ci: add devtest e320 support

This commit adds devtest support for e320 via tftp. The e320 has
a hardware incompatibility with sdmuxes that we use for the n3xx
devices, which makes them unreliable. Instead this loads a small
Linux OS into the e320 system memory and reimages the sd card
from there.

Signed-off-by: Steven Koo <steven.koo@ni.com>

9 files changed, 380 insertions, 14 deletions

diff --git a/.ci/templates/job-uhd-devtest-rhombus.yml b/.ci/templates/job-uhd-devtest-rhombus.yml
index 1395b0de0..3348e4fff 100644
--- a/.ci/templates/job-uhd-devtest-rhombus.yml
+++ b/.ci/templates/job-uhd-devtest-rhombus.yml
@@ -10,7 +10,7 @@ parameters:
   default: current
 - name: testDevices
   type: string
-  default: 'x3xx,b2xx,n3xx'
+  default: 'x3xx,b2xx,n3xx,e320'
 
 jobs:
 - template: job-uhd-devtest.yml
@@ -136,3 +136,20 @@ jobs:
           devtestPattern: 'n3x0'
           devSDImage: gnuradio-image-ni-sulfur-rev11-mender.sdimg.bz2
           devLabgridConfig: .ci/templates/tests/rhombus-labgrid/device-configs/rhombus-n321-0.yml
+
+      ${{ if contains(parameters.testDevices, 'e320') }}:
+        rhombus-e320-0:
+          devAgent: rhombus-e320-0
+          devType: 'e3xx'
+          devModel: 'e320'
+          devName: rhombus-e320-0
+          devSerial: '31A8171'
+          devHostname: 'ni-e320-31a8171'
+          devBus: 'ip'
+          devAddr: '192.168.20.7'
+          sfpAddrs: '192.168.20.7'
+          devFpga: 'XG'
+          devtestPattern: 'e320'
+          devInitramfsImage: fitImage-manufacturing
+          devSDImage: gnuradio-image-ni-neon-rev2-mender.sdimg.bz2
+          devLabgridConfig: .ci/templates/tests/rhombus-labgrid/device-configs/rhombus-e320-0.yml
diff --git a/.ci/templates/job-uhd-devtest.yml b/.ci/templates/job-uhd-devtest.yml
index 2b284c7ab..3e095c5f3 100644
--- a/.ci/templates/job-uhd-devtest.yml
+++ b/.ci/templates/job-uhd-devtest.yml
@@ -67,18 +67,30 @@ jobs:
       cleanDestinationFolder: true
 
   - download: ${{ parameters.uhdArtifactSource }}
-    artifact: $(devType)-images
+    artifact: n3xx-images
     # Only sync the bz2 sdimg since the bmap
     # is incompatible with mender
-    patterns: '**/*.bz2'
+    patterns: |
+      **/*.bz2
+      fitImage-manufacturing
     displayName: Download $(devType)-images artifact
     condition: and(succeeded(), eq(variables.devType, 'n3xx'))
 
