</head>
<body>
-<!--- $Id$ --->
-
<div class="title">Lesson 11: Simulation with TOSSIM</div>
-<div class="subtitle">Last Modified: 18 May 2006</div>
+<div class="subtitle">Last Modified: 20 April 2007</div>
<p>This lesson introduces the TOSSIM simulator. You will become
familiar with how to compile TOSSIM and use some of its
<li>Inject packets.</li>
</ul>
</p>
-
-
+
+ <p><b>Note:</b> This tutorial is for TOSSIM in TinyOS 2.0.1. If
+ you are using TinyOS 2.0.0, it has a slightly different
+ A HREF="lesson11-200.html">tutorial.</A> The principal difference
+ between the two is how you specify noise in RF simulation.
+ </p>
<h1>Introduction</h1>
TOSSIM simulates entire TinyOS applications. It works by
</pre>
-
- <p>Currently, the only platform TOSSIM supports is the
+ <p>Currently, the only platform TOSSIM supports is the
micaz. You should see output similar to this:</p>
+ <pre>
mkdir -p build/micaz
placing object files in build/micaz
writing XML schema to app.xml
linking into shared object ./_TOSSIMmodule.so
g++ -shared build/micaz/pytossim.o build/micaz/sim.o build/micaz/tossim.o -lstdc++ -o _TOSSIMmodule.so
copying Python script interface TOSSIM.py from lib/tossim to local directory
- </pre>
+ </pre>
+
+ <p>Depending on what OS you are using and what packages are installed, TOSSIM may
+ not properly compile on the first try. <A HREF="#appendix">Appendix A</A>
+ addresses some of the common causes and gives possible solutions.</p>
+
+
+ <A name="#compiling"></A>
+
<p>Compiling TOSSIM has five basic steps. Let's go through
them one by one.</p>
<pre>
>>> m = t.getNode(32);
>>> m.bootAtTime(45654);
->>> t.runNextEVent()
+>>> t.runNextEvent()
1
</pre>
+ <p><b>Segmentation faults:</b>If trying to do this causes TOSSIM
+ to throw a segmentation violation (segfault), then chances are
+ you are using a version of gcc that does not work well with the
+ dynamic linking that TOSSIM is doing. In particular, it has been
+ verified to work properly with 4.0.2 and 3.6, but some people
+ have encountered problems with gcc 4.1.1.</p>
+
<p>Instead of using raw simulation ticks, you can also use the
call <code>ticksPerSecond()</code>. However, you want to be careful
to add some random bits into this number: having every node
'__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__str__',
'__swig_getmethods__', '__swig_setmethods__', '__weakref__', 'addChannel',
'currentNode', 'getNode', 'init', 'mac', 'newPacket', 'radio', 'removeChannel',
-'runNextEvent', 'setCurrentNode', 'setTime', 'this', 'thisown', 'time', 'timeStr']
+'runNextEvent', 'setCurrentNode', 'setTime', 'this', 'thisown', 'ticksPerSecond', 'time', 'timeStr']
</pre>
<p>The most common utility functions are:</p>
that the mote has booted. TOSSIM's debugging output can be
configured on a per-channel basis. So, for example, you can
tell TOSSIM to send the "Boot" channel to standard output, but
- another channel, say "AM", to a file. Additionally, you can
- configureBy default, a channel has no destination, and so
+ another channel, say "AM", to a file.
+ By default, a channel has no destination, and so
messages to it are discarded.</p>
<p>In this case, we want to send the Boot channel to standard
<li><b><code>gain(src, dest)</code></b>: Return the gain value of the
link from <i>src</i> to <i>dest</i>.</li>
- <li><b><code>remove(src, dest)</code></b>: Remove the link from
- <i>src</i> to <i>dest</i>.</li>
+ <li><b><code>threshold()</code></b>: Return the CCA threshold.</li>
+ <li><b><code>setThreshold(val)</code></b>: Set the CCA threshold value in
+ dBm. The default is -72dbM.</li>
+
+ </ul>
- <li><b><code>setNoise(node, mean, variance)</code></b>: Set the noise
- floor at <i>node</i> to be a gaussian distribution with
- <i>mean</i> and <i>variance</i>.</li>
+ <p>The default values for TOSSIM's radio model are based on the CC2420 radio,
+ used in the micaZ, telos family, and imote2. It uses an SNR curve derived
+ from experimental data collected using two micaZ nodes, RF shielding, and
+ a variable attenuator.</p>
+
+ <p>In addition to the radio propagation above, TOSSIM
+ also simulates the RF noise and interference a node hears, both from other
+ nodes as well as outside sources. It uses the Closest Pattern Matching (CPM)
+ algorithm. CPM takes a noise trace as input and generates a statistical model
+ from it. This model can capture bursts of interference and other correlated
+ phenomena, such that it greatly improves the quality of the RF simulation.
