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
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
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
623
624
625
626
627
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
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
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
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
|
<html>
<head>
<title>NuttX Porting Guide</title>
<meta name="author" content="Gregory Nutt">
</head>
<body background="backgd.gif">
<hr><hr>
<table width ="100%">
<tr align="center" bgcolor="#e4e4e4">
<td>
<h1><big><font color="#3c34ec">
<i>NuttX RTOS Porting Guide</i>
</font></big></h1>
<p>Last Updated: July 18, 2009</p>
</td>
</tr>
</table>
<hr><hr>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1>Table of Contents</h1>
</td>
</tr>
</table>
<ul>
<a href="#Introduction">1.0 Introduction</a><br>
<a href="#DirectoryStructure">2.0 Directory Structure</a>
<ul>
<a href="#DirStructDocumentation">2.1 Documentation</a></br>
<a href="#DirStructArch">2.2 arch/</a>
<ul>
<a href="#archdirectorystructure">2.2.1 Subdirectory Structure</a><br>
<a href="#summaryofarchfiles">2.2.2 Summary of Files</a><br>
<a href="#supportedarchitectures">2.2.3 Supported Architectures</a>
</ul>
<a href="#DirStructBinFmt">2.2 binfmt/</a><br>
<a href="#DirStructConfigs">2.4 configs/</a>
<ul>
<a href="#configsdirectorystructure">2.3.1 Subdirectory Structure</a><br>
<a href="#summaryofconfigfiles">2.3.2 Summary of Files</a>
<ul>
<a href="#boardlogic">2.4.2.1 Board Specific Logic</a><br>
<a href="#boardconfigsubdirs">2.3.2.2 Board Specific Configuration Sub-Directories</a>
</ul>
<a href="#supportedboards">2.4.3 Supported Boards</a>
</ul>
<a href="#DirStructDrivers">2.5 drivers/</a><br>
<a href="#DirStructExamples">2.6 examples/</a><br>
<a href="#DirStructFs">2.7 fs/</a><br>
<a href="#DirStructGraphics">2.8 graphics/</a><br>
<a href="#DirStructInclude">2.9 include/</a><br>
<a href="#DirStructLib">2.10 lib/</a><br>
<a href="#DirStructLibXX">2.11 libxx/</a><br>
<a href="#DirStructMm">2.12 mm/</a><br>
<a href="#DirStructNet">2.13 net</a><br>
<a href="#DirStructNetUtils">2.14 netutils</a><br>
<a href="#DirStructSched">2.15 sched/</a><br>
<a href="#DirStructTools">2.16 tools/</a><br>
<a href="#topmakefile">2.17 Makefile</a>
</ul>
<a href="#configandbuild">3.0 Configuring and Building</a>
<ul>
<a href="#configuringnuttx">3.1 Configuring NuttX</a><br>
<a href="#buildingnuttx">3.2 Building NuttX</a>
</ul>
<a href="#ArchAPIs">4.0 Architecture APIs</a>
<ul>
<a href="#imports">4.1 APIs Exported by Architecture-Specific Logic to NuttX</a>
<ul>
<a href="#upinitialize">4.1.1 <code>up_initialize()</code></a><br>
<a href="#upidle">4.1.2 <code>up_idle()</code></a><br>
<a href="#upinitialstate">4.1.3 <code>up_initial_state()</code></a><br>
<a href="#upcreatestack">4.1.4 <code>up_create_stack()</code></a><br>
<a href="#upusestack">4.1.5 <code>up_use_stack()</code></a><br>
<a href="#upreleasestack">4.1.6 <code>up_release_stack()</code></a><br>
<a href="#upunblocktask">4.1.7 <code>up_unblock_task()</code></a><br>
<a href="#upblocktask">4.1.8 <code>up_block_task()</code></a><br>
<a href="#upreleasepending">4.1.9 <code>up_release_pending()</code></a><br>
<a href="#upreprioritizertr">4.1.10 <code>up_reprioritize_rtr()</code></a><br>
<a href="#_exit">4.1.11 <code>_exit()</code></a><br>
<a href="#upassert">4.1.12 <code>up_assert()</code></a><br>
<a href="#upschedulesigaction">4.1.13 <code>up_schedule_sigaction()</code></a><br>
<a href="#upallocateheap">4.1.14 <code>up_allocate_heap()</code></a><br>
<a href="#upinterruptcontext">4.1.15 <code>up_interrupt_context()</code></a><br>
<a href="#updisableirq">4.1.16 <code>up_disable_irq()</code></a><br>
<a href="#upenableirq">4.1.17 <code>up_enable_irq()</code></a><br>
<a href="#upprioritizeirq">4.1.18 <code>up_prioritize_irq()</code></a></br>
<a href="#upputc">4.1.19 <code>up_putc()</code></a>
</ul>
<a href="#exports">4.2 APIs Exported by NuttX to Architecture-Specific Logic</a>
<ul>
<a href="#osstart">4.2.1 <code>os_start()</code></a><br>
<a href="#listmgmt">4.2.2 OS List Management APIs</a><br>
<a href="#schedprocesstimer">4.2.3 <code>sched_process_timer()</code></a><br>
<a href="#irqdispatch">4.2.4 <code>irq_dispatch()</code></a>
</ul>
<a href="#ledsupport">4.3 LED Support</a>
<ul>
<a href="#ledheaders">4.3.1 Header Files</a><br>
<a href="#leddefinitions">4.3.2 LED Definitions</a><br>
<a href="#ledapis">4.3.3 Common LED interfaces</a>
</ul>
</ul>
<a href="#NxFileSystem">5.0 NuttX File System</a><br>
<a href="#DeviceDrivers">6.0 NuttX Device Drivers</a><br>
<ul>
<a href="#chardrivers">6.1 Character Device Drivers</a><br>
<a href="#blockdrivers">6.2 Block Device Drivers</a><br>
<a href="#blockdrivers">6.3 Specialized Device Drivers</a>
<ul>
<a href="#ethdrivers">6.3.1 Ethernet Device Drivers</a><br>
<a href="#spidrivers">6.3.2 SPI Device Drivers</a><br>
<a href="#i2cdrivers">6.3.3 I2C Device Drivers</a><br>
<a href="#serialdrivers">6.3.4 Serial Device Drivers</a>
</ul>
</ul>
<a href="#apndxconfigs">Appendix A: NuttX Configuration Settings</a><br>
<a href="#apndxtrademarks">Appendix B: Trademarks</a>
</ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1>1.0 <a name="Introduction">Introduction</a></h1>
</td>
</tr>
</table>
<p><b>Overview</b>
This document provides and overview of the NuttX build and configuration
logic and provides hints for the incorporation of new processor/board architectures
into the build.
</p>
<p>
See also <code>arch/README.txt</code> and <code>configs/README.txt</code>.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1>2.0 <a name="DirectoryStructure">Directory Structure</a></h1>
</td>
</tr>
</table>
<p>
<b>Directory Structure</b>.
The general directly layout for NuttX is very similar to the directory structure
of the Linux kernel -- at least at the most superficial layers.
At the top level is the main makefile and a series of sub-directories identified
below and discussed in the following paragraphs:
</p>
<ul><pre>
.
|-- <a href="#topmakefile">Makefile</a>
|-- <a href="#DirStructDocumentation">Documentation</a>
| `-- <i>(documentation files)</i>/
|-- <a href="#DirStructArch">arch</a>/
| |-- <i><arch-name></i>/
| | |-- include/
| | | |--<i><chip-name></i>/
| | | | `-- <i>(chip-specific header files)</i>
| | | |--<i><other-chips></i>/
| | | `-- <i>(architecture-specific header files)</i>
| | `-- src/
| | |--<i><chip-name></i>/
| | | `-- <i>(chip-specific source files)</i>
| | |--<i><other-chips></i>/
| | `-- <i>(architecture-specific source files)</i>
| `-- <i><other-architecture directories></i>/
|-- <a href="#DirStructBinFmt">binfmt</a>/
| |-- Makefile
| |-- <i>(binfmt-specific sub-directories)</i>/
| | `-- <i>(binfmt-specific source files)</i>
| `-- <i>(common binfmt source files)</i>
|-- <a href="#DirStructConfigs">configs</a>/
| |-- <i><board-name></i>/
| | |-- include/
| | | `-- <i>(other board-specific header files)</i>
| | |-- src/
| | | `-- <i>(board-specific source files)</i>
| | |---<i><config-name></i>/
| | | `-- <i>(board configuration-specific source files)</i>
| | `---<i>(other configuration sub-directories for this board)</i>/
| `-- <i><(other board directories)></i>/
|-- <a href="#DirStructDrivers">drivers</a>/
| |-- Makefile
| |-- <i>(driver-specific sub-directories)/</i>
| | `-- <i>(driver-specific source files)</i>
| `-- <i>(common driver source files)</i>
|-- <a href="#DirStructExamples">examples</a>/
| `-- <i>(example)</i>/
| |-- Makefile
| `-- <i>(example source files)</i>
|-- <a href="#DirStructFs">fs</a>/
| |-- Makefile
| |-- <i>(file system-specific sub-directories)</i>/
| | `-- <i>(file system-specific source files)</i>
| `-- <i>(common file system source files)</i>
|-- <a href="#DirStructGraphics">graphics</a>/
| |-- Makefile
| |-- <i>(feature-specific sub-directories)</i>/
| | `-- <i>(feature-specific source files library source files)</i>
| `-- <i>(common graphics-related source files)</i>
|-- <a href="#DirStructInclude">include</a>/
| |-- <i>(standard header files)</i>
| |-- <i>(standard include sub-directories)</i>
| | `-- <i>(more standard header files)</i>
| |-- <i>(non-standard include sub-directories)</i>
| `-- <i>(non-standard header files)</i>
|-- <a href="#DirStructLib">lib</a>/
| |-- Makefile
| `-- <i>(lib source files)</i>
|-- <a href="#DirStructLibXX">libxx</a>/
| |-- Makefile
| `-- <i>(libxx management source files)</i>
|-- <a href="#DirStructMm">mm</a>/
| |-- Makefile
| `-- <i>(memory management source files)</i>
|-- <a href="#DirStructNet">net</a>/
| |-- Makefile
| |-- uip/
| | `-- <i>(uip source files)</i>
| `-- <i>(BSD socket source files)</i>
|-- <a href="#DirStructNetUtils">netutils</a>/
| |-- Makefile
| |-- <i>(network feature sub-directories)</i>/
| | `-- <i>(network feature source files)</i>
| `-- <i>(netutils common files)</i>
|-- <a href="#DirStructSched">sched</a>/
| |-- Makefile
| `-- <i>(sched source files)</i>
`-- <a href="#DirStructTools">tools</a>/
`-- <i>(miscellaneous scripts and programs)</i>
</pre></ul>
<p>
<b>Configuration Files</b>.
The NuttX configuration consists of:
</p>
<ul>
<li>
<i>Processor architecture specific files</i>.
These are the files contained in the <code>arch/</code><i><arch-name></i><code>/</code> directory
and are discussed in a paragraph <a href="#archdirectorystructure">below</a>.
</li>
<li>
<i>Chip/SoC specific files</i>.
Each processor processor architecture is embedded in chip or <i>System-on-a-Chip</i> (SoC) architecture.
The full chip architecture includes the processor architecture plus chip-specific interrupt logic,
clocking logic, general purpose I/O (GIO) logic, and specialized, internal peripherals (such as UARTs, USB, etc.).
<p>
These chip-specific files are contained within chip-specific sub-directories in the
<code>arch/</code><i><arch-name></i><code>/</code> directory and are selected via
the <code>CONFIG_ARCH_name</code> selection.
</p>
</li>
<li>
<i>Board specific configurations</i>.
In order to be usable, the chip must be contained in a board environment.
The board configuration defines additional properties of the board including such things as
peripheral LEDs, external peripherals (such as network, USB, etc.).
<p>
These board-specific configuration files can be found in the
<code>configs/</code><i><board-name></i><code>/</code> sub-directories and are discussed
in a paragraph <a href="#configsdirectorystructure">below</a>.
</p>
</li>
</ul>
<h2>2.1 <a name="DirStructDocumentation">Documentation</a></h2>
<p>
General documentation for the NuttX OS resides in this directory.
</p>
<h2>2.2 <a name="DirStructArch">arch</a></h2>
<h3><a name="archdirectorystructure">2.2.1 Subdirectory Structure</a></h3>
<p>
This directory contains several sub-directories, each containing
architecture-specific logic.
The task of porting NuttX to a new processor consists of
add a new subdirectory under <code>arch/</code> containing logic specific
to the new architecture.
The complete board port in is defined by the architecture-specific code in this
directory (plus the board-specific configurations in the <code>config/</code>
subdirectory).
