usrp2: uart/udp work in host and fw, working

16 files changed, 254 insertions, 145 deletions

diff --git a/firmware/zpu/apps/txrx_uhd.c b/firmware/zpu/apps/txrx_uhd.c
index 9d0a28b58..f9eedfc7d 100644
--- a/firmware/zpu/apps/txrx_uhd.c
+++ b/firmware/zpu/apps/txrx_uhd.c
@@ -72,12 +72,6 @@ static void handle_udp_data_packet(
         sr_tx_ctrl->cyc_per_up = 0;
         break;
 
-    case USRP2_UDP_UART_BASE_PORT+0:
-    case USRP2_UDP_UART_BASE_PORT+1:
-    case USRP2_UDP_UART_BASE_PORT+2:
-        turn_off_uart(src.port-USRP2_UDP_UART_BASE_PORT);
-        break;
-
     default: return;
     }
 
@@ -116,7 +110,7 @@ static void handle_udp_ctrl_packet(
 
     //ensure that the protocol versions match
     if (payload_len >= sizeof(uint32_t) && ctrl_data_in->proto_ver != USRP2_FW_COMPAT_NUM){
-        printf("!Error in control packet handler: Expected compatibility number %d, but got %d\n",
+        if (ctrl_data_in->proto_ver) printf("!Error in control packet handler: Expected compatibility number %d, but got %d\n",
             USRP2_FW_COMPAT_NUM, ctrl_data_in->proto_ver
         );
         ctrl_data_in_id = USRP2_CTRL_ID_WAZZUP_BRO;
@@ -228,32 +222,6 @@ static void handle_udp_ctrl_packet(
         break;
 
     /*******************************************************************
-     * UART Control
-     ******************************************************************/
-/*
-    case USRP2_CTRL_ID_SO_LIKE_CAN_YOU_READ_THIS_UART_BRO:{
-      //executes a readline()-style read, up to num_bytes long, up to and including newline
-      int num_bytes = ctrl_data_in->data.uart_args.bytes;
-      if(num_bytes > 20) num_bytes = 20;
-      num_bytes = fngets_noblock(ctrl_data_in->data.uart_args.dev, (char *) ctrl_data_out.data.uart_args.data, num_bytes);
-      ctrl_data_out.id = USRP2_CTRL_ID_I_HELLA_READ_THAT_UART_DUDE;
-      ctrl_data_out.data.uart_args.bytes = num_bytes;
-      break;
-    }
-
-    case USRP2_CTRL_ID_HEY_WRITE_THIS_UART_FOR_ME_BRO:{
-      int num_bytes = ctrl_data_in->data.uart_args.bytes;
-      if(num_bytes > 20) num_bytes = 20;
-      //before we write to the UART, we flush the receive buffer
-      //this assumes that we're interested in the reply
-      hal_uart_rx_flush(ctrl_data_in->data.uart_args.dev);
-      fnputstr(ctrl_data_in->data.uart_args.dev, (char *) ctrl_data_in->data.uart_args.data, num_bytes);
-      ctrl_data_out.id = USRP2_CTRL_ID_MAN_I_TOTALLY_WROTE_THAT_UART_DUDE;
-      ctrl_data_out.data.uart_args.bytes = num_bytes;
-      break;
-    }
-*/
-    /*******************************************************************
      * Echo test
      ******************************************************************/
     case USRP2_CTRL_ID_HOLLER_AT_ME_BRO:
@@ -347,11 +315,10 @@ main(void)
   
 #ifdef USRP2P
   register_udp_listener(USRP2_UDP_UPDATE_PORT, handle_udp_fw_update_packet);
-  int i;
-  for(i=0; i<NUM_UARTS; i++)
-    register_udp_listener(USRP2_UDP_UART_BASE_PORT+i, handle_uart_data_packet);
 #endif
 
+  udp_uart_init(USRP2_UDP_UART_BASE_PORT); //setup uart messaging
+
   //3) set the routing mode to slave to set defaults
   pkt_ctrl_set_routing_mode(PKT_CTRL_ROUTING_MODE_SLAVE);
 
@@ -368,10 +335,7 @@ main(void)
         pkt_ctrl_release_incoming_buffer();
     }
 
