Newer
Older
<html>
<head>
<title>NuttX</title>
</head>
<body background="backgd.gif">
<hr><hr>
<table width ="100%">
<tr align="center" bgcolor="#e4e4e4">
<td>
<h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
<p>Last Updated: December 19, 2009</p>
</td>
</tr>
</table>
<hr><hr>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1>Table of Contents</h1>
</td>
</tr>
</table>
<center><table width ="80%">
<tr>
<td>
<table>
<tr>
<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?
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#group">NuttX Discussion Group</a>.<br>
Do you want to talk about NuttX features? Do you need some help? Problems? Bugs?
</td>
</tr>
<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>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#platforms">Supported Platforms</a>.<br>
What target platforms has NuttX been ported to?
</td>
<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>
<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>
<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)
</td>
<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?
</td>
<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.
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#documentation">Other Documentation</a>.<br>
What other NuttX documentation is available?
</td>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td>
<a href="#trademarks">Trademarks</a>.<br>
Some of the words used in this document belong to other people.
</td>
</table></center>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="overview"><h1>Overview</h1></a>
</td>
</tr>
</table>
Nuttx is a real timed embedded operating system (RTOS).
Its goals are:
<p>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Small Footprint</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
Usable in all but the tightest micro-controller environments,
The focus is on the tiny-to-small, deeply embedded environment.
</p>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Rich Feature OS Set</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
The goal is to provide implementations of most standard POSIX OS interfaces
to support a rich, multi-threaded development environment for deeply embedded
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>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Highly Scalable</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<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>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Standards Compliance</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<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>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Real-Time</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
Fully pre-emptible, fixed priority and round-robin scheduling.
</p>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Totally Open</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>GNU Toolchains</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
Compatible GNU toolchains based on <a href="http://buildroot.uclibc.org/">buildroot</a>
available for
<a href="https://sourceforge.net/project/showfiles.php?group_id=189573&package_id=224585">download</a>
to provide a complete development environment for many architectures.
</p>
</tr>
<p>
<b>Feature Set</b>.
Key features of NuttX include:
<p>
<center><table width="90%">
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Standards Compliant Core Task Management</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<tr>
<td><br></td>
<td>
<p>
<li>Highly configurable.</li>
</p>
</tr>
<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>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li>Realtime, deterministic, with support for priority inheritance</li>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li>POSIX/ANSI-like task controls, named message queues, counting semaphores, clocks/timers, signals, pthreads, environment variables, filesystem.</li>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li>Well documented in the NuttX <a href="NuttxUserGuide.html">User Guide</a>.</li>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>File system</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li>Network, USB (device), serial, CAN, driver architecture.</li>
<tr>
<td><br></td>
<td>
<p>
<li>RAMDISK, pipes, FIFO, <code>/dev/null</code>, <code>/dev/zero</code> drivers.</li>
</p>
</tr>
<li>Mount-able volumes. Bind mountpoint, filesystem, and block device driver.</li>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li>Generic driver for SPI-based MMC/SD/SDH cards.</li>
<tr>
<td><br></td>
<td>
<p>
<li>ROMFS filesystem support.</li>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li><a href="NuttXNxFlat.html">NXFLAT</a>.
A new binary format call NXFLAT that can be used to
execute separately linked programs in place in a file system.
</p>
</tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>C Library</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Networking</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<tr>
<td><br></td>
<td>
<p>
<li>
A NuttX port of Jeff Poskanzer's <a href="http://acme.com/software/thttpd">THTTPD</a> HTTP server
integrated with <a href="NuttXNxFlat.html">NXFLAT</a> to provide true, embedded CGI.
</li>
</p>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>USB Device Support</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li><i>Gadget</i>-like architecture for USB device controller drivers and device-dependent USB class drivers.</li>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li>USB device controller drivers available for the NXP LPC214x and TI DM320.</li>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li>Device-dependent USB class drivers available for USB serial and for USB mass storage.</li>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Graphics Support</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li>Framebuffer drivers.</li>
</p>
</tr>
<tr>
<td><br></td>
<td>
<p>
<li>
NX: A graphics library, tiny windowing system and tiny font support.
