Add assembler python script

assembler.py

+#!/usr/bin/env python3
+
+import os
+import sys
+import subprocess
+
+arch_prefix = "riscv64-unknown-elf-"
+march = "rv32i"
+reverse_bytes = True
+
+try:
+    path = os.environ["RV_BIN_PATH"]
+except:
+    print("ERROR:")
+    print("You need to set the RV_BIN_PATH environment variable to the path of the risc-v binutils")
+    exit()
+
+assembler = path + "/" + arch_prefix + "as"
+objdump = path + "/" + arch_prefix + "objdump"
+
+subprocess.run([assembler, sys.argv[1], "-march=" + march])
+with subprocess.Popen([objdump, "-D", "a.out"], stdout=subprocess.PIPE) as objdump_result:
+    text_start = False
+
+    for line in objdump_result.stdout.read().decode("utf-8").splitlines():
+        if not text_start:
+            if line == "00000000 <.text>:":
+                text_start = True
+        elif line == "":
+            break
+        else:
+            components = line.split()
+            offset = components[0]
+            hexval = [components[1][0:2], components[1][2:4], components[1][4:6], components[1][6:8]]
+            if reverse_bytes:
+                hexval.reverse()
+            instruction = " ".join(components[2:])
+            print('          "\\x%s\\x%s\\x%s\\x%s" // %s %s' % (hexval[0], hexval[1], hexval[2], hexval[3], offset, instruction))
+
+subprocess.run(["rm", "a.out"])