Merge branch 'master' into frontend_work

Conflicts:
	host/lib/usrp/usrp_e100/io_impl.cpp

9 files changed, 218 insertions, 47 deletions

diff --git a/host/docs/general.rst b/host/docs/general.rst
index cc00fc0f9..7952abb8b 100644
--- a/host/docs/general.rst
+++ b/host/docs/general.rst
@@ -107,10 +107,10 @@ For the most part, UHD is thread-safe.
 Please observe the following limitations:
 
 **Fast-path thread requirements:**
-It is safe to call send() and recv() simultaneously. However,
-it is not safe to call recv() simultaneously from different thread contexts.
-The same rule applies for recv(), send(), and recv_async_msg().
-One thread context per fast-path device method at a time.
+There are three fast-path methods for a device: send(), recv(), and recv_async_msg().
+All three methods are thread-safe and can be called from different thread contexts.
+For performance, the user should call each method from a separate thread context.
+These methods can also be used in a non-blocking fashion by using a timeout of zero.
 
 **Slow-path thread requirements:**
 It is safe to change multiple settings simultaneously. However,
diff --git a/host/lib/transport/libusb1_zero_copy.cpp b/host/lib/transport/libusb1_zero_copy.cpp
index 19a7a3742..f781f890d 100644
--- a/host/lib/transport/libusb1_zero_copy.cpp
+++ b/host/lib/transport/libusb1_zero_copy.cpp
@@ -222,7 +222,6 @@ public:
             }
         }
         //shutdown the threads
-        _threads_running = false;
         _thread_group.interrupt_all();
         _thread_group.join_all();
     }
@@ -277,15 +276,13 @@ private:
 
     //! event handler threads
     boost::thread_group _thread_group;
-    bool _threads_running;
 
     void run_event_loop(boost::barrier &spawn_barrier){
-        _threads_running = true;
         spawn_barrier.wait();
         set_thread_priority_safe();
         libusb_context *context = libusb::session::get_global_session()->get_context();
         try{
-            while(_threads_running){
+            while (not boost::this_thread::interruption_requested()){
                 timeval tv;
                 tv.tv_sec = 0;
                 tv.tv_usec = 100000; //100ms
diff --git a/host/lib/usrp/b100/b100_ctrl.cpp b/host/lib/usrp/b100/b100_ctrl.cpp
index 70decd4c1..2a87703f7 100644
--- a/host/lib/usrp/b100/b100_ctrl.cpp
+++ b/host/lib/usrp/b100/b100_ctrl.cpp
@@ -51,7 +51,6 @@ public:
     ctrl_data_t read(boost::uint32_t addr, size_t len);
     
     ~b100_ctrl_impl(void) {
-        bbl_out_marauding = false;
         viking_marauders.interrupt_all();
         viking_marauders.join_all();
     }
@@ -67,7 +66,6 @@ private:
     bounded_buffer<ctrl_data_t> sync_ctrl_fifo;
     bounded_buffer<async_metadata_t> async_msg_fifo;
     boost::thread_group viking_marauders;
-    bool bbl_out_marauding;
     
     uhd::transport::usb_zero_copy::sptr _ctrl_transport;
     boost::uint8_t _seq;
@@ -168,11 +166,10 @@ ctrl_data_t b100_ctrl_impl::read(boost::uint32_t addr, size_t len) {
  * wait for a control operation to finish before starting another one.
  **********************************************************************/
 void b100_ctrl_impl::viking_marauder_loop(boost::barrier &spawn_barrier) {
-    bbl_out_marauding = true;
     spawn_barrier.wait();
     set_thread_priority_safe();
     
