blob: 99753437e5f110e0d01ca32edaf32d5e13a177f1 (
plain) (
blame)
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
|
<html>
<head>
<title>NuttX</title>
</head>
<body background="backgd.gif">
<center>
<hr><hr>
<h1><big><i>NuttX RTOS</i></big></h1>
<p>Last Updated: March 14, 2007</p>
<hr><hr>
<h1>Table of Contents</h1>
</center>
<li><a href="#overview">Overview</a></li>
<li><a href="#downloads">Downloads</a></li>
<li><a href="#platforms">Supported Platforms</a></li>
<li><a href="#footprint">Memory Footprint</a></li>
<li><a href="#licensing">Licensing</a></li>
<li><a href="#history">Release History</a></li>
<li><a href="#documentation">Other Documentation</a></li>
<a name="overview"><h1>Overview</h1></a>
<p>
<b>Goals</b>.
Nuttx is a real timed embedded operating system (RTOS).
Its goals are:
<p>
<ol>
<li><b>Small Footprint</b></li>
<p>
Usable in all but the tightest micro-controller environments,
The focus is on the tiny-to-small, deeply embedded environment.
</p>
<li><b>Rich Feature OS Set</b></li>
<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>
<li><b>Highly Scalable</b></li>
<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>
<li><b>Standards Compliance</b></li>
<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>
<li><b>Real-Time</b></li>
<p>
Fully pre-emptible, fixed priority and round-robin scheduling.
</p>
<li><b>Totally Open</b></li>
<p>
Non-restrictive BSD license.
</p>
</ol>
<a name="downloads"><h1>Downloads</h1></a>
<p>
The initial release of NuttX (nuttx-0.1.0) is avalable for download
from the <a href="http://sourceforge.net/project/showfiles.php?group_id=189573">SourceForge</a>
website.
</p>
<a name="platforms"><h1>Supported Platforms</h1></a>
<ul>
<li><b>Linux User Mode</b></li>
<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>
STATUS: Does not support interrupts but is otherwise fully functional.
</p>
<li><b>TI TMS320C5471</b> (also called <b>TMS320DM180</b>).</li>
<p>
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>
STATUS: This port is complete, verified, and included in the initial NuttX
release.
</p>
<li><b>8051 Microcontroller</b></li>
<p>
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>
STATUS: 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>
<li><b>Other ports</b></li>
<p>
There are partial ports for the TI TMS320DM270 and for MIPS.
</p>
</ul>
<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>
<a name="footprint"><h1>Memory Footprint</h1></a>
<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>
<a name="licensing"><h1>Licensing</h1></a>
<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>
<a name="history"><h1>Release History</h1></a>
<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 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
</pre>
<a name="documentation"><h1>Other Documentation</h1></a>
<li><a href="NuttxUserGuide.html">User Guide</li>
<li><a href="NuttxPortingGuide.html">Porting Guide</li>
</body>
</html>
|
