nuttx/Documentation/NuttX.html

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<html>
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<title>NuttX</title>
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<h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
<p>Last Updated: December 4, 2008</p>
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<h1>Table of Contents</h1>
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<center><table width ="80%">
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#overview">Overview</a>.<br>
What is NuttX? Look at all those files and features... How can it be a tiny OS?
</td>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#downloads">Downloads</a>.<br>
Where can I get NuttX? What is the current development status?
</td>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<a href="#platforms">Supported Platforms</a>.<br>
What target platforms has NuttX been ported to?
</td>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#environments">Development Environments</a>.<br>
What kinds of host cross-development platforms can be used with NuttX?
</td>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#footprint">Memory Footprint</a>.<br>
Just how big is it? Do I have enough memory to use NuttX?
</td>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#licensing">Licensing</a>.<br>
Are there any licensing restrictions for the use of NuttX? (Almost none)
Will there be problems if I link my proprietary code with NuttX? (No)
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#history">Release History</a><br>
What has changed in the last release of NuttX?
What unreleased changes are pending in CVS?
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#TODO">Bugs, Issues, <i>Things-To-Do</i></a>.<br>
Software is never finished nor ever tested well enough.
(Do you want to help develop NuttX? If so, send me an email).
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<td>
<a href="#documentation">Other Documentation</a>.<br>
What other NuttX documentation is available?
</td>
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<td>
<a href="#trademarks">Trademarks</a>.<br>
Some of the words used in this document belong to other people.
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<a name="overview"><h1>Overview</h1></a>
</td>
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</table>
<p>
<b>Goals</b>.
Nuttx is a real timed embedded operating system (RTOS).
Its goals are:
<p>
<center><table width="90%">
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>Small Footprint</b>
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<td><br></td>
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<p>
Usable in all but the tightest micro-controller environments,
The focus is on the tiny-to-small, deeply embedded environment.
</p>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>Rich Feature OS Set</b>
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<td><br></td>
<td>
<p>
The goal is to provide implementations of most standard POSIX OS interfaces
to support a rich, multi-threaded development environment for deeply embedded
processors.
</p>
NON-GOALS: (1) It is not a goal to provide the rich level of OS
features like those provided with Linux.
Small footprint is more important than features.
Standard compliance is more important than small footprint.
(2) There is no MMU-based support for processes.
At present, NuttX assumes a flat address space.
</p>
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<b>Highly Scalable</b>
</td>
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<td><br></td>
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<p>
Fully scalable from tiny (8-bit) to moderate embedded (32-bit).
Scalability with rich feature set is accomplished with:
Many tiny source files, link from static libraries, highly configurable, use of
weak symbols when available.
</p>
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<b>Standards Compliance</b>
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<td><br></td>
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<p>
NuttX strives to achieve a high degree of standards compliance.
The primary governing standards are POSIX and ANSI standards.
Additional standard APIs from Unix and other common RTOS's are
adopted for functionality not available under these standards
or for functionality that is not appropriate for the deeply-embedded
RTOS (such as <code>fork()</code>).
</p>
<p>
Because of this standards conformance, software developed under other
standard OSs (such as Linux) should port easily to NuttX.
</p>
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<b>Real-Time</b>
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<p>
Fully pre-emptible, fixed priority and round-robin scheduling.
</p>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>Totally Open</b>
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<p>
Non-restrictive BSD license.
</p>
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</table></center>
<p>
<b>Feature Set</b>.
Key features of NuttX include:
<p>
<center><table width="90%">
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>Standards Compliant Core Task Management</b>
</td>
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<td><br></td>
<td>
<p>
<li>Modular, micro-kernel</li>
</p>
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<td><br></td>
<td>
<p>
<li>Fully pre-emptible.</li>
</p>
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<p>
<li>Naturally scalable.</li>
</p>
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<p>
<li>Highly configurable.</li>
</p>
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<td>
<p>
<li>Easily extensible to new processor architectures, SoC architecture, or board architectures.
