litex/liteeth/common.py

164 lines
4.4 KiB
Python

from collections import OrderedDict
from migen.fhdl.std import *
from migen.fhdl.decorators import ModuleDecorator
from migen.genlib.resetsync import AsyncResetSynchronizer
from migen.genlib.record import *
from migen.genlib.fsm import FSM, NextState
from migen.genlib.misc import chooser
from migen.flow.actor import EndpointDescription
from migen.flow.actor import Sink, Source
from migen.actorlib.structuring import Converter, Pipeline
from migen.actorlib.fifo import SyncFIFO, AsyncFIFO
from migen.bank.description import *
eth_mtu = 1532
eth_preamble = 0xD555555555555555
buffer_depth = 2**log2_int(eth_mtu, need_pow2=False)
class HField():
def __init__(self, byte, offset, width):
self.byte = byte
self.offset = offset
self.width = width
mac_header_len = 14
mac_header = {
"destination_mac_address": HField(0, 0, 48),
"source_mac_address": HField(6, 0, 48),
"ethernet_type": HField(12, 0, 16)
}
arp_header_len = 28
arp_header = {
"hardware_type": HField( 0, 0, 16),
"protocol_type": HField( 2, 0, 16),
"hardware_address_length": HField( 4, 0, 8),
"protocol_address_length": HField( 5, 0, 8),
"operation": HField( 6, 0, 16),
"source_mac_address": HField( 8, 0, 48),
"source_ip_address": HField(14, 0, 32),
"destination_mac_address": HField(18, 0, 48),
"destination_ip_address": HField(24, 0, 32)
}
ipv4_header_len = 24
ipv4_header = {
"version": HField(0, 0, 4),
"ihl": HField(0, 4, 4),
"dscp": HField(1, 0, 6),
"ecn": HField(1, 6, 2),
"total_length": HField(2, 0, 16),
"identification": HField(4, 0, 16),
"flags": HField(6, 0, 3),
"fragment_offset": HField(6, 3, 13),
"time_to_live": HField(8, 0, 8),
"protocol": HField(9, 0, 8),
"header_checksum": HField(10, 0, 16),
"source_ip_address": HField(12, 0, 32),
"destination_ip_address": HField(16, 0, 32),
"options": HField(20, 0, 32)
}
udp_header_len = 8
udp_header = {
"source_port": HField( 0, 0, 16),
"destination_port": HField( 2, 0, 16),
"length": HField( 4, 0, 16),
"checksum": HField( 6, 0, 16)
}
# layouts
def _layout_from_header(header):
_layout = []
for k, v in sorted(header.items()):
_layout.append((k, v.width))
return _layout
def eth_phy_description(dw):
layout = [
("data", dw),
("last_be", dw//8),
("error", dw//8)
]
return EndpointDescription(layout, packetized=True)
def eth_mac_description(dw):
layout = _layout_from_header(mac_header) + [
("data", dw),
("last_be", dw//8),
("error", dw//8)
]
return EndpointDescription(layout, packetized=True)
def eth_arp_description(dw):
layout = _layout_from_header(arp_header) + [
("data", dw),
("error", dw//8)
]
return EndpointDescription(layout, packetized=True)
def eth_ipv4_description(dw):
layout = _layout_from_header(ipv4_header) + [
("data", dw),
("error", dw//8)
]
return EndpointDescription(layout, packetized=True)
def eth_udp_description(dw):
layout = _layout_from_header(udp_header) + [
("data", dw),
("error", dw//8)
]
return EndpointDescription(layout, packetized=True)
# Generic modules
@DecorateModule(InsertReset)
@DecorateModule(InsertCE)
class Counter(Module):
def __init__(self, signal=None, **kwargs):
if signal is None:
self.value = Signal(**kwargs)
else:
self.value = signal
self.width = flen(self.value)
self.sync += self.value.eq(self.value+1)
@DecorateModule(InsertReset)
@DecorateModule(InsertCE)
class Timeout(Module):
def __init__(self, length):
self.reached = Signal()
###
value = Signal(max=length)
self.sync += value.eq(value+1)
self.comb += self.reached.eq(value == length)
class BufferizeEndpoints(ModuleDecorator):
def __init__(self, submodule, *args):
ModuleDecorator.__init__(self, submodule)
endpoints = get_endpoints(submodule)
sinks = {}
sources = {}
for name, endpoint in endpoints.items():
if name in args or len(args) == 0:
if isinstance(endpoint, Sink):
sinks.update({name : endpoint})
elif isinstance(endpoint, Source):
sources.update({name : endpoint})
# add buffer on sinks
for name, sink in sinks.items():
buf = Buffer(sink.description)
self.submodules += buf
setattr(self, name, buf.d)
self.comb += Record.connect(buf.q, sink)
# add buffer on sources
for name, source in sources.items():
buf = Buffer(source.description)
self.submodules += buf
self.comb += Record.connect(source, buf.d)
setattr(self, name, buf.q)