dev: Move generic serial devices to src/dev/serial

Change-Id: I104227fc460f8b561e7375b329a541c1fce881b2
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/4291
Reviewed-by: Gabe Black <gabeblack@google.com>

12 files changed, 1492 insertions, 0 deletions

diff --git a/src/dev/serial/SConscript b/src/dev/serial/SConscript
new file mode 100644
index 000000000..b9f13f54b
--- /dev/null
+++ b/src/dev/serial/SConscript
@@ -0,0 +1,59 @@
+# -*- mode:python -*-
+
+# Copyright (c) 2017 ARM Limited
+# All rights reserved.
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# Copyright (c) 2006 The Regents of The University of Michigan
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Andreas Sandberg
+
+Import('*')
+
+if env['TARGET_ISA'] == 'null':
+    Return()
+
+SimObject('Serial.py')
+SimObject('Terminal.py')
+SimObject('Uart.py')
+
+Source('serial.cc')
+Source('terminal.cc')
+Source('uart.cc')
+Source('uart8250.cc')
+
+DebugFlag('Terminal')
+DebugFlag('TerminalVerbose')
+DebugFlag('Uart')
diff --git a/src/dev/serial/Serial.py b/src/dev/serial/Serial.py
new file mode 100644
index 000000000..3f62ef37f
--- /dev/null
+++ b/src/dev/serial/Serial.py
@@ -0,0 +1,48 @@
+# Copyright (c) 2014, 2017 ARM Limited
+# All rights reserved.
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Andreas Sandberg
+
+from m5.params import *
+from m5.SimObject import SimObject
+
+class SerialDevice(SimObject):
+    type = 'SerialDevice'
+    abstract = True
+    cxx_header = "dev/serial/serial.hh"
+
+class SerialNullDevice(SerialDevice):
+    type = 'SerialNullDevice'
+    cxx_header = "dev/serial/serial.hh"
diff --git a/src/dev/serial/Terminal.py b/src/dev/serial/Terminal.py
new file mode 100644
index 000000000..863c4871c
--- /dev/null
+++ b/src/dev/serial/Terminal.py
@@ -0,0 +1,40 @@
+# Copyright (c) 2005-2007 The Regents of The University of Michigan
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Nathan Binkert
+
+from m5.SimObject import SimObject
+from m5.params import *
+from m5.proxy import *
+from Serial import SerialDevice
+
+class Terminal(SerialDevice):
+    type = 'Terminal'
+    cxx_header = "dev/serial/terminal.hh"
+    intr_control = Param.IntrControl(Parent.any, "interrupt controller")
+    port = Param.TcpPort(3456, "listen port")
+    number = Param.Int(0, "terminal number")
+    output = Param.Bool(True, "Enable output dump to file")
diff --git a/src/dev/serial/Uart.py b/src/dev/serial/Uart.py
new file mode 100644
index 000000000..53337059b
--- /dev/null
+++ b/src/dev/serial/Uart.py
@@ -0,0 +1,43 @@
+# Copyright (c) 2005-2007 The Regents of The University of Michigan
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Nathan Binkert
+
+from m5.params import *
+from m5.proxy import *
+from Device import BasicPioDevice
+from Serial import SerialDevice
+
+class Uart(BasicPioDevice):
+    type = 'Uart'
+    abstract = True
+    cxx_header = "dev/serial/uart.hh"
+    platform = Param.Platform(Parent.any, "Platform this device is part of.")
+    device = Param.SerialDevice(Parent.any, "The terminal")
+
+class Uart8250(Uart):
+    type = 'Uart8250'
+    cxx_header = "dev/serial/uart8250.hh"
diff --git a/src/dev/serial/serial.cc b/src/dev/serial/serial.cc
new file mode 100644
index 000000000..873366860
--- /dev/null
+++ b/src/dev/serial/serial.cc
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2014, 2017 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Andreas Sandberg
+ */
+
+#include "dev/serial/serial.hh"
+
+#include "base/misc.hh"
+#include "params/SerialDevice.hh"
+#include "params/SerialNullDevice.hh"
+
+SerialDevice::SerialDevice(const SerialDeviceParams *p)
+    : SimObject(p), interfaceCallback(nullptr)
+{
+}
+
+SerialDevice::~SerialDevice()
+{
+}
+
+void
+SerialDevice::regInterfaceCallback(Callback *c)
+{
+    // This can happen if the user has connected multiple UARTs to the
+    // same terminal. In that case, each of them tries to register
+    // callbacks.
