aboutsummaryrefslogtreecommitdiff
path: root/gdb/remote.c
blob: 2a1a8788bdc64c97ba9715346ef0767076bb6dc6 (plain)
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
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
/* Remote target communications for serial-line targets in custom GDB protocol
   Copyright 1988, 91, 92, 93, 94, 95, 96, 97, 1998 
   Free Software Foundation, Inc.

This file is part of GDB.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* Remote communication protocol.

   A debug packet whose contents are <data>
   is encapsulated for transmission in the form:

	$ <data> # CSUM1 CSUM2

	<data> must be ASCII alphanumeric and cannot include characters
	'$' or '#'.  If <data> starts with two characters followed by
	':', then the existing stubs interpret this as a sequence number.

	CSUM1 and CSUM2 are ascii hex representation of an 8-bit 
	checksum of <data>, the most significant nibble is sent first.
	the hex digits 0-9,a-f are used.

   Receiver responds with:

	+	- if CSUM is correct and ready for next packet
	-	- if CSUM is incorrect

   <data> is as follows:
   Most values are encoded in ascii hex digits.  Signal numbers are according
   to the numbering in target.h.

	Request		Packet

	set thread	Hct...		Set thread for subsequent operations.
					c = 'c' for thread used in step and 
					continue; t... can be -1 for all
					threads.
					c = 'g' for thread used in other
					operations.  If zero, pick a thread,
					any thread.
	reply		OK		for success
			ENN		for an error.

	read registers  g
	reply		XX....X		Each byte of register data
					is described by two hex digits.
					Registers are in the internal order
					for GDB, and the bytes in a register
					are in the same order the machine uses.
			or ENN		for an error.

	write regs	GXX..XX		Each byte of register data
					is described by two hex digits.
	reply		OK		for success
			ENN		for an error

        write reg	Pn...=r...	Write register n... with value r...,
					which contains two hex digits for each
					byte in the register (target byte
					order).
	reply		OK		for success
			ENN		for an error
	(not supported by all stubs).

	read mem	mAA..AA,LLLL	AA..AA is address, LLLL is length.
	reply		XX..XX		XX..XX is mem contents
					Can be fewer bytes than requested
					if able to read only part of the data.
			or ENN		NN is errno

	write mem	MAA..AA,LLLL:XX..XX
					AA..AA is address,
					LLLL is number of bytes,
					XX..XX is data
	reply		OK		for success
			ENN		for an error (this includes the case
					where only part of the data was
					written).

        write mem       XAA..AA,LLLL:XX..XX
         (binary)                       AA..AA is address,
                                        LLLL is number of bytes,
                                        XX..XX is binary data
        reply           OK              for success
                        ENN             for an error

	continue	cAA..AA		AA..AA is address to resume
					If AA..AA is omitted,
					resume at same address.

	step		sAA..AA		AA..AA is address to resume
					If AA..AA is omitted,
					resume at same address.

	continue with	Csig;AA..AA	Continue with signal sig (hex signal
	signal				number).  If ;AA..AA is omitted, 
					resume at same address.

	step with	Ssig;AA..AA	Like 'C' but step not continue.
	signal

	last signal     ?               Reply the current reason for stopping.
                                        This is the same reply as is generated
					for step or cont : SAA where AA is the
					signal number.

	detach          D               Reply OK.

	There is no immediate reply to step or cont.
	The reply comes when the machine stops.
	It is		SAA		AA is the signal number.

	or...		TAAn...:r...;n...:r...;n...:r...;
					AA = signal number
					n... = register number (hex)
					  r... = register contents
					n... = `thread'
					  r... = thread process ID.  This is
						 a hex integer.
					n... = other string not starting 
					    with valid hex digit.
					  gdb should ignore this n,r pair
					  and go on to the next.  This way
					  we can extend the protocol.
	or...		WAA		The process exited, and AA is
					the exit status.  This is only
					applicable for certains sorts of
					targets.
	or...		XAA		The process terminated with signal
					AA.
        or...           OXX..XX	XX..XX  is hex encoding of ASCII data. This
					can happen at any time while the 
					program is running and the debugger 
					should continue to wait for 
					'W', 'T', etc.

	thread alive	TXX		Find out if the thread XX is alive.
	reply		OK		thread is still alive
			ENN		thread is dead
	
	remote restart	RXX		Restart the remote server

	extended ops 	!		Use the extended remote protocol.
					Sticky -- only needs to be set once.

	kill request	k

	toggle debug	d		toggle debug flag (see 386 & 68k stubs)
	reset		r		reset -- see sparc stub.
	reserved	<other>		On other requests, the stub should
					ignore the request and send an empty
					response ($#<checksum>).  This way
					we can extend the protocol and GDB
					can tell whether the stub it is
					talking to uses the old or the new.
	search		tAA:PP,MM	Search backwards starting at address
					AA for a match with pattern PP and
					mask MM.  PP and MM are 4 bytes.
					Not supported by all stubs.

	general query	qXXXX		Request info about XXXX.
	general set	QXXXX=yyyy	Set value of XXXX to yyyy.
	query sect offs	qOffsets	Get section offsets.  Reply is
					Text=xxx;Data=yyy;Bss=zzz

	Responses can be run-length encoded to save space.  A '*' means that
	the next character is an ASCII encoding giving a repeat count which
	stands for that many repititions of the character preceding the '*'.
	The encoding is n+29, yielding a printable character where n >=3 
	(which is where rle starts to win).  Don't use an n > 126.

	So 
	"0* " means the same as "0000".  */

#include "defs.h"
#include "gdb_string.h"
#include <ctype.h>
#include <fcntl.h>
#include "frame.h"
#include "inferior.h"
#include "bfd.h"
#include "symfile.h"
#include "target.h"
#include "wait.h"
/*#include "terminal.h"*/
#include "gdbcmd.h"
#include "objfiles.h"
#include "gdb-stabs.h"
#include "gdbthread.h"

#include "dcache.h"

#include <ctype.h>
#ifdef USG
#include <sys/types.h>
#endif

#include <signal.h>
#include "serial.h"

/* Prototypes for local functions */

static int remote_write_bytes PARAMS ((CORE_ADDR memaddr,
				       char *myaddr, int len));

static int remote_read_bytes PARAMS ((CORE_ADDR memaddr,
				      char *myaddr, int len));

static void remote_files_info PARAMS ((struct target_ops *ignore));

static int remote_xfer_memory PARAMS ((CORE_ADDR memaddr, char * myaddr,
				       int len, int should_write,
				       struct target_ops * target));

static void remote_prepare_to_store PARAMS ((void));

static void remote_fetch_registers PARAMS ((int regno));

static void remote_resume PARAMS ((int pid, int step,
				   enum target_signal siggnal));

static int remote_start_remote PARAMS ((PTR));

static void remote_open PARAMS ((char *name, int from_tty));

static void extended_remote_open PARAMS ((char *name, int from_tty));

static void remote_open_1 PARAMS ((char *, int, struct target_ops *,
				   int extended_p));

static void remote_close PARAMS ((int quitting));

static void remote_store_registers PARAMS ((int regno));

static void remote_mourn PARAMS ((void));

static void extended_remote_restart PARAMS ((void));

static void extended_remote_mourn PARAMS ((void));

static void extended_remote_create_inferior PARAMS ((char *, char *, char **));

static void remote_mourn_1 PARAMS ((struct target_ops *));

static void remote_send PARAMS ((char *buf));

static int readchar PARAMS ((int timeout));

static int remote_wait PARAMS ((int pid, struct target_waitstatus * status));

static void remote_kill PARAMS ((void));

static int tohex PARAMS ((int nib));

static void remote_detach PARAMS ((char *args, int from_tty));

static void remote_interrupt PARAMS ((int signo));

