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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: October 30, 2009</p>
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<h1>Table of Contents</h1>
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<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>
<a href="#group">NuttX Discussion Group</a>.<br>
Do you want to talk about NuttX features? Do you need some help? Problems? Bugs?
</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>
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<a href="#footprint">Memory Footprint</a>.<br>
Just how big is it? Do I have enough memory to use NuttX?
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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)
</td>
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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>
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<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 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>
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<a name="overview"><h1>Overview</h1></a>
</td>
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<p>
<b>Goals</b>.
Nuttx is a real timed embedded operating system (RTOS).
Its goals are:
<p>
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<b>Small Footprint</b>
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<td><br></td>
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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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<b>Rich Feature OS Set</b>
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<td><br></td>
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<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>
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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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<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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<td><br></td>
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<p>
Non-restrictive BSD license.
</p>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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<b>GNU Toolchains</b>
</td>
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<td><br></td>
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<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>
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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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<b>Standards Compliant Core Task Management</b>
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<p>
<li>Modular, micro-kernel</li>
</p>
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<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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<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, with support for priority inheritance</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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<td><br></td>
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<p>
<li>RAMDISK, pipes, FIFO, <code>/dev/null</code>, <code>/dev/zero</code> drivers.</li>
</p>
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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/SDH cards.</li>
</p>
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<p>
<li>ROMFS filesystem support.</li>
</p>
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<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>
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<b>C Library</b>
</td>
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<td><br></td>
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<p>
<li>Fully integrated into the OS.</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>Networking</b>
</td>
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<td><br></td>
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<p>
<li>TCP/IP, UDP, ICMP stacks.</li>
</p>
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<td><br></td>
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<p>
<li>Small footprint (based on uIP).</li>
</p>
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<td><br></td>
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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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<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>
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<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
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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>
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<tr>
<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>
<td>
<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>
</td>
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<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>
</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>
<td bgcolor="#5eaee1">
<b>NuttShell (NSH)</b>
</td>
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<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>
<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?
</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>
</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).
</p>
</td>
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<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>
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<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></center>
<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>
<p><b>nuttx-0.4.12</b>.
<p>
This 44<sup>th</sup> release of NuttX was made on October 17, 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>.
Unreleased changes after this release are available in CVS.
These unreleased changes are listed <a href="#pendingchanges">here</a>.
</p>
<p>
This release adds basic support for the STMicro STM32, Cortex-M3 MCU.
The specific port is to the STMicro STM3210E-EVAL development board based around the STM32F103ZET6 MCU.
Some highlights of this port:
<ul>
<li>This basic port includes boot-up logic, interrupt driven serial console, and system timer interrupts.<li>
<li>The port includes a basic STMicro RIDE7 project that can be used to perform basic STM32 board bring-up
(due to RIDE7 size limitations, it cannot be used for the full NuttX testing, unfortunately).<li>
<li>Working, Tested Configurations: the NuttX OS test and the NuttShell (NSH) example.<li>
</ul>
</p>
<p>
It is planned to extend this basic STM32 port for the 0.4.13 NuttX release.
Additional functionality needed for complete STM32 support includes:
USB device driver, LCD driver and NX bringup on the development board's display and MicroSD support.
An SPI driver and a DMA support was included in this 0.4.12 release, but is not yet tested.
</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>
<ul>
<p>
<b>STATUS:</b>
Does not support interrupts but is otherwise fully functional.
</p>
</ul>
</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>
<ul>
<p>
<b>STATUS:</b>
This port is complete, verified, and included in the initial NuttX release.
</p>
</ul>
</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>
<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>
</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>
</td>
</tr>
<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>
</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>
<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>
</td>
</tr>
<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.
</p>
<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>
<p>
<b>STMicro STM32F103x</b>.
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).
</p>
<ul>
<p>
<b>STATUS:</b>
The basic STM32 port was released in NuttX version 0.4.12. This basic port includes boot-up
logic, interrupt driven serial console, and system timer interrupts.
Verified configurations are available for NuttX OS test and the NuttShell (NSH) example.
This basic STM32 port will be extended in the 0.4.13 NuttX release. Functionality needed
for complete STM32 support includes: USB device driver, LCD driver and NX bringup on the
development board's display and MicroSD support. An SPI driver and a DMA support was included
in the 0.4.12 release, but is not yet tested.