-    while(bbl_out_marauding){
+    while (not boost::this_thread::interruption_requested()){
         managed_recv_buffer::sptr rbuf = _ctrl_transport->get_recv_buff();
         if(!rbuf.get()) continue; //that's ok, there are plenty of villages to pillage!
         const boost::uint16_t *pkt_buf = rbuf->cast<const boost::uint16_t *>();
diff --git a/host/lib/usrp/usrp2/codec_ctrl.cpp b/host/lib/usrp/usrp2/codec_ctrl.cpp
index ee0ef9ceb..06bf83b15 100644
--- a/host/lib/usrp/usrp2/codec_ctrl.cpp
+++ b/host/lib/usrp/usrp2/codec_ctrl.cpp
@@ -87,7 +87,9 @@ public:
             _ads62p44_regs.power_down = ads62p44_regs_t::POWER_DOWN_NORMAL;
             _ads62p44_regs.output_interface = ads62p44_regs_t::OUTPUT_INTERFACE_LVDS;
             _ads62p44_regs.lvds_current = ads62p44_regs_t::LVDS_CURRENT_2_5MA;
+            _ads62p44_regs.lvds_data_term = ads62p44_regs_t::LVDS_DATA_TERM_100;
             this->send_ads62p44_reg(0x11);
+            this->send_ads62p44_reg(0x12);
             this->send_ads62p44_reg(0x14);
             this->set_rx_analog_gain(1);
             break;
diff --git a/host/lib/usrp/usrp2/io_impl.cpp b/host/lib/usrp/usrp2/io_impl.cpp
index ffe9a88e7..df452942c 100644
--- a/host/lib/usrp/usrp2/io_impl.cpp
+++ b/host/lib/usrp/usrp2/io_impl.cpp
@@ -146,7 +146,6 @@ struct usrp2_impl::io_impl{
     }
 
     ~io_impl(void){
-        recv_pirate_crew_raiding = false;
         recv_pirate_crew.interrupt_all();
         recv_pirate_crew.join_all();
     }
@@ -185,7 +184,6 @@ struct usrp2_impl::io_impl{
     //methods and variables for the pirate crew
     void recv_pirate_loop(boost::barrier &, usrp2_mboard_impl::sptr, zero_copy_if::sptr, size_t);
     boost::thread_group recv_pirate_crew;
-    bool recv_pirate_crew_raiding;
     bounded_buffer<async_metadata_t> async_msg_fifo;
 };
 
@@ -201,14 +199,13 @@ void usrp2_impl::io_impl::recv_pirate_loop(
     zero_copy_if::sptr err_xport,
     size_t index
 ){
-    recv_pirate_crew_raiding = true;
     spawn_barrier.wait();
     set_thread_priority_safe();
 
     //store a reference to the flow control monitor (offset by max dsps)
     flow_control_monitor &fc_mon = *(this->fc_mons[index*usrp2_mboard_impl::MAX_NUM_DSPS]);
 
-    while(recv_pirate_crew_raiding){
+    while (not boost::this_thread::interruption_requested()){
         managed_recv_buffer::sptr buff = err_xport->get_recv_buff();
         if (not buff.get()) continue; //ignore timeout/error buffers
 
diff --git a/host/tests/sph_recv_test.cpp b/host/tests/sph_recv_test.cpp
index 6bb5d1175..cd33452c6 100644
--- a/host/tests/sph_recv_test.cpp
+++ b/host/tests/sph_recv_test.cpp
@@ -27,6 +27,19 @@
     BOOST_CHECK_CLOSE((a).get_real_secs(), (b).get_real_secs(), 0.001)
 
 /***********************************************************************
+ * A dummy overflow handler for testing
+ **********************************************************************/
+struct overflow_handler_type{
+    overflow_handler_type(void){
+        num_overflow = 0;
+    }
+    void handle(void){
+        num_overflow++;
+    }
+    size_t num_overflow;
+};
+
+/***********************************************************************
  * A dummy managed receive buffer for testing
  **********************************************************************/
 class dummy_mrb : public uhd::transport::managed_recv_buffer{
@@ -300,6 +313,10 @@ BOOST_AUTO_TEST_CASE(test_sph_recv_one_channel_inline_message){
     handler.set_xport_chan_get_buff(0, boost::bind(&dummy_recv_xport_class::get_recv_buff, &dummy_recv_xport, _1));
     handler.set_converter(otw_type);
 