Each architecture must provide a subdirectory, <i><arch-name></i>
under <code>arch/</code> with the following characteristics:
</p>
<ul><pre>
<i><arch-name></i>/
|-- include/
| |--<i><chip-name></i>/
| | `-- <i>(chip-specific header files)</i>
| |--<i><other-chips></i>/
| |-- arch.h
| |-- irq.h
| |-- types.h
| `-- limits.h
`-- src/
|--<i><chip-name></i>/
| `-- <i>(chip-specific source files)</i>
|--<i><other-chips></i>/
|-- Makefile
`-- <i>(architecture-specific source files)</i>
</pre></ul>
<h3><a name="summaryofarchfiles">2.2.2 Summary of Files</a></h3>
<ul>
<li>
<code>include/</code><i><chip-name></i><code>/</code>
This sub-directory contains chip-specific header files.
</li>
<li>
<code>include/arch.h</code>:
This is a hook for any architecture specific definitions that may
be needed by the system. It is included by <code>include/nuttx/arch.h</code>.
</li>
<li>
<code>include/types.h</code>:
This provides architecture/toolchain-specific definitions for
standard types. This file should <code>typedef</code>:
<ul><code>
sbyte, ubyte, uint8, boolean, sint16, uint16, sint32, uint32
</code></ul>
<p>and if the architecture supports 64-bit integers</p>
<ul><code>
sint64, uint64
</code></ul>
<p>
and finally
</p>
<ul><code>
irqstate_t
</code></ul>
<p>
Must be defined to the be the size required to hold the interrupt
enable/disable state.
</p>
<p>
This file will be included by include/sys/types.h and be made
available to all files.
</p>
</li>
<li>
<code>include/irq.h</code>:
This file needs to define some architecture specific functions (usually
inline if the compiler supports inlining) and structure. These include:
<ul>
<li>
<code>struct xcptcontext</code>:
This structures represents the saved context of a thread.
</li>
<li>
<code>irqstate_t irqsave(void)</code>:
Used to disable all interrupts.
</li>
<li>
<code>void irqrestore(irqstate_t flags)<code>:
Used to restore interrupt enables to the same state as before <code>irqsave()</code> was called.
</li>
</ul>
<p>
This file must also define <code>NR_IRQS</code>, the total number of IRQs supported
by the board.
</p>
</li>
<li>
<code>src/</code><i><chip-name></i><code>/</code>
This sub-directory contains chip-specific source files.
</li>
<li>
<code>src/Makefile</code>:
This makefile will be executed to build the targets <code>src/libup.a</code> and
<code>src/up_head.o</code>. The <code>up_head.o</code> file holds the entry point into the system
(power-on reset entry point, for example). It will be used in
the final link with <code>libup.a</code> and other system archives to generate the
final executable.
</li>
<li>
<i>(architecture-specific source files)</i>.
The file <code>include/nuttx/arch.h</code> identifies all of the APIs that must
be provided by the architecture specific logic. (It also includes
<code>arch/</code><i><arch-name></i><code>/arch.h</code> as described above).
</li>
</ul>
<h3><a name="supportedarchitectures">2.2.3 Supported Architectures</a></h3>
<p>
<b>Architecture- and Chip-Specific Directories</b>.
All processor architecture-specific directories are maintained in sub-directories of
the <code>arch/</code> directory.
Different chips or SoC's may implement the same processor core.
Chip-specific logic can be found in sub-directories under the architecture
directory.
Current architecture/chip directories are summarized below:
</p>
<ul>
<li><code>arch/sim</code>:
A user-mode port of NuttX to the x86 Linux platform is available.
The purpose of this port is primarily to support OS feature development.
This port does not support interrupts or a real timer (and hence no
round robin scheduler) Otherwise, it is complete.
</li>
<p>NOTE: This target will not run on Cygwin probably for many reasons but
first off because it uses some of the same symbols as does cygwind.dll.
</p>
<li><code>arch/arm</code>:
This directory holds common ARM architectures. At present, this includes
the following subdirectories:
<ul>
<li><code>arch/arm/include</code> and <code>arch/arm/src/common</code>:
Common ARM logic.
</li>
<li><code>arch/arm/include/c5471</code> and <code>arch/arm/src/c5471</code>:
TI TMS320C5471 (also called TMS320DM180 or just C5471).
NuttX operates on the ARM7 of this dual core processor.
This port is complete, verified, and included in the NuttX release 0.1.1.
</li>
<li><code>arch/arm/include/dm320</code> and <code>arch/arm/src/dm320</code>:
TI TMS320DM320 (also called just DM320).
NuttX operates on the ARM9EJS of this dual core processor.
This port complete, verified, and included in the NuttX release 0.2.1.
</li>
<li><code>arch/arm/include/lpc214x</code> and <code>arch/arm/src/lpc214x</code>:
These directories provide support for NXP LPC214x family of
processors.
STATUS: This port is in progress and should be available in the
nuttx-0.2.5 release.
</li>
</ul>
</li>
<li><code>configs/mcu123-lpc214x</code>:
The mcu123.com lpc214x development board.
This is a work in progress.
</li>
<li><code>arch/m68322</code>
A work in progress.
</li>
<li><code>arch/pjrc-8051</code>:
8051 Microcontroller. This port is not quite ready for prime time.
</li>
<li><code>arch/z16f</code>:
Zilog z16f Microcontroller.
This port uses the Zilog z16f2800100zcog Development Kit.
This port was released with nuttx-0.3.7.
</li>
<li><code>arch/z80</code>:
This directory holds 8-bit ZiLOG architectures. At present, this includes the
Zilog z80, ez80Acclaim! and z8Encore! Microcontrollers.
<ul>
<li><code>arch/z80/include</code> and <code>arch/z80/src/common</code>:
Common logic.
</li>
<li><code>arch/z80/include/z80</code> and <code>arch/z80/src/z80</code>:
The Z80 port was released in nuttx-0.3.6 has been verified using only a
z80 instruction simulator.
The set simulator can be found in the NuttX CVS at
http://nuttx.cvs.sourceforge.net/nuttx/misc/sims/z80sim.
This port also uses the SDCC toolchain (http://sdcc.sourceforge.net/")
(verified with version 2.6.0 and 2.7.0).
</li>
<li><code>arch/z80/include/ez80</code> and <code>arch/z80/src/ez80</code>:
The ez80Acclaim! port uses the ZiLOG ez80f0910200kitg development kit, eZ80F091 part,
with the Zilog ZDS-II Windows command line tools.
The development environment is Cygwin under WinXP.
This is a work in progress. Verified ez80 support will be announced in a future NuttX release.
</li>
<li><code>arch/z80/include/z8</code> and <code>arch/z80/src/z8</code>:
The Z8Encore! port uses either the ZiLOG z8encore000zco development kit, Z8F6403 part,
or the z8f64200100kit development kit, Z8F6423 part with the Zilog ZDS-II Windows command line
tools. The development environment is Cygwin under WinXP.
The initial release, verified only on the ZDS-II ez8 simulator, was released in nuttx-0.3.9.
</li>
</ul>
</li>
</ul>
<p>
<b>Deprecated Architecture Directories</b>.
The following architecture directories are deprecated. They have been
replaced by the logic in <code>arm/arm</code> and will deleted when
<code>arch/arm</code> is fully verified.
</p>
<ul>
<li><code>arch/c5471</code>:
Replaced with <code>arch/arm/include/c5471</code> and
<code>arch/arm/src/c5471<code>.
</li>
<li><code>arch/dm320</code>:
Replaced with <code>arch/arm/include/dm320</code> and
<code>arch/arm/src/dm320<code>.
</li>
</ul>
<p>
Other ports for the for the TI TMS320DM270 and for MIPS are in various states
of progress
</p>
<h2>2.3 <a name="DirStructBinFmt">binfmt</a></h2>
<p>
The <code>binfmt/</code> subdirectory contains logic for loading binaries in the file
system into memory in a form that can be used to execute them.
</p>
<h2>2.4 <a name="DirStructConfigs">configs</a></h2>
<p>
The <code>configs/</code> subdirectory contains configuration data for each board.
These board-specific configurations plus the architecture-specific configurations in
the <code>arch/</code> subdirectory complete define a customized port of NuttX.
</p>
<h3><a name="configsdirectorystructure">2.3.1 Subdirectory Structure</a></h3>
<p>
The configs directory contains board specific configuration files. Each board must
provide a subdirectory <board-name> under <code>configs/</code> with the following characteristics:
</p>
<ul><pre>
<i><board-name></i>
|-- include/
| |-- board.h
| `-- <i>(board-specific header files)</i>
|-- src/
| |-- Makefile
| `-- <i>(board-specific source files)</i>
|-- <i><config1-dir></i>
| |-- Make.defs
| |-- defconfig
| `-- setenv.sh
|-- <i><config2-dir></i>
| |-- Make.defs
| |-- defconfig
| `-- setenv.sh
| ...
`-- <i>(other board-specific configuration sub-directories)</i>/
</pre></ul>
<h3><a name="summaryofconfigfiles">2.3.2 Summary of Files</a></h3>
<h4><a name="boardlogic">2.3.2.1 Board Specific Logic</a></h4>
<ul>
<li>
<code>include/</code>:
This directory contains board specific header files.
This directory will be linked as <code>include/arch/board</code> at configuration time
and can be included via <code>#include <arch/board/header.h></code>.
These header file can only be included by files in <code>arch/</code><i><arch-name></i><code>/include/</code>
and <code>arch/</code><i><arch-name></i><code>/src/</code>.
</li>
<li>
<code>src/</code>:
This directory contains board specific drivers.
This directory will be linked as <config>arch/</code><i><arch-name></i><code>/src/board</config> at configuration
time and will be integrated into the build system.
</li>
<li>
<code>src/Makefile</code>:
This makefile will be invoked to build the board specific drivers.
It must support the following targets: <code>libext$(LIBEXT)</code>, <code>clean</code>, and <code>distclean</code>.
</li>
</ul>
<h4><a name="boardconfigsubdirs">2.3.2.2 Board Specific Configuration Sub-Directories</a></h4>
<p>
The <code>configs/</code><i><board-name></i><code>/</code> sub-directory holds all of the
files that are necessary to configure NuttX for the particular board.
A board may have various different configurations using the common source files.
Each board configuration is described by three files: <code>Make.defs</code>, <code>defconfig</code>, and <code>setenv.sh</code>.
Typically, each set of configuration files is retained in a separate configuration sub-directory
(<i><config1-dir></i>, <i><config2-dir></i>, .. in the above diagram).
The procedure for configuring NuttX is described <a href="#configuringnuttx">below</a>,
This paragraph will describe the contents of these configuration files.
</p>
<ul>
<li>
<code>Make.defs</code>: This makefile fragment provides architecture and
tool-specific build options. It will be included by all other
makefiles in the build (once it is installed). This make fragment
should define:
<ul>
<li>Tools: CC, LD, AR, NM, OBJCOPY, OBJDUMP</li>
<li>Tool options: CFLAGS, LDFLAGS</li>
<li>COMPILE, ASSEMBLE, ARCHIVE, CLEAN, and MKDEP macros</li>
</ul>
<p>
When this makefile fragment runs, it will be passed TOPDIR which
is the path to the root directory of the build. This makefile
fragment may include ${TOPDIR}/.config to perform configuration
specific settings. For example, the CFLAGS will most likely be
different if CONFIG_DEBUG=y.
</p>
</li>
<li>
<code>defconfig</code>: This is a configuration file similar to the Linux
configuration file. In contains variable/value pairs like:
<ul>
<li><code>CONFIG_VARIABLE</code>=value</li>
</ul>
<p>
This configuration file will be used at build time:
</p>
<ol>
<li>As a makefile fragment included in other makefiles, and</li>
<li>to generate <code>include/nuttx/config.h</code> which is included by
most C files in the system.</li>
</ol>
</li>
<li>
<code>setenv.sh</code>: This is a script that you can include that will be installed at
the top level of the directory structure and can be sourced to set any
necessary environment variables.
</li>
</ul>
<h3><a name="supportedboards">2.3.3 Supported Boards</a></h3>
<p>
All of the specific boards supported by NuttX are identified below.
These are the specific <i><board-name></i>'s that may be used to configure NuttX
as described <a href="#configuringnuttx">below</a>.
</p>
<ul>
<li><code>configs/c5471evm</code>:
This is a port to the Spectrum Digital C5471 evaluation board. The
C5471 is a dual core processor from TI with an ARM7TDMI general purpose
processor and a c54 SDP. NuttX runs on the ARM core and is built with
with a GNU arm-elf toolchain* under Linux or Cygwin.
This port is complete, verified, and included in the NuttX release.