+    if (interfaceCallback)
+        fatal("A UART has already been associated with this device.\n");
+    interfaceCallback = c;
+}
+
+void
+SerialDevice::notifyInterface()
+{
+    assert(dataAvailable());
+    // Registering a callback is optional.
+    if (interfaceCallback)
+        interfaceCallback->process();
+}
+
+
+
+
+SerialNullDevice::SerialNullDevice(const SerialNullDeviceParams *p)
+    : SerialDevice(p)
+{
+}
+
+uint8_t
+SerialNullDevice::readData()
+{
+    panic("SerialNullDevice does not have pending data.\n");
+}
+
+
+
+SerialNullDevice *
+SerialNullDeviceParams::create()
+{
+    return new SerialNullDevice(this);
+}
diff --git a/src/dev/serial/serial.hh b/src/dev/serial/serial.hh
new file mode 100644
index 000000000..230ecaa74
--- /dev/null
+++ b/src/dev/serial/serial.hh
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2014, 2017 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Andreas Sandberg
+ */
+
+#ifndef __DEV_SERIAL_HH__
+#define __DEV_SERIAL_HH__
+
+#include "base/callback.hh"
+#include "sim/sim_object.hh"
+
+struct SerialDeviceParams;
+struct SerialNullDeviceParams;
+
+/**
+ * Base class for serial devices such as terminals.
+ *
+ * This class provides a unified interface that all serial (RS232 or
+ * similar) devices must implement. A device can be wired to exactly
+ * one host serial interface (serial port model).
+ *
+ * SerialDevices are passive devices that are <i>driven</i> by the
+ * serial interface using the writeData(c) (the interface sends a
+ * character) and readData() (the interface reads a character)
+ * methods. Serial devices need to override these methods to
+ * communicate with the host interface layer.
+ *
+ * To implement basic flow control, serial devices must implement the
+ * dataAvailable() method. This method returns true if a valid
+ * character can be read using the readData() method. When data
+ * becomes available, the serial device must call the
+ * notifyInterface() method to send a callback to the interface layer.
+ *
+ * To send a character (host to device), the interface layer calls
+ * writeData(char) to send a character to the serial device.
+ *
+ * To read a character (device to host), the interface layer calls
+ * dataAvailable() to determine if there is a character pending. If
+ * there is data available, it immediately calls readData() to get the
+ * character. The receive loop in the serial device typically looks
+ * like this:
+ *
+ * \code{.cc}
+ * while (device.dataAvailable()) {
+ *    printf("%c", (int)device.readData());
+ * }
+ * \endcode
+ *
+ * To avoid polling, the interface layer may register a data available
+ * callback using the regInterfaceCallback() method. The device uses
+ * this callback to notify the interface layer whenever there is new
+ * data pending. Note that devices will normally only notify the
+ * interface layer when there is a state transition in the
+ * device. E.g., the dataAvailable() transitions from false to
+ * true. This means that there can be multiple pending characters when
+ * the interface layer receives the callback.
+ */
+class SerialDevice : public SimObject
+{
+  public:
+    SerialDevice(const SerialDeviceParams *p);
+    ~SerialDevice();
+
+  public: // Serial device API (UART->Device)
+    /**
+     * Register a data available callback into the host interface layer.
+     *
+     * Serial devices need to call the underlying host interface layer
+     * to inform it of state change such as pending data that can be
+     * read from the device by the interface layer using the readData()
+     * method. The interface layer may use this method to register a
+     * callback that informs it of pending data.
+     *
+     * @param c Callback instance from interface layer.
+     */
+    void regInterfaceCallback(Callback *c);
+
+    /**
+     * Check if there is pending data from the serial device.
+     *
+     * @return true if there is data pending that can be read using
+     * the readData() method.
+     */
+    virtual bool dataAvailable() const = 0;
+
+    /**
+     * Transmit a character from the host interface to the device.
+     *
+     * @param c Received data.
+     */
+    virtual void writeData(uint8_t c) = 0;
+
+    /**
+     * Read a character from the device.
+     *
+     * @return Character from the device's output buffer, undefined if
+     * no data is pending.
+     */
+    virtual uint8_t readData() = 0;
+
+  protected:
+    /** Notify the host interface of pending data. */
+    void notifyInterface();
+
+  private:
+    /** Currently regisxtered host interface layer callback */
+    Callback *interfaceCallback;
+};
+
+/**
+ * Dummy serial device that discards all data sent to it.