Documented in the <a href="NXGraphicsSubsystem.html">NX Graphics Subsystem</a>
manual.
</li>
<p>
<b>NuttX Add-Ons</b>.
The following packages are available to extend the basic NuttX feature set:
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>NuttShell (NSH)</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<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>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Pascal Compiler with NuttX runtime P-Code interpreter add-on</b>
</td>
</tr>
<tr>
<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?
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
</p>
<center><table width="90%">
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Lots of Features -- More can be smaller!</b>
</td>
</tr>
<tr>
<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, typical, richly featured NuttX builds require more like 64Kb
(and if all of the features are used, this can push 100Kb).
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
<tr>
<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>
</tr>
<tr>
<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>
</tr>
<tr>
<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 width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="group"><h1>NuttX Discussion Group</h1></a>
</td>
</tr>
</table>
<p>
Most Nuttx-related discussion occurs on the <a href="http://tech.groups.yahoo.com/group/nuttx/" target="_top"><i>Yahoo!</i> NuttX group</a>.
You are cordially invited to <a href="http://groups.yahoo.com/group/nuttx/join" target="_top">join</a>.
I make a special effort to answer any questions and provide any help that I can.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="downloads"><h1>Downloads</h1></a>
</td>
</tr>
</table>
This 46<sup>th</sup> release of NuttX was made on December 2, 2009 and 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>.
These unreleased changes are listed <a href="#pendingchanges">here</a>.
The release extends the support for the STMicro STM32 microcontroller.
Minimal support for the STM3210E-EVAL development board based around the STM32F103ZET6
MCU was released in NuttX-0.4.12 and extended in Nuttx-0.4.13 to include initial USB support.
This completes the STM32F103ZET6 support and adds:
</p>
<p>
New Generic RTOS Features:
<li>Added generic support that can be included in any block driver to provide
read-ahead buffering and write buffering for improved driver performance.</li>
<li>Added a generic worker thread that can used to defer processing from an
interrupt to a task.</li>
<li>Defined a generic SD/SDIO interface can can be bound to a MMC/SD or SDIO
driver to orovide SDIO support.</li>
<li>Implemented a an SDIO-based MMC/SD driver using this new SDIO interface</li>
<li>Add support to configure an STM32 input GPIO to generate an EXTI interrupt.</li>
<li>Added support for buttons on the STM3210E-EVAL board.</li>
<li>Implemented an STM32 version of the common the SDIO interface.</li>
<li>Added a configuration to exercise the STM32 with the USB mass storage
device class example.</li>
This release also corrects some important bugs in the earlier STM32 releases:
<ul>
<li>Correct error handling in the mount() logic.</li>
<li> Fixed several STM32 DMA-related issues. Integrated and debugged STM32 DMA
functionality that was added in 0.4.12.</li>
<li>Fixed several bugs in the STM32 USB device-side driver.</li>
</ul>
</p>
NOTE: This version, 4.14, is equivalent to what would have been called 0.4.14
to follow 0.4.13. The zero has been eliminated from the front of the version
number to avoid confusion about the state of development: Some have interpreted
the leading zero to mean that the code is in some way unstable. That was not
the intent. Beginning in January 2010, I will switch to the 2010.nn versioning
as many others have done to avoid such confusion.
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="platforms"><h1>Supported Platforms</h1></a>
</td>
</tr>
</table>
<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>
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.
<ul>
<p>
<b>STATUS:</b>
Does not support interrupts but is otherwise fully functional.
</p>
</ul>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<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.
<ul>
<p>
<b>STATUS:</b>
This port is complete, verified, and included in the initial NuttX release.