+ It is not perfect (there are several things it does not handle, such as
+ correlated interference at nodes that are close to one another), but
+ it is much better than traditional, independent packet loss models. For
+ more details, please refer to the paper "Improving Wireless Simulation through
+ Noise Modeling," by Lee et al.</p>
+
- <li><b><code>sensitivity()</code></b>: Return the receive sensitivity of
- the nodes.</li>
+ <p>To configure CPM, you need to feed it a noise trace. You accomplish this
+ by calling <tt>addNoiseTraceReading</tt> on a Mote object. Once you
+ have fed the entire noise trace, you must call <tt>createNoiseModel</tt>
+ on the node. The directory <tt>tos/lib/tossim/noise</tt> contains
+ sample noise traces, which are a series of noise readings, one per line.
+ For example, these are the first 10 lines of meyer-heavy.txt,
+ which is a noise trace taken from Meyer Library at Stanford University:</p>
- <li><b><code>setSensitivity(val)</code></b>: Set the receive sensitivity
- of nodes to be <i>val</i>. The sensitivity is how much
- stronger a signal must be for it to be received
- uncorrupted. E.g., a sensitivity of 3.0 (the default value)
- means that a packet must be 3dBm greater than the sum of
- noise and concurrent transmissions for it to be received
- uncorrupted.</li>
+ <pre>
+-39
+-98
+-98
+-98
+-99
+-98
+-94
+-98
+-98
+-98
+</pre>
- <li><b><code>threshold()</code></b>: Return the CCA threshold.</li>
+ <p>As you can see, the hardware noise floor is around -98 dBm,
+ but there are spikes of interference around -86dBm and -87dBm.</p>
- <li><b><code>setThreshold(val)</code></b>: Set the CCA threshold value in
- dBm.The default is -95.</li>
-
- </ul>
+ <p>This piece of code will give a node a noise model from a noise trace
+ file. It works for nodes 0-7: you can change the range appropriately:</p>
+
+ <pre>
+noise = open("meyer-heavy.txt", "r")
+lines = noise.readlines()
+for line in lines:
+ str = line.strip()
+ if (str != ""):
+ val = int(str)
+ for i in range(0, 7):
+ t.getNode(i).addNoiseTraceReading(val)
+
+for i in range(0, 7):
+ t.getNode(i).createNoiseModel()</pre>
- <p>The Radio object only deals with physical layer
+
+ <p>CPM can use a good deal of RAM: using the entire meyer-heavy
+ trace as input has a cost of approximately 10MB per node. You
+ can reduce this overhead by using a shorter trace; this will of
+ course reduce simulation fidelity. <u>The trace
+ must be at least 100 entries long, or CPM will not work as it does
+ not have enough data to generate a statistical model.</u> </p>
+
+ <p>You can also use
+ <p>The Radio object only deals with physical layer
propagation. The MAC object deals with the data link layer,
packet lengths, and radio bandwidth. The default TOSSIM MAC
object is for a CSMA protocol. You get a reference to the MAC
t.addChannel("RadioCountToLedsC", sys.stdout)
t.addChannel("Boot", sys.stdout)
+noise = open("meyer-heavy.txt", "r")
+lines = noise.readlines()
+for line in lines:
+ str = line.strip()
+ if (str != ""):
+ val = int(str)
+ for i in range(1, 4):
+ t.getNode(i).addNoiseTraceReading(val)
+
+for i in range(1, 4):
+ print "Creating noise model for ",i;
+ t.getNode(i).createNoiseModel()
+
t.getNode(1).bootAtTime(100001);
t.getNode(2).bootAtTime(800008);
t.getNode(3).bootAtTime(1800009);
-r.setNoise(1, -100.0, 5.0)
-r.setNoise(2, -100.0, 5.0)
-r.setNoise(3, -100.0, 5.0)
-
for i in range(0, 100):
t.runNextEvent()
</pre>
DEBUG (1): Received packet of length 2.