static void remote_interrupt_twice PARAMS ((int signo));

static void interrupt_query PARAMS ((void));

static void set_thread PARAMS ((int, int));

static int remote_thread_alive PARAMS ((int));

static void get_offsets PARAMS ((void));

static int read_frame PARAMS ((char *));

static int remote_insert_breakpoint PARAMS ((CORE_ADDR, char *));

static int remote_remove_breakpoint PARAMS ((CORE_ADDR, char *));

static int hexnumlen PARAMS ((ULONGEST num));

static void init_remote_ops PARAMS ((void));

static void init_extended_remote_ops PARAMS ((void));

static void remote_stop PARAMS ((void));

static int ishex PARAMS ((int ch, int *val));

static int stubhex PARAMS ((int ch));

static int remote_query PARAMS ((int/*char*/, char *, char *, int *));

static int hexnumstr PARAMS ((char *, ULONGEST));

static CORE_ADDR remote_address_masked PARAMS ((CORE_ADDR));

static void print_packet PARAMS ((char *));

static unsigned long crc32 PARAMS ((unsigned char *, int, unsigned int));

static void compare_sections_command PARAMS ((char *, int));

static void packet_command PARAMS ((char *, int));

static int stub_unpack_int PARAMS ((char *buff, int fieldlength));

static int remote_current_thread PARAMS ((int oldpid));

static void remote_find_new_threads PARAMS ((void));

static void record_currthread PARAMS ((int currthread));

/* exported functions */

extern int fromhex PARAMS ((int a));

extern void getpkt PARAMS ((char *buf, int forever));

extern int putpkt PARAMS ((char *buf));

static int putpkt_binary PARAMS ((char *buf, int cnt));

void remote_console_output PARAMS ((char *));

static void check_binary_download PARAMS ((CORE_ADDR addr));

/* Define the target subroutine names */

void open_remote_target PARAMS ((char *, int, struct target_ops *, int));

void _initialize_remote PARAMS ((void));

/* */

static struct target_ops remote_ops;

static struct target_ops extended_remote_ops;

/* This was 5 seconds, which is a long time to sit and wait.
   Unless this is going though some terminal server or multiplexer or
   other form of hairy serial connection, I would think 2 seconds would
   be plenty.  */

/* Changed to allow option to set timeout value.
   was static int remote_timeout = 2; */
extern int remote_timeout;

/* This variable chooses whether to send a ^C or a break when the user
   requests program interruption.  Although ^C is usually what remote
   systems expect, and that is the default here, sometimes a break is
   preferable instead.  */

static int remote_break;

/* Descriptor for I/O to remote machine.  Initialize it to NULL so that
   remote_open knows that we don't have a file open when the program
   starts.  */
static serial_t remote_desc = NULL;

/* This variable (available to the user via "set remotebinarydownload")
   dictates whether downloads are sent in binary (via the 'X' packet).
   We assume that the stub can, and attempt to do it. This will be cleared if
   the stub does not understand it. This switch is still needed, though
   in cases when the packet is supported in the stub, but the connection
   does not allow it (i.e., 7-bit serial connection only). */
static int remote_binary_download = 1;
 
/* Have we already checked whether binary downloads work? */
static int remote_binary_checked;

/* Maximum number of bytes to read/write at once.  The value here
   is chosen to fill up a packet (the headers account for the 32).  */
#define MAXBUFBYTES(N) (((N)-32)/2)

/* Having this larger than 400 causes us to be incompatible with m68k-stub.c
   and i386-stub.c.  Normally, no one would notice because it only matters
   for writing large chunks of memory (e.g. in downloads).  Also, this needs
   to be more than 400 if required to hold the registers (see below, where
   we round it up based on REGISTER_BYTES).  */
/* Round up PBUFSIZ to hold all the registers, at least.  */
#define	PBUFSIZ ((REGISTER_BYTES > MAXBUFBYTES (400)) \
		 ? (REGISTER_BYTES * 2 + 32) \
		 : 400)


/* This variable sets the number of bytes to be written to the target
   in a single packet.  Normally PBUFSIZ is satisfactory, but some
   targets need smaller values (perhaps because the receiving end
   is slow).  */

static int remote_write_size;

/* This variable sets the number of bits in an address that are to be
   sent in a memory ("M" or "m") packet.  Normally, after stripping
   leading zeros, the entire address would be sent. This variable
   restricts the address to REMOTE_ADDRESS_SIZE bits.  HISTORY: The
   initial implementation of remote.c restricted the address sent in
   memory packets to ``host::sizeof long'' bytes - (typically 32
   bits).  Consequently, for 64 bit targets, the upper 32 bits of an
   address was never sent.  Since fixing this bug may cause a break in
   some remote targets this variable is principly provided to
   facilitate backward compatibility. */

static int remote_address_size;

/* This is the size (in chars) of the first response to the `g' command.  This
   is used to limit the size of the memory read and write commands to prevent
   stub buffers from overflowing.  The size does not include headers and
   trailers, it is only the payload size. */

static int remote_register_buf_size = 0;

/* Should we try the 'P' request?  If this is set to one when the stub
   doesn't support 'P', the only consequence is some unnecessary traffic.  */
static int stub_supports_P = 1;

/* These are pointers to hook functions that may be set in order to
   modify resume/wait behavior for a particular architecture.  */

void (*target_resume_hook) PARAMS ((void));
void (*target_wait_loop_hook) PARAMS ((void));



/* These are the threads which we last sent to the remote system.
   -1 for all or -2 for not sent yet.  */
static int general_thread;
static int continue_thread;

/* Call this function as a result of
   1) A halt indication (T packet) containing a thread id
   2) A direct query of currthread
   3) Successful execution of set thread
 */

static void
record_currthread (currthread)
     int currthread;
{
  general_thread = currthread;

  /* If this is a new thread, add it to GDB's thread list.
     If we leave it up to WFI to do this, bad things will happen.  */
  if (!in_thread_list (currthread))
    add_thread (currthread);
}

#define MAGIC_NULL_PID 42000

static void
set_thread (th, gen)
     int th;
     int gen;
{
  char buf[PBUFSIZ];
  int state = gen ? general_thread : continue_thread;

  if (state == th)
    return;

  buf[0] = 'H';
  buf[1] = gen ? 'g' : 'c';
  if (th == MAGIC_NULL_PID)
    {
      buf[2] = '0';
      buf[3] = '\0';
    }
  else if (th < 0)
    sprintf (&buf[2], "-%x", -th);
  else
    sprintf (&buf[2], "%x", th);
  putpkt (buf);
  getpkt (buf, 0);
  if (gen)
    general_thread  = th;
  else
    continue_thread = th;
}

/*  Return nonzero if the thread TH is still alive on the remote system.  */

static int
remote_thread_alive (tid)
     int tid;
{
  char buf[16];

  if (tid < 0)
    sprintf (buf, "T-%08x", -tid);
  else
    sprintf (buf, "T%08x", tid);
  putpkt (buf);
  getpkt (buf, 0);
  return (buf[0] == 'O' && buf[1] == 'K');
}

/* About these extended threadlist and threadinfo packets.  They are
   variable length packets but, the fields within them are often fixed
   length.  They are redundent enough to send over UDP as is the
   remote protocol in general.  There is a matching unit test module
   in libstub.  */

#define OPAQUETHREADBYTES 8

/* a 64 bit opaque identifier */
typedef unsigned char threadref[OPAQUETHREADBYTES];

/* WARNING: This threadref data structure comes from the remote O.S., libstub
   protocol encoding, and remote.c. it is not particularly changable */