+    //create an overflow handler
+    overflow_handler_type overflow_handler;
+    handler.set_overflow_handler(0, boost::bind(&overflow_handler_type::handle, &overflow_handler));
+
     //check the received packets
     size_t num_accum_samps = 0;
     std::vector<std::complex<float> > buff(20);
@@ -326,6 +343,7 @@ BOOST_AUTO_TEST_CASE(test_sph_recv_one_channel_inline_message){
             std::cout << "metadata.error_code " << metadata.error_code << std::endl;
             BOOST_REQUIRE(metadata.error_code == uhd::rx_metadata_t::ERROR_CODE_OVERFLOW);
             BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+            BOOST_CHECK_EQUAL(overflow_handler.num_overflow, size_t(1));
         }
     }
 
diff --git a/host/utils/usrp2_card_burner.py b/host/utils/usrp2_card_burner.py
index 26adb91c7..43689dd20 100755
--- a/host/utils/usrp2_card_burner.py
+++ b/host/utils/usrp2_card_burner.py
@@ -50,7 +50,7 @@ def command(*args):
         stderr=subprocess.STDOUT,
     )
     ret = p.wait()
-    verbose = p.stdout.read().decode('ascii')
+    verbose = p.stdout.read().decode()
     if ret != 0: raise Exception(verbose)
     return verbose
 
@@ -92,12 +92,12 @@ def get_raw_device_hints():
                 if in_info: info += '\n'+line.strip()
         def is_info_valid(info):
             try:
-                assert 'link to' in info
+                if 'link to' not in info: return False
                 #handles two spellings of remov(e)able:
-                assert 'remov' in info.lower()
-                if 'size is' in info: assert int(extract_info_value(info, 'size is')) <= MAX_SD_CARD_SIZE
-                return True
+                if 'remov' not in info.lower(): return False
+                if 'size is' in info and int(extract_info_value(info, 'size is')) > MAX_SD_CARD_SIZE: return False
             except: return False
+            return True
         def extract_info_name(info):
             for key in ('Mounted on', 'link to'):
                 if key in info: return extract_info_value(info, key)
@@ -110,13 +110,11 @@ def get_raw_device_hints():
     ####################################################################
     if platform.system() == 'Linux':
         devs = list()
-        try: output = open('/proc/partitions', 'r').read().decode('ascii')
-        except: return devs
-        for line in output.splitlines():
+        for line in command('cat', '/proc/partitions').splitlines():
             try:
                 major, minor, blocks, name = line.split()
-                assert not name[-1].isdigit() or int(minor) == 0
-                assert int(blocks)*1024 <= MAX_SD_CARD_SIZE
+                if not name[-1].isdigit() and int(minor) == 0: continue
+                if int(blocks)*1024 > MAX_SD_CARD_SIZE: continue
             except: continue
             devs.append(os.path.join('/dev', name))
 
@@ -128,17 +126,17 @@ def get_raw_device_hints():
     if platform.system() == 'Darwin':
         devs = [d.split()[0] for d in [l for l in command('diskutil', 'list').splitlines() if l.startswith('/dev')]]
         def output_to_info(output):
-            return dict([list(map(str.strip, pair.lower().split(':'))) for pair in [l for l in output.splitlines() if ':' in l]])
+            return dict([list(map(lambda x: x.strip(), pair.lower().split(':'))) for pair in [l for l in output.splitlines() if ':' in l]])
         def is_dev_valid(dev):
             info = output_to_info(command('diskutil', 'info', dev))
             try:
-                if 'internal' in info: assert info['internal'] == 'no'
-                if 'ejectable' in info: assert info['ejectable'] == 'yes'
+                if 'internal' in info and info['internal'] == 'yes': return False
+                if 'ejectable' in info and info['ejectable'] == 'no': return False
                 if 'total size' in info:
                     size_match = re.match('^.*\((\d+)\s*bytes\).*$', info['total size'])
-                    if size_match: assert int(size_match.groups()[0]) <= MAX_SD_CARD_SIZE
-                return True
+                    if size_match and int(size_match.groups()[0]) > MAX_SD_CARD_SIZE: return False
             except: return False
+            return True
 
         return sorted(set(filter(is_dev_valid, devs)))
 
diff --git a/host/utils/usrp_n2xx_net_burner.py b/host/utils/usrp_n2xx_net_burner.py
index 06af8c860..1df300c76 100755
--- a/host/utils/usrp_n2xx_net_burner.py
+++ b/host/utils/usrp_n2xx_net_burner.py
@@ -17,8 +17,6 @@
 #
 
 # TODO: make it autodetect UHD devices
-# TODO: you should probably watch sequence numbers
-# TODO: validate images in 1) size and 2) header content so you can't write a Justin Bieber MP3 to Flash
 
 import optparse
 import math
@@ -28,6 +26,8 @@ import struct
 import socket
 import sys
 import time
+import platform
+import subprocess
 