</p>
</ul>
<tr>
<td><br></td>
<td><hr></td>
</tr>
patacongo
committed
<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.
patacongo
committed
</p>
<ul>
<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 <a href="NuttShell.html">(NSH)</a>
configuration is also available.
</p>
<p>
<b>Development Environments:</b>
1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
with Windows native toolchain (CodeSourcery or devkitARM). A DIY toolchain for Linux
or Cygwin is provided by the NuttX
<a href="http://sourceforge.net/project/showfiles.php?group_id=189573&package_id=224585">buildroot</a>
package.
</p>
</ul>
patacongo
committed
</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>
<ul>
<p>
<b>STATUS:</b>
Integration is complete on the basic port (boot logic, system time, serial console).
Two configurations have been verified: (1) The board boots and passes the OS test
with console output visible on UART0, and the NuttShell <a href="NuttShell.html">(NSH)</a>
is fully functional with interrupt driven serial console. An SPI driver is available
but untested (because the Olimex card slot appears to accept only MMC cards; I have
only SD cards). Additional features are needed: USB driver, MMC integration, to name two.
</p>
<p>
<b>Development Environments:</b>
1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
with Windows native toolchain (CodeSourcery or devkitARM). A DIY toolchain for Linux
or Cygwin is provided by the NuttX
<a href="http://sourceforge.net/project/showfiles.php?group_id=189573&package_id=224585">buildroot</a>
package.
</p>
</ul>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>ARM920T</b>.
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>Freescale MC9328MX1</b> or <b>i.MX1</b>.
This port uses the Freescale MX1ADS development board with a GNU arm-elf toolchain*
under either Linux or Cygwin.
</p>
<ul>
<p>
<b>STATUS:</b>
This port is in progress. Coding is complete on the basic port (timer, serial console, SPI).
Verified support for the i.MX1 will be announced in a future release of NuttX (work was
been temporarily stopped to support the Luminary LM3S6918 and I have not yet worked around
some development tool issues.).
</p>
</ul>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
</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>
<ul>
<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 untested.
</p>
</ul>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>ARM Cortex-M3</b>.
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>Luminary LM3S6918</b>.
This port uses the <a href=" http://www.micromint.com/">Micromint</a> Eagle-100 development
board with a GNU arm-elf toolchain* under either Linux or Cygwin.
<ul>
<p>
<b>STATUS:</b>
The initial, release of this port was included in NuttX version 0.4.6.
The current port includes timer, serial console, Ethernet, SSI, and microSD support.
There are working configurations the NuttX OS test, to run the <a href="NuttShell.html">NuttShell
(NSH)</a>, the NuttX networking test, and the uIP web server.
</p>
<p>
<b>Development Environments:</b>
1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
with Windows native toolchain (CodeSourcery or devkitARM). A DIY toolchain for Linux
or Cygwin is provided by the NuttX
<a href="http://sourceforge.net/project/showfiles.php?group_id=189573&package_id=224585">buildroot</a>
package.
</p>
</ul>
</td>
</tr>
<tr>
<td><br></td>
<td>
This port uses the <a href=" http://www.st.com/">STMicro</a> STM3210E-EVAL
development board that features the STM32F103ZET6 MCU.
This port uses a GNU arm-elf toolchain* under either Linux or Cygwin (with native Windows GNU
tools or Cygwin-based GNU tools).
The basic STM32 port was released in NuttX version 0.4.12. The basic port includes boot-up
logic, interrupt driven serial console, and system timer interrupts.
The 0.4.13 release added support for SPI, serial FLASH, and USB device.;
The 4.14 release added support for buttons and SDIO-based MMC/SD and verifed DMA support.
Verified configurations are available for NuttX OS test, the NuttShell (NSH) example,
the USB serial device class, and the USB mass storage device class example.
</p>
<p>
<b>Development Environments:</b>
1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
with Windows native toolchain (RIDE7, CodeSourcery or devkitARM). A DIY toolchain for Linux
or Cygwin is provided by the NuttX
<a href="http://sourceforge.net/project/showfiles.php?group_id=189573&package_id=224585">buildroot</a>
package.