</li>
<li><code>configs/ez80f0910200kitg</code>
ez80Acclaim! Microcontroller. This port use the Zilog ez80f0910200kitg
development kit, eZ80F091 part, and the Zilog ZDS-II Windows command line
tools. The development environment is Cygwin under WinXP.
</li>
<li><code>configs/m68322evb</code>:
This is a work in progress for the venerable m68322evb board from
Motorola.
</li>
<li><code>configs/mcu123-lpc214x</code>:
This port is for the NXP LPC2148 as provided on the mcu123.com
lpc214x development board.
This OS is also built with the arm-elf toolchain* under Linux or Cygwin.
The port supports serial, timer0, spi, and usb.
</li>
<li><code>configs/ntosd-dm320</code>:
This port uses the Neuros OSD with a GNU arm-elf toolchain* under Linux or Cygwin.
See <a href="http://wiki.neurostechnology.com/index.php/Developer_Welcome">Neuros Wiki</a>
for further information.
NuttX operates on the ARM9EJS of this dual core processor.
STATUS: This port is code complete, verified, and included in the
NuttX 0.2.1 release.
</li>
<li><code>configs/olimex-strp711</code>:
This port uses the Olimex STR-P711 board arm-elf toolchain* under Linux or Cygwin.
See the <a href="http://www.olimex.com/dev/str-p711.html">Olimex</a> web site
for further information.
STATUS: Coding for the basic port -- serial console and system timer -- is complete
but untested to problems I am having using OpenOCD with a wiggler clone JTAG.
</li>
<li><code>configs/pjrc-8051</code>:
8051 Microcontroller. This port uses the PJRC 87C52 development system
and the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain under Linux or Cygwin.
This port is not quite ready for prime time.
</li>
<li><code>configs/sim</code>:
A user-mode port of NuttX to the x86 Linux platform is available.
The purpose of this port is primarily to support OS feature development.
This port does not support interrupts or a real timer (and hence no
round robin scheduler) Otherwise, it is complete.
</li>
<li><code>configs/us7032evb1</code>:
This is a port of the Hitachi SH-1 on the Hitachi SH-1/US7032EVB1 board.
STATUS: Work has just began on this port.
</li>
<li><code>configs/xtrs</code>:
TRS80 Model 3. This port uses a vintage computer based on the Z80.
An emulator for this computer is available to run TRS80 programs on a
Linux platform (http://www.tim-mann.org/xtrs.html).
</li>
<li><code>configs/z16f2800100zcog</code>
z16f Microcontroller.
This port use the Zilog z16f2800100zcog development kit and the
Zilog ZDS-II Windows command line tools.
The development environment is Cygwin under WinXP.
</li>
<li><code>configs/z80sim</code>:
z80 Microcontroller. This port uses a Z80 instruction set simulator.
That simulator can be found in the NuttX CVS
<a href="http://nuttx.cvs.sourceforge.net/nuttx/misc/sims/z80sim/">here</a>.
This port also the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain
under Linux or Cygwin(verified with version 2.6.0).
</li>
<li><code>configs/z8encore000zco</code>
z8Encore! Microcontroller. This port use the Zilog z8encore000zco
development kit, Z8F6403 part, and the Zilog ZDS-II Windows command line
tools. The development environment is Cygwin under WinXP.
</li>
<li><code>configs/z8encore000zco</code>
z8Encore! Microcontroller. This port use the Zilog z8f64200100kit
development kit, Z8F6423 part, and the Zilog ZDS-II Windows command line
tools. The development environment is Cygwin under WinXP.
</li>
</ul>
<p><small><blockquote>
* A customized version of the <a href="http://www.buildroot.org">buildroot</a>
is available to build these toolchains under Linux or Cygwin.
</blockquote></small></p>
<h2>2.5 <a name="DirStructDrivers">drivers</a></h2>
<p>
This directory holds architecture-independent device drivers.
</p>
<ul><pre>
drivers/
|-- Makefile
|-- bch/
| |-- Make.defs
| `-- <i>(bch driver source files)</i>
|-- mmcsd/
| |-- Make.defs
| `-- <i>(mmcsd driver source files)</i>
|-- net/
| |-- Make.defs
| `-- <i>(net driver source files)</i>
|-- usbdev/
| |-- Make.defs
| `-- <i>(usbdev driver source files)</i>
`-- <i>(common driver source files)</i>
</pre></ul>
<h2>2.6 <a name="DirStructExamples">examples</a></h2>
<p>
Example and test programs to build against.
</p>
<h2>2.7 <a name="DirStructFs">fs</a></h2>
<p>
This directory contains the NuttX file system.
This file system is described <a href="#NxFileSystem">below</a>.
</p>
<ul><pre>
fs/
|-- Makefile
|-- fat/
| |-- Make.defs
| `-- <i>(fat file system source files)</i>
|-- romfs/
| |-- Make.defs
| `-- <i>(romfs file system source files)</i>
`-- <i>(common file system source files)</i>
</pre></ul>
<h2>2.8 <a name="DirStructGraphics">graphics</a></h2>
<p>
This directory contains files for graphics/video support under NuttX.
</p>
<ul><pre>
graphics/
|-- Makefile
|-- nxglib/
| |-- Make.defs
| `-- <i>(NuttX graphics library source files)</i>
|-- nx/
| |-- Make.defs
| `-- <i>(NuttX X-server source files)</i>
`-- <i>(common file system source files)</i>
</pre></ul>
<h2>2.9 <a name="DirStructInclude">include</a></h2>
<p>
This directory holds NuttX header files.
Standard header files file retained in can be included in the <i>normal</i> fashion:
</p>
<ul>
<code>include <stdio.h></code><br>
<code>include <sys/types.h></code><br>
etc.
</ul>
<p>
Directory structure:
</p>
<ul><pre>
include/
|-- <i>(standard header files)</i>
|-- arpa/
| `-- <i>(standard header files)</i>
|-- net/
| `-- uip/
| `-- <i>(uIP specific header files)</i>
|-- netinet/
| `-- <i>(standard header files)</i>
|-- nuttx/
| `-- <i>(nuttx specific header files)</i>
`- sys/
`-- <i>(more standard header files)</i>
</per></ul>
<h2>2.10 <a name="DirStructLib">lib</a></h2>
<p>
This directory holds a collection of standard libc-like functions with custom
interfaces into NuttX.
</p>
<h2>2.11 <a name="DirStructLibXX">libxx</a></h2>
<p>
This directory holds a tiny, minimal standard std C++ that can be used to
build some, simple C++ applications in NuttX.
</p>
<h2>2.12 <a name="DirStructMm">mm</a></h2>
<p>
This is the NuttX memory manager.
</p>
<h2>2.13 <a name="DirStructNet">net</a></h2>
<p>
This directory contains the implementation of the socket APIs.
The subdirectory, <code>uip</code> contains the uIP port.
</P>
<h2>2.14 <a name="DirStructNetUtils">netutils</a></h2>
<p>
This directory contains most of the network applications.
Some of these are original with NuttX (like tftpc and dhcpd) and others were leveraged from the uIP-1.0 apps directory.
As the uIP apps/README says, these applications "are not all heavily tested."
</p>
<ul><pre>
netutils/
|-- Makefile
|-- dhcp/
| |-- Make.defs
| `-- <i>(dhcp source files)</i>
|-- dhcpd/
| |-- Make.defs
| `-- <i>(dhcpd source files)</i>
|-- resolv/
| |-- Make.defs
| `-- <i>(resolv source files)</i>
|-- smtp/
| |-- Make.defs
| `-- <i>(smtp source files)</i>
|-- telnetd/
| |-- Make.defs
| `-- <i>(telnetd source files)</i>
|-- tftpc/
| |-- Make.defs
| `-- <i>(tftpc source files)</i>
|-- uiplib/
| |-- Make.defs
| `-- <i>(uiplib source files)</i>
|-- weblclient/
| |-- Make.defs
| `-- <i>(webclient source files)</i>
|-- webserver/
| |-- Make.defs
| `-- <i>(webserver source files)</i>
`-- <i>(netutils common files)</i>
</pre></ul>
<h2>2.15 <a name="DirStructSched">sched</a></h2>
<p>
The files forming core of the NuttX RTOS reside here.
</p>
<h2>2.16 <a name="DirStructTools">tools</a></h2>
<p>
This directory holds a collection of tools and scripts to simplify
configuring, building and maintaining NuttX.
</p>
<ul><pre>
tools/
|-- Makefile.mkconfig
|-- configure.sh
|-- incdir.sh
|-- indent.sh
|-- link.sh
|-- mkconfig.c
|-- mkdeps.sh
|-- mkimage.sh
|-- mknulldeps.sh
|-- unlink.sh
|-- winlink.sh
`-- zipme
</pre></ul>
<h2>2.17 <a name="topmakefile">Makefile</a></h2>
<p>
The top-level <code>Makefile</code> in the <code>${TOPDIR}</code> directory contains all of the top-level control
logic to build NuttX.
Use of this <code>Makefile</code> to build NuttX is described <a href="#buildingnuttx">below</a>.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1>3.0 <a name="configandbuild">Configuring and Building</a></h1>
</td>
</tr>
</table>
<h2><a name="configuringnuttx">3.1 Configuring NuttX</a></h2>
<p>
<b>Manual Configuration</b>.
Configuring NuttX requires only copying the
<a href="#boardconfigsubdirs">board-specific configuration files</a> into the top level directory which appears in the make files as the make variable, <code>${TOPDIR}</code>.
This could be done manually as follows:
</p>
<ul>
<li>Copy <code>configs/</code><i><board-name></i><code>/[</code><i><config-dir></i><code>/]Make.def</code> to <code>${TOPDIR}/Make.defs</code>,<li>
<li>Copy <code>configs/</code><i><board-name></i><code>/[</code><i><config-dir></i><code>/]setenv.sh</code> to <code>${TOPDIR}/setenv.sh</code>, and</li>
<li>Copy <code>configs/</code><i><board-name></i><code>/[</code><i><config-dir></i><code>/]defconfig</code> to <code>${TOPDIR}/.config</code></li>
</ul>
<p>
Where <i><board-name></i> is the name of one of the sub-directories of the
NuttX <a href="#DirStructConfigs"><code>configs/</code></a> directory.
This sub-directory name corresponds to one of the supported boards
identified <a href="#supportedboards">above</a>.
And <config-dir> is the optional, specific configuration directory for the board.
</p>
<p>
<b>Automated Configuration</b>.
There is a script that automates these steps. The following steps will
accomplish the same configuration:
</p>
<ul><pre>
cd tools
./configure.sh <i><board-name></i></i><code>[/</code><i><config-dir></i><code>]</code>
</pre></ul>
<p>
<b>Additional Configuration Steps</b>.
The remainder of configuration steps will be performed by <a href="#topmakefile"><code>${TOPDIR}/Makefile</code></a>
the first time the system is built as described below.
</p>
<h2><a name="buildingnuttx">3.2 Building NuttX</a></h2>
<p>
<b>Building NuttX</b>.
Once NuttX has been configured as described <a href="#configuringnuttx">above</a>, it may be built as follows:
</p>
<ul><pre>
cd ${TOPDIR}
source ./setenv.sh
make
</pre></ul>
<p>
The <code>${TOPDIR}</code> directory holds:
</p>
<ul>
<li>The top level <a href="#topmakefile"><code>Makefile</code></a> that controls the NuttX build.
</ul>
<p>
That directory also holds:
</p>
<ul>
<li>The makefile fragment <a href="#boardconfigsubdirs"><code>.config</code></a> that describes the current configuration.</li>
<li>The makefile fragment <a href="#boardconfigsubdirs"><code>Make.defs</code></a> that provides customized build targets, and</li>
<li>The shell script <a href="#boardconfigsubdirs"><code>setenv.sh</code></a> that sets up the configuration environment for the build.</li>
</ul>
<p>
The <a href="#boardconfigsubdirs"><code>setenv.sh</code></a> contains Linux/Cygwin environmental settings that are needed for the build.
The specific environmental definitions are unique for each board but should include, as a minimum, updates to the <code>PATH</code> variable to include the full path to the architecture-specific toolchain identified in <a href="#boardconfigsubdirs"><code>Make.defs</code></a>.
The <a href="#boardconfigsubdirs"><code>setenv.sh</code></a> only needs to be source'ed at the beginning of a session.
The system can be re-made subsequently by just typing <code>make</code>.
</p>
<p>
<b>First Time Make.</b>
Additional configuration actions will be taken the first time that system is built.
These additional steps include:
</p>
<ul>
<li>Auto-generating the file <code>include/nuttx/config.</code> using the <code>${TOPDIR}/.config</code> file.
<li>Creating a link to <code>${TOPDIR}/arch/</code><i><arch-name></i><code>/include</code> at <code>${TOPDIR}/include/arch</code>.