+  - download: ${{ parameters.uhdArtifactSource }}
+    artifact: e320-images
+    # Only sync the bz2 sdimg since the bmap
+    # is incompatible with mender
+    patterns: |
+      **/*.bz2
+      fitImage-manufacturing
+    displayName: Download $(devType)-images artifact
+    condition: and(succeeded(), eq(variables.devModel, 'e320'))
+
   - script: |
       cd $(Build.BinariesDirectory)/uhddev/build
       mkdir -p fpga_images
       rm -rf fpga_images/*
-      python3 utils/uhd_images_downloader.py -t $(devModel) -i fpga_images \
+      python3 utils/uhd_images_downloader.py -t $(devModel)_fpga -i fpga_images \
         -b $(sdr-fileserver)
       if [ "$(devType)" = "b200" ]; then
         python3 utils/uhd_images_downloader.py -t b2xx_common -i fpga_images \
@@ -93,7 +105,7 @@ jobs:
       export LD_LIBRARY_PATH=$(Build.BinariesDirectory)/uhddev/build/lib:$LD_LIBRARY_PATH
       export UHD_IMAGES_DIR=$(Build.BinariesDirectory)/uhddev/build/fpga_images
       python3 ${{ parameters.uhdSrcDir }}/.ci/utils/mutex_hardware.py \
-        --sdimage $(devType),$(devModel),$(uhd_artifact_directory)/$(devType)-images/$(devSDImage),${{ parameters.uhdSrcDir }}/$(devLabgridConfig),$(devHostname) \
+        --sdimage_sdmux $(devType),$(devModel),$(uhd_artifact_directory)/$(devType)-images/$(devSDImage),${{ parameters.uhdSrcDir }}/$(devLabgridConfig),$(devHostname) \
         --fpgas $(devFpga) \
         --sfp_addrs $(sfpAddrs) \
         ${{ parameters.redisHost }} $(devName) \
@@ -114,6 +126,27 @@ jobs:
       export LD_LIBRARY_PATH=$(Build.BinariesDirectory)/uhddev/build/lib:$LD_LIBRARY_PATH
       export UHD_IMAGES_DIR=$(Build.BinariesDirectory)/uhddev/build/fpga_images
       python3 ${{ parameters.uhdSrcDir }}/.ci/utils/mutex_hardware.py \
+        --sdimage_tftp $(devType),$(devModel),$(uhd_artifact_directory)/e320-images/$(devSDImage),$(uhd_artifact_directory)/e320-images/$(devInitramfsImage),${{ parameters.uhdSrcDir }}/$(devLabgridConfig) \
+        --fpgas $(devFpga) \
+        --sfp_addrs $(sfpAddrs) \
+        ${{ parameters.redisHost }} $(devName) \
+        "$(Build.BinariesDirectory)/uhddev/build/utils/uhd_usrp_probe --args addr=$(devAddr)" \
+        "python3 ${{ parameters.uhdSrcDir }}/host/tests/devtest/run_testsuite.py \
+          --src-dir ${{ parameters.uhdSrcDir }}/host/tests/devtest \
+          --devtest-pattern $(devtestPattern) --args addr=$(devAddr),type=$(devType) \
+          --build-type Release --build-dir $(Build.BinariesDirectory)/uhddev/build \
+          --python-interp python3 --xml"
+    continueOnError: true
+    condition: and(succeeded(), eq(variables.devModel, 'e320'), eq(variables.devBus, 'ip'))
+    displayName: Run e320 devtest on $(devName)
+
+  - script: |
+      mkdir -p $(Common.TestResultsDirectory)/devtest
+      cd $(Common.TestResultsDirectory)/devtest
+      export PATH=$(Build.BinariesDirectory)/uhddev/build/utils:$(Build.BinariesDirectory)/uhddev/build/examples:$PATH
+      export LD_LIBRARY_PATH=$(Build.BinariesDirectory)/uhddev/build/lib:$LD_LIBRARY_PATH
+      export UHD_IMAGES_DIR=$(Build.BinariesDirectory)/uhddev/build/fpga_images
+      python3 ${{ parameters.uhdSrcDir }}/.ci/utils/mutex_hardware.py \
         ${{ parameters.redisHost }} $(devName) \
         "$(Build.BinariesDirectory)/uhddev/build/utils/uhd_usrp_probe --args serial=$(devSerial)" \
         "$(Build.BinariesDirectory)/uhddev/build/utils/uhd_image_loader --args serial=$(devSerial),type=$(devType)" \
diff --git a/.ci/templates/stages-uhd-pipeline.yml b/.ci/templates/stages-uhd-pipeline.yml
index 0b30012b4..a93ec5185 100644
--- a/.ci/templates/stages-uhd-pipeline.yml
+++ b/.ci/templates/stages-uhd-pipeline.yml
@@ -238,8 +238,8 @@ stages:
       uhdSrcDir: $(Build.SourcesDirectory)
       testDevices: 'x3xx,b2xx'
 