/* Right now, the internal structure is int. We want it to be bigger.
   Plan to fix this.
   */

typedef int gdb_threadref; /* internal GDB thread reference */

/*  gdb_ext_thread_info is an internal GDB data structure which is
   equivalint to the reply of the remote threadinfo packet */

struct gdb_ext_thread_info
{
  threadref threadid;	  /* External form of thread reference */
  int active;		  /* Has state interesting to GDB? , regs, stack */
  char display[256];	  /* Brief state display, name, blocked/syspended */
  char shortname[32];	  /* To be used to name threads */
  char more_display[256]; /* Long info, statistics, queue depth, whatever */
};

/* The volume of remote transfers can be limited by submitting
   a mask containing bits specifying the desired information.
   Use a union of these values as the 'selection' parameter to
   get_thread_info. FIXME: Make these TAG names more thread specific.
   */

#define TAG_THREADID 1
#define TAG_EXISTS 2
#define TAG_DISPLAY 4
#define TAG_THREADNAME 8
#define TAG_MOREDISPLAY 16 

#define BUF_THREAD_ID_SIZE (OPAQUETHREADBYTES*2)

char *unpack_varlen_hex PARAMS ((char *buff, int *result));

static char *unpack_nibble PARAMS ((char *buf, int *val));

static char *pack_nibble PARAMS ((char *buf, int nibble));

static char *pack_hex_byte PARAMS ((char *pkt, int/*unsigned char*/ byte));

static char *unpack_byte PARAMS ((char *buf, int *value));

static char *pack_int PARAMS ((char *buf, int value));

static char *unpack_int PARAMS ((char *buf, int *value));

static char *unpack_string PARAMS ((char *src, char *dest, int length));

static char *pack_threadid PARAMS ((char *pkt, threadref *id));

static char *unpack_threadid PARAMS ((char *inbuf, threadref *id));

void int_to_threadref PARAMS ((threadref *id, int value));

static int threadref_to_int PARAMS ((threadref *ref));

static void copy_threadref PARAMS ((threadref *dest, threadref *src));

static int threadmatch PARAMS ((threadref *dest, threadref *src));

static char *pack_threadinfo_request PARAMS ((char *pkt, int mode,
					      threadref *id));

static int remote_unpack_thread_info_response PARAMS ((char *pkt,
						       threadref *expectedref,
						       struct gdb_ext_thread_info *info));


static int remote_get_threadinfo PARAMS ((threadref *threadid,
					  int fieldset,	/*TAG mask */
					  struct gdb_ext_thread_info *info));

static int adapt_remote_get_threadinfo PARAMS ((gdb_threadref *ref,
						int selection,
						struct gdb_ext_thread_info *info));

static char *pack_threadlist_request PARAMS ((char *pkt, int startflag,
					      int threadcount,
					      threadref *nextthread));

static int parse_threadlist_response PARAMS ((char *pkt,
					      int result_limit,
					      threadref *original_echo,
					      threadref *resultlist,
					      int *doneflag));

static int remote_get_threadlist PARAMS ((int startflag,
					  threadref *nextthread,
					  int result_limit,
					  int *done,
					  int *result_count,
					  threadref *threadlist));

typedef int (*rmt_thread_action) (threadref *ref, void *context);

static int remote_threadlist_iterator PARAMS ((rmt_thread_action stepfunction,
					       void *context, int looplimit));

static int remote_newthread_step PARAMS ((threadref *ref, void *context));

/* encode 64 bits in 16 chars of hex */

static const char hexchars[] = "0123456789abcdef";

static int
ishex (ch, val)
     int ch;
     int *val;
{
  if ((ch >= 'a') && (ch <= 'f'))
    {
      *val = ch - 'a' + 10;
      return 1;
    }
  if ((ch >= 'A') && (ch <= 'F'))
    {
      *val = ch - 'A' + 10;
      return 1;
    }
  if ((ch >= '0') && (ch <= '9'))
    {
      *val = ch - '0';
      return 1;
    }
  return 0;
}

static int
stubhex (ch)
     int ch;
{
  if (ch >= 'a' && ch <= 'f')
    return ch - 'a' + 10;
  if (ch >= '0' && ch <= '9')
    return ch - '0';
  if (ch >= 'A' && ch <= 'F')
    return ch - 'A' + 10;
  return -1;
}

static int
stub_unpack_int (buff, fieldlength)
     char *buff;
     int fieldlength;
{
  int nibble;
  int retval = 0;

  while (fieldlength)
    {
      nibble = stubhex (*buff++);
      retval |= nibble;
      fieldlength--;
      if (fieldlength)
	retval = retval << 4;
    }
  return retval;
}

char *
unpack_varlen_hex (buff, result)
     char *buff;		/* packet to parse */
     int *result;
{
  int nibble;
  int retval = 0;

  while (ishex (*buff, &nibble))
    {
      buff++;
      retval = retval << 4;
      retval |= nibble & 0x0f;
    }
  *result = retval;
  return buff;
}

static char *
unpack_nibble (buf, val)
     char *buf;
     int *val;
{
  ishex (*buf++, val);
  return buf;
}

static char *
pack_nibble (buf, nibble)
     char *buf;
     int nibble;
{
  *buf++ = hexchars[(nibble & 0x0f)];
  return buf;
}

static char *
pack_hex_byte (pkt, byte)
     char *pkt;
     int byte;
{
  *pkt++ = hexchars[(byte >> 4) & 0xf];
  *pkt++ = hexchars[(byte & 0xf)];
  return pkt;
}

static char *
unpack_byte (buf, value)
     char *buf;
     int *value;
{
  *value = stub_unpack_int (buf, 2);
  return buf + 2;
}

static char *
pack_int (buf, value)
     char *buf;
     int value;
{
  buf = pack_hex_byte (buf, (value >> 24) & 0xff);
  buf = pack_hex_byte (buf, (value >> 16) & 0xff);
  buf = pack_hex_byte (buf, (value >> 8) & 0x0ff);
  buf = pack_hex_byte (buf, (value & 0xff));
  return buf;
}

static char *
unpack_int (buf, value)
     char *buf;
     int *value;
{
  *value = stub_unpack_int (buf, 8);
  return buf + 8;
}

#if 0 /* currently unused, uncomment when needed */
static char *pack_string PARAMS ((char *pkt, char *string));

static char *
pack_string (pkt, string)
     char *pkt;
     char *string;
{
  char ch;
  int len;

  len = strlen (string);
  if (len > 200)
    len = 200;			/* Bigger than most GDB packets, junk??? */
  pkt = pack_hex_byte (pkt, len);
  while (len-- > 0)
    {
      ch = *string++;
      if ((ch == '\0') || (ch == '#'))
	ch = '*';		/* Protect encapsulation */
      *pkt++ = ch;
    }
  return pkt;
}
#endif /* 0 (unused) */

static char *
unpack_string (src, dest, length)
     char *src;
     char *dest;
     int length;
{
  while (length--)
    *dest++ = *src++;
  *dest = '\0';
  return src;
}

static char *
pack_threadid (pkt, id)
     char *pkt;
     threadref *id;
{
  char *limit;
  unsigned char *altid;

  altid = (unsigned char *) id;
  limit = pkt + BUF_THREAD_ID_SIZE;
  while (pkt < limit)
    pkt = pack_hex_byte (pkt, *altid++);
  return pkt;
}


static char *
unpack_threadid (inbuf, id)
     char *inbuf;
     threadref *id;
{
  char *altref;
  char *limit = inbuf + BUF_THREAD_ID_SIZE;
  int x, y;

  altref = (char *) id;

  while (inbuf < limit)
    {
      x = stubhex (*inbuf++);
      y = stubhex (*inbuf++);
      *altref++ = (x << 4) | y;
    }
  return inbuf;
}