<li>Creating a link to <code>${TOPDIR}/configs/</code><i><board-name></i><code>/include</code> at <code>${TOPDIR}/include/arch/board</code>.
<li>Creating a link to <code>${TOPDIR}/configs/</code><i><board-name></i><code>/src</code> at <code>${TOPDIR}/arch/</code><i><arch-name></i><code>/src/board</code>
<li>Creating make dependencies.
</ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1>4.0 <a name="ArchAPIs">Architecture APIs</a></h1>
</td>
</tr>
</table>
<p>
The file <code>include/nuttx/arch.h</code> identifies by prototype all of the APIs that must
be provided by the architecture specific logic.
The internal OS APIs that architecture-specific logic must
interface with also also identified in <code>include/nuttx/arch.h</code> or in
other header files.
</p>
<h2><a name="imports">4.1 APIs Exported by Architecture-Specific Logic to NuttX</a></h2>
<h3><a name="upinitialize">4.1.1 <code>up_initialize()</code></a></h3>
<p><b>Prototype</b>: <code>void up_initialize(void);</code></p>
<p><b>Description</b>.
<code>up_initialize()</code> will be called once during OS
initialization after the basic OS services have been
initialized. The architecture specific details of
initializing the OS will be handled here. Such things as
setting up interrupt service routines, starting the
clock, and registering <a href="#DeviceDrivers">device drivers</a> are some of the
things that are different for each processor and hardware
platform.
</p>
<p>
<code>up_initialize()</code> is called after the OS initialized but
before the init process has been started and before the
libraries have been initialized. OS services and driver
services are available.
</p>
<h3><a name="upidle">4.1.2 <code>up_idle()</code></a></h3>
<p><b>Prototype</b>: <code>void up_idle(void);</code></p>
<p><b>Description</b>.
<code>up_idle()</code> is the logic that will be executed
when their is no other ready-to-run task. This is processor
idle time and will continue until some interrupt occurs to
cause a context switch from the idle task.
</p>
<p>
Processing in this state may be processor-specific. e.g.,
this is where power management operations might be performed.
</p>
<h3><a name="upinitialstate">4.1.3 <code>up_initial_state()</code></a></h3>
<p><b>Prototype</b>: <code>void up_initial_state(FAR _TCB *tcb);</code></p>
<p><b>Description</b>.
A new thread is being started and a new TCB
has been created. This function is called to initialize
the processor specific portions of the new TCB.
</p>
<p>
This function must setup the initial architecture registers
and/or stack so that execution will begin at tcb->start
on the next context switch.
</p>
<h3><a name="upcreatestack">4.1.4 <code>up_create_stack()</code></a></h3>
<p><b>Prototype</b>: <code>STATUS up_create_stack(FAR _TCB *tcb, size_t stack_size);</code></p>
<p><b>Description</b>.
Allocate a stack for a new thread and setup
up stack-related information in the TCB.
</p>
<p>
The following TCB fields must be initialized:
</p>
<ul>
<li><code>adj_stack_size</code>: Stack size after adjustment for hardware,
processor, etc. This value is retained only for debug
purposes.</li>
<li><code>stack_alloc_ptr</code>: Pointer to allocated stack</li>
<li><code>adj_stack_ptr</code>: Adjusted <code>stack_alloc_ptr</code> for HW. The
initial value of the stack pointer.
</ul>
<p>
This API is <i>NOT</i> required if <code>CONFIG_CUSTOM_STACK</code>
is defined.
</p>
<p><b>Inputs</b>:</p?
<ul>
<li>
<code>tcb</code>: The TCB of new task.
</li>
<li>
<code>stack_size</code>: The requested stack size. At least this much
must be allocated.
</li>
</ul>
<h3><a name="upusestack">4.1.5 <code>up_use_stack()</code></a></h3>
<p><b>Prototype</b>:
<code>STATUS up_use_stack(FAR _TCB *tcb, FAR void *stack, size_t stack_size);</code>
</p>
<p><b>Description</b>.
Setup up stack-related information in the TCB
using pre-allocated stack memory.
</p>
<p>
The following TCB fields must be initialized:
</p>
<ul>
<li><code>adj_stack_size</code>: Stack size after adjustment for hardware,
processor, etc. This value is retained only for debug
purposes.</li>
<li><code>stack_alloc_ptr</code>: Pointer to allocated stack</li>
<li><code>adj_stack_ptr</code>: Adjusted <code>stack_alloc_ptr</code> for HW. The
initial value of the stack pointer.
</ul>
<p>
This API is <i>NOT</i> required if <code>CONFIG_CUSTOM_STACK</code>
is defined.
</p>
<p><b>Inputs:</b></p>
<ul>
<li>
<code>tcb</code>: The TCB of new task.
</li>
<li>
<code>stack_size</code>: The allocated stack size.
</li>
</ul>
<h3><a name="upreleasestack">4.1.6 <code>up_release_stack()</code></a></h3>
<p><b>Prototype</b>: <code>void up_release_stack(FAR _TCB *dtcb);</code></p>
<p><b>Description</b>.
A task has been stopped. Free all stack
related resources retained int the defunct TCB.
</p>
<p>
This API is <i>NOT</i> required if <code>CONFIG_CUSTOM_STACK</code>
is defined.
</p>
<h3><a name="upunblocktask">4.1.7 <code>up_unblock_task()</code></a></h3>
<p><b>Prototype</b>: <code>void up_unblock_task(FAR _TCB *tcb);</code></p>
<p><b>Description</b>.
A task is currently in an inactive task list
but has been prepped to execute. Move the TCB to the
ready-to-run list, restore its context, and start execution.
</p>
<p>
This function is called only from the NuttX scheduling
logic. Interrupts will always be disabled when this
function is called.
</p>
<p><b>Inputs</b>:
<ul>
<li><code>tcb</code>: Refers to the tcb to be unblocked. This tcb is
in one of the waiting tasks lists. It must be moved to
the ready-to-run list and, if it is the highest priority
ready to run tasks, executed.
</li>
</ul>
<h3><a name="upblocktask">4.1.8 <code>up_block_task()</code></a></h3>
<p><b>Prototype</b>: <code>void up_block_task(FAR _TCB *tcb, tstate_t task_state);</code></p>
<p><b>Description</b>.
The currently executing task at the head of
the ready to run list must be stopped. Save its context
and move it to the inactive list specified by task_state.
This function is called only from the NuttX scheduling
logic. Interrupts will always be disabled when this
function is called.
<p><b>Inputs:</b></p>
<ul>
<li><code>tcb</code>: Refers to a task in the ready-to-run list (normally
the task at the head of the list). It most be
stopped, its context saved and moved into one of the
waiting task lists. It it was the task at the head
of the ready-to-run list, then a context to the new
ready to run task must be performed.
</li>
<li><code>task_state</code>: Specifies which waiting task list should be
hold the blocked task TCB.
</li>
</ul>
<h3><a name="upreleasepending">4.1.9 <code>up_release_pending()</code></a></h3>
<p><b>Prototype</b>: <code>void up_release_pending(void);</code></p>
<p><b>Description</b>.
When tasks become ready-to-run but cannot run because pre-emption
is disabled, they are placed into a pending task list.
This function releases and makes ready-to-run all of the tasks that have
collected in the pending task list. This can cause a
context switch if a new task is placed at the head of
the ready to run list.
</p>
<p>
This function is called only from the NuttX scheduling logic when
pre-emption is re-enabled. Interrupts will always be disabled when this
function is called.
</p>
<h3><a name="upreprioritizertr">4.1.10 <code>up_reprioritize_rtr()</code></a></h3>
<p><b>Prototype</b>: <code>void up_reprioritize_rtr(FAR _TCB *tcb, ubyte priority);</code></p>
<p><b>Description</b>.
Called when the priority of a running or
ready-to-run task changes and the reprioritization will
cause a context switch. Two cases:
</p>
<ol>
<li>
The priority of the currently running task drops and the next
task in the ready to run list has priority.
</li>
<li>
An idle, ready to run task's priority has been raised above the
the priority of the current, running task and it now has the
priority.
</li>
</ol>
<p>
This function is called only from the NuttX scheduling
logic. Interrupts will always be disabled when this
function is called.
</p>
<p><b>Inputs:</b></p>
<ul>
<li>
<code>tcb</code>: The TCB of the task that has been reprioritized
</li>
<li>
<code>priority</code>: The new task priority
</li>
</ul>
<h3><a name="_exit">4.1.11 <code>_exit()</code></a></h3>
<p><b>Prototype</b>: <code>void _exit(int status) noreturn_function;</code></p>
<p><b>Description</b>.
This function causes the currently executing task to cease
to exist. This is a special case of task_delete().
</p>
<p>
Unlike other UP APIs, this function may be called
directly from user programs in various states. The
implementation of this function should disable interrupts
before performing scheduling operations.
</p>
<h3><a name="upassert">4.1.12 <code>up_assert()</code></a></h3>
<p><b>Prototype</b>:<br>
<code>void up_assert(FAR const ubyte *filename, int linenum);</code></br>
<code>void up_assert_code(FAR const ubyte *filename, int linenum, int error_code);</code></br>
</p>
<p><b>Description</b>.
Assertions may be handled in an architecture-specific
way.
</p>
<h3><a name="upschedulesigaction">4.1.13 <code>up_schedule_sigaction()</code></a></h3>
<p><b>Prototype</b>:
<code>void up_schedule_sigaction(FAR _TCB *tcb, sig_deliver_t sigdeliver);</code>
</p>
<p><b>Description</b>.
This function is called by the OS when one or more
signal handling actions have been queued for execution.
The architecture specific code must configure things so
that the 'sigdeliver' callback is executed on the thread
specified by 'tcb' as soon as possible.
</p>
<p>
This function may be called from interrupt handling logic.
</p>
<p>
This operation should not cause the task to be unblocked
nor should it cause any immediate execution of sigdeliver.
Typically, a few cases need to be considered:
</p>
<ol>
<li>
This function may be called from an interrupt handler
During interrupt processing, all xcptcontext structures
should be valid for all tasks. That structure should
be modified to invoke sigdeliver() either on return
from (this) interrupt or on some subsequent context
switch to the recipient task.
</li>
<li>
If not in an interrupt handler and the tcb is NOT
the currently executing task, then again just modify
the saved xcptcontext structure for the recipient
task so it will invoke sigdeliver when that task is
later resumed.
</li>
<li>
If not in an interrupt handler and the tcb IS the
currently executing task -- just call the signal
handler now.
</li>
</ol>
<p>
This API is <i>NOT</i> required if <code>CONFIG_DISABLE_SIGNALS</code>
is defined.
</p>
<h3><a name="upallocateheap">4.1.14 <code>up_allocate_heap()</code></a></h3>
<p><b>Prototype</b>: <code>void up_allocate_heap(FAR void **heap_start, size_t *heap_size);</code></p>
<p><b>Description</b>.
The heap may be statically allocated by
defining CONFIG_HEAP_BASE and CONFIG_HEAP_SIZE. If these
are not defined, then this function will be called to
dynamically set aside the heap region.
</p>
<p>
This API is <i>NOT</i> required if <code>CONFIG_HEAP_BASE</code>
is defined.
</p>
<h3><a name="upinterruptcontext">4.1.15 <code>up_interrupt_context()</code></a></h3>
<p><b>Prototype</b>: <code>boolean up_interrupt_context(void)</code></p>
<p><b>Description</b>.
Return TRUE is we are currently executing in
the interrupt handler context.
</p>
<h3><a name="updisableirq">4.1.16 <code>up_disable_irq()</code></a></h3>
<p><b>Prototype</b>:</p>
<ul><pre>
#ifndef CONFIG_ARCH_NOINTC
void up_disable_irq(int irq);
#endif
</pre></ul>
<p><b>Description</b>.
Disable the IRQ specified by 'irq'
On many architectures, there are three levels of interrupt enabling: (1)
at the global level, (2) at the level of the interrupt controller,
and (3) at the device level. In order to receive interrupts, they
must be enabled at all three levels.
</p>
<p>
This function implements enabling of the device specified by 'irq'
at the interrupt controller level if supported by the architecture
(irqsave() supports the global level, the device level is hardware
specific).
<p>
If the architecture does not support <code>up_disable_irq</code>,
<code>CONFIG_ARCH_NOINTC</code> should be defined in the NuttX configuration file.
Since this API cannot be supported on all architectures, it should be
avoided in common implementations where possible.
</p>
<h3><a name="upenableirq">4.1.17 <code>up_enable_irq()</code></a></h3>
<p><b>Prototype</b>:</p>
<ul><pre>
#ifndef CONFIG_ARCH_NOINTC
void up_enable_irq(int irq);
#endif
</pre></ul>
<p><b>Description</b>.
