diff --git a/test/test_stream.py b/test/test_stream.py
index feed1144b..3ef4f4703 100644
--- a/test/test_stream.py
+++ b/test/test_stream.py
@@ -3,47 +3,333 @@
 
 import unittest
 import random
+import itertools
+import sys
 
 from migen import *
 
 from litex.soc.interconnect.stream import *
 
+# Function to iterate over chunks of data, from
+# https://docs.python.org/3/library/itertools.html#itertools-recipes
+def grouper(iterable, n, fillvalue=None):
+    "Collect data into fixed-length chunks or blocks"
+    # grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx"
+    args = [iter(iterable)] * n
+    return itertools.zip_longest(*args, fillvalue=fillvalue)
+
+class StreamPacket:
+    def __init__(self, data, params={}):
+        # Data must be a list of bytes
+        assert type(data) == list
+        for b in data:
+            assert type(b) == int and b >= 0 and b < 256
+
+        # Params must be a dictionary of strings mapping to integers
+        assert type(params) == dict
+        for param_key, param_value in params.items():
+            assert type(param_key) == str
+            assert type(param_value) == int
+
+        self.data = data
+        self.params = params
+
+    def compare(self, other, quiet=True, output_target=sys.stdout):
+        if len(self.data) != len(other.data):
+            if not quiet:
+                print("Length mismatch in number of received bytes of packet:" \
+                      " {} {}".format(len(self.data), len(other.data)),
+                      file=sys.stdout)
+            return False
+
+
+        for nbyte, (byte_a, byte_b) in enumerate(zip(self.data, other.data)):
+            if byte_a != byte_b:
+                if not quiet:
+                    print("Mismatch between sent and received bytes {}: " \
+                          "0x{:02x} 0x{:02x}".format(nbyte, byte_a, byte_b),
+                          file=sys.stdout)
+                return False
+
+        if set(self.params.keys()) != set(other.params.keys()):
+            if not quiet:
+                print("Sent and received packets have different param fields:" \
+                      " {} {}".format(self.params.keys(), other.params.keys()),
+                      file=sys.stdout)
+            return False
+
+        for param_name, self_param_value in self.params.items():
+            other_param_value = other.params[param_name]
+            if self_param_value != other_param_value:
+                if not quiet:
+                    print("Sent and received packets have different value for" \
+                          " param signal \"{}\": 0x{:x} 0x{:x}".format(
+                              param_name,
+                              self_param_value,
+                              other_param_value),
+                          file=sys.stdout)
+                return False
+
+        return True
+
+def stream_inserter(
+        sink,
+        src,
+        seed=42,
+        valid_rand=50,
+        debug_print=False,
+        broken_8bit_last_be=True):
+    """Insert a list of packets of bytes on to the stream interface `sink`. If
+    `sink` has a `last_be` signal, that is set accordingly.
+
+    """
+
+    prng = random.Random(seed)
+
+    # Extract the data width from the provided sink Endpoint
+    dw = len(sink.data)
+
+    # Make sure dw is evenly divisible by 8 as the logic below relies on
+    # that. Also, last_be wouldn't make much sense otherwise.
+    assert dw % 8 == 0
+
+    # If a last_be signal is provided, it must contain one bit per byte of data,
+    # i.e. be dw // 8 long.
+    if hasattr(sink, "last_be"):
+        assert dw // 8 == len(sink.last_be)
+
+    # src is a list of lists. Each list represents a packet of bytes. Send each
+    # packet over the bus.
+    for pi, packet in enumerate(src):
+        assert len(packet.data) > 0, "Packets of length 0 are not compatible " \
+            "with the ready/valid stream interface"
+
+        # Each packet is a list. We must send dw // 8 bytes at a time. Use the
+        # grouper method to get a chunked iterator over the packet bytes and
+        # shift them to their correct position. Use a random filler byte to
+        # complete a bus word.
+        words = []
+        for chunk in grouper(packet.data, dw // 8, prng.randrange(256)):
+            word = 0
+            for i, b in enumerate(chunk):
+                assert b >= 0 and b < 256
+                word |= b << (i * 8)
+            words += [word]
+
+        if hasattr(sink, "last_be"):
+            encoded_last_be = Constant(
+                1 << ((len(packet.data) - 1) % (dw // 8)),
+                bits_sign=len(sink.last_be)
+            )
+
+            # In legacy code for 8bit data paths last_be might not be set
+            # properly: while last_be should always be equal to last for 8bit
+            # data paths, if new code interacts with old code which is not yet
+            # last_be aware, it might always be deasserted. If
+            # broken_8bit_last_be is set and we have an 8bit data path, randomly
+            # set last_be to either one or zero to check whether the DUT handles
+            # these cases properly.
+            if broken_8bit_last_be and dw == 8:
+                encoded_last_be = Constant(prng.randrange(2), bits_sign=1)
+
+        # At the very beginning of the packet transmission, set the param
+        # signals
+        for param_signal, param_value in packet.params.items():
+            yield getattr(sink, param_signal).eq(param_value)
+
+        for i, word in enumerate(words):
+            last = i == len(words) - 1