+ */
+class SerialNullDevice : public SerialDevice
+{
+  public:
+    SerialNullDevice(const SerialNullDeviceParams *p);
+
+  public:
+    bool dataAvailable() const override { return false; }
+    void writeData(uint8_t c) override {};
+    uint8_t readData() override;
+};
+
+#endif // __DEV_SERIAL_HH__
diff --git a/src/dev/serial/terminal.cc b/src/dev/serial/terminal.cc
new file mode 100644
index 000000000..7230698d3
--- /dev/null
+++ b/src/dev/serial/terminal.cc
@@ -0,0 +1,345 @@
+/*
+ * Copyright (c) 2001-2005 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Nathan Binkert
+ *          Ali Saidi
+ */
+
+/* @file
+ * Implements the user interface to a serial terminal
+ */
+
+#include <sys/ioctl.h>
+
+#if defined(__FreeBSD__)
+#include <termios.h>
+
+#else
+#include <sys/termios.h>
+
+#endif
+#include "dev/serial/terminal.hh"
+
+#include <poll.h>
+#include <unistd.h>
+
+#include <cctype>
+#include <cerrno>
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <string>
+
+#include "base/atomicio.hh"
+#include "base/misc.hh"
+#include "base/output.hh"
+#include "base/socket.hh"
+#include "base/trace.hh"
+#include "debug/Terminal.hh"
+#include "debug/TerminalVerbose.hh"
+#include "dev/platform.hh"
+#include "dev/serial/uart.hh"
+
+using namespace std;
+
+
+/*
+ * Poll event for the listen socket
+ */
+Terminal::ListenEvent::ListenEvent(Terminal *t, int fd, int e)
+    : PollEvent(fd, e), term(t)
+{
+}
+
+void
+Terminal::ListenEvent::process(int revent)
+{
+    term->accept();
+}
+
+/*
+ * Poll event for the data socket
+ */
+Terminal::DataEvent::DataEvent(Terminal *t, int fd, int e)
+    : PollEvent(fd, e), term(t)
+{
+}
+
+void
+Terminal::DataEvent::process(int revent)
+{
+    // As a consequence of being called from the PollQueue, we might
+    // have been called from a different thread. Migrate to "our"
+    // thread.
+    EventQueue::ScopedMigration migrate(term->eventQueue());
+
+    if (revent & POLLIN)
+        term->data();
+    else if (revent & POLLNVAL)
+        term->detach();
+}
+
+/*
+ * Terminal code
+ */
+Terminal::Terminal(const Params *p)
+    : SerialDevice(p), listenEvent(NULL), dataEvent(NULL),
+      number(p->number), data_fd(-1), txbuf(16384), rxbuf(16384),
+      outfile(p->output ? simout.findOrCreate(p->name) : NULL)
+#if TRACING_ON == 1
+      , linebuf(16384)
+#endif
+{
+    if (outfile)
+        outfile->stream()->setf(ios::unitbuf);
+
+    if (p->port)
+        listen(p->port);
+}
+
+Terminal::~Terminal()
+{
+    if (data_fd != -1)
+        ::close(data_fd);
+
+    if (listenEvent)
+        delete listenEvent;
+
+    if (dataEvent)
+        delete dataEvent;
+}
+
+
+///////////////////////////////////////////////////////////////////////
+// socket creation and terminal attach
+//
+
+void
+Terminal::listen(int port)
+{
+    if (ListenSocket::allDisabled()) {
+        warn_once("Sockets disabled, not accepting terminal connections");
+        return;
+    }
+
+    while (!listener.listen(port, true)) {
+        DPRINTF(Terminal,
+                ": can't bind address terminal port %d inuse PID %d\n",
+                port, getpid());
+        port++;
+    }
+
+    int p1, p2;
+    p2 = name().rfind('.') - 1;
+    p1 = name().rfind('.', p2);
+    ccprintf(cerr, "Listening for %s connection on port %d\n",
+            name().substr(p1+1,p2-p1), port);
+
+    listenEvent = new ListenEvent(this, listener.getfd(), POLLIN);
+    pollQueue.schedule(listenEvent);
+}
+
+void
+Terminal::accept()
+{
+    if (!listener.islistening())
+        panic("%s: cannot accept a connection if not listening!", name());
+
+    int fd = listener.accept(true);
+    if (data_fd != -1) {
+        char message[] = "terminal already attached!\n";
+        atomic_write(fd, message, sizeof(message));
+        ::close(fd);
+        return;
+    }
+
+    data_fd = fd;
+    dataEvent = new DataEvent(this, data_fd, POLLIN);
+    pollQueue.schedule(dataEvent);
+
