1 files changed, 59 insertions, 0 deletions
diff --git a/util/exynos/fixed_cksum.py b/util/exynos/fixed_cksum.py
new file mode 100755
index 0000000000..66da06025d
--- /dev/null
+++ b/util/exynos/fixed_cksum.py
@@ -0,0 +1,59 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2013 Google Inc.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. The name of the author may not be used to endorse or promote products
+#    derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+
+"""
+This utility computes and fills Exynos ROM checksum (for BL1 or BL2).
+(Algorithm from U-Boot: tools/mkexynosspl.c)
+
+Input: IN OUT DATA_SIZE
+
+Output:
+
+  IN padded out to DATA_SIZE, checksum at the end, written to OUT.
+"""
+
+import struct
+import sys
+
+def main(argv):
+  if len(argv) != 4:
+    exit('usage: %s IN OUT DATA_SIZE' % argv[0])
+
+  in_name, out_name = argv[1:3]
+  size = int(argv[3], 0)
+  checksum_format = "<I"
+  with open(in_name, "rb") as in_file, open(out_name, "wb") as out_file:
+    data = in_file.read()
+    checksum_size = struct.calcsize(checksum_format)
+    data_size = size - checksum_size
+    assert len(data) <= data_size
+    checksum = struct.pack(checksum_format, sum(map(ord, data)))
+    out_file.write(data + bytearray(data_size - len(data)) + checksum)
+
+
+if __name__ == '__main__':
+  main(sys.argv)