</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>
</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>
<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>
<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>
<ul>
<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>
</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>
<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>
</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>.
There are two eZ80Acclaim! ports:
</p>
<ul>
<li>One uses the ZiLOG ez80f0910200kitg development kit, and
<li>The other uses the ZiLOG ez80f0910200zcog-d development kit.
</ul>
<p>
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.
</p>
<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>
</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>
<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>
</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>
<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>
</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 <code>make</code> + 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 <code>make</code> + 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 <code>make</code> + 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 <code>make</code> + 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 <code>make</code> + 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
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>
</ul>
<p>
<b>Supported Windows Native Toolchains</b>.
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>
<b>Environment Dependencies</b>.
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>
<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>
<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>
<ul><pre>
0.4.12 2009-10-17 Gregory Nutt <spudmonkey@racsa.co.cr>
* arch/arm/src/stm32 and configs/stm3210e-eval. Added basic support for the
STMicro STM32, Cortex-M3 MCU. The specific port is to the STMicro STM3210E-EVAL
development board based around the STM32F103ZET6 MCU.
* configs/stm3210e-eval/RIDE. Added a basic STMicro RIDE7 project that can be
used to perform basic STM32 board bring-up (due to RIDE7 size limitations, it
cannot be used for the full NuttX bring-up).
* configs/stm3210e-eval/ostest. The STM32 now passes the basic NuttX OS test
at examples/ostest. The rest should be a piece of cake.
* configs/stm3210e-eval/nsh. Added NuttShell (NSH) example.
* configs/stm3210e-eval/src/stm32102e-internal.h. Fix on-board LED GPIO definitions.
* arch/arm/src/stm32/src/stm32/stm32_dma.c. Added DMA channel support for the STM32
* arch/arm/src/stm32/src/stm32/stm32_spi.c. Added a DMA-based SPI driver for the STM32.
* arch/arm/src/stm32/src/stm32/stm32_serial.c. Finished interrupt-drivent,
USART console driver. This makes NSH work perfectly.
* Things left to do for the STM32 deferred to the 0.4.13 release: USB device driver,
LCD driver and NX bringup on the eval board's display and MicroSD support. An SPI
driver was included in the 0.4.12 release, but is not yet tested.
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-0.1.7 2009-06-26 &lt;spudmonkey@racsa.co.cr&gt;
* 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>
nuttx-0.4.13 2009-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
* include/nuttx/mtd.h. Added a simple interface definition to support some
FLASH, EEPROM, NVRAM, etc. devices.
* driver/mtd/m25px.c. Added a driver for SPI based FLASH parts M25P64 and M25P128.
* configs/stm3210e-eval/usbserial. Add a USB serial configuration for the STM32.
Depends on the STM32 USB driver.
* arch/arm/src/cortexm3/up_switchcontext.S & up_svccall.c. Made an improvement
to context switching. There are two types of context switches: interrupt
context switches and background/user context switches. This change should
improve the performance of those background/user context switches by a factor
of about two.
* arch/arm/src/stm32/ - fix several typos in the serial logic. It turns out
that these typose don't make any difference as long as you use only one
serial port and all uarts are configured the same. But the typos are bugs
waiting to happen in any other configuration.
* arch/arm/src/stm32/ - You have to configure CTS/RTS function pins for USART
2 and USART 3 even if you are not using flow control.
* arch/arm/src/stm32/stm32_usbdev.c - Added a USB device-side driver for the
STM32.
NOTE: This STM32 USB driver is not yet fully tested
* arch/arm/src/stm32/stm32_rcc.c - Fixed an error in clock initialization.
On some boards (none of mine), the HSE (high speed external clock) delay
loop times out if the optimization level is high. The STM32 then falls
back to the HSI (internal clock), and the system clock is too slow by a
factor of 11.1%. This was fixed by simply add the volatile storage class
to the timeout loop counter
* arch/arm/src/stm32/stm32_irq.c - Fixed a critical bug in the interrupt
control logic. The wrong register was being used for interrupts in a
certain range. Worked fine until you try to use an interrupt in that
range!
pascal-0.1.3 2009-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
buildroot-0.1.8 2009-xx-xx &lt;spudmonkey@racsa.co.cr&gt;
</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="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>
<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, 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>
</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>