+    stringstream stream;
+    ccprintf(stream, "==== m5 slave terminal: Terminal %d ====", number);
+
+    // we need an actual carriage return followed by a newline for the
+    // terminal
+    stream << "\r\n";
+
+    write((const uint8_t *)stream.str().c_str(), stream.str().size());
+
+    DPRINTFN("attach terminal %d\n", number);
+    char buf[1024];
+    for (size_t i = 0; i < txbuf.size(); i += sizeof(buf)) {
+        const size_t chunk_len(std::min(txbuf.size() - i, sizeof(buf)));
+        txbuf.peek(buf, i, chunk_len);
+        write((const uint8_t *)buf, chunk_len);
+    }
+}
+
+void
+Terminal::detach()
+{
+    if (data_fd != -1) {
+        ::close(data_fd);
+        data_fd = -1;
+    }
+
+    pollQueue.remove(dataEvent);
+    delete dataEvent;
+    dataEvent = NULL;
+
+    DPRINTFN("detach terminal %d\n", number);
+}
+
+void
+Terminal::data()
+{
+    uint8_t buf[1024];
+    int len;
+
+    len = read(buf, sizeof(buf));
+    if (len) {
+        rxbuf.write((char *)buf, len);
+        notifyInterface();
+    }
+}
+
+size_t
+Terminal::read(uint8_t *buf, size_t len)
+{
+    if (data_fd < 0)
+        panic("Terminal not properly attached.\n");
+
+    ssize_t ret;
+    do {
+      ret = ::read(data_fd, buf, len);
+    } while (ret == -1 && errno == EINTR);
+
+
+    if (ret < 0)
+        DPRINTFN("Read failed.\n");
+
+    if (ret <= 0) {
+        detach();
+        return 0;
+    }
+
+    return ret;
+}
+
+// Terminal output.
+size_t
+Terminal::write(const uint8_t *buf, size_t len)
+{
+    if (data_fd < 0)
+        panic("Terminal not properly attached.\n");
+
+    ssize_t ret = atomic_write(data_fd, buf, len);
+    if (ret < len)
+        detach();
+
+    return ret;
+}
+
+#define MORE_PENDING (ULL(1) << 61)
+#define RECEIVE_SUCCESS (ULL(0) << 62)
+#define RECEIVE_NONE (ULL(2) << 62)
+#define RECEIVE_ERROR (ULL(3) << 62)
+
+uint8_t
+Terminal::readData()
+{
+    uint8_t c;
+
+    assert(!rxbuf.empty());
+    rxbuf.read((char *)&c, 1);
+
+    DPRINTF(TerminalVerbose, "in: \'%c\' %#02x more: %d\n",
+            isprint(c) ? c : ' ', c, !rxbuf.empty());
+
+    return c;
+}
+
+uint64_t
+Terminal::console_in()
+{
+    uint64_t value;
+
+    if (dataAvailable()) {
+        value = RECEIVE_SUCCESS | readData();
+        if (!rxbuf.empty())
+            value  |= MORE_PENDING;
+    } else {
+        value = RECEIVE_NONE;
+    }
+
+    DPRINTF(TerminalVerbose, "console_in: return: %#x\n", value);
+
+    return value;
+}
+
+void
+Terminal::writeData(uint8_t c)
+{
+#if TRACING_ON == 1
+    if (DTRACE(Terminal)) {
+        static char last = '\0';
+
+        if ((c != '\n' && c != '\r') || (last != '\n' && last != '\r')) {
+            if (c == '\n' || c == '\r') {
+                int size = linebuf.size();
+                char *buffer = new char[size + 1];
+                linebuf.read(buffer, size);
+                buffer[size] = '\0';
+                DPRINTF(Terminal, "%s\n", buffer);
+                delete [] buffer;
+            } else {
+                linebuf.write(&c, 1);
+            }
+        }
+
+        last = c;
+    }
+#endif
+
+    txbuf.write(&c, 1);
+
+    if (data_fd >= 0)
+        write(c);
+
+    if (outfile)
+        outfile->stream()->put((char)c);
+
+    DPRINTF(TerminalVerbose, "out: \'%c\' %#02x\n",
+            isprint(c) ? c : ' ', (int)c);
+
+}
+
+Terminal *
+TerminalParams::create()
+{
+    return new Terminal(this);
+}
diff --git a/src/dev/serial/terminal.hh b/src/dev/serial/terminal.hh
new file mode 100644
index 000000000..48bfc0771
--- /dev/null
+++ b/src/dev/serial/terminal.hh
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2001-2005 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Nathan Binkert
+ *          Ali Saidi
+ */
+
+/* @file
+ * User Terminal Interface
+ */
+
+#ifndef __DEV_TERMINAL_HH__
+#define __DEV_TERMINAL_HH__
+
+#include <iostream>
+
+#include "base/callback.hh"
+#include "base/circlebuf.hh"