-#ifdef USRP2P
-    //look for incoming data on the four UARTs and handle it
-    poll_uarts();
-#endif
+    udp_uart_poll(); //uart message handling
 
     pic_interrupt_handler();
     /*
diff --git a/firmware/zpu/lib/net_common.c b/firmware/zpu/lib/net_common.c
index 698ed97f4..42e365393 100644
--- a/firmware/zpu/lib/net_common.c
+++ b/firmware/zpu/lib/net_common.c
@@ -201,7 +201,7 @@ send_pkt(
 
     //create a list of all buffers to copy
     const void *buffs[] = {&ctrl_word, &ehdr, buf0, buf1, buf2};
-    size_t lens[] = {sizeof(ctrl_word), sizeof(ehdr), len0, len1, len2};
+    size_t lens[] = {sizeof(ctrl_word), sizeof(ehdr), len0, len1, (len2 + 3) & ~3};
 
     //copy each buffer into the out buffer
     for (size_t i = 0; i < sizeof(buffs)/sizeof(buffs[0]); i++){
diff --git a/firmware/zpu/lib/udp_uart.c b/firmware/zpu/lib/udp_uart.c
new file mode 100644
index 000000000..6f6b9ee91
--- /dev/null
+++ b/firmware/zpu/lib/udp_uart.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright 2011 Ettus Research LLC
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "udp_uart.h"
+#include "hal_uart.h"
+#include "net_common.h"
+#include "compiler.h"
+#include <stdbool.h>
+
+/***********************************************************************
+ * Constants
+ **********************************************************************/
+#define MAX_NUM_UARTS 4
+#ifndef UDP_UART_MASK
+    #error missing definition for UDP_UART_MASK enable mask
+#endif
+static const size_t num_idle_cyc_b4_flush = 11; //small but lucky number
+
+/***********************************************************************
+ * Globals
+ **********************************************************************/
+static uint16_t _base_port;
+
+typedef struct{
+    struct socket_address dst;
+    _AL4 uint8_t buf[256];
+    size_t len; //length of buffer
+    size_t cyc; //idle cycle count
+} udp_uart_state_t;
+
+static udp_uart_state_t _states[MAX_NUM_UARTS];
+
+/***********************************************************************
+ * UDP handler for UARTs
+ **********************************************************************/
+static void handle_uart_data_packet(
+    struct socket_address src, struct socket_address dst,
+    unsigned char *payload, int payload_len
+){
+    //handle ICMP destination unreachable
+    if (payload == NULL){
+        const size_t which = src.port-_base_port;
+        if (which >= MAX_NUM_UARTS) return;
+        _states[which].dst.port = 0;
+    }
+
+    //handle a regular blocking UART write
+    else{
+        const size_t which = dst.port-_base_port;
+        if (which >= MAX_NUM_UARTS) return;
+        _states[which].dst = src;
+        for (size_t i = 0; i < payload_len; i++){
+            hal_uart_putc((hal_uart_name_t)which, (int)payload[i]);
+        }
+    }
+}
+
+/***********************************************************************
+ * Public init function
+ **********************************************************************/
+void udp_uart_init(const uint16_t base_port){
+    _base_port = base_port;
+    for(size_t i = 0; i < MAX_NUM_UARTS; i++){
+        _states[i].dst.port = 0; //reset to null port
+        _states[i].len = 0;
+        _states[i].cyc = 0;
+        register_udp_listener(_base_port+i, handle_uart_data_packet);
+    }
+}
+
+/***********************************************************************
+ * Public poll function
+ **********************************************************************/
+void udp_uart_poll(void){
+    for (size_t i = 0; i < MAX_NUM_UARTS; i++){
+        if (((UDP_UART_MASK) & (1 << i)) == 0) continue;
+
+        bool newline = false;
+        udp_uart_state_t *state = &_states[i];
+
+        //read all characters we can without blocking
+        for (size_t j = state->len; j < sizeof(_states[0].buf); j++){
+            uint8_t ch = hal_uart_getc_noblock((hal_uart_name_t)i);
+            if (ch == 255) break;
+            if (ch == '\n' || ch == '\r') newline = true;
+            state->buf[j] = ch;
+            state->len++;
+            state->cyc = 0; //reset idle cycles
+        }
+
+        //nothing in buffer, continue to next uart
+        if (state->len == 0) continue;
+
+        //send out a message if newline or forced flush
+        if (newline || state->cyc++ > num_idle_cyc_b4_flush){
+            if (state->dst.port != 0) send_udp_pkt(_base_port+i, state->dst, state->buf, state->len);
+            state->len = 0;
+            state->cyc = 0;
+        }
+    }
+}
diff --git a/firmware/zpu/lib/udp_uart.h b/firmware/zpu/lib/udp_uart.h
new file mode 100644
index 000000000..d448e7611
--- /dev/null
+++ b/firmware/zpu/lib/udp_uart.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2011 Ettus Research LLC
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef INCLUDED_UDP_UART_H
+#define INCLUDED_UDP_UART_H
+
+#include <stdint.h>
+
+/*!
+ * Initialize the UDP/UART module.
+ * Registers handler into the network.
+ * \param base_port the source port for UART0
+ */
+void udp_uart_init(const uint16_t base_port);
+
+/*!
+ * Polls the UART state machine,
+ * and sends messages over UDP.
+ */
+void udp_uart_poll(void);
+
+#endif /* INCLUDED_UDP_UART_H */
diff --git a/firmware/zpu/usrp2/CMakeLists.txt b/firmware/zpu/usrp2/CMakeLists.txt
index 190ea9af1..3662532f1 100644
--- a/firmware/zpu/usrp2/CMakeLists.txt
+++ b/firmware/zpu/usrp2/CMakeLists.txt
@@ -20,6 +20,7 @@ INCLUDE(${CMAKE_SOURCE_DIR}/lib/CMakeLists.txt)
 INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR})
 