</p>
</ul>
<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>
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.
<ul>
<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>
</ul>
</td>
<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>
<ul>
<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>
</ul>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Renesas M16C/26</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>Renesas M16C/26 Microncontroller</b>.
This port uses the Renesas SKP16C26 Starter kit and the GNU M32C toolchain.
The development environment is either Linux or Cygwin under WinXP.
</p>
<p>
<b>STATUS:</b>
Initial source files released in nuttx-0.4.2.
At this point, the port has not been integrated; the target cannot be built
because the GNU <code>m16c-elf-ld</code> link fails with the following message:
</p>
<ul>
<code>m32c-elf-ld: BFD (GNU Binutils) 2.19 assertion fail /home/Owner/projects/nuttx/buildroot/toolchain_build_m32c/binutils-2.19/bfd/elf32-m32c.c:482</code>
</ul>
<p>Where the reference line is:</p>
<ul><pre>
/* If the symbol is out of range for a 16-bit address,
we must have allocated a plt entry. */
BFD_ASSERT (*plt_offset != (bfd_vma) -1);
</pre></ul>
<p>
No workaround is known at this time. This is a show stopper for M16C for
the time being.
</p>
</ul>
</td>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<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.
<ul>
<p>
<b>STATUS:</b>
The initial release of support for the z16f was made available in NuttX version 0.3.7.
</p>
</ul>
</td>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<b>Zilog eZ80Acclaim! Microncontroller</b>.
<ul>
<li>One uses the ZiLOG ez80f0910200kitg development kit, and
<li>The other uses the ZiLOG ez80f0910200zcog-d development kit.
</ul>
Both boards are based on the eZ80F091 part and both use the Zilog ZDS-II
Windows command line tools.
The development environment is Cygwin under WinXP.
<ul>
<p>
<b>STATUS:</b>
Integration and testing of NuttX on the ZiLOG ez80f0910200zcog-d is complete.
The first integrated version was released in NuttX version 0.4.2 (with important early bugfixes
in 0.4.3 and 0.4.4).
As of this writing, that port provides basic board support with a serial console, SPI, and eZ80F91 EMAC driver.
</p>
</ul>
</td>
<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>
<ul>
<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>
<ul>
</td>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
</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>
<ul>
<p>
<b>STATUS:</b>
This port is complete and stable to the extent that it can be tested
using an instruction set simulator.
</p>
<ul>
</td>
<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>
<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">
</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">
</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">
</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">
</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">
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
This is a tougher environment.
In this case, the Windows native toolchain is unaware of 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>
<li>
<b>Dependencies</b>
NuttX uses the GCC compiler's <code>-M</code> option to generate make dependencies. These
dependencies are retained in files called <code>Make.deps</code> throughout the system.
For compilers other than GCC, there is no support for making dependencies in this way.
For Windows native GCC compilers, the generated dependencies are windows paths and not
directly usable in the Cygwin make. By default, dependencies are surpressed for these
compilers as well.
</li>
<p><small>
NOTE: dependencies are suppress by setting the make variable <code>MKDEPS</code> to point
to the do-nothing dependency script, <code>tools/mknulldeps.sh</code>.
Dependencies can be enabled for the Windows native GCC compilers by setting
<code>MKDEPS</code> to point to <code>$(TOPDIR)/tools/mkdeps.sh --winpaths $(TOPDIR)</code>.
</small></p>
At present, only the Zilog Z16F, z8Encore, and eZ80Acclaim ports use a non-GCC native Windows
toolchain(the Zilog ZDS-II toolchain).
Support for Windows native GCC toolchains (CodeSourcery and devkitARM) is currently implemented
for the NXP LPC214x, STMicro STR71x, and Luminary LMS6918 ARM ports.
(but could easily be extended to any other GCC-based platform with a small effort).
