Import('env') import os import shutil import gzip OUTPUT_DIR = "build_output{}".format(os.path.sep) def bin_gzip(source, target, env): variant = str(target[0]).split(os.path.sep)[2] # create string with location and file names based on variant bin_file = "{}firmware{}{}.bin".format(OUTPUT_DIR, os.path.sep, variant) gzip_file = "{}firmware{}{}.bin.gz".format(OUTPUT_DIR, os.path.sep, variant) # check if new target files exist and remove if necessary if os.path.isfile(gzip_file): os.remove(gzip_file) # write gzip firmware file with open(bin_file,"rb") as fp: with gzip.open(gzip_file, "wb", compresslevel = 9) as f: shutil.copyfileobj(fp, f) ORG_FIRMWARE_SIZE = os.stat(bin_file).st_size GZ_FIRMWARE_SIZE = os.stat(gzip_file).st_size print("Compression reduced firmware size by {:.0f}% (was {} bytes, now {} bytes)".format((GZ_FIRMWARE_SIZE / ORG_FIRMWARE_SIZE) * 100, ORG_FIRMWARE_SIZE, GZ_FIRMWARE_SIZE)) env.AddPostAction("$BUILD_DIR/${PROGNAME}.bin", [bin_gzip])