 ADD_DEFINITIONS(-DUSRP2)
+ADD_DEFINITIONS(-DUDP_UART_MASK=0)
 
 ADD_LIBRARY(libusrp2fw STATIC
     ${COMMON_SRCS}
diff --git a/firmware/zpu/usrp2p/CMakeLists.txt b/firmware/zpu/usrp2p/CMakeLists.txt
index 976dccb9a..4cb663742 100644
--- a/firmware/zpu/usrp2p/CMakeLists.txt
+++ b/firmware/zpu/usrp2p/CMakeLists.txt
@@ -20,6 +20,7 @@ INCLUDE(${CMAKE_SOURCE_DIR}/lib/CMakeLists.txt)
 INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR})
 
 ADD_DEFINITIONS(-DUSRP2P)
+ADD_DEFINITIONS(-DUDP_UART_MASK=4) #GPS=UART2 streaming enabled
 
 ADD_LIBRARY(libusrp2pfw STATIC
     ${COMMON_SRCS}
diff --git a/host/include/uhd/transport/udp_simple.hpp b/host/include/uhd/transport/udp_simple.hpp
index 83f895ba9..83d1072ee 100644
--- a/host/include/uhd/transport/udp_simple.hpp
+++ b/host/include/uhd/transport/udp_simple.hpp
@@ -19,6 +19,7 @@
 #define INCLUDED_UHD_TRANSPORT_UDP_SIMPLE_HPP
 
 #include <uhd/config.hpp>
+#include <uhd/types/serial.hpp>
 #include <boost/asio/buffer.hpp>
 #include <boost/utility.hpp>
 #include <boost/shared_ptr.hpp>
@@ -62,6 +63,13 @@ public:
     static sptr make_broadcast(const std::string &addr, const std::string &port);
 
     /*!
+     * Make a UART interface from a UDP transport.
+     * \param udp the UDP transport object
+     * \return a new UART interface
+     */
+    static uart_iface::sptr make_uart(sptr udp);
+
+    /*!
      * Send a single buffer.
      * Blocks until the data is sent.
      * \param buff single asio buffer
diff --git a/host/include/uhd/types/serial.hpp b/host/include/uhd/types/serial.hpp
index 8a5ed1c32..f66822775 100644
--- a/host/include/uhd/types/serial.hpp
+++ b/host/include/uhd/types/serial.hpp
@@ -184,17 +184,17 @@ namespace uhd{
 