A <a href="NuttxPortingGuide.html">Porting Guide</a> is in development.</li>
</p>
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<td><br></td>
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<p>
<li>FIFO and round-robin scheduling.</li>
</p>
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<p>
<li>Realtime, deterministic.</li>
</p>
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<p>
<li>POSIX/ANSI-like task controls, named message queues, counting semaphores, clocks/timers, signals, pthreads, environment variables, filesystem.</li>
</p>
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<p>
<li>VxWorks-like task management and watchdog timers.</li>
</p>
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<p>
<li>BSD socket interface.</li>
</p>
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<p>
<li>Extensions to manage pre-emption.</li>
</p>
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<p>
<li>Well documented in the NuttX <a href="NuttxUserGuide.html">User Guide</a>.</li>
</p>
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<b>File system</b>
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<p>
<li>Tiny in-memory, root pseudo-file-system.</li>
</p>
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<p>
<li>Supports character and block drivers.</li>
</p>
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<p>
<li>Network, USB (device), serial, CAN, driver architecture.</li>
</p>
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<p>
<li>RAMDISK, pipes, FIFO, <code>/dev/null</code>, <code>/dev/zero</code> drivers.</li>
</p>
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<td><br></td>
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<p>
<li>Mount-able volumes. Bind mountpoint, filesystem, and block device driver.</li>
</p>
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<p>
<li>FAT12/16/32 filesystem support.</li>
</p>
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<p>
<li>Generic driver for SPI-based MMC/SD cards.</li>
</p>
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<p>
<li>ROMFS filesystem support.</li>
</p>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>C Library</b>
</td>
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<p>
<li>Fully integrated into the OS.</li>
</p>
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<b>Networking</b>
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<p>
<li>TCP/IP, UDP, ICMP stacks.</li>
</p>
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<p>
<li>Small footprint (based on uIP).</li>
</p>
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<p>
<li>BSD compatible socket layer.</li>
</p>
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<p>
<li>Networking utilities (DHCP, SMTP, TELNET, TFTP, HTTP)</li>
</p>
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<b>USB Device Support</b>
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<td><br></td>
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<p>
<li><i>Gadget</i>-like architecture for USB device controller drivers and device-dependent USB class drivers.</li>
</p>
</tr>
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<td><br></td>
<td>
<p>
<li>USB device controller drivers available for the NXP LPC214x and TI DM320.</li>
</p>
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<td><br></td>
<td>
<p>
<li>Device-dependent USB class drivers available for USB serial and for USB mass storage.</li>
</p>
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<td><br></td>
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<p>
<li>Built-in USB trace functionality for USB debug.</li>
</p>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>Graphics Support</b>
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<p>
<li>Framebuffer drivers.</li>
</p>
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<p>
<li>Graphics library and tiny windowing system under development.</li>
</p>
</tr>
</table></center>
<p>
<b>NuttX Add-Ons</b>.
The following packages are available to extend the basic NuttX feature set:
</p>
<center><table width="90%">
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>NuttShell (NSH)</b>
</td>
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<td><br></td>
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<p>
<li>A small, scalable, bash-like shell for NuttX with rich feature set and small footprint.
See the <a href="NuttShell.html">NuttShell User Guide</a>.</li>
</p>
</tr>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>Pascal Compiler with NuttX runtime P-Code interpreter add-on</b>
</td>
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<td><br></td>
<td>
<p>
<li>The Pascal add-on is available for download from the
<a href="http://sourceforge.net/project/showfiles.php?group_id=189573">SourceForge</a>
website.</li>
</p>
</td>
</tr>
</table></center>
<p>
<b>Look at all those files and features... How can it be a tiny OS?</b>.
The NuttX feature list (above) is fairly long and if you look at the NuttX
source tree, you will see that there are hundreds of source files comprising
NuttX. How can NuttX be a tiny OS with all of that?
</p>
<center><table width="90%">
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>Lots of Features -- More can be smaller!</b>
</td>
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<td><br></td>
<td>
<p>
The philosophy behind that NuttX is that lots of features are great... <i>BUT</i>
also that if you don't use those features, then you should not have to pay a penalty
for the unused features.
And, with NuttX, you don't! If you don't use a feature, it will not
be included in the final executable binary.
You only have to pay the penalty of increased footprint for the features
that you actually use.
</p>
<p>
Using a variety of technologies, NuttX can scale from the very tiny to
the moderate-size system. I have executed NuttX with some simple applications
in as little as 32Kb <i>total</i> memory (code and data).