This function implements disabling of the device specified by 'irq'
at the interrupt controller level if supported by the architecture
(irqrestore() supports the global level, the device level is hardware
specific).
</p>
<p>
If the architecture does not support <code>up_disable_irq</code>,
<code>CONFIG_ARCH_NOINTC</code> should be defined in the NuttX configuration file.
Since this API cannot be supported on all architectures, it should be
avoided in common implementations where possible.
</p>
<h3><a name="upprioritizeirq">4.1.18 <code>up_prioritize_irq()</code></a></h3>
<p><b>Prototype</b>:</p>
<ul><pre>
#ifdef CONFIG_ARCH_IRQPRIO
void up_enable_irq(int irq);
#endif
</pre></ul>
<p><b>Description</b>.
Set the priority of an IRQ.
</p>
<p>
If the architecture supports <code>up_enable_irq</code>,
<code>CONFIG_ARCH_IRQPRIO</code> should be defined in the NuttX configuration file.
Since this API cannot be supported on all architectures, it should be
avoided in common implementations where possible.
</p>
<h3><a name="upputc">4.1.19 <code>up_putc()</code></a></h3>
<p><b>Prototype</b>: <code>int up_putc(int ch);</code></p>
<p><b>Description</b>.
This is a debug interface exported by the architecture-specific logic.
Output one character on the console
</p>
<h2><a name="exports">4.2 APIs Exported by NuttX to Architecture-Specific Logic</a></h2>
<p>
These are standard interfaces that are exported by the OS
for use by the architecture specific logic.
</p>
<h3><a name="osstart">4.2.1 <code>os_start()</code></a></h3>
<p>
<b><i>To be provided</i></b>
</p>
<h3><a name="listmgmt">4.2.2 OS List Management APIs</a></h3></h3>
<p>
<b><i>To be provided</i></b>
</p>
<h3><a name="schedprocesstimer">4.2.3 <code>sched_process_timer()</code></a></h3>
<p><b>Prototype</b>: <code>void sched_process_timer(void);</code></p>
<p><b>Description</b>.
This function handles system timer events.
The timer interrupt logic itself is implemented in the
architecture specific code, but must call the following OS
function periodically -- the calling interval must be
<code>MSEC_PER_TICK</code>.
</p>
<h3><a name="irqdispatch">4.2.4 <code>irq_dispatch()</code></a></h3>
<p><b>Prototype</b>: <code>void irq_dispatch(int irq, FAR void *context);</code></p>
<p><b>Description</b>.
This function must be called from the architecture-
specific logic in order to display an interrupt to
the appropriate, registered handling logic.
</p>
<h2><a name="ledsupport">4.3 LED Support</a></h2>
<p>
A board architecture may or may not have LEDs.
If the board does have LEDs, then most architectures provide similar LED support that is enabled when <code>CONFIG_ARCH_LEDS</code>
is selected in the NuttX configuration file.
This LED support is part of architecture-specific logic and is not managed by the core NuttX logic.
However, the support provided by each architecture is sufficiently similar that it can be documented here.
</p>
<h3><a name="ledheaders">4.3.1 Header Files</a></h3>
<p>
LED-related definitions are provided in two header files:
<ul>
<li>
LED definitions are provided for each board in the <code>board.h</code> that resides
in the <code><i><board-name></i>/include/board.h</code> file (which is also
linked to <code>include/arch/board/board.h</code> when the RTOS is configured).
Those definitions are discussed <a href="#leddefinitions">below</a>.
</li>
<li>
The board-specific logic provides unique instances of the LED interfaces.
This is because the implementation of LED support may be very different
on different boards.
Prototypes for these board-specific implementations are, however, provided
in architecture-common header files.
That header file is usually at <code><i><arch-name></i>/src/common/up_internal.h</code>,
but could be at other locations in particular architectures.
These prototypes are discussed <a href="#ledapis">below</a>.
</li>
</ul>
</p>
<h3><a name="leddefinitions">4.3.2 LED Definitions</a></h3>
<p>
The implementation of LED support is very specific to a board architecture.
Some boards have several LEDS, others have only one or two.
Some have none.
Others LED matrices and show alphanumeric data, etc.
The NuttX logic does not refer to specific LEDS, rather, it refers to an event to be shown on the LEDS
in whatever manner is appropriate for the board;
the way that this event is presented depends upon the hardware available on the board.
</p>
<p>
The model used by NuttX is that the board can show 8 events defined as follows in <code><i><board-name></i>/include/board.h</code>:
</p>
<ul><pre>
#define LED_STARTED ??
#define LED_HEAPALLOCATE ??
#define LED_IRQSENABLED ??
#define LED_STACKCREATED ??
#define LED_INIRQ ??
#define LED_SIGNAL ??
#define LED_ASSERTION ??
#define LED_PANIC ??
</pre></ul>
<p>
The specific value assigned to each pre-processor variable can be whatever makes the implementation easiest for the board logic.
The <i>meaning</i> associated with each definition is as follows:
</p>
<ul>
<li>
<code>LED_STARTED</code> is the value that describes the setting of the LEDs when the LED logic is first initialized.
This LED value is set but never cleared.
</li>
<li>
<code>LED_HEAPALLOCATE</code> indicates that the NuttX heap has been configured.
This is an important place in the boot sequence because if the memory is configured wrong, it will probably crash leaving this LED setting.
This LED value is set but never cleared.
</li>
<li>
<code>LED_IRQSENABLED</code> indicates that interrupts have been enabled.
Again, during bring-up (or if there are hardware problems), it is very likely that the system may crash just when interrupts are enabled, leaving this setting on the LEDs.
This LED value is set but never cleared.
</li>
<li>
<code>LED_STACKCREATED</code> is set each time a new stack is created.
If set, it means that the system attempted to start at least one new thread.
This LED value is set but never cleared.
</li>
<li>
<code>LED_INIRQ</code> is set and cleared on entry and exit from each interrupt.
If interrupts are working okay, this LED will have a dull glow.
</li>
<li>
<code>LED_SIGNAL</code> is set and cleared on entry and exit from a signal handler.
Signal handlers are tricky so this is especially useful during bring-up or a new architecture.
</li>
<li>
<code>LED_ASSERTION</code> is set if an assertion occurs.
</li>
<li>
<code>LED_PANIC</code> will blink at around 1Hz if the system panics and hangs.
</li>
</ul>
<h3><a name="ledapis">4.3.3 Common LED interfaces</a></h3>
<p>
The <code><i><arch-name></i>/src/common/up_internal.h</code> probably has definitions
like:
</p>
<ul><pre>
/* Defined in board/up_leds.c */
#ifdef CONFIG_ARCH_LEDS
extern void up_ledinit(void);
extern void up_ledon(int led);
extern void up_ledoff(int led);
#else
# define up_ledinit()
# define up_ledon(led)
# define up_ledoff(led)
#endif
</pre></ul>
<p>
Where:
<p>
<ul>
<li>
<code>void up_ledinit(void)</code> is called early in power-up initialization to initialize the LED hardware.
</li>
<li>
<code>up_ledon(int led)</code> is called to instantiate the LED presentation of the event.
The <code>led</code> argument is one of the definitions provided in <code><i><board-name></i>/include/board.h</code>.
</li>
<li>
<code>up_ledoff(int led</code>is called to terminate the LED presentation of the event.
The <code>led</code> argument is one of the definitions provided in <code><i><board-name></i>/include/board.h</code>.
Note that only <code>LED_INIRQ</code>, <code>LED_SIGNAL</code>, <code>LED_ASSERTION</code>, and <code>LED_PANIC</code>
indications are terminated.
</li>
</ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1><a name="NxFileSystem">5.0 NuttX File System</a></h1>
</td>
</tr>
</table>
<p><b>Overview</b>.
NuttX includes an optional, scalable file system.
This file-system may be omitted altogether; NuttX does not depend on the presence
of any file system.
</p>
<p><b>Pseudo Root File System</b>.
Or, a simple <i>in-memory</i>, <i>pseudo</i> file system can be enabled.
This simple file system can be enabled setting the CONFIG_NFILE_DESCRIPTORS
option to a non-zero value (see <a href="#apndxconfigs">Appendix A</a>).
This is an <i>in-memory</i> file system because it does not require any
storage medium or block driver support.
Rather, file system contents are generated on-the-fly as referenced via
standard file system operations (open, close, read, write, etc.).
In this sense, the file system is <i>pseudo</i> file system (in the
same sense that the Linux <code>/proc</code> file system is also
referred to as a pseudo file system).
</p>
<p>
Any user supplied data or logic can be accessed via the pseudo-file system.
Built in support is provided for character and block <a href="#DeviceDrivers">drivers</a> in the
<code>/dev</code> pseudo file system directory.
</p>
<p><b>Mounted File Systems</b>
The simple in-memory file system can be extended my mounting block
devices that provide access to true file systems backed up via some
mass storage device.
NuttX supports the standard <code>mount()</code> command that allows
a block driver to be bound to a mountpoint within the pseudo file system
and to a file system.
At present, NuttX supports only the VFAT file system.
</p>
<p><b>Comparison to Linux</b>
From a programming perspective, the NuttX file system appears very similar
to a Linux file system.
However, there is a fundamental difference:
The NuttX root file system is a pseudo file system and true file systems may be
mounted in the pseudo file system.
In the typical Linux installation by comparison, the Linux root file system
is a true file system and pseudo file systems may be mounted in the true,
root file system.
The approach selected by NuttX is intended to support greater scalability
from the very tiny platform to the moderate platform.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1><a name="DeviceDrivers">6.0 NuttX Device Drivers</a></h1>
</td>
</tr>
</table>
<p>
NuttX supports a variety of device drivers including:
<ul>
<li><i>Character</i> Device Drivers,</li>
<li><i>Block</i> Device Drivers, and</li>
<li>Other <i>Specialized</i> Drivers.</li>
</ul>
These different device driver types are discussed in the following paragraphs.
Note: device driver support requires that the <i>in-memory</i>, <i>pseudo</i> file system
is enabled by setting the CONFIG_NFILE_DESCRIPTORS in the NuttX configuration file to a
non-zero value.
</p>
<h2><a name="chardrivers">6.1 Character Device Drivers</a></h2>
<p>
Character device drivers have these properties:
</p>
<ul>
<li>
<b><code>include/nuttx/fs.h</code></b>.
All structures and APIs needed to work with character drivers are provided in this header file.
</li>
<li>
<b><code>struct file_operations</code></b>.
Each character device driver must implement an instance of <code>struct file_operations</code>.
That structure defines a call table with the following methods:
<ul>
<p><code>int open(FAR struct file *filp);</code><br>
<code>int close(FAR struct file *filp);</code><br>
<code>ssize_t read(FAR struct file *filp, FAR char *buffer, size_t buflen);</code><br>
<code>ssize_t write(FAR struct file *filp, FAR const char *buffer, size_t buflen);</code><br>
<code>off_t seek(FAR struct file *filp, off_t offset, int whence);</code><br>
<code>int ioctl(FAR struct file *filp, int cmd, unsigned long arg);</code><br>
<code>int poll(FAR struct file *filp, struct pollfd *fds, boolean setup);</code></p>
</ul>
</li>
<li>
<b><code>int register_driver(const char *path, const struct file_operations *fops, mode_t mode, void *priv);</code></b>.
Each character driver registers itself by calling <code>register_driver()</code>, passing it the
<code>path</code> where it will appear in the <a href="#NxFileSystem">pseudo-file-system</a> and it's
initialized instance of <code>struct file_operations</code>.
</li>
<li>
<b>User Access</b>.
After it has been registered, the character driver can be accessed by user code using the standard
<a href="NuttxUserGuide.html#driveroperations">driver operations</a> including
<code>open()</code>, <code>close()</code>, <code>read()</code>, <code>write()</code>, etc.
</li>
<li>
<b>Examples</b>:
<code>drivers/dev_null.c</code>, <code>drivers/fifo.c</code>, <code>drivers/serial.c</code>, etc.
</li>
</ul>
<h2><a name="blockdrivers">6.2 Block Device Drivers</a></h2>
<p>
Block device drivers have these properties:
</p>
<ul>
<li>
<b><code>include/nuttx/fs.h</code></b>.
All structures and APIs needed to work with block drivers are provided in this header file.
</li>
<li>
<b><code>struct block_operations</code></b>.
Each block device driver must implement an instance of <code>struct block_operations</code>.