 ########################################################################
 # constants
@@ -54,6 +54,14 @@ FLASH_DATA_PACKET_SIZE = 256
 FLASH_ARGS_FMT = '!LLLLL256s'
 FLASH_INFO_FMT = '!LLLLL256x'
 FLASH_IP_FMT =   '!LLLL260x'
+FLASH_HW_REV_FMT = '!LLLL260x'
+
+n2xx_revs = {
+             0x0a00: ["n200_r3", "n200_r2"],
+             0x0a10: ["n200_r4"],
+             0x0a01: ["n210_r3", "n210_r2"],
+             0x0a11: ["n210_r4"]
+            }
 
 class update_id_t:
   USRP2_FW_UPDATE_ID_WAT = ord(' ')
@@ -72,6 +80,8 @@ class update_id_t:
   USRP2_FW_UPDATE_ID_KK_READ_TEH_FLASHES_OMG = ord('R')
   USRP2_FW_UPDATE_ID_RESET_MAH_COMPUTORZ_LOL = ord('s')
   USRP2_FW_UPDATE_ID_RESETTIN_TEH_COMPUTORZ_OMG = ord('S')
+  USRP2_FW_UPDATE_ID_I_CAN_HAS_HW_REV_LOL = ord('v')
+  USRP2_FW_UPDATE_ID_HERES_TEH_HW_REV_OMG = ord('V')
   USRP2_FW_UPDATE_ID_KTHXBAI = ord('~')
 
 _seq = -1
@@ -92,12 +102,18 @@ def unpack_flash_info_fmt(s):
 def unpack_flash_ip_fmt(s):
     return struct.unpack(FLASH_IP_FMT, s) #(proto_ver, pktid, seq, ip_addr)
 
+def unpack_flash_hw_rev_fmt(s):
+    return struct.unpack(FLASH_HW_REV_FMT, s) #proto_ver, pktid, seq, hw_rev
+
 def pack_flash_args_fmt(proto_ver, pktid, seq, flash_addr, length, data=bytes()):
     return struct.pack(FLASH_ARGS_FMT, proto_ver, pktid, seq, flash_addr, length, data)
 
 def pack_flash_info_fmt(proto_ver, pktid, seq, sector_size_bytes, memory_size_bytes):
     return struct.pack(FLASH_INFO_FMT, proto_ver, pktid, seq, sector_size_bytes, memory_size_bytes)
 
+def pack_flash_hw_rev_fmt(proto_ver, pktid, seq, hw_rev):
+    return struct.pack(FLASH_HW_REV_FMT, proto_ver, pktid, seq, hw_rev)
+
 def is_valid_fpga_image(fpga_image):
     for i in range(0,63):
         if fpga_image[i:i+1] == bytes(b'\xFF'): continue
@@ -107,6 +123,96 @@ def is_valid_fpga_image(fpga_image):
 def is_valid_fw_image(fw_image):
     return fw_image[:4] == bytes(b'\x0B\x0B\x0B\x0B')
 