On the other hand, I often run richly featured NuttX builds that require
memory up to 100Kb.
</p>
</td>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Many, many files -- More really is smaller!</b>
</td>
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<td><br></td>
<td>
<p>
One may be intimidated by the size NuttX source tree. There are hundreds of source files!
How can that be a tiny OS?
Actually, the large number of files is one of the tricks to keep NuttX small and
as scalable as possible.
Most files contain only a single function.
Sometimes just one tiny function with only a few lines of code.
Why?
</p>
<ul>
<li>
<b>Static Libraries</b>.
Because in the NuttX build processed, objects are compiled and saved into
<i>static libraries</i> (<i>archives</i>).
Then, when the file executable is linked, only the object files that are needed
are extracted from the archive and added to the final executable.
By having many, many tiny source files, you can assure that no code that you do
not execute is ever included in the link.
And by having many, tiny source files you have better granularity --
if you don't use that tiny function of even just a few lines of code, it will
not be included in the binary.
</li>
</ul>
</td>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Other Tricks</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
As mentioned above, the use of many, tiny source files and linking from static
libraries keeps the size of NuttX down.
Other tricks used in NuttX include:
</p>
<ul>
<li>
<b>Configuration Files</b>.
Before you build NuttX, you must provide a configuration file that specifies
what features you plan to use and which features you do not.
This configuration file contains a long list of settings that control
what is built into NuttX and what is not.
There are hundreds of such settings
(see the <a href="NuttxPortingGuide.html#apndxconfigs">NuttX Porting Guide</a>
for a partial list that excludes platform specific settings).
These many, many configuration options allow NuttX to be highly tuned to
meet size requirements.
The downside to all of these configuration options is that it greatly
complicates the maintenance of NuttX -- but that is my problem, not yours.
</li>
<li>
<b>Weak Symbols</b>
The GNU toolchain supports <i>weak</i> symbols and these also help to keep
the size of NuttX down.
Weak symbols prevent object files from being drawn into the link even if they
are accessed from source code.
Careful use of weak symbols is another trick for keep unused code out of the
final binary.
</li>
</ul>
</td>
</tr>
</table></center>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="downloads"><h1>Downloads</h1></a>
</td>
</tr>
</table>
<p><b>nuttx-0.3.19</b>.
The 31<sup>st</sup> release of NuttX (nuttx-0.3.19) is available for download
from the <a href="http://sourceforge.net/project/showfiles.php?group_id=189573">SourceForge</a>
website.
The change log associated with the release is available <a href="#currentrelease">here</a>.
Unreleased changes after this release are available in CVS.
These unreleased changes are listed <a href="#pendingchanges">here</a>.
</p>
<p>
This release includes the following new feature:
<p>
<ul>
<li>Add <code>poll()</code> and <code>select()</code> APIs that may be used to monitor for data
availability on character devices or TCP/IP sockets.
</li>
<li>Implemented support TCP/IP connection backlog.
This allows <code>poll()</code>/<code>select()</code> to wake-up on new connections to a listener socket.
</li>
<li>Added definition of a framebuffer driver and implement framebuffer drivers for the
simulated platform and the TI DM320 (untested as of the initial check-in).
</li>
<li>Partially developed a graphics framework based on the framebuffer drivers, however,
this will not be ready for use for a few more release.
Currently this includes only a few color conversion routines and some rasterizing functions.
A tiny windowing system is under development but not ready for check-in yet.
<li>Added support for fixed precision math.
</li>
<li>Added support for outgoing multicast packets.
</li>
</ul>
<p>
Several bugs were fixed, the most important of which are:
</p>
<li>Fixed an important bug in the TCP/IP buffering logic.
When TCP/IP read-ahead is enabled and not recv() is in-place when a TCP/IP packet is received,
the packet is placed into a read-ahead buffer.
However, the old contents of the read-ahead buffer were not being cleared and old data would
contaminate the newly received buffer.
</li>
<li>Changed the behavior of the serial driver read.
It now returns data as it is available rather than waiting for the full requested read size.
This makes functions like <code>fgetc()</code> work much more smoothly.
</li>
<p>
These changes were verified only on the Neuros OSD (ARM) and the Linux simulator using a
Linux development environment.