-- stage: devtest_uhd_n3xx_stage
-  displayName: devtest UHD n3xx
+- stage: devtest_uhd_n3xx_e320_stage
+  displayName: devtest UHD n3xx e320
   dependsOn:
   - build_uhd_stage_linux
   - build_uhd_embedded_system_images
@@ -248,7 +248,7 @@ stages:
     parameters:
       testOS: ubuntu2004
       uhdSrcDir: $(Build.SourcesDirectory)
-      testDevices: 'n3xx'
+      testDevices: 'n3xx,e320'
 
 - stage: test_uhd_x4xx_stage
   displayName: Test UHD x4xx
diff --git a/.ci/templates/tests/rhombus-labgrid/crossbar/places.yaml b/.ci/templates/tests/rhombus-labgrid/crossbar/places.yaml
index baf68bbd1..2fbf5052b 100755
--- a/.ci/templates/tests/rhombus-labgrid/crossbar/places.yaml
+++ b/.ci/templates/tests/rhombus-labgrid/crossbar/places.yaml
@@ -32,3 +32,19 @@ rhombus-n321-0:
   reservation: null
   tags: {}
 
+rhombus-e320-0:
+  acquired: null
+  acquired_resources: []
+  aliases: []
+  allowed: []
+  changed: 1654034475.1935894
+  comment: ''
+  created: 1654034136.0077882
+  matches:
+  - cls: '*'
+    exporter: '*'
+    group: rhombus-e320-0-group
+    name: null
+    rename: null
+  reservation: null
+  tags: {}
diff --git a/.ci/templates/tests/rhombus-labgrid/device-configs/rhombus-e320-0.yml b/.ci/templates/tests/rhombus-labgrid/device-configs/rhombus-e320-0.yml
new file mode 100644
index 000000000..e9c934817
--- /dev/null
+++ b/.ci/templates/tests/rhombus-labgrid/device-configs/rhombus-e320-0.yml
@@ -0,0 +1,14 @@
+targets:
+  main:
+    resources:
+      RemotePlace:
+        name: 'rhombus-e320-0'
+    drivers:
+    - SerialDriver:
+        name: 'linux_serial_driver'
+        bindings:
+          port: 'console-linux'
+    - SerialDriver:
+        name: 'scu_serial_driver'
+        bindings:
+          port: 'console-scu'
diff --git a/.ci/templates/tests/rhombus-labgrid/exporter-conf/exporter.yaml b/.ci/templates/tests/rhombus-labgrid/exporter-conf/exporter.yaml
index f13ebbe07..c15385aac 100755
--- a/.ci/templates/tests/rhombus-labgrid/exporter-conf/exporter.yaml
+++ b/.ci/templates/tests/rhombus-labgrid/exporter-conf/exporter.yaml
@@ -32,3 +32,16 @@ rhombus-n321-0-group:
     match:
       ID_SERIAL_SHORT: '000000001140'
 