/* Externally, threadrefs are 64 bits but internally, they are still
   ints. This is due to a mismatch of specifications.  We would like
   to use 64bit thread references internally.  This is an adapter
   function.  */

void
int_to_threadref (id, value)
     threadref *id;
     int value;
{
  unsigned char *scan;

  scan = (unsigned char *) id;
  {
    int i = 4;
    while (i--)
      *scan++ = 0;
  }
  *scan++ = (value >> 24) & 0xff;
  *scan++ = (value >> 16) & 0xff;
  *scan++ = (value >> 8) & 0xff;
  *scan++ = (value & 0xff);
}

static int
threadref_to_int (ref)
     threadref *ref;
{
  int i, value = 0;
  unsigned char *scan;

  scan = (char *) ref;
  scan += 4;
  i = 4;
  while (i-- > 0)
    value = (value << 8) | ((*scan++) & 0xff);
  return value;
}

static void
copy_threadref (dest, src)
     threadref *dest;
     threadref *src;
{
  int i;
  unsigned char *csrc, *cdest;

  csrc = (unsigned char *) src;
  cdest = (unsigned char *) dest;
  i = 8;
  while (i--)
    *cdest++ = *csrc++;
}

static int
threadmatch (dest, src)
     threadref *dest;
     threadref *src;
{
  /* things are broken right now, so just assume we got a match */
#if 0
  unsigned char *srcp, *destp;
  int i, result;
  srcp = (char *) src;
  destp = (char *) dest;

  result = 1;
  while (i-- > 0)
    result &= (*srcp++ == *destp++) ? 1 : 0;
  return result;
#endif
  return 1;
}

/*
  threadid:1,        # always request threadid
  context_exists:2,
  display:4,
  unique_name:8,
  more_display:16
*/

/* Encoding:  'Q':8,'P':8,mask:32,threadid:64 */

static char *
pack_threadinfo_request (pkt, mode, id)
     char *pkt;
     int mode;
     threadref *id;
{
  *pkt++ = 'q';			/* Info Query */
  *pkt++ = 'P';			/* process or thread info */
  pkt = pack_int (pkt, mode);	/* mode */
  pkt = pack_threadid (pkt, id);	/* threadid */
  *pkt = '\0';			/* terminate */
  return pkt;
}

/* These values tag the fields in a thread info response packet */
/* Tagging the fields allows us to request specific fields and to
   add more fields as time goes by */

#define TAG_THREADID 1      /* Echo the thread identifier */
#define TAG_EXISTS 2        /* Is this process defined enough to
			       fetch registers and its stack */
#define TAG_DISPLAY 4       /* A short thing maybe to put on a window */
#define TAG_THREADNAME 8    /* string, maps 1-to-1 with a thread is */
#define TAG_MOREDISPLAY 16  /* Whatever the kernel wants to say about 
			       the process*/

static int
remote_unpack_thread_info_response (pkt, expectedref, info)
     char *pkt;
     threadref *expectedref;
     struct gdb_ext_thread_info *info;
{
  int mask, length;
  unsigned int tag;
  threadref ref;
  char *limit = pkt + PBUFSIZ;  /* plausable parsing limit */
  int retval = 1;

  /* info->threadid = 0; FIXME: implement zero_threadref */
  info->active = 0;
  info->display[0] = '\0';
  info->shortname[0] = '\0';
  info->more_display[0] = '\0';

  /* Assume the characters indicating the packet type have been stripped */
  pkt = unpack_int (pkt, &mask);	/* arg mask */
  pkt = unpack_threadid (pkt, &ref);

  if (mask == 0)
    warning ("Incomplete response to threadinfo request\n");
  if (!threadmatch (&ref, expectedref))
    {				/* This is an answer to a different request */
      warning ("ERROR RMT Thread info mismatch\n");
      return 0;
    }
  copy_threadref (&info->threadid, &ref);

  /* Loop on tagged fields , try to bail if somthing goes wrong */

  while ((pkt < limit) && mask && *pkt)	/* packets are terminated with nulls */
    {
      pkt = unpack_int (pkt, &tag);	/* tag */
      pkt = unpack_byte (pkt, &length);		/* length */
      if (!(tag & mask))	/* tags out of synch with mask */
	{
	  warning ("ERROR RMT: threadinfo tag mismatch\n");
	  retval = 0;
	  break;
	}
      if (tag == TAG_THREADID)
	{
	  if (length != 16)
	    {
	      warning ("ERROR RMT: length of threadid is not 16\n");
	      retval = 0;
	      break;
	    }
	  pkt = unpack_threadid (pkt, &ref);
	  mask = mask & ~TAG_THREADID;
	  continue;
	}
      if (tag == TAG_EXISTS)
	{
	  info->active = stub_unpack_int (pkt, length);
	  pkt += length;
	  mask = mask & ~(TAG_EXISTS);
	  if (length > 8)
	    {
	      warning ("ERROR RMT: 'exists' length too long\n");
	      retval = 0;
	      break;
	    }
	  continue;
	}
      if (tag == TAG_THREADNAME)
	{
	  pkt = unpack_string (pkt, &info->shortname[0], length);
	  mask = mask & ~TAG_THREADNAME;
	  continue;
	}
      if (tag == TAG_DISPLAY)
	{
	  pkt = unpack_string (pkt, &info->display[0], length);
	  mask = mask & ~TAG_DISPLAY;
	  continue;
	}
      if (tag == TAG_MOREDISPLAY)
	{
	  pkt = unpack_string (pkt, &info->more_display[0], length);
	  mask = mask & ~TAG_MOREDISPLAY;
	  continue;
	}
      warning ("ERROR RMT: unknown thread info tag\n");
      break;			/* Not a tag we know about */
    }
  return retval;
}

static int
remote_get_threadinfo (threadid, fieldset, info)
     threadref *threadid;
     int fieldset;		/* TAG mask */
     struct gdb_ext_thread_info *info;
{
  int result;
  char threadinfo_pkt[PBUFSIZ];

  pack_threadinfo_request (threadinfo_pkt, fieldset, threadid);
  putpkt (threadinfo_pkt);
  getpkt (threadinfo_pkt, 0);
  result = remote_unpack_thread_info_response (threadinfo_pkt + 2, threadid,
					       info);
  return result;
}

/* Unfortunately, 61 bit thread-ids are bigger than the internal
   representation of a threadid.  */

static int
adapt_remote_get_threadinfo (ref, selection, info)
     gdb_threadref *ref;
     int selection;
     struct gdb_ext_thread_info *info;
{
  threadref lclref;

  int_to_threadref (&lclref, *ref);
  return remote_get_threadinfo (&lclref, selection, info);
}

/*    Format: i'Q':8,i"L":8,initflag:8,batchsize:16,lastthreadid:32   */

static char *
pack_threadlist_request (pkt, startflag, threadcount, nextthread)
     char *pkt;
     int startflag;
     int threadcount;
     threadref *nextthread;
{
  *pkt++ = 'q';			/* info query packet */
  *pkt++ = 'L';			/* Process LIST or threadLIST request */
  pkt = pack_nibble (pkt, startflag);	/* initflag 1 bytes */
  pkt = pack_hex_byte (pkt, threadcount);	/* threadcount 2 bytes */
  pkt = pack_threadid (pkt, nextthread);	/* 64 bit thread identifier */
  *pkt = '\0';
  return pkt;
}