+
+            # Place the word on the bus, if its the last word set last and
+            # last_be accordingly and finally set sink to valid
+            yield sink.data.eq(word)
+            yield sink.last.eq(last)
+            if hasattr(sink, "last_be"):
+                if last:
+                    yield sink.last_be.eq(encoded_last_be)
+                else:
+                    yield sink.last_be.eq(0)
+            yield sink.valid.eq(1)
+            yield
+
+            # Wait until the sink has become ready for one clock cycle
+            while not (yield sink.ready):
+                yield
+
+            # Set sink to not valid for a random amount of time
+            yield sink.valid.eq(0)
+            while prng.randrange(100) < valid_rand:
+                yield
+
+        # Okay, we've transmitted a packet. We must set sink.valid to false, for
+        # good measure clear all other signals as well. We don't explicitly
+        # yield, given a there might be a new packet waiting already.
+        yield sink.data.eq(0)
+        yield sink.last.eq(0)
+        if hasattr(sink, "last_be"):
+            yield sink.last_be.eq(0)
+        for param_signal in packet.params.keys():
+            yield getattr(sink, param_signal).eq(0)
+        yield sink.valid.eq(0)
+
+        if debug_print:
+            print("Sent packet {}.".format(pi), file=sys.stderr)
+
+    # All packets have been transmitted. sink.valid has already been
+    # deasserted, yield once to properly apply that value.
+    yield
+
+def stream_collector(
+        source,
+        dest=[],
+        expect_npackets=None,
+        seed=42,
+        ready_rand=50,
+        debug_print=False):
+    """Consume some packets of bytes from the stream interface
+    `source`. If `source` has a `last_be` signal, that is respected
+    properly.
+
+    """
+
+    prng = random.Random(seed)
+
+    # Extract the data width from the provided source endpoint
+    dw = len(source.data)
+
+    # Make sure dw is evenly divisible by 8 as the logic below relies on
+    # that. Also, last_be wouldn't make much sense otherwise.
+    assert dw % 8 == 0
+
+    # If a last_be signal is provided, it must contain one bit per byte of data,
+    # i.e. be dw // 8 long.
+    if hasattr(source, "last_be"):
+        assert dw // 8 == len(source.last_be)
+
+    # Extract "param_signals" from the source Endpoint. They are extracted on
+    # the first valid word of a packet. If dest will be a list of tuples with
+    # data and param signals if there are any, otherwise just a list of lists.
+    param_signals = [
+        signal_name for signal_name, _, _ in source.param.layout
+    ] if hasattr(source, "param") else []
+
+    # Loop for collecting individual packets, separated by source.last
+    while expect_npackets == None or len(dest) < expect_npackets:
+        # Buffer for the current packet
+        collected_bytes = []
+        param_signal_states = {}
+
+        # Iterate until "last" has been seen. That concludes the end of a bus
+        # transaction / packet.
+        read_last = False
+        first_word = True
+        while not read_last:
+            # We are ready to accept another bus word
+            yield source.ready.eq(1)
+            yield
+
+            # Wait for data to become valid
+            while (yield source.valid) == 0:
+                yield
+
+            # Data is now valid, read it byte by byte
+            data = yield source.data
+            for byte in range(dw // 8):
+                if (yield source.last) == 1:
+                    read_last = True
+                    if hasattr(source, "last_be") and \
+                       2**byte > (yield source.last_be):
+                        break
+                collected_bytes += [((data >> (byte * 8)) & 0xFF)]
+
+            # Also, if this is the first loop iteration, latch all param signals
+            for param_signal in param_signals:
+                param_signal_states[param_signal] = \
+                    yield getattr(source, param_signal)
+
+            # Set source to not valid for a random amount of time
+            yield source.ready.eq(0)
+            while prng.randrange(100) < ready_rand:
+                yield
+
+            # This is no longer the first loop iteration
+            first_word = False
+
+        # A full packet has been read. Append it to dest.
+        dest += [StreamPacket(collected_bytes, param_signal_states)]
+        if debug_print:
+            print("Received packet {}.".format(len(dest) - 1), file=sys.stderr)
+
+def generate_test_packets(npackets, seed=42):
+    # Generate a number of last-terminated bus transaction byte contents (dubbed
+    # packets)
+    prng = random.Random(42)
+
+    packets = []
+    for _ in range(npackets):
+        # With a random number of bytes from [1, 1024)
+        values = []
+        for _ in range(prng.randrange(1023) + 1):
+            # With random values from [0, 256).
+            values += [prng.randrange(256)]
+        packets += [StreamPacket(values)]
+
+    return packets
+
+def compare_packets(packets_a, packets_b):
+    if len(packets_a) != len(packets_b):
+        print("Length mismatch in number of received packets: {} {}"
+              .format(len(packets_a), len(packets_b)), file=sys.stderr)
+        return False
+
+    for npacket, (packet_a, packet_b) in enumerate(zip(packets_a, packets_b)):
+        if not packet_a.compare(packet_b):
+            print("Error in packet", npacket)
+            packet_a.compare(packet_b, quiet=False)
+            return False
+
+    return True
 