</pre>
- <p>If you set the noise to be 30 plus or minus 5 dBm instead
- of 80 plus or minus 5 dBm, then nodes will never transmit, as
- the default CCA threshold is -95 dBm. You'll see something
- like this:</p>
+ <p>If you set node's clear channel assessment to be at -110dBm,
+ then nodes will never transmit, as noise and interference never
+ drop this low. You'll see something like this:</p>
<pre>
1 2 -54.0
2 1 -55.0
topology. There are two approaches you can take. The first is
to take data from a real world network and input this into
TOSSIM. The second is to generate it from applying a
- theoretical propagation model to a physical layout. TOSSIM has
- an example of the first from the <A
- HREF="https://mirage.berkeley.intel-research.net/">Mirage
- testbed</A> at Intel Research Berkeley. The network topology
- is from data gathered from one hundred micaZ nodes over an
- eight hour period in February 2006. It can be found in <code><A
- HREF="../../../tos/lib/tossim/topologies/mirage-1.txt">tos/lib/tossim/topologies/mirage-1.txt</A></code>, and has the following format:
+ theoretical propagation model to a physical layout. The standard
+ file format is
<pre>
-noise n avg std
gain src dest g
</pre>
- where each statement is on a separate line. The <i>noise</i>
- statement defines the noise observed at node <i>n</i> with
- an average of <i>avg</i> and a standard deviation of
- <i>std</i>. The <i>gain</i> statement defines a propagation
+ where each statement is on a separate line.
+ The <i>gain</i> statement defines a propagation
gain <i>g</i> when <i>src</i> transmits to <i>dest</i>. This
is a snippet of python code that will parse this file
format:
<pre>
-f = open("mirage-1.txt", "r")
+f = open("15-15-tight-mica2-grid.txt", "r")
lines = f.readlines()
for line in lines:
if (len(s) > 0):
if (s[0] == "gain"):
r.add(int(s[1]), int(s[2]), float(s[3]))
- elif (s[0] == "noise"):
- r.setNoise(int(s[1]), float(s[2]), float(s[3]))
</pre></p>
<p>TOSSIM has a tool for the second option of generating a
<p>The format of a configuration file is beyond the scope of
this document: the tool has its own <A
- HREF="">documentation</A>. TOSSIM has two sample configuration
+ HREF="usc-topologies.html">documentation</A>. TOSSIM has a few sample configuration
files generated from the tool in
- <code>tos/lib/tossim/topologies</code>. The first is <code><A
- HREF="">grid.txt</A></code>, which is a 10x10 grid of nodes
- spaced roughly 40 feet apart. Each node is placed randomly
- within a 40'x40' "cell." The cells follow a strict grid. The
- second file is <code><A HREF="">scatter.txt</A></code>, which is
- 100 nodes scattered randomly (with a uniform distribution)
- over a 360'x360' area. Note that the tool uses random numbers,
+ <code>tos/lib/tossim/topologies</code>.
+ Note that the tool uses random numbers,
these configuration files can generate multiple different
network topologies. Network topology files generated from the
- tool follow the same format as <code>mirage-1.txt</code>.</p>
+ tool follow the same format as <code>15-15-tight-mica2-grid.txt</code>.
+ If you have topologies measured from real networks, we would love
+ to include them in the TOSSIM distribution.</p>
<h1>Variables</h1>
variables properly. You do this by instantiating a Python
object that parses the XML file to extract all of the relevant
information. You have to import the Python support package for
- TOSSIM to do this:</p>
+ TOSSIM to do this. First, set your PYTHONPATH environment variable
+ to point to <tt>tinyos-2.x/support/sdk/python</tt>. This tells
+ Python where to find the TOSSIM packages. Then, in an interpreter
+ type this:</p>
<pre>
from tinyos.tossim.TossimApp import *
if (len(s) > 0):
if (s[0] == "gain"):
r.add(int(s[1]), int(s[2]), float(s[3]))
- elif (s[0] == "noise"):
- r.setNoise(int(s[1]), float(s[2]), float(s[3]))
-for i in range (0, 9):
- m = t.getNode(i)
- m.bootAtTime(randint(1000, 2000) * 1000000)
+noise = open("meyer-heavy.txt", "r")
+lines = noise.readlines()
+for line in lines:
+ str = line.strip()
+ if (str != ""):
+ val = int(str)
+ for i in range(0, 4):
+ t.getNode(i).addNoiseTraceReading(val)
+
+for i in range (0, 4):
+ t.getNode(i).createNoiseModel()
+ t.getNode(i).bootAtTime(i * 2351217 + 23542399)
m = t.getNode(0)
v = m.getVariable("RadioCountToLedsC.counter")
+
+
while (v.getData() < 10):
t.runNextEvent()
+print "Counter variable at node 0 reached 10."
