add scripts to prepare firmware

.gitignore

@@ -1 +1,5 @@
 /Debug/
+/scripts/
+!/scripts/*.py
+!/scripts/*.sh
+*.cfg

scripts/fw_load.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+case "$1" in
+"firmware")
+    address="0x8002000"
+    ;;
+"recovery")
+    address="0x8041000"
+    ;;
+"upgrade")
+    address="0x8080000"
+    ;;    
+*)
+	echo "You must tell which part of memory you want to load. Possible values are firmware, recovery and upgrade"
+	exit 1
+    ;;
+esac
+
+st-flash write fw.bin $address

scripts/fw_prepare.py

@@ -0,0 +1,19 @@
+#!/usr/bin/env python
+
+import struct
+
+SIGNATURE_AREA_SIZE = 512 - 8
+
+def main():
+    fw = open("fw.bin", "rb").read()
+    
+    if fw[:4] == b'SHWF':
+        print("Firmware already prepared")
+        exit(1)
+    
+    header = b'SHWF'
+    header += struct.pack('<I', len(fw))
+    header += b'\x00' * SIGNATURE_AREA_SIZE
+    open("fw.bin", "wb").write(header + fw)
+if __name__ == '__main__':
+    main()

scripts/fw_sign.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+
+import ecdsa
+import hashlib
+import sys
+
+SIG_LEN = 64
+SIG_OFF = 8
+HEADER_SIZE = 512
+
+def main(index):
+    fw = open("fw.bin", "rb").read()
+    
+    if index < 0 or index > 6:
+        print("Index must be between 0 and 6")
+        exit(1)
+    
+    if fw[:4] != b'SHWF':
+        print("Firmware must be prepared with fw_prepare.py first!")
+        exit(1)
+        
+    sk_pem = open("secret_key.pem", "r").read()
+    sk = ecdsa.SigningKey.from_pem(sk_pem)
+    plain_fw = fw[HEADER_SIZE:]
+    fw_sig = sk.sign_deterministic(plain_fw, hashfunc=hashlib.sha256)
+    fw = fw[:SIG_OFF + SIG_LEN * (index) ] + fw_sig + fw[SIG_OFF + SIG_LEN * (index + 1):]
+    open("fw.bin", "wb").write(fw)
+if __name__ == '__main__':
+    if len(sys.argv) != 2:
+        print("You must insert the (zero-based) index of the signature")
+        exit(1)
+    main(int(sys.argv[1]))