+
+########################################################################
+# interface discovery and device enumeration
+########################################################################
+def get_interfaces():
+    if(platform.system() is "Windows"): return win_get_interfaces()
+    else: return unix_get_interfaces()
+
+def unix_get_interfaces():
+    ifconfig = subprocess.check_output("/sbin/ifconfig")
+    ip_addr_re = "cast\D*(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})"
+    bcasts = re.findall(ip_addr_re, ifconfig)
+    return bcasts
+
+def win_get_interfaces():
+    from ctypes import Structure, windll, sizeof
+    from ctypes import POINTER, byref
+    from ctypes import c_ulong, c_uint, c_ubyte, c_char
+    MAX_ADAPTER_DESCRIPTION_LENGTH = 128
+    MAX_ADAPTER_NAME_LENGTH = 256
+    MAX_ADAPTER_ADDRESS_LENGTH = 8
+    class IP_ADDR_STRING(Structure):
+        pass
+    LP_IP_ADDR_STRING = POINTER(IP_ADDR_STRING)
+    IP_ADDR_STRING._fields_ = [
+        ("next", LP_IP_ADDR_STRING),
+        ("ipAddress", c_char * 16),
+        ("ipMask", c_char * 16),
+        ("context", c_ulong)]
+    class IP_ADAPTER_INFO (Structure):
+        pass
+    LP_IP_ADAPTER_INFO = POINTER(IP_ADAPTER_INFO)
+    IP_ADAPTER_INFO._fields_ = [
+        ("next", LP_IP_ADAPTER_INFO),
+        ("comboIndex", c_ulong),
+        ("adapterName", c_char * (MAX_ADAPTER_NAME_LENGTH + 4)),
+        ("description", c_char * (MAX_ADAPTER_DESCRIPTION_LENGTH + 4)),
+        ("addressLength", c_uint),
+        ("address", c_ubyte * MAX_ADAPTER_ADDRESS_LENGTH),
+        ("index", c_ulong),
+        ("type", c_uint),
+        ("dhcpEnabled", c_uint),
+        ("currentIpAddress", LP_IP_ADDR_STRING),
+        ("ipAddressList", IP_ADDR_STRING),
+        ("gatewayList", IP_ADDR_STRING),
+        ("dhcpServer", IP_ADDR_STRING),
+        ("haveWins", c_uint),
+        ("primaryWinsServer", IP_ADDR_STRING),
+        ("secondaryWinsServer", IP_ADDR_STRING),
+        ("leaseObtained", c_ulong),
+        ("leaseExpires", c_ulong)]
+    GetAdaptersInfo = windll.iphlpapi.GetAdaptersInfo
+    GetAdaptersInfo.restype = c_ulong
+    GetAdaptersInfo.argtypes = [LP_IP_ADAPTER_INFO, POINTER(c_ulong)]
+    adapterList = (IP_ADAPTER_INFO * 10)()
+    buflen = c_ulong(sizeof(adapterList))
+    rc = GetAdaptersInfo(byref(adapterList[0]), byref(buflen))
+    if rc == 0:
+        for a in adapterList:
+            adNode = a.ipAddressList
+            while True:
+                #convert ipAddr and ipMask into hex addrs that can be turned into a bcast addr
+                ipAddr = adNode.ipAddress.decode()
+                ipMask = adNode.ipMask.decode()
+                if ipAddr and ipMask:
+                    hexAddr = struct.unpack("<L", socket.inet_aton(ipAddr))[0]
+                    hexMask = struct.unpack("<L", socket.inet_aton(ipMask))[0]
+                    if(hexAddr and hexMask): #don't broadcast on 255.255.255.255, that's just lame
+                        yield socket.inet_ntoa(struct.pack("<L", (hexAddr & hexMask) | (~hexMask) & 0xFFFFFFFF))
+                adNode = adNode.next
+                if not adNode:
+                    break
+
+def enumerate_devices():
+    for bcast_addr in get_interfaces():
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
+        sock.settimeout(0.1)
+        out_pkt = pack_flash_args_fmt(USRP2_FW_PROTO_VERSION, update_id_t.USRP2_FW_UPDATE_ID_OHAI_LOL, 0, 0, 0)
+        sock.sendto(out_pkt, (bcast_addr, UDP_FW_UPDATE_PORT))
+        still_goin = True
+        while(still_goin):
+            try:
+                pkt = sock.recv(UDP_MAX_XFER_BYTES)
+                (proto_ver, pktid, rxseq, ip_addr) = unpack_flash_ip_fmt(pkt)
+                if(pktid == update_id_t.USRP2_FW_UPDATE_ID_OHAI_OMG):
+                    yield socket.inet_ntoa(struct.pack("<L", socket.ntohl(ip_addr)))
+            except socket.timeout:
+                still_goin = False
+
 ########################################################################
 # Burner class, holds a socket and send/recv routines
 ########################################################################
@@ -117,6 +223,7 @@ class burner_socket(object):
         self._sock.connect((addr, UDP_FW_UPDATE_PORT))
         self.set_callbacks(lambda *a: None, lambda *a: None)
         self.init_update() #check that the device is there
+        self.get_hw_rev()
 
     def set_callbacks(self, progress_cb, status_cb):
         self._progress_cb = progress_cb
@@ -137,14 +244,19 @@ class burner_socket(object):
         else:
             raise Exception("Invalid reply received from device.")
 