/* Encoding:   'q':8,'M':8,count:16,done:8,argthreadid:64,(threadid:64)* */

static int
parse_threadlist_response (pkt, result_limit, original_echo, resultlist,
			   doneflag)
     char *pkt;
     int result_limit;
     threadref *original_echo;
     threadref *resultlist;
     int *doneflag;
{
  char *limit;
  int count, resultcount, done;

  resultcount = 0;
  /* Assume the 'q' and 'M chars have been stripped.  */
  limit = pkt + (PBUFSIZ - BUF_THREAD_ID_SIZE);	/* done parse past here */
  pkt = unpack_byte (pkt, &count);	/* count field */
  pkt = unpack_nibble (pkt, &done);
  /* The first threadid is the argument threadid.  */
  pkt = unpack_threadid (pkt, original_echo);	/* should match query packet */
  while ((count-- > 0) && (pkt < limit))
    {
      pkt = unpack_threadid (pkt, resultlist++);
      if (resultcount++ >= result_limit)
	break;
    }
  if (doneflag)
    *doneflag = done;
  return resultcount;
}

static int
remote_get_threadlist (startflag, nextthread, result_limit,
		       done, result_count, threadlist)
     int startflag;
     threadref *nextthread;
     int result_limit;
     int *done;
     int *result_count;
     threadref *threadlist;

{
  static threadref echo_nextthread;
  char threadlist_packet[PBUFSIZ];
  char t_response[PBUFSIZ];
  int result = 1;

  /* Trancate result limit to be smaller than the packet size */
  if ((((result_limit + 1) * BUF_THREAD_ID_SIZE) + 10) >= PBUFSIZ)
    result_limit = (PBUFSIZ / BUF_THREAD_ID_SIZE) - 2;

  pack_threadlist_request (threadlist_packet,
			   startflag, result_limit, nextthread);
  putpkt (threadlist_packet);
  getpkt (t_response, 0);

  *result_count =
    parse_threadlist_response (t_response + 2, result_limit, &echo_nextthread,
			       threadlist, done);

  if (!threadmatch (&echo_nextthread, nextthread))
    {
      /* FIXME: This is a good reason to drop the packet */
      /* Possably, there is a duplicate response */
      /* Possabilities :
         retransmit immediatly - race conditions
         retransmit after timeout - yes
         exit
         wait for packet, then exit
       */
      warning ("HMM: threadlist did not echo arg thread, dropping it\n");
      return 0;			/* I choose simply exiting */
    }
  if (*result_count <= 0)
    {
      if (*done != 1)
	{
	  warning ("RMT ERROR : failed to get remote thread list\n");
	  result = 0;
	}
      return result;		/* break; */
    }
  if (*result_count > result_limit)
    {
      *result_count = 0;
      warning ("RMT ERROR: threadlist response longer than requested\n");
      return 0;
    }
  return result;
}

/* This is the interface between remote and threads, remotes upper interface */

/* remote_find_new_threads retrieves the thread list and for each
   thread in the list, looks up the thread in GDB's internal list,
   ading the thread if it does not already exist.  This involves
   getting partial thread lists from the remote target so, polling the
   quit_flag is required.  */


/* About this many threadisds fit in a packet. */

#define MAXTHREADLISTRESULTS 32

static int
remote_threadlist_iterator (stepfunction, context, looplimit)
     rmt_thread_action stepfunction;
     void *context;
     int looplimit;
{
  int done, i, result_count;
  int startflag = 1;
  int result = 1;
  int loopcount = 0;
  static threadref nextthread;
  static threadref resultthreadlist[MAXTHREADLISTRESULTS];

  done = 0;
  while (!done)
    {
      if (loopcount++ > looplimit)
	{
	  result = 0;
	  warning ("Remote fetch threadlist -infinite loop-\n");
	  break;
	}
      if (!remote_get_threadlist (startflag, &nextthread, MAXTHREADLISTRESULTS,
				  &done, &result_count, resultthreadlist))
	{
	  result = 0;
	  break;
	}
      /* clear for later iterations */
      startflag = 0;
      /* Setup to resume next batch of thread references, set nextthread.  */
      if (result_count >= 1)
	copy_threadref (&nextthread, &resultthreadlist[result_count - 1]);
      i = 0;
      while (result_count--)
	if (!(result = (*stepfunction) (&resultthreadlist[i++], context)))
	  break;
    }
  return result;
}

static int
remote_newthread_step (ref, context)
     threadref *ref;
     void *context;
{
  int pid;

  pid = threadref_to_int (ref);
  if (!in_thread_list (pid))
    add_thread (pid);
  return 1;			/* continue iterator */
}

#define CRAZY_MAX_THREADS 1000

static int
remote_current_thread (oldpid)
     int oldpid;
{
  char buf[PBUFSIZ];

  putpkt ("qC");
  getpkt (buf, 0);
  if (buf[0] == 'Q' && buf[1] == 'C')
    return strtol (&buf[2], NULL, 16);
  else
    return oldpid;
}

/* Find new threads for info threads command.  */

static void
remote_find_new_threads ()
{
  remote_threadlist_iterator (remote_newthread_step, 0, 
				    CRAZY_MAX_THREADS);
  if (inferior_pid == MAGIC_NULL_PID)	/* ack ack ack */
    inferior_pid = remote_current_thread (inferior_pid);
}


/*  Restart the remote side; this is an extended protocol operation.  */

static void
extended_remote_restart ()
{
  char buf[PBUFSIZ];

  /* Send the restart command; for reasons I don't understand the
     remote side really expects a number after the "R".  */
  buf[0] = 'R';
  sprintf (&buf[1], "%x", 0);
  putpkt (buf);

  /* Now query for status so this looks just like we restarted
     gdbserver from scratch.  */
  putpkt ("?");
  getpkt (buf, 0);
}

/* Clean up connection to a remote debugger.  */

/* ARGSUSED */
static void
remote_close (quitting)
     int quitting;
{
  if (remote_desc)
    SERIAL_CLOSE (remote_desc);
  remote_desc = NULL;
}

/* Query the remote side for the text, data and bss offsets. */

static void
get_offsets ()
{
  char buf[PBUFSIZ], *ptr;
  int lose;
  CORE_ADDR text_addr, data_addr, bss_addr;
  struct section_offsets *offs;

  putpkt ("qOffsets");

  getpkt (buf, 0);

  if (buf[0] == '\000')
    return;			/* Return silently.  Stub doesn't support
				   this command. */
  if (buf[0] == 'E')
    {
      warning ("Remote failure reply: %s", buf);
      return;
    }

  /* Pick up each field in turn.  This used to be done with scanf, but
     scanf will make trouble if CORE_ADDR size doesn't match
     conversion directives correctly.  The following code will work
     with any size of CORE_ADDR.  */
  text_addr = data_addr = bss_addr = 0;
  ptr = buf;
  lose = 0;

  if (strncmp (ptr, "Text=", 5) == 0)
    {
      ptr += 5;
      /* Don't use strtol, could lose on big values.  */
      while (*ptr && *ptr != ';')
	text_addr = (text_addr << 4) + fromhex (*ptr++);
    }
  else
    lose = 1;

  if (!lose && strncmp (ptr, ";Data=", 6) == 0)
    {
      ptr += 6;
      while (*ptr && *ptr != ';')
	data_addr = (data_addr << 4) + fromhex (*ptr++);
    }
  else
    lose = 1;

  if (!lose && strncmp (ptr, ";Bss=", 5) == 0)
    {
      ptr += 5;
      while (*ptr && *ptr != ';')
	bss_addr = (bss_addr << 4) + fromhex (*ptr++);
    }
  else
    lose = 1;

  if (lose)
    error ("Malformed response to offset query, %s", buf);

  if (symfile_objfile == NULL)
    return;

  offs = (struct section_offsets *) alloca (sizeof (struct section_offsets)
					    + symfile_objfile->num_sections
					    * sizeof (offs->offsets));
  memcpy (offs, symfile_objfile->section_offsets,
	  sizeof (struct section_offsets)
	  + symfile_objfile->num_sections
	  * sizeof (offs->offsets));

  ANOFFSET (offs, SECT_OFF_TEXT) = text_addr;

  /* This is a temporary kludge to force data and bss to use the same offsets
     because that's what nlmconv does now.  The real solution requires changes
     to the stub and remote.c that I don't have time to do right now.  */

