Lays groundword for Rv64i extension

Some base files had to be modified to support 64-bit architecture
as well as the Makefile to load 64-bit words into memory

common/swap_endian.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+import sys
+
+if len(sys.argv) < 3:
+    print("Usage: swap_endian.py <input> <output> [word_size]")
+    sys.exit(1)
+
+input_file = sys.argv[1]
+output_file = sys.argv[2]
+word_size = int(sys.argv[3]) if len(sys.argv) > 3 else 4  # par défaut 32 bits
+
+with open(input_file, "rb") as f:
+    data = f.read()
+
+# Vérifie que la taille est multiple de la taille de mot
+if len(data) % word_size != 0:
+    print("⚠️  Attention : la taille du fichier n'est pas multiple de la taille de mot")
+
+swapped = bytearray()
+for i in range(0, len(data), word_size):
+    word = data[i:i+word_size]
+    swapped.extend(word[::-1])  # inverse les octets dans chaque mot
+
+with open(output_file, "wb") as f:
+    f.write(swapped)