+rhombus-e320-0-group:
+  console-scu:
+    cls: USBSerialPort
+    match:
+      ID_SERIAL: 'Silicon_Labs_CP2105_Dual_USB_to_UART_Bridge_Controller_0097841B'
+      ID_USB_INTERFACE_NUM: '00'
+    speed: 115200
+  console-linux:
+    cls: USBSerialPort
+    match:
+      ID_SERIAL: 'Silicon_Labs_CP2105_Dual_USB_to_UART_Bridge_Controller_0097841B'
+      ID_USB_INTERFACE_NUM: '01'
+    speed: 115200
diff --git a/.ci/utils/httpd.py b/.ci/utils/httpd.py
new file mode 100644
index 000000000..53741566e
--- /dev/null
+++ b/.ci/utils/httpd.py
@@ -0,0 +1,63 @@
+import http.server
+import time
+import os
+import pyroute2
+import socket
+import socketserver
+import threading
+from functools import partial
+from pathlib import Path
+
+class ThreadingHTTPServer(socketserver.ThreadingMixIn, http.server.HTTPServer):
+    pass
+
+class HTTPServer:
+    def __init__(self, path, remote_ip):
+        self.path = path
+        self.port = None
+        self.old_path = None
+        self.httpd = None
+
+        with pyroute2.IPRoute() as ipr:
+            r = ipr.route('get', dst=remote_ip)
+            for attr in r[0]['attrs']:
+                if attr[0] == 'RTA_PREFSRC':
+                    self.ip = attr[1]
+        with socket.socket() as s:
+            s.bind(('', 0))
+            self.port = s.getsockname()[1]
+
+    def get_url(self, filename):
+        path = Path(self.path) / filename
+        assert path.exists()
+        return f"http://{self.ip}:{self.port}/{filename}"
+
+    def __enter__(self):
+        def start_server():
+            Handler = http.server.SimpleHTTPRequestHandler
+            self.httpd = ThreadingHTTPServer(("", self.port), Handler)
+            self.httpd.serve_forever()
+
+        # Kind of annoying, but to work with older pythons where
+        # SimpleHTTPRequestHandler doesn't take a directory parameter but only
+        # serves the current directory:
+        self.old_path = os.getcwd()
+        os.chdir(self.path)
+
+        self.thread = threading.Thread(target=start_server)
+        self.thread.start()
+        return self
+
+    def __exit__(self, type, value, exc):
+        if self.httpd is not None:
+            self.httpd.shutdown()
+            self.httpd.server_close()
+        if self.old_path is not None:
+            os.chdir(self.old_path)
+
+if __name__ == '__main__':
+    with HTTPServer("/tmp", "127.0.0.1") as server:
+        print("server ip", server.ip)
+        print("server port", server.port)
+        time.sleep(300)
+
diff --git a/.ci/utils/mutex_hardware.py b/.ci/utils/mutex_hardware.py
index 485f0fcbd..9f48ed22e 100644
--- a/.ci/utils/mutex_hardware.py
+++ b/.ci/utils/mutex_hardware.py
@@ -8,17 +8,22 @@ import labgrid
 import os
 import pathlib
 import shlex
+import socket
 import subprocess
 import sys
 import time
 
 from fabric import Connection
+from httpd import HTTPServer
 from pottery import Redlock
 from redis import Redis
+from tftp import TFTPServer
 
 bitfile_name = "usrp_{}_fpga_{}.bit"
 
 def jtag_x3xx(dev_type, dev_model, jtag_server, jtag_serial, fpga_folder, fpga, redis_server):
+    if dev_model not in ["x300", "x310"]:
+        raise RuntimeError(f'{dev_type} not supported with jtag_x3xx')
     remote_working_dir = "pipeline_fpga"
     vivado_program_jtag = "/opt/Xilinx/Vivado_Lab/2020.1/bin/vivado_lab -mode batch -source {}/viv_hardware_utils.tcl -nolog -nojournal -tclargs program".format(
         remote_working_dir)
@@ -50,7 +55,12 @@ def set_sfp_addrs(mgmt_addr, sfp_addrs):
             dut.run(f"ip link set sfp{idx} up")
     time.sleep(30)
 