  ANOFFSET (offs, SECT_OFF_DATA) = data_addr;
  ANOFFSET (offs, SECT_OFF_BSS) = data_addr;

  objfile_relocate (symfile_objfile, offs);
}

/* Stub for catch_errors.  */

static int
remote_start_remote (dummy)
     PTR dummy;
{
  immediate_quit = 1;		/* Allow user to interrupt it */

  /* Ack any packet which the remote side has already sent.  */
  SERIAL_WRITE (remote_desc, "+", 1);

  /* Let the stub know that we want it to return the thread.  */
  set_thread (-1, 0);

  inferior_pid = remote_current_thread (inferior_pid);

  get_offsets ();		/* Get text, data & bss offsets */

  putpkt ("?");			/* initiate a query from remote machine */
  immediate_quit = 0;

  start_remote ();		/* Initialize gdb process mechanisms */
  return 1;
}

/* Open a connection to a remote debugger.
   NAME is the filename used for communication.  */

static void
remote_open (name, from_tty)
     char *name;
     int from_tty;
{
  remote_open_1 (name, from_tty, &remote_ops, 0);
}

/* Open a connection to a remote debugger using the extended
   remote gdb protocol.  NAME is the filename used for communication.  */

static void
extended_remote_open (name, from_tty)
     char *name;
     int from_tty;
{
  remote_open_1 (name, from_tty, &extended_remote_ops, 1/*extended_p*/);
}

/* Generic code for opening a connection to a remote target.  */

static DCACHE *remote_dcache;

static void
remote_open_1 (name, from_tty, target, extended_p)
     char *name;
     int from_tty;
     struct target_ops *target;
     int extended_p;
{
  if (name == 0)
    error ("To open a remote debug connection, you need to specify what\n\
serial device is attached to the remote system (e.g. /dev/ttya).");

  target_preopen (from_tty);

  unpush_target (target);

  remote_dcache = dcache_init (remote_read_bytes, remote_write_bytes);

  remote_desc = SERIAL_OPEN (name);
  if (!remote_desc)
    perror_with_name (name);

  if (baud_rate != -1)
    {
      if (SERIAL_SETBAUDRATE (remote_desc, baud_rate))
	{
	  SERIAL_CLOSE (remote_desc);
	  perror_with_name (name);
	}
    }


  SERIAL_RAW (remote_desc);

  /* If there is something sitting in the buffer we might take it as a
     response to a command, which would be bad.  */
  SERIAL_FLUSH_INPUT (remote_desc);

  if (from_tty)
    {
      puts_filtered ("Remote debugging using ");
      puts_filtered (name);
      puts_filtered ("\n");
    }
  push_target (target);	/* Switch to using remote target now */

  /* Start out by trying the 'P' request to set registers.  We set
     this each time that we open a new target so that if the user
     switches from one stub to another, we can (if the target is
     closed and reopened) cope.  */
  stub_supports_P = 1;

  general_thread  = -2;
  continue_thread = -2;

  /* Force remote_write_bytes to check whether target supports
     binary downloading. */
  remote_binary_checked = 0;

  /* Without this, some commands which require an active target (such
     as kill) won't work.  This variable serves (at least) double duty
     as both the pid of the target process (if it has such), and as a
     flag indicating that a target is active.  These functions should
     be split out into seperate variables, especially since GDB will
     someday have a notion of debugging several processes.  */

  inferior_pid = MAGIC_NULL_PID;
  /* Start the remote connection; if error (0), discard this target.
     In particular, if the user quits, be sure to discard it
     (we'd be in an inconsistent state otherwise).  */
  if (!catch_errors (remote_start_remote, NULL, 
		     "Couldn't establish connection to remote target\n", 
		     RETURN_MASK_ALL))
    {
      pop_target ();
      return;
    }

  if (extended_p)
    {
      /* tell the remote that we're using the extended protocol.  */
      char buf[PBUFSIZ];
      putpkt ("!");
      getpkt (buf, 0);
    }
}

/* This takes a program previously attached to and detaches it.  After
   this is done, GDB can be used to debug some other program.  We
   better not have left any breakpoints in the target program or it'll
   die when it hits one.  */

static void
remote_detach (args, from_tty)
     char *args;
     int from_tty;
{
  char buf[PBUFSIZ];

  if (args)
    error ("Argument given to \"detach\" when remotely debugging.");

  /* Tell the remote target to detach.  */
  strcpy (buf, "D");
  remote_send (buf);

  pop_target ();
  if (from_tty)
    puts_filtered ("Ending remote debugging.\n");
}

/* Convert hex digit A to a number.  */

int
fromhex (a)
     int a;
{
  if (a >= '0' && a <= '9')
    return a - '0';
  else if (a >= 'a' && a <= 'f')
    return a - 'a' + 10;
  else if (a >= 'A' && a <= 'F')
    return a - 'A' + 10;
  else 
    error ("Reply contains invalid hex digit %d", a);
}

/* Convert number NIB to a hex digit.  */

static int
tohex (nib)
     int nib;
{
  if (nib < 10)
    return '0'+nib;
  else
    return 'a'+nib-10;
}

/* Tell the remote machine to resume.  */

static enum target_signal last_sent_signal = TARGET_SIGNAL_0;

static int last_sent_step;

static void
remote_resume (pid, step, siggnal)
     int pid, step;
     enum target_signal siggnal;
{
  char buf[PBUFSIZ];

  if (pid == -1)
    set_thread (0, 0);		/* run any thread */
  else
    set_thread (pid, 0);	/* run this thread */

  dcache_flush (remote_dcache);

  last_sent_signal = siggnal;
  last_sent_step = step;

  /* A hook for when we need to do something at the last moment before
     resumption.  */
  if (target_resume_hook)
    (*target_resume_hook) ();

  if (siggnal != TARGET_SIGNAL_0)
    {
      buf[0] = step ? 'S' : 'C';
      buf[1] = tohex (((int)siggnal >> 4) & 0xf);
      buf[2] = tohex ((int)siggnal & 0xf);
      buf[3] = '\0';
    }
  else
    strcpy (buf, step ? "s": "c");

  putpkt (buf);
}

/* Send ^C to target to halt it.  Target will respond, and send us a
   packet.  */

static void (*ofunc) PARAMS ((int));

/* The command line interface's stop routine. This function is installed
   as a signal handler for SIGINT. The first time a user requests a
   stop, we call remote_stop to send a break or ^C. If there is no
   response from the target (it didn't stop when the user requested it),
   we ask the user if he'd like to detach from the target. */
static void
remote_interrupt (signo)
     int signo;
{
  /* If this doesn't work, try more severe steps. */
  signal (signo, remote_interrupt_twice);

  if (remote_debug)
    printf_unfiltered ("remote_interrupt called\n");

  target_stop ();
}

/* The user typed ^C twice.  */

static void
remote_interrupt_twice (signo)
     int signo;
{
  signal (signo, ofunc);
  interrupt_query ();
  signal (signo, remote_interrupt);
}

/* This is the generic stop called via the target vector. When a target
   interrupt is requested, either by the command line or the GUI, we
   will eventually end up here. */
static void
remote_stop ()
{
  /* Send a break or a ^C, depending on user preference.  */
  if (remote_debug)
    printf_unfiltered ("remote_stop called\n");

  if (remote_break)
    SERIAL_SEND_BREAK (remote_desc);
  else
    SERIAL_WRITE (remote_desc, "\003", 1);
}

