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>
</td>
</tr>
</table>
<hr><hr>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1>Table of Contents</h1>
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
</td>
</tr>
</table>
<center><table width ="80%">
<tr>
<td>
<table>
<tr>
<td><img src="favicon.ico"></td>
<td><a href="#overview">Overview</a></td>
</tr>
<tr>
<td><img src="favicon.ico"></td>
<td><a href="#downloads">Downloads</a></td>
</tr>
<tr>
<td><img src="favicon.ico"></td>
<td><a href="#platforms">Supported Platforms</a></td>
</tr>
<tr>
<td><img src="favicon.ico"></td>
<td><a href="#footprint">Memory Footprint</a></td>
</tr>
<tr>
<td><img src="favicon.ico"></td>
<td><a href="#licensing">Licensing</a></td>
</tr>
<tr>
<td><img src="favicon.ico"></td>
<td><a href="#history">Release History</a></td>
</tr>
<tr>
<td><img src="favicon.ico"></td>
<td><a href="#documentation">Other Documentation</a></td>
</tr>
</table>
</td>
</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>
<center><table width="90%">
<tr>
<td valign="top"><img 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>
</tr>
<tr>
<td valign="top"><img src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Rich Feature OS Set</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
The goal is to provide most standard POSIX OS interfaces to support
a rich multi-threaded development environment.
</p>
NON-GOALS: (1) It is not a goal to provide OS subsystems such
as network or USB (but these could obviously be added).
(2) There is no MMU-based support for processes.
At present, NuttX assumes a flat address space.
</p>
</tr>
<tr>
<td valign="top"><img 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>
</tr>
<tr>
<td valign="top"><img 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 functionaly 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>
</tr>
<tr>
<td valign="top"><img 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>
</tr>
<tr>
<td valign="top"><img src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>Totally Open</b>
</td>
</tr>
<tr>
<td><br></td>
<td>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="downloads"><h1>Downloads</h1></a>
</td>
</tr>
</table>
The second release of NuttX (nuttx-0.1.1) is avalable for download
from the <a href="http://sourceforge.net/project/showfiles.php?group_id=189573">SourceForge</a>
website.
</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 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 platform is available.
The purpose of this port is primarily to support OS feature developement.
</p>
<p>
<b>STATUS:</b>
Does not support interrupts but is otherwise fully functional.
</td>
</tr>
<tr>
<td valign="top"><img src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>TI TMS320C5471</b> (also called a <b>C5471</b> or <b>TMS320DM180</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*.
</p>
<p>
<b>STATUS:</b>
This port is complete, verified, and included in the initial NuttX release.
</p>
</td>
</tr>
<tr>
<td valign="top"><img src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>ARM9EJS</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*.
</p>
<p>
<b>STATUS:</b>
This port is code complete but totally untested due to hardware issues with my OSD.
</td>
</tr>
<tr>
<td valign="top"><img 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.
</p>
<p>
<b>STATUS:</b>
This port is complete but not stable with timer interrupts enabled.
There seems to be some issue when the stack pointer enters into the indirect IRAM
address space during interrupt handling.
</td>
</tr>
<tr>
<td valign="top"><img 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 be used to build a NuttX-compatible arm-elf toolchain.</blockquote>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="footprint"><h1>Memory Footprint</h1></a>
</td>
</tr>
</table>
<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):
<pre>
text data bss dec hex filename
53272 428 3568 57268 dfb4 nuttx
</pre>
<p><b>87C52</b>
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>
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
0.1.0 2007-03-09 Gregory Nutt <spudmonkey@racsa.co.cr>
* Initial Release
* Support for Linux user mode simulation and TI
TMS320C5471 (Arm7) provided
0.1.1 2007-03-14 Gregory Nutt <spudmonkey@racsa.co.cr>
* Corrected an error in interrupt level context switching
for C5471
* Added fgets() and gets() logic; verified c5471 console read.
* Corrected error in reading from the C5471 serial port:
Improper use of semaphore can cause deadlock.
* Fixed an error in the memory cleanup: The idle task
cannot take sempahores (because it must always be ready
to run).
* Tasks can now accept a configurable maximum number of
input parameters (argc)
* _task_init() was divided into separate functions that
require fewer parameters. This was necessary to keep
the stack usage down for the 8051/2 (which has only
256 bytes of stack).
* Attempts to use C5471 console from interrupt handlers
can casue errors. Added a special path for this case.
* Refuse calls to sem_wait and sem_trywait from interrupt
handlers. This was happening because interrupt handlers
were calling printf-like functions.
* Added strtok() and strtok_r()
* Added a simple shell called nsh (see examples/nsh).
* Platform support for 8052 is complete but not stable
when the timer interrupt is enabled. Seems to be an
issue when SP enters indirect address space.
* Documentation updates
0.1.2 2007-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
* Add dirent.h, opendir(), readdir(), closedir(), etc.
* Added 'ls' command to nsh
* Added C5471 watchdog driver
* Added support for the Neuros OSD / DM320
* Fixed another bug where free() is called from IDEL task.
Can't do this; the caller must be able to wait for access
to memory.
* Separated C5471 serial driver; a shareable part is
in drivers/. ; the C5471 specific part is in arch/C5471.
serial.h defines the interface.
* Fixed mq_receive() -- bad memcpy()
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="documentation"><h1>Other Documentation</h1></a>
</td>
</tr>
</table>
<ul><table>
<tr>
<td><img src="favicon.ico"></td>
<td><a href="NuttxUserGuide.html">User Guide</td>
</tr>
<tr>
<td><img src="favicon.ico"></td>
<td><a href="NuttxPortingGuide.html">Porting Guide</td>
</tr>
</center></ul>