-def flash_sdimage(dev_model, sdimage_path, labgrid_device_yaml, mgmt_addr, sfp_addrs):
+def flash_sdimage_sdmux(dev_model, sdimage_path, labgrid_device_yaml, mgmt_addr, sfp_addrs):
+    """ This method uses an sdmux (https://linux-automation.com/en/products/usb-sd-mux.html)
+    to reimage the sd card.
+    """
+    if dev_model not in ["n300", "n310", "n320", "n321"]:
+        raise RuntimeError(f'{dev_model} not supported with sdimage_sdmux')
     subprocess.run(shlex.split(f"labgrid-client -c {labgrid_device_yaml} release --kick"))
     subprocess.run(shlex.split(f"labgrid-client -c {labgrid_device_yaml} acquire"))
     env = labgrid.Environment(labgrid_device_yaml)
@@ -101,6 +111,97 @@ def flash_sdimage(dev_model, sdimage_path, labgrid_device_yaml, mgmt_addr, sfp_a
 
     subprocess.run(shlex.split(f"labgrid-client -c {labgrid_device_yaml} release"))
 
+def flash_sdimage_tftp(dev_model, sdimage_path, initramfs_path, labgrid_device_yaml, sfp_addrs, redis_server):
+    """ This method uses tftp to boot the device into a small Linux envionment to
+    write to the device's sd card. This method is used on the E320 since it has
+    a hardware incompatibility with sdmuxes.
+    """
+    if dev_model not in ["e320"]:
+        raise RuntimeError(f'{dev_model} not supported with sdimage_tftp')
+
+    if dev_model == "e320":
+        dev_ram_address = '0x20000000'
+        dev_bootm_config = 'conf@zynq-ni-${mboard}.dtb'
+
+    subprocess.run(shlex.split(f"labgrid-client -c {labgrid_device_yaml} release --kick"))
+    subprocess.run(shlex.split(f"labgrid-client -c {labgrid_device_yaml} acquire"))
+    env = labgrid.Environment(labgrid_device_yaml)
+    target = env.get_target()
+
+    cp_scu = target.get_driver(labgrid.protocol.ConsoleProtocol, name="scu_serial_driver")
+    cp_linux = target.get_driver(labgrid.protocol.ConsoleProtocol, name="linux_serial_driver")
+
+    print("Powering down DUT", flush=True)
+    cp_scu.write("\napshutdown\n".encode())
+    time.sleep(10)
+
+    print("Powering on DUT", flush=True)
+    cp_scu.write("\npowerbtn\n".encode())
+    # Sometimes it requires multiple powerbtn calls to turn on device
+    try:
+        cp_linux.expect("Enter 'noautoboot' to enter prompt without timeout", timeout=5)
+    except Exception:
+        print("Device didn't power on with first attempt. Trying again...", flush=True)
+        cp_scu.write("\npowerbtn\n".encode())
+        cp_linux.expect("Enter 'noautoboot' to enter prompt without timeout", timeout=5)
+
+    print("Attempting to get into uboot console", flush=True)
+    cp_linux.write("noautoboot".encode())
+    # Handle if the watchdog triggers
+    try:
+        cp_linux.expect("Enter 'noautoboot' to enter prompt without timeout", timeout=30)
+        cp_linux.write("noautoboot".encode())
+    except Exception:
+        pass
+    cp_linux.expect("uboot>")
+    print("Waiting for NIC to come up", flush=True)
+    time.sleep(10)
+    cp_linux.write(f"setenv autoload no; dhcp;\n".encode())
+    cp_linux.expect("DHCP client bound to address")
+    expect_index, expect_before, expect_match , expect_after = cp_linux.expect(r"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b")
+    mgmt_addr = expect_match[0].decode()
+    print(f"Dev got IP Address {mgmt_addr}")
+
+    with TFTPServer(initramfs_path, mgmt_addr) as server:
+        time.sleep(10)
+        cp_linux.expect("uboot>")
+        cp_linux.write(f"setenv tftpdstp {server.port}\n".encode())
+        cp_linux.expect("uboot>")
+        print("TFTPing initramfs image", flush=True)
+        cp_linux.write(f"tftpboot {dev_ram_address} {server.ip}:{os.path.basename(initramfs_path)}\n".encode())
+        cp_linux.expect("uboot>", timeout=120)
+        print("Booting into initramfs", flush=True)
+        cp_linux.write(f"bootm {dev_ram_address}#{dev_bootm_config}\n".encode())
+        cp_linux.expect("mender login:", timeout=120)
+        print("Logging into Linux", flush=True)
+        cp_linux.write("root\n".encode())
+        cp_linux.expect("mender:~#")
+        print("Waiting for NIC to DHCP", flush=True)
+        time.sleep(10)
+
+    with HTTPServer(os.path.dirname(sdimage_path), mgmt_addr) as server:
+        print(f"Writing SD Card using {sdimage_path}", flush=True)
+        print("Running bmaptool... This will take awhile", flush=True)
+        cp_linux.write(f"bmaptool copy --nobmap {server.get_url(os.path.basename(sdimage_path))} /dev/mmcblk0\n".encode())
+        cp_linux.expect("mender:~#", timeout=1800)
+        cp_linux.write("echo bmaptool exit code: $?\n".encode())
+        cp_linux.expect("bmaptool exit code: 0", timeout=10)
+        time.sleep(10)
+        print("Rebooting into new image from sd card", flush=True)
+        cp_linux.write("reboot\n".encode())
+
+    print("Waiting 2 minutes for device to boot", flush=True)
+    time.sleep(120)
+    cp_linux.expect("login:", timeout=30)
+    known_hosts_path = os.path.expanduser("~/.ssh/known_hosts")
+    subprocess.run(shlex.split(f"ssh-keygen -f \"{known_hosts_path}\" -R \"{mgmt_addr}\""))
+
+    if sfp_addrs:
+        set_sfp_addrs(mgmt_addr, sfp_addrs)
+
+    subprocess.run(shlex.split(f"labgrid-client -c {labgrid_device_yaml} release"))
+    return mgmt_addr
+
 def main(args):
     redis_server = {Redis.from_url(
         "redis://{}:6379/0".format(args.redis_server))}
@@ -108,13 +209,21 @@ def main(args):
     with Redlock(key=args.dut_name, masters=redis_server, auto_release_time=1000 * 60 * args.dut_timeout):
         print("Got mutex for {}".format(args.dut_name), flush=True)
 