+#include "base/pollevent.hh"
+#include "base/socket.hh"
+#include "cpu/intr_control.hh"
+#include "dev/serial/serial.hh"
+#include "params/Terminal.hh"
+#include "sim/sim_object.hh"
+
+class OutputStream;
+class TerminalListener;
+
+class Terminal : public SerialDevice
+{
+  protected:
+    class ListenEvent : public PollEvent
+    {
+      protected:
+        Terminal *term;
+
+      public:
+        ListenEvent(Terminal *t, int fd, int e);
+        void process(int revent);
+    };
+
+    friend class ListenEvent;
+    ListenEvent *listenEvent;
+
+    class DataEvent : public PollEvent
+    {
+      protected:
+        Terminal *term;
+
+      public:
+        DataEvent(Terminal *t, int fd, int e);
+        void process(int revent);
+    };
+
+    friend class DataEvent;
+    DataEvent *dataEvent;
+
+  protected:
+    int number;
+    int data_fd;
+
+  public:
+    typedef TerminalParams Params;
+    Terminal(const Params *p);
+    ~Terminal();
+
+  protected:
+    ListenSocket listener;
+
+    void listen(int port);
+    void accept();
+
+  protected:
+    CircleBuf<char> txbuf;
+    CircleBuf<char> rxbuf;
+    OutputStream *outfile;
+#if TRACING_ON == 1
+    CircleBuf<char> linebuf;
+#endif
+
+  public:
+    ///////////////////////
+    // Terminal Interface
+
+    void data();
+
+    void read(uint8_t &c) { read(&c, 1); }
+    size_t read(uint8_t *buf, size_t len);
+    void write(uint8_t c) { write(&c, 1); }
+    size_t write(const uint8_t *buf, size_t len);
+    void detach();
+
+  public: // SerialDevice interface
+    uint8_t readData() override;
+    void writeData(uint8_t c) override;
+    bool dataAvailable() const override { return !rxbuf.empty(); }
+
+  public:
+    /////////////////
+    // OS interface
+
+    // get a character from the terminal in the console specific format
+    // corresponds to GETC:
+    // retval<63:61>
+    //     000: success: character received
+    //     001: success: character received, more pending
+    //     100: failure: no character ready
+    //     110: failure: character received with error
+    //     111: failure: character received with error, more pending
+    // retval<31:0>
+    //     character read from console
+    //
+    // Interrupts are cleared when the buffer is empty.
+    uint64_t console_in();
+};
+
+#endif // __DEV_TERMINAL_HH__
diff --git a/src/dev/serial/uart.cc b/src/dev/serial/uart.cc
new file mode 100644
index 000000000..3a4c13c43
--- /dev/null
+++ b/src/dev/serial/uart.cc
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2004-2005 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Ali Saidi
+ */
+
+/** @file
+ * Implements a base class for UARTs
+ */
+
+#include "dev/serial/uart.hh"
+
+Uart::Uart(const Params *p, Addr pio_size)
+    : BasicPioDevice(p, pio_size),
+      platform(p->platform), device(p->device),
+      callbackDataAvail(this)
+{
+    status = 0;
+
+    // setup serial device callbacks
+    device->regInterfaceCallback(&callbackDataAvail);
+}
diff --git a/src/dev/serial/uart.hh b/src/dev/serial/uart.hh
new file mode 100644
index 000000000..04e9ec2e0
--- /dev/null
+++ b/src/dev/serial/uart.hh
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2004-2005 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Ali Saidi
+ */
+
+/** @file
+ * Base class for UART
+ */
+
+#ifndef __UART_HH__
+#define __UART_HH__
+
+#include "base/callback.hh"
+#include "dev/io_device.hh"
+#include "dev/serial/serial.hh"
+#include "params/Uart.hh"
+
+class Platform;
+
+const int RX_INT = 0x1;
+const int TX_INT = 0x2;
+
+class Uart : public BasicPioDevice
+{
+  protected:
+    int status;
+    Platform *platform;
+    SerialDevice *device;
+
+  public:
+    typedef UartParams Params;
+    Uart(const Params *p, Addr pio_size);
+
+    const Params *
+    params() const
+    {
+        return dynamic_cast<const Params *>(_params);
+    }
+
+    /**
+     * Inform the uart that there is data available.