         /*!
          * Write to a serial port.
-         * \param dev which UART to write to
          * \param buf the data to write
          */
-        virtual void write_uart(boost::uint8_t dev, const std::string &buf) = 0;
+        virtual void write_uart(const std::string &buf) = 0;
 
         /*!
          * Read from a serial port.
-         * \param dev which UART to read from
+         * Reads until complete line or timeout.
+         * \param timeout the timeout in seconds
          * \return the data read from the serial port
          */
-        virtual std::string read_uart(boost::uint8_t dev) = 0;
+        virtual std::string read_uart(double timeout) = 0;
     };
 
 } //namespace uhd
diff --git a/host/include/uhd/usrp/gps_ctrl.hpp b/host/include/uhd/usrp/gps_ctrl.hpp
index 6ff00e03c..3b643a30c 100644
--- a/host/include/uhd/usrp/gps_ctrl.hpp
+++ b/host/include/uhd/usrp/gps_ctrl.hpp
@@ -18,17 +18,14 @@
 #ifndef INCLUDED_GPS_CTRL_HPP
 #define INCLUDED_GPS_CTRL_HPP
 
+#include <uhd/types/serial.hpp>
+#include <uhd/types/sensors.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/utility.hpp>
 #include <boost/function.hpp>
-#include <boost/date_time/posix_time/posix_time_types.hpp>
 #include <vector>
-#include <uhd/types/sensors.hpp>
 
-using namespace boost::posix_time;
-
-typedef boost::function<void(std::string)> gps_send_fn_t;
-typedef boost::function<std::string(void)> gps_recv_fn_t;
+namespace uhd{
 
 class gps_ctrl : boost::noncopyable{
 public:
@@ -37,7 +34,7 @@ public:
   /*!
    * Make a GPS config for Jackson Labs or generic NMEA GPS devices
    */
-  static sptr make(gps_send_fn_t, gps_recv_fn_t);
+  static sptr make(uart_iface::sptr uart);
 
   /*!
    * Retrieve the list of sensors this GPS object provides
@@ -59,4 +56,6 @@ public:
 
 };
 
+} //namespace uhd
+
 #endif /* INCLUDED_GPS_CTRL_HPP */
diff --git a/host/lib/transport/udp_simple.cpp b/host/lib/transport/udp_simple.cpp
index ed778fbf4..bc1bdaf2f 100644
--- a/host/lib/transport/udp_simple.cpp
+++ b/host/lib/transport/udp_simple.cpp
@@ -81,3 +81,49 @@ udp_simple::sptr udp_simple::make_broadcast(
 ){
     return sptr(new udp_simple_impl(addr, port, true, false /* bcast, no connect */));
 }
+
+/***********************************************************************
+ * Simple UART over UDP
+ **********************************************************************/
+#include <boost/thread/thread.hpp>
+class udp_simple_uart_impl : public uhd::uart_iface{
+public:
+    udp_simple_uart_impl(udp_simple::sptr udp){
+        _udp = udp;
+        _len = 0;
+        _off = 0;
+        this->write_uart(""); //send an empty packet to init
+    }
+
+    void write_uart(const std::string &buf){
+        _udp->send(asio::buffer(buf));
+    }
+
+    std::string read_uart(double timeout){
+        std::string line;
+        const boost::system_time exit_time = boost::get_system_time() + boost::posix_time::milliseconds(long(timeout*1000));
+        do{
+            //drain anything in current buffer
+            while (_off < _len){
+                const char ch = _buf[_off]; _off++;
+                line += std::string(1, ch);
+                if (ch == '\n' or ch == '\r') return line;
+            }
+
+            //recv a new packet into the buffer
+            _len = _udp->recv(asio::buffer(_buf), std::max((exit_time - boost::get_system_time()).total_milliseconds()/1000., 0.0));
+            _off = 0;
+
+        } while (_len != 0);
+        return line;
+    }
+
+private:
+    udp_simple::sptr _udp;
+    size_t _len, _off;
+    boost::uint8_t _buf[udp_simple::mtu];
+};
+
+uhd::uart_iface::sptr udp_simple::make_uart(sptr udp){
+    return uart_iface::sptr(new udp_simple_uart_impl(udp));
+}
diff --git a/host/lib/usrp/gps_ctrl.cpp b/host/lib/usrp/gps_ctrl.cpp
index 342b0e2fe..96cb76ffc 100644
--- a/host/lib/usrp/gps_ctrl.cpp
+++ b/host/lib/usrp/gps_ctrl.cpp
@@ -40,19 +40,18 @@ using namespace boost::this_thread;
 