/* Ask the user what to do when an interrupt is received.  */

static void
interrupt_query ()
{
  target_terminal_ours ();

  if (query ("Interrupted while waiting for the program.\n\
Give up (and stop debugging it)? "))
    {
      target_mourn_inferior ();
      return_to_top_level (RETURN_QUIT);
    }

  target_terminal_inferior ();
}

/* If nonzero, ignore the next kill.  */

int kill_kludge;

void
remote_console_output (msg)
     char *msg;
{
  char *p;

  for (p = msg; *p; p +=2) 
    {
      char tb[2];
      char c = fromhex (p[0]) * 16 + fromhex (p[1]);
      tb[0] = c;
      tb[1] = 0;
      if (target_output_hook)
	target_output_hook (tb);
      else 
	fputs_filtered (tb, gdb_stdout);
    }
}

/* Wait until the remote machine stops, then return, storing status in
   STATUS just as `wait' would.  Returns "pid" (though it's not clear
   what, if anything, that means in the case of this target).  */

static int
remote_wait (pid, status)
     int pid;
     struct target_waitstatus *status;
{
  unsigned char buf[PBUFSIZ];
  int thread_num = -1;

  status->kind = TARGET_WAITKIND_EXITED;
  status->value.integer = 0;

  while (1)
    {
      unsigned char *p;

      ofunc = signal (SIGINT, remote_interrupt);
      getpkt ((char *) buf, 1);
      signal (SIGINT, ofunc);

      /* This is a hook for when we need to do something (perhaps the
	 collection of trace data) every time the target stops.  */
      if (target_wait_loop_hook)
	(*target_wait_loop_hook) ();

      switch (buf[0])
	{
	case 'E':		/* Error of some sort */
	  warning ("Remote failure reply: %s", buf);
	  continue;
	case 'T':		/* Status with PC, SP, FP, ... */
	  {
	    int i;
	    long regno;
	    char regs[MAX_REGISTER_RAW_SIZE];

	    /* Expedited reply, containing Signal, {regno, reg} repeat */
	    /*  format is:  'Tssn...:r...;n...:r...;n...:r...;#cc', where
		ss = signal number
		n... = register number
		r... = register contents
		*/
	    p = &buf[3];	/* after Txx */

	    while (*p)
	      {
		unsigned char *p1;
		char *p_temp;

		/* Read the register number */
		regno = strtol ((const char *) p, &p_temp, 16);
		p1 = (unsigned char *)p_temp;

		if (p1 == p) /* No register number present here */
		  {
		    p1 = (unsigned char *) strchr ((const char *) p, ':');
		    if (p1 == NULL)
		      warning ("Malformed packet(a) (missing colon): %s\n\
Packet: '%s'\n",
			       p, buf);
		    if (strncmp ((const char *) p, "thread", p1 - p) == 0)
		      {
			p_temp = unpack_varlen_hex (++p1, &thread_num);
			record_currthread (thread_num);
			p = (unsigned char *) p_temp;
		      }
		  }
		else
		  {
		    p = p1;

		    if (*p++ != ':')
		      warning ("Malformed packet(b) (missing colon): %s\n\
Packet: '%s'\n",
			       p, buf);

		    if (regno >= NUM_REGS)
		      warning ("Remote sent bad register number %ld: %s\n\
Packet: '%s'\n",
			       regno, p, buf);

		    for (i = 0; i < REGISTER_RAW_SIZE (regno); i++)
		      {
			if (p[0] == 0 || p[1] == 0)
			  warning ("Remote reply is too short: %s", buf);
			regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
			p += 2;
		      }
		    supply_register (regno, regs);
		  }

		if (*p++ != ';')
		  {
		    warning ("Remote register badly formatted: %s", buf);
		    warning ("            here: %s",p);
		  }
	      }
	  }
	  /* fall through */
	case 'S':		/* Old style status, just signal only */
	  status->kind = TARGET_WAITKIND_STOPPED;
	  status->value.sig = (enum target_signal)
	    (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));

	  goto got_status;
	case 'W':		/* Target exited */
	  {
	    /* The remote process exited.  */
	    status->kind = TARGET_WAITKIND_EXITED;
	    status->value.integer = (fromhex (buf[1]) << 4) + fromhex (buf[2]);
	    goto got_status;
	  }
	case 'X':
	  status->kind = TARGET_WAITKIND_SIGNALLED;
	  status->value.sig = (enum target_signal)
	    (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));
	  kill_kludge = 1;

	  goto got_status;
	case 'O':		/* Console output */
	  remote_console_output (buf + 1);
	  continue;
	case '\0':
	  if (last_sent_signal != TARGET_SIGNAL_0)
	    {
	      /* Zero length reply means that we tried 'S' or 'C' and
		 the remote system doesn't support it.  */
	      target_terminal_ours_for_output ();
	      printf_filtered
		("Can't send signals to this remote system.  %s not sent.\n",
		 target_signal_to_name (last_sent_signal));
	      last_sent_signal = TARGET_SIGNAL_0;
	      target_terminal_inferior ();

	      strcpy ((char *) buf, last_sent_step ? "s" : "c");
	      putpkt ((char *) buf);
	      continue;
	    }
	  /* else fallthrough */
	default:
	  warning ("Invalid remote reply: %s", buf);
	  continue;
	}
    }
 got_status:
  if (thread_num != -1)
    {
      /* Initial thread value can only be acquired via wait, so deal with
	 this marker which is used before the first thread value is
	 acquired.  */
      if (inferior_pid == MAGIC_NULL_PID)
	{
	  inferior_pid = thread_num;
	  if (!in_thread_list (inferior_pid))
	    add_thread (inferior_pid);
	}
      return thread_num;
    }
  return inferior_pid;
}

/* Number of bytes of registers this stub implements.  */

static int register_bytes_found;

/* Read the remote registers into the block REGS.  */
/* Currently we just read all the registers, so we don't use regno.  */

/* ARGSUSED */
static void
remote_fetch_registers (regno)
     int regno;
{
  char buf[PBUFSIZ];
  int i;
  char *p;
  char regs[REGISTER_BYTES];

  set_thread (inferior_pid, 1);

  sprintf (buf, "g");
  remote_send (buf);

  if (remote_register_buf_size == 0)
    remote_register_buf_size = strlen (buf);

  /* Unimplemented registers read as all bits zero.  */
  memset (regs, 0, REGISTER_BYTES);

  /* We can get out of synch in various cases.  If the first character
     in the buffer is not a hex character, assume that has happened
     and try to fetch another packet to read.  */
  while ((buf[0] < '0' || buf[0] > '9')
	 && (buf[0] < 'a' || buf[0] > 'f')
	 && buf[0] != 'x')	/* New: unavailable register value */
    {
      if (remote_debug)
	printf_unfiltered ("Bad register packet; fetching a new packet\n");
      getpkt (buf, 0);
    }

  /* Reply describes registers byte by byte, each byte encoded as two
     hex characters.  Suck them all up, then supply them to the
     register cacheing/storage mechanism.  */

  p = buf;
  for (i = 0; i < REGISTER_BYTES; i++)
    {
      if (p[0] == 0)
	break;
      if (p[1] == 0)
	{
	  warning ("Remote reply is of odd length: %s", buf);
	  /* Don't change register_bytes_found in this case, and don't
	     print a second warning.  */
	  goto supply_them;
	}
      if (p[0] == 'x' && p[1] == 'x')
	regs[i] = 0;	/* 'x' */
      else
	regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
      p += 2;
    }

  if (i != register_bytes_found)
    {
      register_bytes_found = i;
#ifdef REGISTER_BYTES_OK
      if (!REGISTER_BYTES_OK (i))
	warning ("Remote reply is too short: %s", buf);
#endif
    }
  
  supply_them:
  for (i = 0; i < NUM_REGS; i++)
  {
    supply_register (i, &regs[REGISTER_BYTE(i)]);
    if (buf[REGISTER_BYTE(i) * 2] == 'x')
      register_valid[i] = -1;	/* register value not available */
  }
}

