Add firmware bundles in cpio.gz format too to help netboot users.

Thanks to Alex Owen for the patch, slightly tweaked.

debian/changelog

@@ -14,6 +14,8 @@ debian-cd (3.1.18) UNRELEASED; urgency=medium
     checked. Now fixed.
   * Try to make VOLIDs shorter when given long alpha / beta release names
     in DEBVERSION
+  * Add firmware bundles in cpio.gz format too to help netboot users.
+    Thanks to Alex Owen for the patch, slightly tweaked.
 
   [ Didier Raboud ]
   * For stretch, swap amd64 and i386 to let the first be the norm, and the

tools/make-firmware-image

@@ -39,4 +39,5 @@ cd $TMPDIR/firmware
 tar czf ../firmware.tar.gz .
 zip -9rq ../firmware.zip .
 cd ..
-ls -l $PWD/firmware.tar.gz $PWD/firmware.zip
+find firmware | cpio --quiet -o -H newc | gzip -9 > firmware.cpio.gz
+ls -l $PWD/firmware.cpio.gz $PWD/firmware.tar.gz $PWD/firmware.zip