That structure defines a call table with the following methods:
<ul>
<p><code>int open(FAR struct inode *inode);</code><br>
<code>int close(FAR struct inode *inode);</code><br>
<code>ssize_t read(FAR struct inode *inode, FAR unsigned char *buffer, size_t start_sector, unsigned int nsectors);</code><br>
<code>ssize_t write(FAR struct inode *inode, FAR const unsigned char *buffer, size_t start_sector, unsigned int nsectors);</code><br>
<code>int geometry(FAR struct inode *inode, FAR struct geometry *geometry);</code><br>
<code>int ioctl(FAR struct inode *inode, int cmd, unsigned long arg);</code></p>
</ul>
</li>
<li>
<b><code>int register_blockdriver(const char *path, const struct block_operations *bops, mode_t mode, void *priv);</code></b>.
Each block driver registers itself by calling <code>register_blockdriver()</code>, passing it the
<code>path</code> where it will appear in the <a href="#NxFileSystem">pseudo-file-system</a> and it's
initialized instance of <code>struct block_operations</code>.
</li>
<li>
<b>User Access</b>.
Users do not normally access block drivers directly, rather, they access block drivers
indirectly through the <code>mount()</code> API.
The <code>mount()</code> API binds a block driver instance with a file system and with a mountpoint.
Then the user may use the block driver to access the file system on the underlying media.
<i>Example</i>: See the <code>cmd_mount()</code> implementation in <code>examples/nsh/nsh_fscmds.c</code>.
</li>
<li>
<b>Accessing a Character Driver as a Block Device</b>.
See the loop device at <code>drivers/loop.c</code>.
<i>Example</i>: See the <code>cmd_losetup()</code> implementation in <code>examples/nsh/nsh_fscmds.c</code>.
</li>
<li>
<b>Accessing a Block Driver as Character Device</b>.
See the Block-to-Character (BCH) conversion logic in <code>drivers/bch/</code>.
<i>Example</i>: See the <code>cmd_dd()</code> implementation in <code>examples/nsh/nsh_ddcmd.c</code>.
</li>
<li>
<b>Examples</b>.
<code>drivers/loop.c</code>, <code>drivers/mmcsd/mmcsd_spi.c</code>, <code>drivers/ramdisk.c</code>, etc.
</li>
</ul>
<h2><a name="blockdrivers">6.3 Specialized Device Drivers</a></h2>
<h3><a name="ethdrivers">6.3.1 Ethernet Device Drivers</a></h3>
<ul>
<li>
<b><code>include/net/uip/uip-arch.h</code></b>.
All structures and APIs needed to work with Ethernet drivers are provided in this header file.
The structure <code>struct uip_driver_s</code> defines the interface and is passed to uIP via
<code>netdev_register()</code>.
</li>
<li>
<b><code>int netdev_register(FAR struct uip_driver_s *dev);</code></b>.
Each Ethernet driver registers itself by calling <code>netdev_register()</code>.
</li>
<li>
<b>Examples</b>:
<code>drivers/net/dm90x0.c</code>, <code>arch/drivers/arm/src/c5471/c5471_ethernet.c</code>, <code>arch/z80/src/ez80/ez80_emac.c</code>, etc.
</li>
</ul>
<h3><a name="spidrivers">6.3.2 SPI Device Drivers</a></h3>
<ul>
<li>
<b><code>include/nuttx/spi.h</code></b>.
All structures and APIs needed to work with SPI drivers are provided in this header file.
</li>
<li>
<b><code>struct spi_ops_s</code></b>.
Each SPI device driver must implement an instance of <code>struct spi_ops_s</code>.
That structure defines a call table with the following methods:
<ul>
<p><code>void select(FAR struct spi_dev_s *dev, enum spi_dev_e devid, boolean selected);</code><br>
<code>uint32 setfrequency(FAR struct spi_dev_s *dev, uint32 frequency);</code><br>
<code>void setmode(FAR struct spi_dev_s *dev, enum spi_mode_e mode);</code><br>
<code>void setbits(FAR struct spi_dev_s *dev, int nbits);</code><br>
<code>ubyte status(FAR struct spi_dev_s *dev, enum spi_dev_e devid);</code><br>
<code>uint16 send(FAR struct spi_dev_s *dev, uint16 wd);</code><br>
<code>void exchange(FAR struct spi_dev_s *dev, FAR const void *txbuffer, FAR void *rxbuffer, size_t nwords);</code><br>
<p><code>int registercallback(FAR struct spi_dev_s *dev, mediachange_t callback, void *arg);</code></p>
</ul>
<li>
<b>Binding SPI Drivers</b>.
SPI drivers are not normally directly accessed by user code, but are usually bound to another,
higher level device driver.
See for example, <code>int mmcsd_spislotinitialize(int minor, int slotno, FAR struct spi_dev_s *spi)</code> in <code>drivers/mmcsd/mmcsd_spi.c</code>.
In general, the binding sequence is:
<ul>
<li>Get an instance of <code>struct spi_dev_s</code> from the hardware-specific SPI device driver, and </li>
<li>Provide that instance to the initialization method of the higher level device driver.</li>
</ul>
</li>
<li>
<b>Examples</b>:
<code>drivers/loop.c</code>, <code>drivers/mmcsd/mmcsd_spi.c</code>, <code>drivers/ramdisk.c</code>, etc.
</li>
</ul>
<h3><a name="i2cdrivers">6.3.3 I2C Device Drivers</a></h3>
<ul>
<li>
<b><code>include/nuttx/i2c.h</code></b>.
All structures and APIs needed to work with I2C drivers are provided in this header file.
</li>
<li>
<b><code>struct i2c_ops_s</code></b>.
Each I2C device driver must implement an instance of <code>struct i2c_ops_s</code>.
That structure defines a call table with the following methods:
<ul>
<p><code>uint32 setfrequency(FAR struct i2c_dev_s *dev, uint32 frequency);</code><br>
<code>int setaddress(FAR struct i2c_dev_s *dev, int addr, int nbits);</code><br>
<code>int write(FAR struct i2c_dev_s *dev, const ubyte *buffer, int buflen);</code><br>
<code>int read(FAR struct i2c_dev_s *dev, ubyte *buffer, int buflen);</code></p>
</ul>
<li>
<b>Binding I2C Drivers</b>.
I2C drivers are not normally directly accessed by user code, but are usually bound to another,
higher level device driver.
In general, the binding sequence is:
<ul>
<li>Get an instance of <code>struct i2c_dev_s</code> from the hardware-specific I2C device driver, and </li>
<li>Provide that instance to the initialization method of the higher level device driver.</li>
</ul>
</li>
<li>
<b>Examples</b>:
<code>arch/z80/src/ez80/ez80_i2c.c</code>, <code>arch/z80/src/z8/z8_i2c.c</code>, etc.
</li>
</ul>
<h3><a name="serialdrivers">6.3.4 Serial Device Drivers</a></h3>
<ul>
<li>
<b><code>include/nuttx/serial.h</code></b>.
All structures and APIs needed to work with serial drivers are provided in this header file.
</li>
<li>
<b><code>struct uart_ops_s</code></b>.
Each serial device driver must implement an instance of <code>struct uart_ops_s</code>.
That structure defines a call table with the following methods:
<ul>
<p><code>int setup(FAR struct uart_dev_s *dev);</code><br>
<code>void shutdown(FAR struct uart_dev_s *dev);</code><br>
<code>int attach(FAR struct uart_dev_s *dev);</code><br>
<code>void detach(FAR struct uart_dev_s *dev);</code><br>
<code>int ioctl(FAR struct file *filep, int cmd, unsigned long arg);</code><br>
<code>int receive(FAR struct uart_dev_s *dev, unsigned int *status);</code><br>
<code>void rxint(FAR struct uart_dev_s *dev, boolean enable);</code><br>
<code>boolean rxavailable(FAR struct uart_dev_s *dev);</code><br>
<code>void send(FAR struct uart_dev_s *dev, int ch);</code><br>
<code>void txint(FAR struct uart_dev_s *dev, boolean enable);</code><br>
<code>boolean txready(FAR struct uart_dev_s *dev);</code><br>
<code>boolean txempty(FAR struct uart_dev_s *dev);</code></p>
</ul>
</li>
<li>
<b><code>int uart_register(FAR const char *path, FAR uart_dev_t *dev);</code></b>.
A serial driver may register itself by calling <code>uart_register()</code>, passing it the
<code>path</code> where it will appear in the <a href="#NxFileSystem">pseudo-file-system</a> and it's
initialized instance of <code>struct uart_ops_s</code>.
By convention, serial device drivers are registered at paths like <code>/dev/ttyS0</code>, <code>/dev/ttyS1</code>, etc.
See the <code>uart_register()</code> implementation in <code>drivers/serial.c</code>.
</li>
<li>
<b>User Access</b>.
Serial drivers are, ultimately, normal <a href="#chardrivers">character drivers</a> and are accessed as other character drivers.
</li>
<li>
<b>Examples</b>:
<code>arch/arm/src/chip/lm3s_serial.c</code>, <code>arch/arm/src/lpc214x/lpc214x_serial.c</code>, <code>arch/z16/src/z16f/z16f_serial.c</code>, etc.
</li>
</ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1><a name="apndxconfigs">Appendix A: NuttX Configuration Settings</a></h1>
</td>
</tr>
</table>
<p>
The following variables are recognized by the build (you may
also include architecture-specific settings).
</p>
<h2>Architecture selection</h2>
<p>
The following configuration items select the architecture, chip, and
board configuration for the build.
</p>
<ul>
<li><code>CONFIG_ARCH</code>:
Identifies the arch subdirectory</li>
<li><code>CONFIG_ARCH_name</code>:
For use in C code</li>
<li><code>CONFIG_ARCH_CHIP</code>:
Identifies the arch/*/chip subdirectory</li>
<li><code>CONFIG_ARCH_CHIP_name</code>:
For use in C code</li>
<li><code>CONFIG_ARCH_BOARD</code>:
Identifies the configs subdirectory and hence, the board that supports
the particular chip or SoC.</li>
<li><code>CONFIG_ARCH_BOARD_name</code>:
For use in C code</li>
<li><code>CONFIG_ENDIAN_BIG</code>:
Define if big endian (default is little endian).</li>
<li><code>CONFIG_ARCH_NOINTC</code>:
Define if the architecture does not support an interrupt controller
or otherwise cannot support APIs like up_enable_irq() and up_disable_irq().</li>
<li><code>CONFIG_ARCH_IRQPRIO</code>:
Define if the architecture supports prioritization of interrupts and the
up_prioritize_irq() API.</li>
</ul>
<p>
Some architectures require a description of the RAM configuration:
</p>
<ul>
<li><code>CONFIG_DRAM_SIZE</code>:
Describes the installed DRAM.</li>
<li><code>CONFIG_DRAM_START</code>:
The start address of DRAM (physical)</li>
<li><code>CONFIG_DRAM_VSTART</code>:
The start address of DRAM (virtual)</li>
</ul>
<p>
General build options:
</p>
<ul>
<li><code>CONFIG_RRLOAD_BINARY</code>:
Make the rrload binary format used with BSPs from <a href="www.ridgerun.com">ridgerun.com</a>
using the <code>tools/mkimage.sh</code> script.
</li>
<li><code>CONFIG_INTELHEX_BINARY</code>:
Make the Intel HEX binary format used with many different loaders using the GNU objcopy program
This option should not be selected if you are not using the GNU toolchain.
</li>
<li><code>CONFIG_MOTOROLA_SREC</code>:
Make the Motorola S-Record binary format used with many different loaders using the GNU objcopy program
Should not be selected if you are not using the GNU toolchain.
</li>
<li><code>CONFIG_RAW_BINARY</code>:
Make a raw binary format file used with many different loaders using the GNU objcopy program.
This option should not be selected if you are not using the GNU toolchain.
</li>
<li><code>CONFIG_HAVE_LIBM</code>:
Toolchain supports libm.a
</li>
<li><code>CONFIG_HAVE_CXX</code>:
Toolchain supports C++ and <code>CXX</code>, <code>CXXFLAGS</code>, and <code>COMPILEXX</code>
have been defined in the configurations <code>Make.defs</code> file.
</li>
</ul>
<h2>General OS setup</h2>
<ul>
<li>
<code>CONFIG_EXAMPLE</code>: identifies the subdirectory in examples
that will be used in the build.