Please report any errors to me.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="platforms"><h1>Supported Platforms</h1></a>
</td>
</tr>
</table>
<center><table width="90%">
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Linux User Mode</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
A user-mode port of NuttX to the x86 Linux/Cygwin platform is available.
The purpose of this port is primarily to support OS feature development.
</p>
<p>
<b>STATUS:</b>
Does not support interrupts but is otherwise fully functional.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>ARM7TDMI</b>.
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>TI TMS320C5471</b> (also called <b>C5471</b> or <b>TMS320DA180</b> or <b>DA180</b>).
NuttX operates on the ARM7 of this dual core processor.
This port uses the <a href="http://www.spectrumdigital.com/">Spectrum Digital</a>
evaluation board with a GNU arm-elf toolchain* under Linux or Cygwin.
</p>
<p>
<b>STATUS:</b>
This port is complete, verified, and included in the initial NuttX release.
</p>
</td>
</tr>
<tr>
<td><br></td>
<td><hr></td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>NXP LPC214x</b>.
Support is provided for the NXP LPC214x family of processors. In particular,
support is provided for the mcu123.com lpc214x evaluation board (LPC2148).
This port also used the GNU arm-elf toolchain* under Linux or Cygwin.
</p>
<p>
<b>STATUS:</b>
This port boots and passes the OS test (examples/ostest).
The port is complete and verified. As of NuttX 0.3.17, the port includes:
timer interrupts, serial console, USB driver, and SPI-based MMC/SD card
support. A verified NuttShell (NSH) configuration is also available.
</p>
</td>
</tr>
<tr>
<td><br></td>
<td><hr></td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>STMicro STR71x</b>.
Support is provided for the STMicro STR71x family of processors. In particular,
support is provided for the Olimex STR-P711 evaluation board.
This port also used the GNU arm-elf toolchain* under Linux or Cygwin.
</p>
<p>
<b>STATUS:</b>
Coding is complete on the basic port (boot logic, system time, serial console),
but no testing has been performed due to some problems I am having with my
JTAG wiggler and OpenOCD on Linux.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>ARM926EJS</b>.
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>TI TMS320DM320</b> (also called <b>DM320</b>).
NuttX operates on the ARM9 of this dual core processor.
This port uses the
<a href="http://wiki.neurostechnology.com/index.php/Developer_Welcome">Neuros OSD</a>
with a GNU arm-elf toolchain* under Linux or Cygwin.
</p>
<p>
<b>STATUS:</b>
The basic port (timer interrupts, serial ports, network, framebuffer, etc.) is complete.
All implemented features have been verified with the exception of the USB device-side
driver; that implementation is complete but completely untested.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>8052 Microcontroller</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>PJRC 87C52 Development Board</b>.
This port uses the <a href="http://www.pjrc.com/">PJRC</a> 87C52 development system
and the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain under Linux or Cygwin.
</p>
<p>
<b>STATUS:</b>
This port is complete but not stable with timer interrupts enabled.
There seems to be some issue when the stack pointer enters into the indirect IRAM
address space during interrupt handling.
This architecture has not been built in some time will likely have some compilation
problems because of SDCC compiler differences.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Renesas/Hitachi SuperH</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>SH-1 SH7032</b>.
This port uses the Hitachi SH-1 Low-Cost Evaluation Board (SH1_LCEVB1), US7032EVB,
with a GNU arm-elf toolchain* under Linux or Cygwin.
</p>
<p>
<b>STATUS:</b>
This port is available as of release 0.3.18 of NuttX. The port is basically complete
and many examples run correctly. However, there are remaining instabilities that
make the port un-usable. The nature of these is not understood; the behavior is
that certain SH-1 instructions stop working as advertised. This could be a silicon
problem, some pipeline issue that is not handled properly by the gcc 3.4.5 toolchain
(which has very limit SH-1 support to begin with), or perhaps with the CMON debugger.
At any rate, I have exhausted all of the energy that I am willing to put into this cool
old processor for the time being.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Zilog Z16F</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>Zilog z16f Microncontroller</b>.
This port use the Zilog z16f2800100zcog development kit and the Zilog
ZDS-II Windows command line tools.
The development environment is Cygwin under WinXP.
