Merge pull request #1 from makigumo/master

add python script

Readme.txt

@@ -3,4 +3,8 @@ Useful to make core with alternative boot ROM.
 
 Usage. In command prompt type:
 
+For Windows:
 injector.exe core.rbf boot.rom my_new_core.rbf
+
+For Linux/macOS:
+./injector.py core.rbf boot.rom my_new_core.rbf

injector.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+
+
+import os
+import struct
+import sys
+
+MAGIC = 'MiSTer\0\0\0\0\0\0'
+
+
+def print_usage():
+    print("Utility to inject ROM into RBF file for MiSTer.")
+    print("Usage: %s <core.rbf> <boot.rom> <my_new_core.rbf>" % sys.argv[0])
+
+
+if len(sys.argv) < 3:
+    print_usage()
+    exit(1)
+
+
+with open(sys.argv[3], 'wb') as rbf_out:
+    with open(sys.argv[1], 'rb') as rbf:
+        rbf_data = rbf.read()
+        if (rbf_data.startswith(MAGIC)):
+            print("Source core already injected with ROM.")
+            exit(2)
+        # header is 16 bytes
+        # 6 bytes magic
+        rbf_out.write(MAGIC)
+        # 4 bytes size of core, after which the rom follows
+        rbf_size = len(rbf_data)
+        rbf_out.write(struct.pack("i", rbf_size))
+        rbf_out.write(rbf_data)
+        with open(sys.argv[2], 'rb') as rom:
+            rbf_out.write(rom.read())