1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
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
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
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
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
|
<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: March 21, 2007</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><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>
<p>
<b>Goals</b>.
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>
<p>
Non-restrictive BSD license.
</p>
</tr>
</table></center>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<a name="downloads"><h1>Downloads</h1></a>
</td>
</tr>
</table>
<p>
The third release of NuttX (nuttx-0.1.2) 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.
</p>
</td>
</tr>
<tr>
<td valign="top"><img src="favicon.ico"></td>
<td bgcolor="#5eaee1">
<b>ARM7TDMI</b>.
</td>
</tr>
<tr>
<td><br></td>
<td>
<p>
<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.
</p>
</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>
<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.
</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.
</p>
</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>
</td>
</tr>
</table></center>
<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>
<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>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><pre>
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 cause 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 2007-03-19 Gregory Nutt <spudmonkey@racsa.co.cr>
* Add dirent.h, opendir(), readdir(), closedir(), etc.
* Add strerror()
* Added 'ls' command to nsh
* Added C5471 watchdog driver
* Fixed another bug where free() is called from IDLE task.
Can't do this; the caller must be able to wait for access
to memory.
* Fixed bugs associated with debug output:
Cannot do dbg() in middle of context switch logic.
because it may require use of semaphores and cause
additional context switches. lldbg() is safe.
* Interrupt must be disabled throughout all context switches.
* 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() and mq_send() -- bad memcpy()
* Fixed C5471 signal deliver logic: use of dbg() and
other actions by use signal handler can alter errno.
need to protect errno during signal handling.
* Fixed uninitialized variable in filesystem that could
cause various problems
* Added a test for roundrobin scheduler.
0.1.3 2007-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
* Fix error in handing signed decimal in vsprintf().
* Major restructuring of header files to get closer to
POSIX compliance.
* Eliminate compilation warnings that that crept into
recent check-ins
* Add kill()
* Added support for POSIX timers
* Some Documentation updates
* Added support for the Neuros OSD / DM320
</pre></ul>
<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>
</body>
</html>
|