+     */
+    virtual void dataAvailable() = 0;
+
+    /**
+     * Return if we have an interrupt pending
+     * @return interrupt status
+     */
+    bool intStatus() { return status ? true : false; }
+
+  protected:
+    MakeCallback<Uart, &Uart::dataAvailable> callbackDataAvail;
+};
+
+#endif // __UART_HH__
diff --git a/src/dev/serial/uart8250.cc b/src/dev/serial/uart8250.cc
new file mode 100644
index 000000000..43300f5e8
--- /dev/null
+++ b/src/dev/serial/uart8250.cc
@@ -0,0 +1,326 @@
+/*
+ * Copyright (c) 2005 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Ali Saidi
+ */
+
+/** @file
+ * Implements a 8250 UART
+ */
+
+#include "dev/serial/uart8250.hh"
+
+#include <string>
+#include <vector>
+
+#include "base/inifile.hh"
+#include "base/trace.hh"
+#include "config/the_isa.hh"
+#include "debug/Uart.hh"
+#include "dev/platform.hh"
+#include "mem/packet.hh"
+#include "mem/packet_access.hh"
+
+using namespace std;
+using namespace TheISA;
+
+void
+Uart8250::processIntrEvent(int intrBit)
+{
+    if (intrBit & IER) {
+       DPRINTF(Uart, "UART InterEvent, interrupting\n");
+       platform->postConsoleInt();
+       status |= intrBit;
+       lastTxInt = curTick();
+    }
+    else
+       DPRINTF(Uart, "UART InterEvent, not interrupting\n");
+
+}
+
+/* The linux serial driver (8250.c about line 1182) loops reading from
+ * the device until the device reports it has no more data to
+ * read. After a maximum of 255 iterations the code prints "serial8250
+ * too much work for irq X," and breaks out of the loop. Since the
+ * simulated system is so much slower than the actual system, if a
+ * user is typing on the keyboard it is very easy for them to provide
+ * input at a fast enough rate to not allow the loop to exit and thus
+ * the error to be printed. This magic number provides a delay between
+ * the time the UART receives a character to send to the simulated
+ * system and the time it actually notifies the system it has a
+ * character to send to alleviate this problem. --Ali
+ */
+void
+Uart8250::scheduleIntr(Event *event)
+{
+    static const Tick interval = 225 * SimClock::Int::ns;
+    DPRINTF(Uart, "Scheduling IER interrupt for %s, at cycle %lld\n",
+            event->name(), curTick() + interval);
+    if (!event->scheduled())
+        schedule(event, curTick() + interval);
+    else
+        reschedule(event, curTick() + interval);
+}
+
+
+Uart8250::Uart8250(const Params *p)
+    : Uart(p, 8), IER(0), DLAB(0), LCR(0), MCR(0), lastTxInt(0),
+      txIntrEvent([this]{ processIntrEvent(TX_INT); }, "TX"),
+      rxIntrEvent([this]{ processIntrEvent(RX_INT); }, "RX")
+{
+}
+
+Tick
+Uart8250::read(PacketPtr pkt)
+{
+    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
+    assert(pkt->getSize() == 1);
+
+    Addr daddr = pkt->getAddr() - pioAddr;
+
+    DPRINTF(Uart, " read register %#x\n", daddr);
+
+    switch (daddr) {
+        case 0x0:
+            if (!(LCR & 0x80)) { // read byte
+                if (device->dataAvailable())
+                    pkt->set(device->readData());
+                else {
+                    pkt->set((uint8_t)0);
+                    // A limited amount of these are ok.
+                    DPRINTF(Uart, "empty read of RX register\n");
+                }
+                status &= ~RX_INT;
+                platform->clearConsoleInt();
+
+                if (device->dataAvailable() && (IER & UART_IER_RDI))
+                    scheduleIntr(&rxIntrEvent);
+            } else { // dll divisor latch
+               ;
+            }
+            break;
+        case 0x1:
+            if (!(LCR & 0x80)) { // Intr Enable Register(IER)
+                pkt->set(IER);
+            } else { // DLM divisor latch MSB
+                ;
+            }
+            break;
+        case 0x2: // Intr Identification Register (IIR)
+            DPRINTF(Uart, "IIR Read, status = %#x\n", (uint32_t)status);
+
+            if (status & RX_INT) /* Rx data interrupt has a higher priority */
+                pkt->set(IIR_RXID);
+            else if (status & TX_INT) {
+                pkt->set(IIR_TXID);
+                //Tx interrupts are cleared on IIR reads
+                status &= ~TX_INT;
+            } else
+                pkt->set(IIR_NOPEND);
+
+            break;
+        case 0x3: // Line Control Register (LCR)
+            pkt->set(LCR);
+            break;
+        case 0x4: // Modem Control Register (MCR)
+            pkt->set(MCR);
+            break;
+        case 0x5: // Line Status Register (LSR)
+            uint8_t lsr;
+            lsr = 0;
+            // check if there are any bytes to be read
+            if (device->dataAvailable())
+                lsr = UART_LSR_DR;
+            lsr |= UART_LSR_TEMT | UART_LSR_THRE;
+            pkt->set(lsr);
+            break;
+        case 0x6: // Modem Status Register (MSR)
+            pkt->set((uint8_t)0);
+            break;
+        case 0x7: // Scratch Register (SCR)
+            pkt->set((uint8_t)0); // doesn't exist with at 8250.