</pre>
<p>The TOSSIM <A
if (len(s) > 0):
if (s[0] == "gain"):
r.add(int(s[1]), int(s[2]), float(s[3]))
- elif (s[0] == "noise"):
- r.setNoise(int(s[1]), float(s[2]), float(s[3]))
+
+noise = open("meyer-heavy.txt", "r")
+lines = noise.readlines()
+for line in lines:
+ str = line.strip()
+ if (str != ""):
+ val = int(str)
+ for i in range(0, 4):
+ t.getNode(i).addNoiseTraceReading(val)
+
+for i in range (0, 4):
+ t.getNode(i).createNoiseModel()
for i in range(0, 60):
t.runNextEvent();
pkt.setType(msg.get_amType())
pkt.setDestination(0)
-print "Delivering " + msg.__str__() + " to 0 at " + str(t.time() + 3);
+print "Delivering " + str(msg) + " to 0 at " + str(t.time() + 3);
pkt.deliver(0, t.time() + 3)
want to deliver a packet through C++, you can do so.</p>
<p>Usually, the C++ and Python versions of a program look pretty
- similar. For example:</p>
+ similar. For example (note that this program will use a lot of RAM
+ and take a long time to start due to its noise models):</p>
<table WIDTH=800>
<PRE>
import TOSSIM
import sys
+import random
from RadioCountMsg import *
for i in range(0, 999):
m = t.getNode(i);
m.bootAtTime(5000003 * i + 1);
- r.setNoise(i, -99.0, 3.0);
+
for j in range (0, 2):
if (j != i):
r.add(i, j, -50.0);
-
-
+ # Create random noise stream
+ for j in range (0, 500):
+ m.addNoiseTraceReading(int(random.random() * 20) - 70);
+ m.createNoiseModel()
for i in range(0, 1000000):
t.runNextEvent();
<TD VALIGN=TOP>
<PRE>
#include <tossim.h>
-
+#include <stdlib.h>
int main() {
for (int i = 0; i < 999; i++) {
Mote* m = t->getNode(i);
m->bootAtTime(5000003 * i + 1);
- r->setNoise(i, -99.0, 3);
for (int j = 0; j < 2; j++) {
if (i != j) {
r->add(i, j, -50.0);
}
}
+ for (int j = 0; j < 500; j++) {
+ m->addNoiseTraceReading((char)(drand48() * 20) - 70);
+ }
+ m->createNoiseModel();
}
+
for (int i = 0; i < 1000000; i++) {
t->runNextEvent();
}
all:
make micaz sim
g++ -g -c -o Driver.o Driver.c -I../../tos/lib/tossim/
- g++ -o Driver Driver.o build/micaz/tossim.o build/micaz/sim.o
+ g++ -o Driver Driver.o build/micaz/tossim.o build/micaz/sim.o build/micaz/c-support.o
</pre>
<i>slow</i>:</p>
<pre>
-(gdb) watch UscGainInterferenceModelC$receiving[23]
-Hardware watchpoint 2: UscGainInterferenceModelC$receiving[23]
+(gdb) watch CpmModelC$receiving[23]
+Hardware watchpoint 2: CpmModelC$receiving[23]
</pre>
<p>This variable happens to be an internal variable in the
you how to configure a network, how to run a simulation, how to
inspect variables, how to inject packets, and how to compile with C++.