 class TestStream(unittest.TestCase):
-    def pipe_test(self, dut):
-        prng = random.Random(42)
-        def generator(dut, valid_rand=90):
-            for data in range(128):
-                yield dut.sink.valid.eq(1)
-                yield dut.sink.data.eq(data)
-                yield
-                while (yield dut.sink.ready) == 0:
-                    yield
-                yield dut.sink.valid.eq(0)
-                while prng.randrange(100) < valid_rand:
-                    yield
+    def pipe_test(self, dut, seed=42, npackets=64, debug_print=False):
+        # Get some data to test with
+        packets = generate_test_packets(npackets, seed=seed)
 
-        def checker(dut, ready_rand=90):
-            dut.errors = 0
-            for data in range(128):
-                yield dut.source.ready.eq(0)
-                yield
-                while (yield dut.source.valid) == 0:
-                    yield
-                while prng.randrange(100) < ready_rand:
-                    yield
-                yield dut.source.ready.eq(1)
-                yield
-                if ((yield dut.source.data) != data):
-                    dut.errors += 1
-            yield
-        run_simulation(dut, [generator(dut), checker(dut)])
-        self.assertEqual(dut.errors, 0)
+        # Buffer for received packets (filled by collector)
+        recvd_packets = []
+
+        run_simulation(
+            dut,
+            [
+                stream_inserter(
+                    dut.sink,
+                    src=packets,
+                    debug_print=debug_print,
+                    seed=seed,
+                ),
+                stream_collector(
+                    dut.source,
+                    dest=recvd_packets,
+                    expect_npackets=npackets,
+                    debug_print=debug_print,
+                    seed=seed,
+                ),
+            ],
+        )
+        self.assertTrue(compare_packets(packets, recvd_packets))
 
     def test_pipe_valid(self):
-        dut = PipeValid([("data", 8)])
+        # PipeValid either connects the entire payload or not. Thus we don't
+        # need to test for 8bit support or a missing last_be signal
+        # specifically. This test does however ensure that last_be will continue
+        # to be respected in the future.
+        dut = PipeValid([("data", 32), ("last_be", 4)])
         self.pipe_test(dut)
 
     def test_pipe_ready(self):
-        dut = PipeReady([("data", 8)])
+        # PipeReady either connects the entire stream Endpoint or not. Thus we
+        # don't need to test for 8bit support or a missing last_be signal
+        # specifically. This test does however ensure that last_be will continue
+        # to be respected in the future.
+        dut = PipeReady([("data", 64), ("last_be", 8)])
         self.pipe_test(dut)