 class gps_ctrl_impl : public gps_ctrl{
 public:
-  gps_ctrl_impl(gps_send_fn_t send, gps_recv_fn_t recv){
-    _send = send;
-    _recv = recv;
+  gps_ctrl_impl(uart_iface::sptr uart){
+    _uart = uart;
 
     std::string reply;
     bool i_heard_some_nmea = false, i_heard_something_weird = false;
     gps_type = GPS_TYPE_NONE;
     
     //first we look for a Jackson Labs Firefly (since that's what we provide...)
-    _recv(); //get whatever junk is in the rx buffer right now, and throw it away
+    _flush(); //get whatever junk is in the rx buffer right now, and throw it away
     _send("HAAAY GUYYYYS\n"); //to elicit a response from the Firefly
 
-	//wait for _send(...) to return
+    //wait for _send(...) to return
     sleep(milliseconds(FIREFLY_STUPID_DELAY_MS));
 
     //then we loop until we either timeout, or until we get a response that indicates we're a JL device
@@ -155,7 +154,7 @@ private:
         return std::string();
     }
 
-    while(_recv().size() != 0) sleep(milliseconds(GPS_TIMEOUT_DELAY_MS));
+    _flush(); //flush all input before waiting for a message
 
     int timeout = GPS_TIMEOUT_TRIES;
     while(timeout--) {
@@ -242,8 +241,21 @@ private:
     return false;
   }
 
-  gps_send_fn_t _send;
-  gps_recv_fn_t _recv;
+  uart_iface::sptr _uart;
+
+  void _flush(void){
+    while (not _uart->read_uart(0.0).empty()){
+        //NOP
+    }
+  }
+
+  std::string _recv(void){
+      return _uart->read_uart(GPS_TIMEOUT_DELAY_MS/1000.);
+  }
+
+  void _send(const std::string &buf){
+      return _uart->write_uart(buf);
+  }
 
   enum {
     GPS_TYPE_JACKSON_LABS,
@@ -259,6 +271,6 @@ private:
 /***********************************************************************
  * Public make function for the GPS control
  **********************************************************************/
-gps_ctrl::sptr gps_ctrl::make(gps_send_fn_t send, gps_recv_fn_t recv){
-    return sptr(new gps_ctrl_impl(send, recv));
+gps_ctrl::sptr gps_ctrl::make(uart_iface::sptr uart){
+    return sptr(new gps_ctrl_impl(uart));
 }
diff --git a/host/lib/usrp/usrp2/fw_common.h b/host/lib/usrp/usrp2/fw_common.h
index 2da4e1e48..7ad06f33f 100644
--- a/host/lib/usrp/usrp2/fw_common.h
+++ b/host/lib/usrp/usrp2/fw_common.h
@@ -31,8 +31,8 @@ extern "C" {
 
 //fpga and firmware compatibility numbers
 #define USRP2_FPGA_COMPAT_NUM 7
-#define USRP2_FW_COMPAT_NUM 10
-#define USRP2_FW_VER_MINOR 4
+#define USRP2_FW_COMPAT_NUM 11
+#define USRP2_FW_VER_MINOR 0
 
 //used to differentiate control packets over data port
 #define USRP2_INVALID_VRT_HEADER 0
@@ -45,6 +45,7 @@ extern "C" {
 #define USRP2_UDP_TX_DSP0_PORT 49157
 #define USRP2_UDP_RX_DSP1_PORT 49158
 #define USRP2_UDP_UART_BASE_PORT 49170
+#define USRP2_UDP_UART_GPS_PORT 49172
 
 // Map for virtual firmware regs (not very big so we can keep it here for now)
 #define U2_FW_REG_LOCK_TIME 0
@@ -90,9 +91,6 @@ typedef enum{
     USRP2_CTRL_ID_HEY_WRITE_THIS_UART_FOR_ME_BRO = 'u',
     USRP2_CTRL_ID_MAN_I_TOTALLY_WROTE_THAT_UART_DUDE = 'U',
 