</p>
</td>
</tr>
<tr>
<td valign="top"><img height="20" width="20" src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Other Environments?
Windows Native <code>make</code> + Windows Native Toolchain?</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 cat, sed, etc.).
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>
<b>GNUWin32</b>.
For example, with suitable make system changes, it should be possible to
use native GNU tools (such as those from
<a href="http://sourceforge.net/projects/gnuwin32/">GNUWin32</a>)
to build NuttX.
However, that environment has not been used as of this writing.
</p>
</td>
</tr>
</table></center>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="footprint"><h1>Memory Footprint</h1></a>
</td>
</tr>
</table>
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):
<pre>
text data bss dec hex filename
53272 428 3568 57268 dfb4 nuttx
</pre>
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
<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>
A reduced functionality OS test for the 8052 target requires only
about 18-19Kb:
<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>
<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>.
you should feel absolutely free to use NuttX in any environment and
without any concern for jeopardizing any proprietary software that
<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>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<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>
nuttx-4.14 2009-12-02 Gregory Nutt <spudmonkey@racsa.co.cr>
* arch/arm/src/stm32/stm32_gpio.c - Add support for configure an input GPIO
to generate an EXTI interrupt.
* config/stm3210e-eval/src/up_buttons.c - Add support for on-board buttons.
* include/nuttx/rwbuffer.h -- Add generic support for read-ahead buffering
and write buffering that can be used in any block driver.
* include/nuttx/wqueue.h -- Added a generic worker thread that can used to
defer processing from an interrupt to a task.
* include/nuttx/sdio.h -- Defines a generic SD/SDIO interface can can be
bound to a MMC/SD driver to provide SDIO-based MMC/SD support.
* drivers/mmcsd/mmcsd_sdio.c -- Provides a an SDIO-based MMC/SD driver.
* arch/arm/src/stm32/stm32_sdio.c -- Provides an STM32 implementation of
the SDIO interface defined in include/nuttx/sdio.h.
* fs/fs_mount.c -- Correct error handling logic. If the bind() method
fails, then a reserved node is left in the tree. This causes subsequent
attempts to mount at the location to fail (reporting that the node
already exists). This is a problem for block drivers for removable
media: The bind method could fail repeatedly until media is inserted.
* arch/arm/src/stm32/chip.h & stm32_dma.c -- Fixed several definitions
that can cause compilation errors when DMA2 is enabled.
* arch/arm/src/stm32/stm32_dma.c - Integrated and debugged STM32 DMA
functionality that was added in 0.4.12.
* configs/stm3210e-eval/usbstorage - Add a configuration to exercise
the STM32 with the USB mass storage device class example
(examples/usbstorage).
* configs/mcu123-lpc214x/up_usbstrg - Move LPC-specific code from
examples/usbstorage to configs/mcu123-lpc214x.
* configs/stm321e-eval/up_usbstrg - Add STM32-specific logic for the
examples/usbstorage test.
* arch/arm/src/stm32/stm32_usbdev.c - Fix bugs in STM32 USB device-side
driver: (1) Need to disconnect after reset received, (2) Status setup
to recover from stall on TX endpoint.
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
pascal-0.1.2 2008-02-10 Gregory Nutt <spudmonkey@racsa.co.cr>
* 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-0.1.7 2009-06-26 <spudmonkey@racsa.co.cr>
* configs/avr-defconfig-4.3.3: Added support for AVR to support a NuttX
port of the ATmega128.
* toolchain/nxflat: Added logic to build NuttX NXFLAT binding support tools
* toolchain/genromfs: Added support for the genromfs tool
</pre></ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="pendingchanges">Unreleased Changes</a>
</td>
</tr>
</table>
<ul><pre>
* arch/hc: Adding framework to support m68hc11/12
* configs/demo9s12ne64: Configuration to support Freescale DEMO9S12NE64
development board (MC9S12NE64 m68hcs12 processor).