+<center>
+<p>< <b><a href="lesson10.html">Previous Lesson</a></b> | <b><a
+ href="index.html">Top</a></b> | <b><a href="lesson12.html">Next
+Lesson </a> ></b>
+ </center>
+</p>
+
+
+ <A name="appendix"><H1>Appendix A: Troubleshooting TOSSIM compilation</H1></A>
-<p><b><a href="lesson5.html">< Previous Lesson</a></b> | <b><a
- href="index.html">Top</a></b>
+ <p>TOSSIM is a C/C++ shared library with an optional
+ Python translation layer. Almost all of the problems
+ encountered in compiling TOSSIM are due to C linking
+ issues. If you don't know what a linker is (or have never
+ linked a C program), then chances are the rest of this
+ appendix is going to be cryptic and
+ incomprehensible. You're best off starting with learning
+ about <A
+ HREF="http://en.wikipedia.org/wiki/Linker">linkers</A>, <A
+ HREF="http://www.iecc.com/linker/linker01.html">why they
+ are needed</A>, and how you <A
+ HREF="http://www.linuxjournal.com/article/6463">use the
+ gcc/g++ compilers</A> to link code.</p>
+
+
+ <p>Generally, when compiling TOSSIM using <tt>make micaz sim</tt>,
+ one of four things can go wrong:</p>
+
+ <ol>
+ <li>You are using Cygwin but the <tt>sim</tt> compilation option
+ can't figure this out.</li>
+
+ <li>You do not have the needed Python support installed.</li>
+
+ <li>You have Python support installed, but the make
+ system can't find it.</li>
+
+ <li>You have Python support installed, but it turns out to
+ be incompatible with TOSSIM.</li>
+
+ <li>You have a variant of gcc/g++ installed that
+ expects slightly different compilation options than the
+ normal installation.</li>
+ </ol>
+
+ <p>We'll visit each in turn.</p>
+
+ <h2>You are using Cygwin but the <tt>sim</tt> compilation option
+ can't figure this out</h2>
+
+ <p>It turns out that the Cygwin and Linux versions of gcc/g++
+ have different command-line flags and require different options
+ to compile TOSSIM properly. For example, telling the Linux
+ compiler to build a library requires <tt>-fPIC</tt> while
+ the Cygwin is <tt>-fpic</tt>. If you're using Cygwin and
+ you see the output look like this:
+
+ <pre>
+ ncc -c -shared -fPIC -o build/micaz/sim.o ...
+ </pre>
+
+ rather than
+
+ <pre>
+ ncc -c -DUSE_DL_IMPORT -fpic -o build/micaz/sim.o ...
+ </pre>
+
+ then you have encountered this problem. The problem
+ occurs because Cygwin installations do not have a
+ consistent naming scheme, and so it's difficult for the
+ compilation toolchain to always figure out whether it's
+ under Linux or Cygwin.</p>
+
+ <p><b>Symptom:</b> You're running cygwin but you see the
+ <tt>-fPIC</tt> rather than <tt>-fpic</tt> option being
+ passed to the compiler.</b></p>
+
+ <p><b>Solution:</b> Explicitly set the OSTYPE environment
+ variable to be <tt>cygwin</tt> either in your <tt>.bashrc</tt>
+ or when you compile. For example, in bash:</p>
+
+ <pre>
+$ OSTYPE=cygwin make micaz sim
+ </pre>
+
+ or in tcsh
+
+ <pre>
+$ setenv OSTYPE cygwin
+$ make micaz sim
+ </pre>
+
+ <p>Note that often this problem occurs in addition to
+ other ones, due to using a nonstandard Cygwin
+ installation. So you might have more problems to track
+ down.</p>
+
+ <h2>You do not have the needed Python support installed</h2>
+
+ <p>If when you compile you see lots of errors such as
+ "undefined reference to" or "Python.h: No such file or
+ directory" then this might be your problem. It is a
+ subcase of the more general problem of TOSSIM not being
+ able to find needed libraries and files.</p>
+
+ <p>Compiling Python scripting support requires that you
+ have certain Python development libraries installed. First, check
+ that you have Python installed:</p>
+
+ <pre>
+$ python -V
+Python 2.4.2
+ </pre>
+
+ <p>In the above example, the system has Python 2.4.2. If
+ you see "command not found" then you do not have Python
+ installed. You'll need to track down an RPM and install
+ it. TOSSIM has been tested with Python versions 2.3 and
+ 2.4. You can install other versions, but there's no
+ assurance things will work.</p>
+
+ <p>In addition to the Python interpreter itself, you need
+ the libraries and files for Python development. This is
+ essentially a set of header files and shared libraries. If
+ you have the <tt>locate</tt> command, you can type
+ <tt>locate libpython</tt>, or if you don't, you can look
+ in <tt>/lib</tt>, <tt>/usr/lib</tt> and
+ <tt>/usr/local/lib</tt>. You're looking for a file with a
+ name such as <tt>libpython2.4.so</tt> and a file named