+            break;
+        default:
+            panic("Tried to access a UART port that doesn't exist\n");
+            break;
+    }
+/*    uint32_t d32 = *data;
+    DPRINTF(Uart, "Register read to register %#x returned %#x\n", daddr, d32);
+*/
+    pkt->makeAtomicResponse();
+    return pioDelay;
+}
+
+Tick
+Uart8250::write(PacketPtr pkt)
+{
+
+    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
+    assert(pkt->getSize() == 1);
+
+    Addr daddr = pkt->getAddr() - pioAddr;
+
+    DPRINTF(Uart, " write register %#x value %#x\n", daddr, pkt->get<uint8_t>());
+
+    switch (daddr) {
+        case 0x0:
+            if (!(LCR & 0x80)) { // write byte
+                device->writeData(pkt->get<uint8_t>());
+                platform->clearConsoleInt();
+                status &= ~TX_INT;
+                if (UART_IER_THRI & IER)
+                    scheduleIntr(&txIntrEvent);
+            } else { // dll divisor latch
+               ;
+            }
+            break;
+        case 0x1:
+            if (!(LCR & 0x80)) { // Intr Enable Register(IER)
+                IER = pkt->get<uint8_t>();
+                if (UART_IER_THRI & IER)
+                {
+                    DPRINTF(Uart, "IER: IER_THRI set, scheduling TX intrrupt\n");
+                    if (curTick() - lastTxInt > 225 * SimClock::Int::ns) {
+                        DPRINTF(Uart, "-- Interrupting Immediately... %d,%d\n",
+                                curTick(), lastTxInt);
+                        txIntrEvent.process();
+                    } else {
+                        DPRINTF(Uart, "-- Delaying interrupt... %d,%d\n",
+                                curTick(), lastTxInt);
+                        scheduleIntr(&txIntrEvent);
+                    }
+                }
+                else
+                {
+                    DPRINTF(Uart, "IER: IER_THRI cleared, descheduling TX intrrupt\n");
+                    if (txIntrEvent.scheduled())
+                        deschedule(txIntrEvent);
+                    if (status & TX_INT)
+                        platform->clearConsoleInt();
+                    status &= ~TX_INT;
+                }
+
+                if ((UART_IER_RDI & IER) && device->dataAvailable()) {
+                    DPRINTF(Uart, "IER: IER_RDI set, scheduling RX intrrupt\n");
+                    scheduleIntr(&rxIntrEvent);
+                } else {
+                    DPRINTF(Uart, "IER: IER_RDI cleared, descheduling RX intrrupt\n");
+                    if (rxIntrEvent.scheduled())
+                        deschedule(rxIntrEvent);
+                    if (status & RX_INT)
+                        platform->clearConsoleInt();
+                    status &= ~RX_INT;
+                }
+             } else { // DLM divisor latch MSB
+                ;
+            }
+            break;
+        case 0x2: // FIFO Control Register (FCR)
+            break;
+        case 0x3: // Line Control Register (LCR)
+            LCR = pkt->get<uint8_t>();
+            break;
+        case 0x4: // Modem Control Register (MCR)
+            if (pkt->get<uint8_t>() == (UART_MCR_LOOP | 0x0A))
+                    MCR = 0x9A;
+            break;
+        case 0x7: // Scratch Register (SCR)
+            // We are emulating a 8250 so we don't have a scratch reg
+            break;
+        default:
+            panic("Tried to access a UART port that doesn't exist\n");
+            break;
+    }
+    pkt->makeAtomicResponse();
+    return pioDelay;
+}
+
+void
+Uart8250::dataAvailable()
+{
+    // if the kernel wants an interrupt when we have data