-        if args.sdimage:
-            dev_type, dev_model, sdimage_path, labgrid_device_yaml, mgmt_addr = args.sdimage.split(',')
+        if args.sdimage_sdmux:
+            dev_type, dev_model, sdimage_path, labgrid_device_yaml, mgmt_addr = args.sdimage_sdmux.split(',')
+            if args.sfp_addrs:
+                sfp_addrs = args.sfp_addrs.split(',')
+            else:
+                sfp_addrs = None
+            flash_sdimage_sdmux(dev_model, sdimage_path, labgrid_device_yaml, mgmt_addr, sfp_addrs)
+
+        if args.sdimage_tftp:
+            dev_type, dev_model, sdimage_path, initramfs_path, labgrid_device_yaml = args.sdimage_tftp.split(',')
             if args.sfp_addrs:
                 sfp_addrs = args.sfp_addrs.split(',')
             else:
                 sfp_addrs = None
-            flash_sdimage(dev_model, sdimage_path, labgrid_device_yaml, mgmt_addr, sfp_addrs)
+            mgmt_addr = flash_sdimage_tftp(dev_model, sdimage_path, initramfs_path, labgrid_device_yaml, sfp_addrs, redis_server)
 
         if args.fpgas:
             working_dir = os.getcwd()
@@ -146,14 +255,17 @@ def main(args):
 