-    USRP2_CTRL_ID_SO_LIKE_CAN_YOU_READ_THIS_UART_BRO = 'v',
-    USRP2_CTRL_ID_I_HELLA_READ_THAT_UART_DUDE = 'V',
-
     USRP2_CTRL_ID_HOLLER_AT_ME_BRO = 'l',
     USRP2_CTRL_ID_HOLLER_BACK_DUDE = 'L',
 
@@ -144,11 +142,6 @@ typedef struct{
             uint8_t action;
         } reg_args;
         struct {
-            uint8_t dev;
-            uint8_t bytes;
-            uint8_t data[20];
-        } uart_args;
-        struct {
             uint32_t len;
         } echo_args;
     } data;
diff --git a/host/lib/usrp/usrp2/usrp2_iface.cpp b/host/lib/usrp/usrp2/usrp2_iface.cpp
index d91dd0e40..c1e92e7d4 100644
--- a/host/lib/usrp/usrp2/usrp2_iface.cpp
+++ b/host/lib/usrp/usrp2/usrp2_iface.cpp
@@ -245,66 +245,6 @@ public:
     }
 
 /***********************************************************************
- * UART
- **********************************************************************/
-    void write_uart(boost::uint8_t dev, const std::string &buf){
-      //first tokenize the string into 20-byte substrings
-      boost::offset_separator f(20, 20, true, true);
-      boost::tokenizer<boost::offset_separator> tok(buf, f);
-      std::vector<std::string> queue(tok.begin(), tok.end());
-
-      BOOST_FOREACH(std::string item, queue) {
-        //setup the out data
-        usrp2_ctrl_data_t out_data = usrp2_ctrl_data_t();
-        out_data.id = htonl(USRP2_CTRL_ID_HEY_WRITE_THIS_UART_FOR_ME_BRO);
-        out_data.data.uart_args.dev = dev;
-        out_data.data.uart_args.bytes = item.size();
-
-        //limitation of uart transaction size
-        UHD_ASSERT_THROW(item.size() <= sizeof(out_data.data.uart_args.data));
-
-        //copy in the data
-        std::copy(item.begin(), item.end(), out_data.data.uart_args.data);
-
-        //send and recv
-        usrp2_ctrl_data_t in_data = this->ctrl_send_and_recv(out_data, MIN_PROTO_COMPAT_UART);
-        UHD_ASSERT_THROW(ntohl(in_data.id) == USRP2_CTRL_ID_MAN_I_TOTALLY_WROTE_THAT_UART_DUDE);
-      }
-    }
-
-    std::string read_uart(boost::uint8_t dev){
-      int readlen = 20;
-      std::string result;
-      while(readlen == 20) { //while we keep receiving full packets
-        //setup the out data
-        usrp2_ctrl_data_t out_data = usrp2_ctrl_data_t();
-        out_data.id = htonl(USRP2_CTRL_ID_SO_LIKE_CAN_YOU_READ_THIS_UART_BRO);
-        out_data.data.uart_args.dev = dev;
-        out_data.data.uart_args.bytes = 20;
-
-        //limitation of uart transaction size
-        //UHD_ASSERT_THROW(num_bytes <= sizeof(out_data.data.uart_args.data));
-
-        //send and recv
-        usrp2_ctrl_data_t in_data = this->ctrl_send_and_recv(out_data, MIN_PROTO_COMPAT_UART);
-        UHD_ASSERT_THROW(ntohl(in_data.id) == USRP2_CTRL_ID_I_HELLA_READ_THAT_UART_DUDE);
-        readlen = in_data.data.uart_args.bytes;
-
-        //copy out the data
-        result += std::string((const char *)in_data.data.uart_args.data, (size_t)readlen);
-      }
-      return result;
-    }
-    
-    gps_send_fn_t get_gps_write_fn(void) {
-        return boost::bind(&usrp2_iface_impl::write_uart, this, 2, _1); //2 is the GPS UART port on USRP2
-    }
-    
-    gps_recv_fn_t get_gps_read_fn(void) {
-        return boost::bind(&usrp2_iface_impl::read_uart, this, 2); //2 is the GPS UART port on USRP2
-    }
-
-/***********************************************************************
  * Send/Recv over control
  **********************************************************************/
     usrp2_ctrl_data_t ctrl_send_and_recv(
diff --git a/host/lib/usrp/usrp2/usrp2_iface.hpp b/host/lib/usrp/usrp2/usrp2_iface.hpp
index b3c3ef4a2..9aa1a16aa 100644
--- a/host/lib/usrp/usrp2/usrp2_iface.hpp
+++ b/host/lib/usrp/usrp2/usrp2_iface.hpp
@@ -28,16 +28,12 @@
 #include "wb_iface.hpp"
 #include <string>
 