+    if (IER & UART_IER_RDI)
+    {
+        platform->postConsoleInt();
+        status |= RX_INT;
+    }
+
+}
+
+AddrRangeList
+Uart8250::getAddrRanges() const
+{
+    AddrRangeList ranges;
+    ranges.push_back(RangeSize(pioAddr, pioSize));
+    return ranges;
+}
+
+void
+Uart8250::serialize(CheckpointOut &cp) const
+{
+    SERIALIZE_SCALAR(status);
+    SERIALIZE_SCALAR(IER);
+    SERIALIZE_SCALAR(DLAB);
+    SERIALIZE_SCALAR(LCR);
+    SERIALIZE_SCALAR(MCR);
+    Tick rxintrwhen;
+    if (rxIntrEvent.scheduled())
+        rxintrwhen = rxIntrEvent.when();
+    else
+        rxintrwhen = 0;
+    Tick txintrwhen;
+    if (txIntrEvent.scheduled())
+        txintrwhen = txIntrEvent.when();
+    else
+        txintrwhen = 0;
+     SERIALIZE_SCALAR(rxintrwhen);
+     SERIALIZE_SCALAR(txintrwhen);
+}
+
+void
+Uart8250::unserialize(CheckpointIn &cp)
+{
+    UNSERIALIZE_SCALAR(status);
+    UNSERIALIZE_SCALAR(IER);
+    UNSERIALIZE_SCALAR(DLAB);
+    UNSERIALIZE_SCALAR(LCR);
+    UNSERIALIZE_SCALAR(MCR);
+    Tick rxintrwhen;
+    Tick txintrwhen;
+    UNSERIALIZE_SCALAR(rxintrwhen);
+    UNSERIALIZE_SCALAR(txintrwhen);
+    if (rxintrwhen != 0)
+        schedule(rxIntrEvent, rxintrwhen);
+    if (txintrwhen != 0)
+        schedule(txIntrEvent, txintrwhen);
+}
+
+Uart8250 *
+Uart8250Params::create()
+{
+    return new Uart8250(this);
+}
diff --git a/src/dev/serial/uart8250.hh b/src/dev/serial/uart8250.hh
new file mode 100644
index 000000000..585fbb21e
--- /dev/null
+++ b/src/dev/serial/uart8250.hh
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2005 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Ali Saidi
+ */
+
+/** @file
+ * Defines a 8250 UART
+ */
+
+#ifndef __DEV_UART8250_HH__
+#define __DEV_UART8250_HH__
+
+#include "dev/io_device.hh"
+#include "dev/serial/uart.hh"
+#include "params/Uart8250.hh"
+
+/* UART8250 Interrupt ID Register
+ *  bit 0    Interrupt Pending 0 = true, 1 = false
+ *  bit 2:1  ID of highest priority interrupt
+ *  bit 7:3  zeroes
+ */
+const uint8_t IIR_NOPEND = 0x1;
+
+// Interrupt IDs
+const uint8_t IIR_MODEM = 0x00; /* Modem Status (lowest priority) */
+const uint8_t IIR_TXID  = 0x02; /* Tx Data */
+const uint8_t IIR_RXID  = 0x04; /* Rx Data */
+const uint8_t IIR_LINE  = 0x06; /* Rx Line Status (highest priority)*/
+
+const uint8_t UART_IER_RDI  = 0x01;
+const uint8_t UART_IER_THRI = 0x02;
+const uint8_t UART_IER_RLSI = 0x04;
+
+
+const uint8_t UART_LSR_TEMT = 0x40;
+const uint8_t UART_LSR_THRE = 0x20;
+const uint8_t UART_LSR_DR   = 0x01;
+
+const uint8_t UART_MCR_LOOP = 0x10;
+
+
+class Terminal;
+class Platform;
+
+class Uart8250 : public Uart
+{
+  protected:
+    uint8_t IER, DLAB, LCR, MCR;
+    Tick lastTxInt;
+
+    void processIntrEvent(int intrBit);
+    void scheduleIntr(Event *event);
+
+    EventFunctionWrapper txIntrEvent;
+    EventFunctionWrapper rxIntrEvent;
+
+  public:
+    typedef Uart8250Params Params;
+    const Params *
+    params() const
+    {
+        return dynamic_cast<const Params *>(_params);
+    }
+    Uart8250(const Params *p);
+
+    Tick read(PacketPtr pkt) override;
+    Tick write(PacketPtr pkt) override;
+    AddrRangeList getAddrRanges() const override;
+
+    /**
+     * Inform the uart that there is data available.
+     */
+    void dataAvailable() override;
+
+
+    /**
+     * Return if we have an interrupt pending
+     * @return interrupt status
+     */
+    virtual bool intStatus() { return status ? true : false; }
+
+    void serialize(CheckpointOut &cp) const override;
+    void unserialize(CheckpointIn &cp) override;
+};
+
+#endif // __TSUNAMI_UART_HH__