</p>
<p>
<b>STATUS:</b>
The initial release of support for the z16f was made available in NuttX version 0.3.7.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Zilog eZ80 Acclaim!</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>Zilog eZ80Acclaim! Microncontroller</b>.
This port uses the ZiLOG ez80f0910200kitg development kit, eZ80F091 part
and the Zilog ZDS-II Windows command line tools.
The development environment is Cygwin under WinXP.
</p>
<p>
<b>STATUS:</b>
This is a work in progress. Verified ez80 support will be announced in a future NuttX release.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Zilog Z8Encore!</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>Zilog Z8Encore! Microncontroller</b>.
This port uses the either:
</p>
<ul>
<li>Zilog z8encore000zco development kit, Z8F6403 part, or</li>
<li>Zilog z8f64200100kit development kit, Z8F6423 part</li>
</ul>
<p>
and the Zilog ZDS-II Windows command line tools.
The development environment is Cygwin under WinXP.
</p>
<p>
<b>STATUS:</b>
This release has been verified only on the ZiLOG ZDS-II Z8Encore! chip simulation
as of nuttx-0.3.9.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Zilog Z80</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>Z80 Instruction Set Simulator</b>.
This port uses the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain
under Linux or Cygwin (verified using version 2.6.0).
This port has been verified using only a Z80 instruction simulator.
That simulator can be found in the NuttX CVS
<a href="http://nuttx.cvs.sourceforge.net/nuttx/misc/sims/z80sim/">here</a>.
</p>
<p>
<b>STATUS:</b>
This port is complete and stable to the extent that it can be tested
using an instruction set simulator.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Other ports</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
There are partial ports for the TI TMS320DM270 and for MIPS.
</p>
</td>
</tr>
</table></center>
<blockquote>* A highly modified <a href="http://buildroot.uclibc.org/">buildroot</a>
is available that may be used to build a NuttX-compatible ELF toolchain under
Linux or Cygwin. Configurations are available in that buildroot to support ARM,
m68k, m68hc11, m68hc12, and SuperH ports.</blockquote>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="environments"><h1>Development Environments</h1></a>
</td>
</tr>
</table>
<center><table width="90%">
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Linux + GNU make + GCC/binutils</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
The is the most natural development environment for NuttX.
Any version of the GCC/binutils toolchain may be used.
There is a highly modified <a href="http://buildroot.uclibc.org/">buildroot</a>
available for download from the
<a href="http://sourceforge.net/project/showfiles.php?group_id=189573">NuttX SourceForge</a>
page.
This download may be used to build a NuttX-compatible ELF toolchain under Linux or Cygwin.
That toolchain will support ARM, m68k, m68hc11, m68hc12, and SuperH ports.
The buildroot CVS may be accessed in the
<a href="http://nuttx.cvs.sourceforge.net/nuttx/misc/buildroot/">NuttX CVS</a>.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Linux + GNU make + SDCC</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
Also very usable is the Linux environment using the
<a href="http://sdcc.sourceforge.net/">SDCC</a> compiler.
The SDCC compiler provides support for the 8051/2, z80, hc08, and other microcontrollers.
The SDCC-based logic is less well exercised and you will likely find some compilation
issues if you use parts of NuttX with SDCC that have not been well-tested.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Cygwin + GNU make + GCC/binutils</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
This combination works well too.
It works just as well as the native Linux environment except
that compilation and build times are a little longer.
The custom NuttX buildroot referenced above may be build in
the Cygwin environment as well.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Cygwin + GNU make + SDCC</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
I have never tried this combination, but it would probably work just fine.
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Cygwin + GNU make + Windows Native Toolchain</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
This is a tougher environment.
In this case, the Windows native toolchain is unaware of the the
Cygwin <i>sandbox</i> and, instead, operates in the native Windows environment.
The primary difficulties with this are:
</p>
<ul>
<li>
<b>Paths</b>.
Full paths for the native toolchain must follow Windows standards.
For example, the path <code>/home/my\ name/nuttx/include</code> my have to be
converted to something like <code>'C:\cygwin\home\my name\nuttx\include'</code>
to be usable by the toolchain.
</li>
<p>
Fortunately, this conversion is done simply using the <code>cygpath</code> utility.
</p>
<li>
<b>Symbolic Links</b>
NuttX depends on symbolic links to install platform-specific directories in the build system.