-        #  print "Incoming:\n\tVer: %i\n\tID: %c\n\tSeq: %i\n\tIP: %i\n" % (proto_ver, chr(pktid), rxseq, ip_addr)
+    def get_hw_rev(self):
+        out_pkt = pack_flash_hw_rev_fmt(USRP2_FW_PROTO_VERSION, update_id_t.USRP2_FW_UPDATE_ID_I_CAN_HAS_HW_REV_LOL, seq(), 0)
+        in_pkt = self.send_and_recv(out_pkt)
+        (proto_ver, pktid, rxseq, hw_rev) = unpack_flash_hw_rev_fmt(in_pkt)
+        if(pktid != update_id_t.USRP2_FW_UPDATE_ID_HERES_TEH_HW_REV_OMG): hw_rev = 0
+        return socket.ntohs(hw_rev)
 
     memory_size_bytes = 0
     sector_size_bytes = 0
     def get_flash_info(self):
         if (self.memory_size_bytes != 0) and (self.sector_size_bytes != 0):
             return (self.memory_size_bytes, self.sector_size_bytes)
-            
+
         out_pkt = pack_flash_args_fmt(USRP2_FW_PROTO_VERSION, update_id_t.USRP2_FW_UPDATE_ID_WATS_TEH_FLASH_INFO_LOL, seq(), 0, 0)
         in_pkt = self.send_and_recv(out_pkt)
 
@@ -157,10 +269,16 @@ class burner_socket(object):
 
     def burn_fw(self, fw, fpga, reset, safe):
         (flash_size, sector_size) = self.get_flash_info()
+        hw_rev = self.get_hw_rev()
 
-        print("Flash size: %i\nSector size: %i\n\n" % (flash_size, sector_size))
+        if(hw_rev != 0): print("Hardware type: %s" % n2xx_revs[hw_rev][0])
+        print("Flash size: %i\nSector size: %i\n" % (flash_size, sector_size))
 
         if fpga:
+            #validate fpga image name against hardware rev
+            if(hw_rev != 0 and not any(name in fpga for name in n2xx_revs[hw_rev])):
+                raise Exception("Error: incorrect FPGA image version. Please use the correct image for device %s" % n2xx_revs[hw_rev][0])
+
             if safe: image_location = SAFE_FPGA_IMAGE_LOCATION_ADDR
             else:    image_location = PROD_FPGA_IMAGE_LOCATION_ADDR
 
@@ -172,7 +290,7 @@ class burner_socket(object):
 
             if not is_valid_fpga_image(fpga_image):
                 raise Exception("Error: Invalid FPGA image file.")
-                
+
             if (len(fpga_image) + image_location) > flash_size:
                 raise Exception("Error: Cannot write past end of device")
 
@@ -196,7 +314,7 @@ class burner_socket(object):
 
             if not is_valid_fw_image(fw_image):
                 raise Exception("Error: Invalid firmware image file.")
-                
+
             if (len(fw_image) + image_location) > flash_size:
                 raise Exception("Error: Cannot write past end of device")
 
@@ -218,7 +336,7 @@ class burner_socket(object):
         (mem_size, sector_size) = self.get_flash_info()
         if (addr + len(writedata)) > mem_size:
             raise Exception("Error: Cannot write past end of device")
-            
+
         while writedata:
             out_pkt = pack_flash_args_fmt(USRP2_FW_PROTO_VERSION, update_id_t.USRP2_FW_UPDATE_ID_WRITE_TEH_FLASHES_LOL, seq(), addr, FLASH_DATA_PACKET_SIZE, writedata[:FLASH_DATA_PACKET_SIZE])
             in_pkt = self.send_and_recv(out_pkt)
@@ -305,7 +423,7 @@ class burner_socket(object):
         (flash_size, sector_size) = self.get_flash_info()
         if (addr + length) > flash_size:
             raise Exception("Cannot erase past end of device")
-            
+
         out_pkt = pack_flash_args_fmt(USRP2_FW_PROTO_VERSION, update_id_t.USRP2_FW_UPDATE_ID_ERASE_TEH_FLASHES_LOL, seq(), addr, length)
         in_pkt = self.send_and_recv(out_pkt)
 