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
+    group = parser.add_mutually_exclusive_group()
     # jtag_x3xx will flash the fpga for a given jtag_serial using
     # Vivado on jtag_server. It uses SSH to control jtag_server.
     # Provide fpga_path as a local path and it will be copied
     # to jtag_server.
-    parser.add_argument("--jtag_x3xx", type=str,
+    group.add_argument("--jtag_x3xx", type=str,
                         help="dev_type,dev_model,user@jtag_server,jtag_serial,fpga_folder")
-    parser.add_argument("--sdimage", type=str,
+    group.add_argument("--sdimage_sdmux", type=str,
                         help="dev_type,dev_model,sdimg_path,labgrid_device_yaml,mgmt_addr")
+    group.add_argument("--sdimage_tftp", type=str,
+                        help="dev_type,dev_model,sdimg_path,initramfs_path,labgrid_device_yaml")
     parser.add_argument("--sfp_addrs", type=str,
                         help="sfp0ip,sfp1ip,...")
     parser.add_argument("--fpgas", type=str,
diff --git a/.ci/utils/tftp.py b/.ci/utils/tftp.py
new file mode 100644
index 000000000..44291cd93
--- /dev/null
+++ b/.ci/utils/tftp.py
@@ -0,0 +1,98 @@
+#!/usr/bin/env python3
+
+import asyncio
+import py3tftp.protocols
+import pyroute2
+import socket
+import threading
+from pathlib import Path
+
+
+class FileReaderSingle:
+    def __init__(self, path, fname_req, chunk_size=0):
+        self.path = path
+        # TODO: Should check fname_req against actual name
+        self.chunk_size = chunk_size
+        self._f = None
+        self._f = open(self.path, 'rb')
+        self.finished = False
+
+    def file_size(self):
+        return self.path.stat().st_size
+
+    def read_chunk(self, size=None):
+        size = size or self.chunk_size
+        if self.finished:
+            return b''
+
+        data = self._f.read(size)
+        if not data or (size > 0 and len(data) < size):
+            self._f.close()
+            self.finished = True
+
+        return data
+
+    def __del__(self):
+        if self._f and not self._f.closed:
+            self._f.close()
+
+
+class TFTPServerSingle(py3tftp.protocols.BaseTFTPServerProtocol):
+    def __init__(self, path, host_interface, loop, extra_opts):
+        super().__init__(host_interface, loop, extra_opts)
+        self.path = path
+
+    def select_protocol(self, packet):
+        if packet.is_rrq():
+            return py3tftp.protocols.RRQProtocol
+        raise py3tftp.protocols.ProtocolException("Unhandled protocol")
+
+    def select_file_handler(self, packet):
+        if packet.is_rrq():
+            return lambda filename, opts: FileReaderSingle(self.path, filename, opts)
+
+
+class TFTPServer:
+    """
+    Simple TFTP server, meant to be short-lived and capable of serving a single
+    file only
+    """
+    def __init__(self, filename, remote_ip, port=None):
+        self.path = Path(filename).absolute()
+        assert self.path.exists()
+        assert self.path.is_file()
+
+        self.filename = self.path.name
+
+        if port == None:
+            with socket.socket() as s:
+                s.bind(('', 0))
+                self.port = s.getsockname()[1]
+        else:
+            self.port = port
+
+        with pyroute2.IPRoute() as ipr:
+            r = ipr.route('get', dst=remote_ip)
+            for attr in r[0]['attrs']:
+                if attr[0] == 'RTA_PREFSRC':
+                    self.ip = attr[1]
+
+    def __enter__(self):
+        self.loop = asyncio.new_event_loop()
+        listen = self.loop.create_datagram_endpoint(
+                lambda: TFTPServerSingle(self.path, self.ip, self.loop, {}),
+                local_addr=(self.ip, self.port))
+
+        def start_loop(loop):
+            asyncio.set_event_loop(loop)
+            loop.run_forever()
+
+        self.transport, protocol = self.loop.run_until_complete(listen)
+        self.thread = threading.Thread(target=start_loop, args=(self.loop,))
+        self.thread.start()
+        return self
+
+    def __exit__(self, type, value, exc):
+        self.transport.close()
+        self.loop.call_soon_threadsafe(self.loop.stop)
+        self.thread.join()