+ <tt>Python.h</tt>. If you can't find these files, then you
+ need to install a <tt>python-devel</tt> package.</p>
+
+
+ <p><b>Symptom:</b> Compilation can't find critical files
+ such as the Python interpreter, <tt>Python.h</tt> or a
+ Python shared library, and searching your filesystem shows
+ that you don't have them.</p>
+
+ <p><b>Solution:</b> Installed the needed files from Python
+ and/or Python development RPMS.</p>
+
+ <p>If you have all of the needed files, but are still
+ getting errors such as "undefined reference" or "Python.h:
+ No such file or directory", then you have the next
+ problem: they're on your filesystem, but TOSSIM can't find
+ them.</p>
+
+ <h2>You have Python support installed, but the make
+ system can't find it</h2>
+
+ <p>You've found libpython and Python.h, but when TOSSIM compiles
+ it says that it can't find one or both of them. If it can't
+ find Python.h then compilation will fail pretty early, as g++ won't
+ be able to compile the Python glue code. If it can't find the python
+ library, then compilation will fail at linking, and you'll see
+ errors along the lines of "undefined reference to __Py...". You
+ need to point the make system at the right place.</p>
+
+ <p>Open up <tt>support/make/sim.extra</tt>. If the make
+ system can't find Python.h, then chances are it isn't in
+ one of the standard places (e.g., /usr/include). You need to tell
+ the make system to look in the directory where Python.h is with
+ a <tt>-I</tt> option. At the top of sim.extra, under the PFLAGS entry,
+ add
+
+ <pre>
+CFLAGS += -I/path
+ </pre>
+
+ where <tt>/path</tt> is the path of the directory where Python.h
+ lives. For example, if it is in <tt>/opt/python/include</tt>,
+ then add <tt>CFLAGS += -I/opt/python/include</tt>.</p>
+
+ <p>If the make system can't find the python library for
+ linking (causing "undefined reference") error messages,
+ then you need to make sure the make system can find
+ it. The sim.extra file uses two variables to find the
+ library: <tt>PYDIR</tt> and <tt>PYTHON_VERSION</tt>. It
+ looks for a file named libpython$(PYTHON_VERSION).so. So
+ if you have Python 2.4 installed, make sure that
+ PYTHON_VERSION is 2.4 (be sure to use no spaces!) and if
+ 2.3, make sure it is 2.3.</p>
+
+ <p>Usually the Python library is found in
+ <tt>/usr/lib</tt>. If it isn't there, then you will need
+ to modify the <tt>PLATFORM_LIB_FLAGS</tt> variable. The
+ -L flag tells gcc in what directories to look for
+ libraries. So if libpython2.4.so is in
+ <tt>/opt/python/lib</tt>, then add
+ <tt>-L/opt/python/lib</tt> to the
+ <tt>PLATFORM_LIB_FLAGS</tt>. Note that there are three
+ different versions of this variable, depending on what OS
+ you're using. Be sure to modify the correct one (or be
+ paranoid and modify all three).
+
+
+ <p><b>Symptom:</b> You've verified that you have the
+ needed Python files and libraries, but compilation is
+ still saying that it can't link to them ("undefined
+ reference") or can't find them ("cannot find -lpython2.4").</p>
+
+ <p><b>Solution:</b> Change the sim.extra file to point to
+ the correct directories using -L and -I flags.</p>
+
+ <h2>You have Python support installed, but it turns out to
+ be incompatible with TOSSIM.</h2>
+
+ <p><b>Symptom:</b> You get a "This python version requires
+ to use swig with the -classic option" error message.</p>
+
+ <p><b>Solution:</b> Install SWIG and regenerate Python
+ support with the sing-generate script in
+ <tt>tos/lib/tossim</tt>, or install a different version of
+ Python.</p>
+
+ <h2>You have a variant of gcc/g++ installed that
+ expects slightly different compilation options than the
+ normal installation.</h2>
+
+ <p><b>Symptom:</b> g++ complains that it cannot find
+ main() when you are compiling the shared library
+ ("undefined reference to `_WinMain@16'").</p>
+
+ <p><b>Solution:</b> There are two possible solutions.
+ The first is to include a dummy main(), as described
+ in this <A HREF="http://mail.millennium.berkeley.edu/pipermail/tinyos-help/2006-December/021719.html">tinyos-help posting.</A> The
+ second is to add the -shared option, as described in
+ this <A HREF="http://curl.haxx.se/mail/archive-2003-01/0056.html">web page</A>.
+
+ <p>Hopefully, these solutions worked and you can get back
+ to <A HREF="#compiling">compiling</A>, If not, then you
+ should email tinyos-help.</p>
+</center>
</body>
</html>
projects / tinyos-2.x.git / blobdiff