* drivers/mtd/ftl.c - A FLASH translation layer (FTL) has been implemented.
This layer will convert a FLASH MTD interface into a block driver that
can be used with any file system. Good performance of this layer will
depend upon functioning write buffer support!
NOTE: FTL support is untested as of the initial check-in.
patacongo
committed
* Numerous minor changes for m68hc12 to eliminate compilation errors and
warnings due to the fact that it uses 16-bit integer types and for casts
between uint32 (32-bits) and an mc68hc12 pointer (16-bits).
* sys/types: Size of off_t and blkcnt_t should not depend on size of
int in the architecture; Removed non-standard type STATUS
patacongo
committed
* include/ - Added header files stdint.h, stdbool.h, cxx/cstdint, and
cxx/cstdbool
patacongo
committed
* Changed ALL references to non-standard fixed-size types (like uint32,
ubyte, etc.) to standard types (like uint32_t, uint8_t, etc.) from
stdint.h. Use type bool and {true, false} from stdbool. This effected
most of the files in the system! Almost all configurations have been
re-built and many have been re-verified in order to get confidence in
these changes.
* graphics/ and examples/nx - Fix numerous build errors that have been
introduced lately. NXGL has suffered some bit-rot from not being used
in some of the most recent ports.
* The misc/pascal NuttX add-on package has been updated to use the new
standard types from stdint.h and stdbool.h and re-integrated with NuttX.
The released pascal-2.0 will be the first version that contains the
compatible changes.
* arch/arm/src/lm3s/lm3s_ethernet.c - Fixed an important bug in the LM3S
ethernet driver: If full packet is received, the packet-too-big check
will fail because it needs to subtract 6 from the packet size (to
account for the 2-byte packet length and the 4-byte packet FCS in the
FIFO).
* net/accept.c - Fixed a bad assertion (only happens when debug is enabled).
* net/send.c net/uip/uip_tcpseqno.c - Fixed a critical error in the TCP/IP
logic. The NuttX port of uIP imcludes logic to send data ahead without
waiting for ACKs from the recipient; this greatly improves throughput.
However, the packet sequence number was not being updated correctly and,
as a result, packets were not be ACKed by the recipient and transfers
would sometimes stall. This is a very important bug fix (in fact, I
don't understand how TCP/IP worked at all without this fix???)
pascal-2.0 2010-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
* Updated to use standard C99 types in stdint.h and
stdbool.h. This change was necessary for compatibility
with NuttX-5.0.
buildroot-1.8 2010-xx-xx <spudmonkey@racsa.co.cr>
* configs/cortexm3-defconfig-4.3.3: Added support for NuttX NXFLAT
tools.
* configs/arm7tdmi-defconfig-4.3.3: Update to arm7tdmi-defconfig-4.2.4.
Also builds NuttX NXFLAT tools.
* configs/m68hc12-defconfig-4.3.3: Update to m68ch11-defconfig.
* configs/m68hc12-defconfig-3.4.6: There are problems building GCC
4.3.3 for the hc12.
* configs/m32c-defconfig-4.2.4: Added genromfs
* configs/m32c-defconfig-4.3.3: Update to m32c-defconfig-4.2.4
<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>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<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="NuttXNxFlat.html">NXFLAT</a> Binary Format</td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td><a href="NXGraphicsSubsystem.html">NX Graphics Subsystem</a></td>
</tr>
<tr>
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
<td><a href="README.html">NuttX README Files</a></td>
</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>
<small>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="trademarks"><h1>Trademarks</h1></a>
</td>
</tr>
</table>
<ul>
<li>ARM, ARM7 ARM7TDMI, ARM9, ARM920T, ARM926EJS Cortex-M3 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>Eagle-100 is a trademark of <a href=" http://www.micromint.com/">Micromint USA, LLC</a>.
<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>
NOTE: NuttX is <i>not</i> licensed to use the POSIX trademark. NuttX uses the POSIX
standard as a development guideline only.