</li>
<li>
<code>CONFIG_DEBUG</code>: enables built-in debug options
</li>
<li>
<code>CONFIG_DEBUG_VERBOSE</code>: enables verbose debug output
</li>
<li>
<code>CONFIG_DEBUG_SCHED</code>: enable OS debug output (disabled by default)
</li>
<li>
<code>CONFIG_DEBUG_MM</code>: enable memory management debug output (disabled by default)
</li>
<li>
<code>CONFIG_DEBUG_NET</code>: enable network debug output (disabled by default)
</li>
<li>
<code>CONFIG_DEBUG_FS</code>: enable file system debug output (disabled by default)
</li>
<li>
<code>CONFIG_DEBUG_LIB</code>: enable C library debug output (disabled by default)
</li>
<li>
<code>CONFIG_ARCH_LOWPUTC</code>: architecture supports low-level, boot
time console output
</li>
<li>
<code>CONFIG_MM_REGIONS</code>: If the architecture includes multiple
regions of memory to allocate from, this specifies the
number of memory regions that the memory manager must
handle and enables the API mm_addregion(start, end);
</li>
<li>
<code>CONFIG_TICKS_PER_MSEC</code>: The default system timer is 100Hz
or <code>TICKS_PER_MSEC</code>=10. This setting may be defined to inform NuttX
that the processor hardware is providing system timer interrupts at some interrupt
interval other than 10 msec.
</li>
<li>
<code>CONFIG_RR_INTERVAL</code>: The round robin time slice will be set
this number of milliseconds; Round robin scheduling can
be disabled by setting this value to zero.
</li>
<li>
<code>CONFIG_SCHED_INSTRUMENTATION</code>: enables instrumentation in
scheduler to monitor system performance
</li>
<li>
<code>CONFIG_TASK_NAME_SIZE</code>: Specifies that maximum size of a
task name to save in the TCB. Useful if scheduler
instrumentation is selected. Set to zero to disable.
</li>
<li>
<code>CONFIG_START_YEAR, CONFIG_START_MONTH, CONFIG_START_DAY -
Used to initialize the internal time logic.
</li>
<li>
<code>CONFIG_GREGORIAN_TIME</code>: Enables Gregorian time conversions.
You would only need this if you are concerned about accurate time conversions in
the recent past or in the distant future.
</li>
<li>
<code>CONFIG_JULIAN_TIME</code>: Enables Julian time conversions.
You would only need this if you are concerned about accurate time conversion in the distand past.
You must also define <code>CONFIG_GREGORIAN_TIME</code> in order to use Julian time.
</li>
<li>
<code>CONFIG_DEV_CONSOLE</code>: Set if architecture-specific logic
provides /dev/console. Enables stdout, stderr, stdin.
</li>
<li>
<code>CONFIG_MUTEX_TYPES</code>: Set to enable support for recursive and
errorcheck mutexes. Enables <code>pthread_mutexattr_settype()</code>.
</li>
<li>
<code>CONFIG_PRIORITY_INHERITANCE</code>: Set to enable support for
priority inheritance on mutexes and semaphores.
Priority inheritance is a strategy of addressing
<a href="NuttxUserGuide.html#priorityinversion"><i>priority inversion</i></a>.
Details of the NuttX implementation of priority inheritance is
discussed <a href="NuttxUserGuide.html#priorityinheritance">elsewhere</a>.
</li>
<li>
<code>CONFIG_SEM_PREALLOCHOLDERS</code>: This setting is only used
if priority inheritance is enabled.
It defines the maximum number of different threads (minus one) that
can take counts on a semaphore with priority inheritance support.
This may be set to zero if priority inheritance is disabled OR if you
are only using semaphores as mutexes (only one holder) OR if no more
than two threads participate using a counting semaphore.
</li>
<li>
<code>CONFIG_SEM_NNESTPRIO</code>: If priority inheritance is enabled,
then this setting is the maximum number of higher priority threads (minus
1) than can be waiting for another thread to release a count on a semaphore.
This value may be set to zero if no more than one thread is expected to
wait for a semaphore.
</li>
<li>
<code>CONFIG_FDCLONE_DISABLE</code>: Disable cloning of all file descriptors
by task_create() when a new task is started.
If set, all files/drivers will appear to be closed in the new task.
</li>
<li>
<code>CONFIG_FDCLONE_STDIO</code>: Disable cloning of all but the first
three file descriptors (stdin, stdout, stderr) by task_create()
when a new task is started.
If set, all files/drivers will appear to be closed in the new task except
for stdin, stdout, and stderr.
</li>
<li>
<code>CONFIG_SDCLONE_DISABLE</code>: Disable cloning of all socket
desciptors by task_create() when a new task is started.
If set, all sockets will appear to be closed in the new task.
</li>:
<li>
<code>CONFIG_NXFLAT</code>: Enable support for the NXFLAT binary format.
This format will support execution of NuttX binaries located
in a ROMFS filesystem (see <code>examples/nxflat</code>).
</li>
</ul>
<p>
The following can be used to disable categories of APIs supported
by the OS. If the compiler supports weak functions, then it
should not be necessary to disable functions unless you want to
restrict usage of those APIs.
</p>
<p>
There are certain dependency relationships in these features.
</p>
<ul>
<li>
<code>mq_notify()</code> logic depends on signals to awaken tasks
waiting for queues to become full or empty.
</li>
<li>
<code>pthread_condtimedwait()</code> depends on signals to wake
up waiting tasks.
</li>
</ul>
<ul>
<code>CONFIG_DISABLE_CLOCK</code>, <code>CONFI_DISABLE_POSIX_TIMERS</code>,
<code>CONFIG_DISABLE_PTHREAD</code>, <code>CONFIG_DISABLE_SIGNALS</code>,
<code>CONFIG_DISABLE_MQUEUE</code>, <code>CONFIG_DISABLE_MOUNTPOUNT</code>
</ul>
<h2>Miscellaneous libc settings</h2>
<ul>
<li>
<code>CONFIG_NOPRINTF_FIELDWIDTH</code>: sprintf-related logic is a
little smaller if we do not support fieldwidthes
</li>
</ul>
<h2>Allow for architecture optimized implementations</h2>
<p>
The architecture can provide optimized versions of the
following to improve system performance.
</p>
<ul>
<p>
<code>CONFIG_ARCH_MEMCPY</code>, <code>CONFIG_ARCH_MEMCMP</code>, <code>CONFIG_ARCH_MEMMOVE</code>,
<code>CONFIG_ARCH_MEMSET</code>, <code>CONFIG_ARCH_STRCMP</code>, <code>CONFIG_ARCH_STRCPY</code>,
<code>CONFIG_ARCH_STRNCPY</code>, <code>CONFIG_ARCH_STRLEN</code>, <code>CONFIG_ARCH_BZERO</code>,
<code>CONFIG_ARCH_KMALLOC</code>, <code>CONFIG_ARCH_KZMALLOC</code>, <code>ONFIG_ARCH_KFREE</code>,
</p>
</ul>
<h2>Sizes of configurable things (0 disables)</h2>
<ul>
<li>
<code>CONFIG_MAX_TASKS</code>: The maximum number of simultaneously
active tasks. This value must be a power of two.
</li>
<li>
<code>CONFIG_NPTHREAD_KEYS</code>: The number of items of thread-
specific data that can be retained
</li>
<li>
<code>CONFIG_NFILE_DESCRIPTORS</code>: The maximum number of file
descriptors (one for each open)
</li>
<li>
<code>CONFIG_NFILE_STREAMS</code>: The maximum number of streams that
can be fopen'ed
</li>
<li>
<code>CONFIG_NAME_MAX</code>: The maximum size of a file name.
</li>
<li>
<code>CONFIG_STDIO_BUFFER_SIZE</code>: Size of the buffer to allocate
on fopen. (Only if CONFIG_NFILE_STREAMS > 0)
</li>
<li>
<code>CONFIG_NUNGET_CHARS</code>: Number of characters that can be
buffered by ungetc() (Only if CONFIG_NFILE_STREAMS > 0)
</li>
<li>
<code>CONFIG_PREALLOC_MQ_MSGS</code>: The number of pre-allocated message
structures. The system manages a pool of preallocated
message structures to minimize dynamic allocations
</li>
<li>
<code>CONFIG_MQ_MAXMSGSIZE</code>: Message structures are allocated with
a fixed payload size given by this setting (does not include
other message structure overhead.
</li>
<li>
<code>CONFIG_PREALLOC_WDOGS</code>: The number of pre-allocated watchdog
structures. The system manages a pool of preallocated
watchdog structures to minimize dynamic allocations
</li>
<li>
<code>CONFIG_DEV_PIPE_SIZE</code>: Size, in bytes, of the buffer to allocated
for pipe and FIFO support (default is 1024).
</li>
</ul>
<h2>File Systems</h2>
<ul>
<li>
<code>CONFIG_FS_FAT</code>: Enable FAT filesystem support.
</li>
<li>
<code>CONFIG_FAT_SECTORSIZE</code>: Max supported sector size.
</li>
<li>
<code>CONFIG_FS_ROMFS</code>: Enable ROMFS filesystem support
</li>
</ul>
<h2>SPI-based MMC/SD driver</h2>
<ul>
<li>
<code>CONFIG_MMCSD_NSLOTS</code>: Number of MMC/SD slots supported by the driver. Default is one.
</li>
<li>
<code>CONFIG_MMCSD_READONLY</code>: Provide read-only access. Default is Read/Write
</li>
<li>
<code>CONFIG_MMCSD_SPICLOCK</code>: Maximum SPI clock to drive MMC/SD card. Default is 20MHz.
</li>
</ul>
<h2>Network Support</h2>
<h3>TCP/IP and UDP support via uIP</h2>
<ul>
<li>
<code>CONFIG_NET</code>: Enable or disable all network features
</li>
<li>
<code>CONFIG_NET_IPv6</code>: Build in support for IPv6
</li>
<li>
<code>CONFIG_NSOCKET_DESCRIPTORS</code>: Maximum number of socket descriptors per task/thread.
</li>
<li>
<code>CONFIG_NET_NACTIVESOCKETS</code>: Maximum number of concurrent socket operations (recv, send, etc.).
Default: <code>CONFIG_NET_TCP_CONNS</code>+<code>CONFIG_NET_UDP_CONNS</code>.
</li>
<li>
<code>CONFIG_NET_SOCKOPTS</code>: Enable or disable support for socket options.
</li>
<li>
<code>CONFIG_NET_BUFSIZE</code>: uIP buffer size
</li>
<li>
<code>CONFIG_NET_TCP</code>: TCP support on or off
</li>
<li>
<code>CONFIG_NET_TCP_CONNS</code>: Maximum number of TCP connections (all tasks).
</li>
<li>
<code>CONFIG_NET_TCPBACKLOG</code>:
Incoming connections pend in a backlog until <code>accept()</code> is called.
The size of the backlog is selected when <code>listen()</code> is called.
</li>
<li>
<code>CONFIG_NET_TCP_READAHEAD_BUFSIZE</code>: Size of TCP read-ahead buffers
</li>
<li>
<code>CONFIG_NET_NTCP_READAHEAD_BUFFERS</code>: Number of TCP read-ahead buffers (may be zero)
</li>
<li>
<code>CONFIG_NET_MAX_LISTENPORTS</code>: Maximum number of listening TCP ports (all tasks).
</li>
<li>
<code>CONFIG_NET_TCPURGDATA</code>: Determines if support for TCP urgent data
notification should be compiled in. Urgent data (out-of-band data)
is a rarely used TCP feature that is very seldom would be required.
</li>
<li>
<code>CONFIG_NET_UDP</code>: UDP support on or off
</li>
<li>
<code>CONFIG_NET_UDP_CHECKSUMS</code>: UDP checksums on or off
</li>
<li>
<code>CONFIG_NET_UDP_CONNS</code>: The maximum amount of concurrent UDP connections
</li>
<li>
<code>CONFIG_NET_ICMP</code>: Enable minimal ICMP support. Includes built-in support
for sending replies to received ECHO (ping) requests.
</li>
<li>
<code>CONFIG_NET_ICMP_PING</code>: Provide interfaces to support application level
support for sending ECHO (ping) requests and associating ECHO replies.
</li>
<li>
<code>CONFIG_NET_PINGADDRCONF</code>: Use "ping" packet for setting IP address
</li>
<li>
<code>CONFIG_NET_STATISTICS</code>: uIP statistics on or off
</li>
<li>
<code>CONFIG_NET_RECEIVE_WINDOW</code>: The size of the advertised receiver's window
</li>
<li>
<code>CONFIG_NET_ARPTAB_SIZE</code>: The size of the ARP table
</li>
<li>
<code>CONFIG_NET_BROADCAST</code>: Incoming UDP broadcast support
</li>
<li>
<code>CONFIG_NET_MULTICAST</code>: Outgoing multi-cast address support
</li>
<li>
<code>CONFIG_NET_LLH_LEN</code>: The link level header length
</li>
<li>
<code>CONFIG_NET_FWCACHE_SIZE</code>: number of packets to remember when looking for duplicates
</li>
</ul>
<h3>UIP Network Utilities</h3>
<ul>
<li>
<code>CONFIG_NET_DHCP_LIGHT</code>: Reduces size of DHCP
</li>
<li>
<code>CONFIG_NET_RESOLV_ENTRIES</code>: Number of resolver entries
</li>
</ul>
<h3>THTTPD</h3>
<ul>
<li>
<code>CONFIG_THTTPD_PORT</code>: THTTPD Server port number
</li>
<li>
<code>CONFIG_THTTPD_IPADDR</code>: Server IP address (no host name)
</li>
<li>
<code>CONFIG_THTTPD_SERVER_ADDRESS</code>: SERVER_ADDRESS: response
</li>
<li>
<code>CONFIG_THTTPD_SERVER_SOFTWARE</code>: SERVER_SOFTWARE: response
</li>
<li>
<code>CONFIG_THTTPD_CGI_PATH</code>:
</li>
<li>
<code>CONFIG_THTTPD_CGI_PATTERN</code>: Only CGI programs matching this
pattern will be executed. In fact, if this value is not defined
then no CGI logic will be built.