On Linux, true symbolic links are used.
On Cygwin, emulated symbolic links are used.
Unfortunately, for native Windows applications that operate outside of the
Cygwin <i>sandbox</i>, these symbolic links cannot be used.
</li>
<p>
The NuttX make system works around this limitation by copying the platform
specific directories in place.
These copied directories make work a little more complex, but otherwise work well.
</p>
</ul>
<p>
At present, on the Zilog Z16F port uses a native Windows toolchain
(the Zilog ZDS-II toolchain).
</p.
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Other Environments?</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
The primary environmental dependency of NuttX are (1) GNU make,
(2) bash scripting, and (3) Linux utilities (such as sed).
If you have other platforms that support GNU make or make
utilities that are compatible with GNU make, then it is very
likely that NuttX would work in that environment as well (with some
porting effort). If GNU make is not supported, then some significant
modification of the Make system would be required.
</p>
</td>
</tr>
</table></center>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="footprint"><h1>Memory Footprint</h1></a>
</td>
</tr>
</table>
<ul>
<p><b>C5471 (ARM7)</b>
The build for this ARM7 target that includes most of the OS features and
a broad range of OS tests. The size of this executable as given by the
Linux <tt>size</tt> command is (3/9/07):
</p>
<pre>
text data bss dec hex filename
53272 428 3568 57268 dfb4 nuttx
</pre>
<p><b>DM320 (ARM9)</b>
This build for the ARM9 target includes a significant subset of OS
features, a filesystem, Ethernet driver, full TCP/IP, UDP and (minimal)
ICMP stacks (via uIP) and a small network test application: (11/8/07,
configuration netconfig, examples/nettest)
</p>
<pre>
text data bss dec hex filename
49472 296 3972 53740 d1ec nuttx
</pre>
<p>
Another build for the ARM9 target includes a minimal OS feature
set, Ethernet driver, full TCP/IP and (minimal) ICMP stacks, and
a small webserver: (11/20/07, configuration uipconfig, examples/uip)
</p>
<pre>
text data bss dec hex filename
52040 72 4148 56260 dbc4 nuttx
</pre>
<p><b>87C52</b>
A reduced functionality OS test for the 8052 target requires only
about 18-19Kb:
</p>
<pre>
Stack starts at: 0x21 (sp set to 0x20) with 223 bytes available.
Other memory:
Name Start End Size Max
---------------- -------- -------- -------- --------
PAGED EXT. RAM 0 256
EXTERNAL RAM 0x0100 0x02fd 510 7936
ROM/EPROM/FLASH 0x2100 0x6e55 19798 24384
</pre>
</ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="licensing"><h1>Licensing</h1></a>
</td>
</tr>
</table>
<ul>
<p>
NuttX is available under the highly permissive
<a href="http://en.wikipedia.org/wiki/BSD_license">BSD license</a>.
Other than some fine print that you agree to respect the copyright
you should feel absolutely free to use NuttX in any environment and
without any concern for jeopardizing any proprietary software that
you may link with it.
</p>
</ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="history"><h1>Release History</h1></a>
</td>
</tr>
</table>
<ul>
<p>
The current NuttX Change Log is available in CVS <a href="http://nuttx.cvs.sourceforge.net/*checkout*/nuttx/nuttx/ChangeLog">here</a>.
ChangeLog snapshots associated with the current release are available below.
</p>
</ul>
<center><table width ="80%">
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="ChangeLog.txt">Change Logs for All NuttX Releases</a><br>
</td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#currentrelease">ChangeLog for Current Releases</a><br>
</td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#pendingchanges">Unreleased Changes</a>
</td>
</tr>
</table></center>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="currentrelease">ChangeLog for Current Release</a>
</td>
</tr>
</table>
<pre><ul>
nuttx-0.3.19 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
* Add poll() and select() APIs (in the initial check-in, these work only with character devices)
* Add poll() methods to /dev/null, /dev/zero, pipes, fifos, and serial drivers.
* Add examples/poll for testing poll() and select()
* Fix hostile behavior of getc, fgetc, getchar, etc.: the serial driver was waiting for a
full buffer of read data before return. This means that getc would stall when it needed
to refill the input buffer. The old behavior (read full blocks) might be useful in other
contexts, so it is still available within the driver as a configuration option.
