpdir/lib/firmware" ]; then
+	mv "$tmpdir/lib/firmware" "$fwdir/lib/"
+
+	cat <<EOF >> debian/control
+
+Package: $fwpackagename
+Architecture: all
+Description: Linux kernel firmware, version $version
+ This package contains firmware from the Linux kernel, version $version
+EOF
+
+	dpkg-gencontrol -isp -p$fwpackagename -P"$fwdir"
+	dpkg --build "$fwdir" ..
+fi
+
 # Perform the final magic
-dpkg-gencontrol -isp
+dpkg-gencontrol -isp -p$packagename
 dpkg --build "$tmpdir" ..
 
 exit 0