</li>
<li>
<code>CONFIG_THTTPD_CGI_PRIORITY</code>: Provides the priority of CGI child tasks
</li>
<li>
<code>CONFIG_THTTPD_CGI_STACKSIZE</code>: Provides the initial stack size of
CGI child task (will be overridden by the stack size in the NXFLAT
header)
</li>
<li>
<code>CONFIG_THTTPD_CGI_BYTECOUNT</code>: Byte output limit for CGI tasks.
</li>
<li>
<code>CONFIG_THTTPD_CGI_TIMELIMIT</code>: How many seconds to allow CGI programs
to run before killing them.
</li>
<li>
<code>CONFIG_THTTPD_CHARSET- The default character set name to use with
text MIME types.
</li>
<li>
<code>CONFIG_THTTPD_IOBUFFERSIZE</code>:
</li>
<li>
<code>CONFIG_THTTPD_INDEX_NAMES</code>: A list of index filenames to check. The
files are searched for in this order.
</li>
<li>
<code>CONFIG_AUTH_FILE</code>: The file to use for authentication. If this is
defined then thttpd checks for this file in the local directory
before every fetch. If the file exists then authentication is done,
otherwise the fetch proceeds as usual. If you leave this undefined
then thttpd will not implement authentication at all and will not
check for auth files, which saves a bit of CPU time. A typical
value is ".htpasswd&quout;
</li>
<li>
<code>CONFIG_THTTPD_LISTEN_BACKLOG</code>: The listen() backlog queue length.
</li>
<li>
<code>CONFIG_THTTPD_LINGER_MSEC</code>: How many milliseconds to leave a connection
open while doing a lingering close.
</li>
<li>
<code>CONFIG_THTTPD_OCCASIONAL_MSEC</code>: How often to run the occasional
cleanup job.
</li>
<li>
<code>CONFIG_THTTPD_IDLE_READ_LIMIT_SEC</code>: How many seconds to allow for
reading the initial request on a new connection.
</li>
<li>
<code>CONFIG_THTTPD_IDLE_SEND_LIMIT_SEC</code>: How many seconds before an
idle connection gets closed.
</li>
<li>
<code>CONFIG_THTTPD_TILDE_MAP1 and CONFIG_THTTPD_TILDE_MAP2</code>: Tilde mapping.
Many URLs use ~username to indicate a user's home directory. thttpd
provides two options for mapping this construct to an actual filename.
<ol>
<li>
Map ~username to <prefix>/username. This is the recommended choice.
Each user gets a subdirectory in the main web tree, and the tilde
construct points there. The prefix could be something like "users",
or it could be empty.
</li>
<li>
Map ~username to <user's homedir>/<postfix>. The postfix would be
the name of a subdirectory off of the user's actual home dir,
something like "public_html".
</li>
</ol>
You can also leave both options undefined, and thttpd will not do
anything special about tildes. Enabling both options is an error.
Typical values, if they're defined, are "users" for
CONFIG_THTTPD_TILDE_MAP1 and "public_html" forCONFIG_THTTPD_TILDE_MAP2.
</li>
<li>
<code>CONFIG_THTTPD_GENERATE_INDICES
</li>
<li>
<code>CONFIG_THTTPD_URLPATTERN</code>: If defined, then it will be used to match
and verify referrers.
</li>
</ul>
<h2>USB Device-Side Support</h2>
<h3>USB Device Controller Driver</h3>
<ul>
<li>
<code>CONFIG_USBDEV</code>: Enables USB device support
</li>
<li>
<code>CONFIG_USBDEV_ISOCHRONOUS</code>: Build in extra support for isochronous endpoints
</li>
<li>
<code>CONFIG_USBDEV_DUALSPEED</code>: Hardware handles high and full speed operation (USB 2.0)
</li>
<li>
<code>CONFIG_USBDEV_SELFPOWERED</code>: Will cause USB features to indicate that the device is self-powered
</li>
<li>
<code>CONFIG_USBDEV_MAXPOWER</code>: Maximum power consumption in mA
</li>
<li>
<code>CONFIG_USBDEV_TRACE</code>: Enables USB tracing for debug
</li>
<li>
<code>CONFIG_USBDEV_TRACE_NRECORDS</code>: Number of trace entries to remember
</li>
</ul>
<h3>USB Serial Device Class Driver</h3>
<ul>
<li>
<code>CONFIG_USBSER</code>: Enable compilation of the USB serial driver
</li>
<li>
<code>CONFIG_USBSER_EPINTIN</code>: The logical 7-bit address of a hardware endpoint that supports interrupt IN operation
</li>
<li>
<code>CONFIG_USBSER_EPBULKOUT</code>: The logical 7-bit address of a hardware endpoint that supports bulk OUT operation
</li>
<li>
<code>CONFIG_USBSER_EPBULKIN</code>: The logical 7-bit address of a hardware endpoint that supports bulk IN operation
</li>
<li>
<code>CONFIG_USBSER_NWRREQS</code> and <code>CONFIG_USBSER_NRDREQS</code>: The number of write/read requests that can be in flight
</li>
<li>
<code>CONFIG_USBSER_VENDORID</code> and <code>CONFIG_USBSER_VENDORSTR</code>: The vendor ID code/string
</li>
<li>
<code>CONFIG_USBSER_PRODUCTID</code> and <code>CONFIG_USBSER_PRODUCTSTR</code>: The product ID code/string
</li>
<li>
<code>CONFIG_USBSER_RXBUFSIZE</code> and <code>CONFIG_USBSER_TXBUFSIZE</code>: Size of the serial receive/transmit buffers
</li>
</ul>
<h3>USB Storage Device Configuration</h3>
<ul>
<li>
<code>CONFIG_USBSTRG</code>:
Enable compilation of the USB storage driver
</li>
<li>
<code>CONFIG_USBSTRG_EP0MAXPACKET</code>:
Max packet size for endpoint 0
</li>
<li>
<code>CONFIG_USBSTRGEPBULKOUT</code> and <code>CONFIG_USBSTRG_EPBULKIN</code>:
The logical 7-bit address of a hardware endpoints that support bulk OUT and IN operations
</li>
<li>
<code>CONFIG_USBSTRG_NWRREQS</code> and <code>CONFIG_USBSTRG_NRDREQS</code>:
The number of write/read requests that can be in flight
</li>
<li>
<code>CONFIG_USBSTRG_BULKINREQLEN</code> and <code>CONFIG_USBSTRG_BULKOUTREQLEN</code>:
The size of the buffer in each write/read request.
This value needs to be at least as large as the endpoint maxpacket and
ideally as large as a block device sector.
</li>
<li>
<code>CONFIG_USBSTRG_VENDORID</code> and <code>CONFIG_USBSTRG_VENDORSTR</code>:
The vendor ID code/string
</li>
<li>
<code>CONFIG_USBSTRG_PRODUCTID</code> and <code>CONFIG_USBSTRG_PRODUCTSTR</code>:
The product ID code/string
</li>
<li>
<code>CONFIG_USBSTRG_REMOVABLE</code>:
Select if the media is removable
</li>
</ul>
<h2>Graphics related configuration settings</h3>
<ul>
<li>
<code>CONFIG_NX</code>
Enables overall support for graphics library and NX
</li>
</ul>
<h3>NX configuration setting</h3>
<ul>
<li>
<code>CONFIG_NX_MULTIUSER</code>:
Configures NX in multi-user mode.
</li>
<li>
<code>CONFIG_NX_NPLANES</code>:
Some YUV color formats requires support for multiple planes,
one for each color component. Unless you have such special
hardware, this value should be undefined or set to 1.
</li>
<li>
<code>CONFIG_NX_DISABLE_1BPP</code>, <code>CONFIG_NX_DISABLE_2BPP</code>,
<code>CONFIG_NX_DISABLE_4BPP</code>, <code>CONFIG_NX_DISABLE_8BPP</code>
<code>CONFIG_NX_DISABLE_16BPP</code>, <code>CONFIG_NX_DISABLE_24BPP</code>, and
<code>CONFIG_NX_DISABLE_32BPP</code>:
NX supports a variety of pixel depths. You can save some
memory by disabling support for unused color depths.
</li>
<li>
<code>CONFIG_NX_PACKEDMSFIRST</code>:
If a pixel depth of less than 8-bits is used, then NX needs
to know if the pixels pack from the MS to LS or from LS to MS
</li>
<li>
<code>CONFIG_NX_MOUSE</code>:
Build in support for mouse input.
</li>
<li>
<code>CONFIG_NX_KBD</code>:
Build in support of keypad/keyboard input.
</li>
<li>
<code>CONFIG_NXTK_BORDERWIDTH</code>:
Specifies with with of the border (in pixels) used with
framed windows. The default is 4.
</li>
<li>
<code>CONFIG_NXTK_BORDERCOLOR1</code> and <code>CONFIG_NXTK_BORDERCOLOR2</code>:
Specify the colors of the border used with framed windows.
<code>CONFIG_NXTK_BORDERCOLOR2</code> is the shadow side color and so
is normally darker. The default is medium and dark grey,
respectively
</li>
<li>
<code>CONFIG_NXTK_AUTORAISE</code>:
If set, a window will be raised to the top if the mouse position
is over a visible portion of the window. Default: A mouse
button must be clicked over a visible portion of the window.
</li>
<li>
<code>CONFIG_NXFONTS_CHARBITS</code>:
The number of bits in the character set. Current options are
only 7 and 8. The default is 7.
</li>
<li>
<code>CONFIG_NXFONT_SANS</code>:
At present, there is only one font. But if there were were more,
then this option would select the sans serif font.
</li>
</ul>
<h3>NX Multi-user only options</h3>
<ul>
<li>
<code>CONFIG_NX_BLOCKING</code>
Open the client message queues in blocking mode. In this case,
<code>nx_eventhandler()</code> will not return until a message is received and processed.
</li>
<li>
<code>CONFIG_NX_MXSERVERMSGS</code> and <code>CONFIG_NX_MXCLIENTMSGS</code>
Specifies the maximum number of messages that can fit in
the message queues. No additional resources are allocated, but
this can be set to prevent flooding of the client or server with
too many messages (<code>CONFIG_PREALLOC_MQ_MSGS</code> controls how many
messages are pre-allocated).
</li>
</ul>
<h2>Stack and heap information</h2>
<ul>
<li>
<code>CONFIG_BOOT_RUNFROMFLASH</code>: Some configurations support XIP
operation from FLASH but must copy initialized .data sections to RAM.
</li>
<li>
<code>CONFIG_BOOT_COPYTORAM</code>: Some configurations boot in FLASH
but copy themselves entirely into RAM for better performance.
</li>
<li>
<code>CONFIG_STACK_POINTER</code>: The initial stack pointer
</li>
<li>
<code>CONFIG_IDLETHREAD_STACKSIZE</code>: The size of the initial stack.
This is the thread that (1) performs the initial boot of the system up
to the point where user_start() is spawned, and (2) there after is the
IDLE thread that executes only when there is no other thread ready to
run.
</li>
<li>
<code>CONFIG_USERMAIN_STACKSIZE</code>: The size of the stack to allocate
for the main user thread that begins at the user_start() entry point.
</li>
<li>
<code>CONFIG_PTHREAD_STACK_MIN</code>: Minimum pthread stack size
</li>
<li>
<code>CONFIG_PTHREAD_STACK_DEFAULT</code>: Default pthread stack size
</li>
<li>
<code>CONFIG_HEAP_BASE</code>: The beginning of the heap
</li>
<li>
<code>CONFIG_HEAP_SIZE</code>: The size of the heap
</li>
</ul>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
<h1><a name="apndxtrademarks">Appendix B: Trademarks</a></h1>
</td>
</tr>
</table>
<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 trade name 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>
<p>
NOTE: NuttX is <i>not</i> licensed to use the POSIX trademark. NuttX uses the POSIX
standard as a development guideline only.
</p>
</body>
</html>
|