diff --git a/tools/flash.py b/tools/flash.py
new file mode 100755
index 0000000..755b75a
--- /dev/null
+++ b/tools/flash.py
@@ -0,0 +1,115 @@
+#!/usr/bin/env python
+
+# -------------------------------------------------------------------------- --
+#              TRASHERNET SoC - A Trashy Ethernet SoC for FPGAs              --
+# -------------------------------------------------------------------------- --
+# Interface program for the bootrom. Basically a serial-to-wishbone bridge.
+# -------------------------------------------------------------------------- --
+# Author       : Markus Koch <markus@notsyncing.net>
+# Contributors : None
+# License      : Mozilla Public License (MPL) Version 2
+# -------------------------------------------------------------------------- --
+
+import serial
+import sys
+from ast import literal_eval
+
+def eprint(*args, **kwargs):
+	print(*args, file=sys.stderr, **kwargs)
+
+ser = serial.Serial('/dev/ttyUSB0', 19200, timeout=2)
+
+def sread(address, length, quiet = False):
+	if not quiet:
+		eprint(f'Reading {length} bytes from 0x{address:08x}...')
+	ser.write(b'\x02' + address.to_bytes(4, byteorder='big') + length.to_bytes(4, byteorder='big'))
+	data = bytes()
+	while length > 0:
+		maxpkg = min(length, 128)
+		rd = ser.read(maxpkg)
+		if len(rd) == 0:
+			eprint("ERROR: Receive timeout")
+			return None
+		data += rd
+		length -= len(rd)
+	return data
+
+def swrite(address, data, quiet = False):
+	if not quiet:
+		eprint('Writing {} bytes to 0x{:08x}...'.format(len(data), address))
+	ser.write(b'\x01' + address.to_bytes(4, byteorder='big') + len(data).to_bytes(4, byteorder='big') + data)
+	return 0
+
+def sjump(address, quiet = False):
+	if not quiet:
+		eprint(f'Jumping to 0x{address:08x}...')
+	ser.write(b'\x03' + address.to_bytes(4, byteorder='big'))
+	return 0
+
+def get_diff(a, b):
+	diff = 0
+	for i in range(0, len(a)):
+		if a[i] != b[i]:
+			print('[0x{:08x}] 0x{:02x} => 0x{:02x}'.format(i, a[i], b[i]))
+			diff += 1
+	return diff
+
+def probe():
+	r = sread(0, 4, quiet = True);
+	if r != b'7\x03\x00\x81':
+		eprint("ERROR: Probe failed! Check that the device is in bootloader mode.")
+		return 1
+	return 0
+
+def program(filename, addr=0, check=True):
+	f = open(filename, "rb")
+	d = bytes(f.read())
+	swrite(addr, d)
+	if check:
+		r = sread(addr, len(d))
+		if r is None:
+			eprint("Programming failed")
+			return 1
+		diff_cnt = get_diff(d, r)
+		if diff_cnt == 0:
+			eprint("Programming OK.")
+			return 0
+		else:
+			print(f"Programming failed, {diff_cnt} bytes differ.")
+		return 2
+	else:
+		return 0
+
+def monitor():
+	print("Monitoring serial, press Ctrl+C to stop.")
+	while 1:
+		rd = ser.read(1)
+		if len(rd) > 0:
+			sys.stdout.buffer.write(bytes(rd))
+			sys.stdout.buffer.flush()
+
+if len(sys.argv) < 3:
+	eprint("usage: " + sys.argv[0] + " [write|dump|jump] [address] [file]")
+	exit()
+
+command = sys.argv[1]
+addr = literal_eval(sys.argv[2])
+
+if probe():
+	exit(-1)
+
+ret = 0
+if command == "write":
+	file = sys.argv[3]
+	ret = program(file, addr)
+elif command == "dump":
+	length = literal_eval(sys.argv[3])
+	sys.stdout.buffer.write(sread(addr, length))
+elif command == "jump":
+	ret = sjump(addr)
+	monitor()
+else:
+	ret = -2
+	eprint("Unknown command")
+
+exit(ret)