* Implement poll() and select() support for TCP/IP sockets
* Fixed an important bug in the TCP/IP buffering logic. When TCP/IP read-ahead is enabled
and not recv() is in-place when a TCP/IP packet is received, the packet is placed into
a read-ahead buffer. However, the old contents of the read-ahead buffer were not being
cleared and old data would contaminate the newly received buffer.
* Implemented support for connection backlog. The size of the backlog is specified by the
second argument of the standard listen() API. Hooks are provided to support poll()/select()
waiting for connections, with a subsequent call to accept() to use the backlogged connection.
* Fixed a minor bug in accept(). It should allow the address and addresslen values to be NULL
* Added first-cut definition for a framebuffer interface (and simulated framebuffer for testing
purposes only)
* Added fixed precision math support
* Added some color converson routines into what may become a real graphics library someday.
* Added a framebuffer driver for the DM320 (untested on initial check-in)
* Network: add support for outgoing multicast addresses
* Added some rasterizers to the graphics library
pascal-0.1.2 2008-02-10 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
* Add logic to build and link with the ZDS-II toolchain
use with the z16f.
* Make sure that POFF header structures are aligned
* Standardized POFF file format to big-endian
* Break up large switch statements to lower complexity
and eliminate a compiler bug
* Changes so that runtime compiles with SDCC.
buildroot-0.1.2 2007-11-06 &lt;spudmonkey@racsa.co.cr&gt
* Support for m68k-elf and m68hc11 toolchain
* Add patch to build older binutils with newer Texinfo version
* Add support for SH-1 toolchain
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="pendingchanges">Unreleased Changes</a>
</td>
</tr>
</table>
<pre><ul>
nuttx-0.3.20 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
* Initial release of a tiny windowing system for NuttX
* Add fixed precision sin() and cos() (not well tested at initial check-in)
* Add an X11-based simulated framebuffer driver
* The simulated target now has an option (CONFIG_SIM_WALLTIME) that will let the simulation
run in more-or-less realtime.
* Added more more extensive window support: frames, toolbars, etc.
* Added support for bitmap fonts
* Integrated the new font support with a font test in examples/nx
pascal-0.1.3 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
buildroot-0.1.3 2008-xx-xx &lt;spudmonkey@racsa.co.cr&gt;
* Add support for H8/300 toolchain
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="TODO"><h1>Bugs, Issues, <i>Things-To-Do</i></h1></a>
</td>
</tr>
</table>
<ul>
<p>
The current list of NuttX <i>Things-To-Do</i> in CVS <a href="http://nuttx.cvs.sourceforge.net/*checkout*/nuttx/nuttx/TODO">here</a>.
A snapshot of the <i>To-Do</i> list associated with the current release are available <a href="TODO.txt">here</a>.
</p>
</ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="documentation"><h1>Other Documentation</h1></a>
</td>
</tr>
</table>
<ul><table>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td><a href="NuttxUserGuide.html">User Guide</a></td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td><a href="NuttxPortingGuide.html">Porting Guide</a></td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td><a href="NuttShell.html">NuttShell (NSH)</a></td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td><a href="ChangeLog.txt">Change Log</a></td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td><a href="TODO.txt">To-Do List</a></td>
</tr>
</center></ul>
<small>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="trademarks"><h1>Trademarks</h1></a>
</td>
</tr>
</table>
<ul>
<li>ARM, ARM7 ARM7TDMI, ARM9, ARM926EJS are trademarks of Advanced RISC Machines, Limited.</li>
<li>Cygwin is a trademark of Red Hat, Incorporated.</li>
<li>Linux is a registered trademark of Linus Torvalds.</li>
<li>LPC2148 is a trademark of NXP Semiconductors.</li>
<li>TI is a tradename of Texas Instruments Incorporated.</li>
<li>UNIX is a registered trademark of The Open Group.</li>
<li>VxWorks is a registered trademark of Wind River Systems, Incorporated.</li>
<li>ZDS, ZNEO, Z16F, Z80, and Zilog are a registered trademark of Zilog, Inc.</li>
</ul>
<p>
NOTE: NuttX is <i>not</i> licensed to use the POSIX trademark. NuttX uses the POSIX
standard as a development guideline only.
</p>
</small>
</body>
</html>