It's used for files with custom build rules, eg. the objcopy stuff surrounding smm and sipi_vector. Change-Id: Ie9ab4c9c6008ca42f82f768c5f33f90c7f5f4db5 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Reviewed-on: http://review.coreboot.org/9287 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin <adurbin@google.com> Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>