@@ -342,6 +460,7 @@ def get_options():
     parser.add_option("--reset", action="store_true",          help="reset the device after writing", default=False)
     parser.add_option("--read", action="store_true",           help="read to file instead of write from file", default=False)
     parser.add_option("--overwrite-safe", action="store_true", help="never ever use this option", default=False)
+    parser.add_option("--list", action="store_true",           help="list possible network devices", default=False)
     (options, args) = parser.parse_args()
 
     return options
@@ -351,6 +470,12 @@ def get_options():
 ########################################################################
 if __name__=='__main__':
     options = get_options()
+
+    if options.list:
+        print('Possible network devices:')
+        print('  ' + '\n  '.join(enumerate_devices()))
+        exit()
+
     if not options.addr: raise Exception('no address specified')
 
     if not options.fpga and not options.fw and not options.reset: raise Exception('Must specify either a firmware image or FPGA image, and/or reset.')
diff --git a/host/utils/usrp_n2xx_net_burner_gui.py b/host/utils/usrp_n2xx_net_burner_gui.py
index 3b414a918..e2b79e72c 100755
--- a/host/utils/usrp_n2xx_net_burner_gui.py
+++ b/host/utils/usrp_n2xx_net_burner_gui.py
@@ -84,6 +84,45 @@ class ProgressBar(tkinter.Canvas):
         if frac: self.create_rectangle(0, 0, fill_pixels, self._height, fill="#357EC7")
         else:    self.create_rectangle(0, 0, self._width, self._height, fill="#E8E8E8")
 
+class DeviceEntryWidget(tkinter.Frame):
+    """
+    Simple entry widget for getting the network device name.
+    Combines a label, entry, and helpful text box with hints.
+    """
+
+    def __init__(self, root, text=''):
+        tkinter.Frame.__init__(self, root)
+
+        tkinter.Button(self, text="Rescan for Devices", command=self._reload_cb).pack()
+
+        self._hints = tkinter.Listbox(self)
+        self._hints.bind("<<ListboxSelect>>", self._listbox_cb)
+        self._reload_cb()
+        self._hints.pack(expand=tkinter.YES, fill=tkinter.X)
+
+        frame = tkinter.Frame(self)
+        frame.pack()
+
+        tkinter.Label(frame, text="Network Address:").pack(side=tkinter.LEFT)
+        self._entry = tkinter.Entry(frame, width=50)
+        self._entry.insert(tkinter.END, text)
+        self._entry.pack(side=tkinter.LEFT)
+
+    def _reload_cb(self):
+        self._hints.delete(0, tkinter.END)
+        for hint in usrp_n2xx_net_burner.enumerate_devices():
+            self._hints.insert(tkinter.END, hint)
+
+    def _listbox_cb(self, event):
+        try:
+            sel = self._hints.get(self._hints.curselection()[0])
+            self._entry.delete(0, tkinter.END)
+            self._entry.insert(0, sel)
+        except Exception as e: print(e)
+
+    def get_devname(self):
+        return self._entry.get()
+
 class SectionLabel(tkinter.Label):
     """
     Make a text label with bold font.
@@ -115,10 +154,9 @@ class USRPN2XXNetBurnerApp(tkinter.Frame):
         self._fpga_img_entry.pack()
 
         #pack the destination entry widget
-        SectionLabel(self, text="Select Address").pack(pady=5)
-        self._addr_entry = tkinter.Entry(self, width=30)
-        self._addr_entry.insert(tkinter.END, addr)
-        self._addr_entry.pack()
+        SectionLabel(self, text="Select Device").pack(pady=5)
+        self._net_dev_entry = DeviceEntryWidget(self, text=addr)
+        self._net_dev_entry.pack()
 
         #the do it button
         SectionLabel(self, text="").pack(pady=5)
@@ -136,12 +174,10 @@ class USRPN2XXNetBurnerApp(tkinter.Frame):
         self._pbar.pack(side=tkinter.RIGHT, expand=True)
 
     def _burn(self):
-        self._disable_input()
-
         #grab strings from the gui
         fw = self._fw_img_entry.get_filename()
         fpga = self._fpga_img_entry.get_filename()
-        addr = self._addr_entry.get()
+        addr = self._net_dev_entry.get_devname()
 
         #check input
         if not addr:
@@ -157,6 +193,7 @@ class USRPN2XXNetBurnerApp(tkinter.Frame):
             tkinter.messagebox.showerror('Error:', 'FPGA image not found!')
             return
 
+        self._disable_input()
         try:
             #make a new burner object and attempt the burner operation
             burner = usrp_n2xx_net_burner.burner_socket(addr=addr)