-//TODO: kill this crap when you have the top level GPS include file
-typedef boost::function<void(std::string)> gps_send_fn_t;
-typedef boost::function<std::string(void)> gps_recv_fn_t;
-
 /*!
  * The usrp2 interface class:
  * Provides a set of functions to implementation layer.
  * Including spi, peek, poke, control...
  */
-class usrp2_iface : public wb_iface, public uhd::spi_iface, public uhd::i2c_iface, public uhd::uart_iface{
+class usrp2_iface : public wb_iface, public uhd::spi_iface, public uhd::i2c_iface{
 public:
     typedef boost::shared_ptr<usrp2_iface> sptr;
     /*!
@@ -47,9 +43,6 @@ public:
      */
     static sptr make(uhd::transport::udp_simple::sptr ctrl_transport);
 
-    virtual gps_recv_fn_t get_gps_read_fn(void) = 0;
-    virtual gps_send_fn_t get_gps_write_fn(void) = 0;
-
     //! The list of possible revision types
     enum rev_type {
         USRP2_REV3 = 3,
diff --git a/host/lib/usrp/usrp2/usrp2_impl.cpp b/host/lib/usrp/usrp2/usrp2_impl.cpp
index 03a9d09fe..47aec08d5 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.cpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.cpp
@@ -438,10 +438,9 @@ usrp2_impl::usrp2_impl(const device_addr_t &_device_addr){
         // create gpsdo control objects
         ////////////////////////////////////////////////////////////////
         if (_mbc[mb].iface->mb_eeprom["gpsdo"] == "internal"){
-            _mbc[mb].gps = gps_ctrl::make(
-                _mbc[mb].iface->get_gps_write_fn(),
-                _mbc[mb].iface->get_gps_read_fn()
-            );
+            _mbc[mb].gps = gps_ctrl::make(udp_simple::make_uart(udp_simple::make_connected(
+                addr, BOOST_STRINGIZE(USRP2_UDP_UART_GPS_PORT)
+            )));
             if(_mbc[mb].gps->gps_detected()) {
                 BOOST_FOREACH(const std::string &name, _mbc[mb].gps->get_sensors()){
                     _tree->create<sensor_value_t>(mb_path / "sensors" / name)
@@ -624,8 +623,10 @@ usrp2_impl::usrp2_impl(const device_addr_t &_device_addr){
 
         //GPS installed: use external ref, time, and init time spec
         if (_mbc[mb].gps.get() and _mbc[mb].gps->gps_detected()){
+            UHD_MSG(status) << "Setting references to the internal GPSDO" << std::endl;
             _tree->access<std::string>(root / "time_source/value").set("external");
             _tree->access<std::string>(root / "clock_source/value").set("external");
+            UHD_MSG(status) << "Initializing time to the internal GPSDO" << std::endl;
             _mbc[mb].time64->set_time_next_pps(time_spec_t(time_t(_mbc[mb].gps->get_sensor("gps_time").to_int()+1)));
         }
     }
diff --git a/host/lib/usrp/usrp2/usrp2_impl.hpp b/host/lib/usrp/usrp2/usrp2_impl.hpp
index 28cbaf479..6f133f411 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.hpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.hpp
@@ -93,7 +93,7 @@ private:
         usrp2_iface::sptr iface;
         usrp2_clock_ctrl::sptr clock;
         usrp2_codec_ctrl::sptr codec;
-        gps_ctrl::sptr gps;
+        uhd::gps_ctrl::sptr gps;
         rx_frontend_core_200::sptr rx_fe;
         tx_frontend_core_200::sptr tx_fe;
         std::vector<rx_dsp_core_200::sptr> rx_dsps;