/* Prepare to store registers.  Since we may send them all (using a
   'G' request), we have to read out the ones we don't want to change
   first.  */

static void 
remote_prepare_to_store ()
{
  /* Make sure the entire registers array is valid.  */
  read_register_bytes (0, (char *)NULL, REGISTER_BYTES);
}

/* Store register REGNO, or all registers if REGNO == -1, from the contents
   of REGISTERS.  FIXME: ignores errors.  */

static void
remote_store_registers (regno)
     int regno;
{
  char buf[PBUFSIZ];
  int i;
  char *p;

  set_thread (inferior_pid, 1);

  if (regno >= 0 && stub_supports_P)
    {
      /* Try storing a single register.  */
      char *regp;

      sprintf (buf, "P%x=", regno);
      p = buf + strlen (buf);
      regp = &registers[REGISTER_BYTE (regno)];
      for (i = 0; i < REGISTER_RAW_SIZE (regno); ++i)
	{
	  *p++ = tohex ((regp[i] >> 4) & 0xf);
	  *p++ = tohex (regp[i] & 0xf);
	}
      *p = '\0';
      remote_send (buf);
      if (buf[0] != '\0')
	{
	  /* The stub understands the 'P' request.  We are done.  */
	  return;
	}

      /* The stub does not support the 'P' request.  Use 'G' instead,
	 and don't try using 'P' in the future (it will just waste our
	 time).  */
      stub_supports_P = 0;
    }

  buf[0] = 'G';

  /* Command describes registers byte by byte,
     each byte encoded as two hex characters.  */

  p = buf + 1;
  /* remote_prepare_to_store insures that register_bytes_found gets set.  */
  for (i = 0; i < register_bytes_found; i++)
    {
      *p++ = tohex ((registers[i] >> 4) & 0xf);
      *p++ = tohex (registers[i] & 0xf);
    }
  *p = '\0';

  remote_send (buf);
}

/* Use of the data cache *used* to be disabled because it loses for looking
   at and changing hardware I/O ports and the like.  Accepting `volatile'
   would perhaps be one way to fix it.  Another idea would be to use the
   executable file for the text segment (for all SEC_CODE sections?
   For all SEC_READONLY sections?).  This has problems if you want to
   actually see what the memory contains (e.g. self-modifying code,
   clobbered memory, user downloaded the wrong thing).  

   Because it speeds so much up, it's now enabled, if you're playing
   with registers you turn it of (set remotecache 0).  */

/* Read a word from remote address ADDR and return it.
   This goes through the data cache.  */

#if 0	/* unused? */
static int
remote_fetch_word (addr)
     CORE_ADDR addr;
{
  return dcache_fetch (remote_dcache, addr);
}

/* Write a word WORD into remote address ADDR.
   This goes through the data cache.  */

static void
remote_store_word (addr, word)
     CORE_ADDR addr;
     int word;
{
  dcache_poke (remote_dcache, addr, word);
}
#endif	/* 0 (unused?) */



/* Return the number of hex digits in num.  */

static int
hexnumlen (num)
     ULONGEST num;
{
  int i;

  for (i = 0; num != 0; i++)
    num >>= 4;

  return max (i, 1);
}

/* Set BUF to the hex digits representing NUM.  */

static int
hexnumstr (buf, num)
     char *buf;
     ULONGEST num;
{
  int i;
  int len = hexnumlen (num);

  buf[len] = '\0';

  for (i = len - 1; i >= 0; i--)
    {
      buf[i] = "0123456789abcdef" [(num & 0xf)];
      num >>= 4;
    }

  return len;
}

/* Mask all but the least significant REMOTE_ADDRESS_SIZE bits. */

static CORE_ADDR
remote_address_masked (addr)
     CORE_ADDR addr;
{
  if (remote_address_size > 0
      && remote_address_size < (sizeof (ULONGEST) * 8))
    {
      /* Only create a mask when that mask can safely be constructed
         in a ULONGEST variable. */
      ULONGEST mask = 1;
      mask = (mask << remote_address_size) - 1;
      addr &= mask;
    }
  return addr;
}

/* Determine whether the remote target supports binary downloading.
   This is accomplished by sending a no-op memory write of zero length
   to the target at the specified address. It does not suffice to send
   the whole packet, since many stubs strip the eighth bit and subsequently
   compute a wrong checksum, which causes real havoc with remote_write_bytes.

   NOTE: This can still lose if the serial line is not eight-bit clean. In
   cases like this, the user should clear "remotebinarydownload". */
static void
check_binary_download (addr)
     CORE_ADDR addr;
{
  if (remote_binary_download && !remote_binary_checked)
    {
      char buf[PBUFSIZ], *p;
      remote_binary_checked = 1;

      p = buf;
      *p++ = 'X';
      p += hexnumstr (p, (ULONGEST) addr);
      *p++ = ',';
      p += hexnumstr (p, (ULONGEST) 0);
      *p++ = ':';
      *p = '\0';

      putpkt_binary (buf, (int) (p - buf));
      getpkt (buf, 0);

      if (buf[0] == '\0')
	remote_binary_download = 0;
    }

  if (remote_debug)
    {
      if (remote_binary_download)
	printf_unfiltered ("binary downloading suppported by target\n");
      else
	printf_unfiltered ("binary downloading NOT suppported by target\n");
    }
}

/* Write memory data directly to the remote machine.
   This does not inform the data cache; the data cache uses this.
   MEMADDR is the address in the remote memory space.
   MYADDR is the address of the buffer in our space.
   LEN is the number of bytes.

   Returns number of bytes transferred, or 0 for error.  */

static int
remote_write_bytes (memaddr, myaddr, len)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
{
  int max_buf_size;		/* Max size of packet output buffer */
  int origlen;

  /* Verify that the target can support a binary download */
  check_binary_download (memaddr);

  /* Chop the transfer down if necessary */

  max_buf_size = min (remote_write_size, PBUFSIZ);
  if (remote_register_buf_size != 0)
    max_buf_size = min (max_buf_size, remote_register_buf_size);

  /* Subtract header overhead from max payload size -  $M<memaddr>,<len>:#nn */
  max_buf_size -= 2 + hexnumlen (memaddr + len - 1) + 1 + hexnumlen (len) + 4;

  origlen = len;
  while (len > 0)
    {
      unsigned char buf[PBUFSIZ];
      unsigned char *p, *plen;
      int todo;
      int i;

      /* construct "M"<memaddr>","<len>":" */
      /* sprintf (buf, "M%lx,%x:", (unsigned long) memaddr, todo); */
      memaddr = remote_address_masked (memaddr);
      p = buf;
      if (remote_binary_download)
	{
	  *p++ = 'X';
	  todo = min (len, max_buf_size);
	}
      else
	{
	  *p++ = 'M';
	  todo = min (len, max_buf_size / 2); /* num bytes that will fit */
	}

      p += hexnumstr (p, (ULONGEST) memaddr);
      *p++ = ',';

      plen = p;			/* remember where len field goes */
      p += hexnumstr (p, (ULONGEST) todo);
      *p++ = ':';
      *p = '\0';

      /* We send target system values byte by byte, in increasing byte
	 addresses, each byte encoded as two hex characters (or one
	 binary character).  */
      if (remote_binary_download)
	{
	  int escaped = 0;
          for (i = 0;
	       (i < todo) && (i + escaped) < (max_buf_size - 2);
	       i++)
            {
              switch (myaddr[i] & 0xff)
                {
                case '$':
                case '#':
                case 0x7d:
                  /* These must be escaped */
                  escaped++;
                  *p++ = 0x7d;
                  *p++ = (myaddr[i] & 0xff) ^ 0x20;
                  break;
                default:
                  *p++ = myaddr[i] & 0xff;
                  break;
                }
            }

          if (i < todo)
            {
              /* Escape chars have filled up the buffer prematurely, 
                 and we have actually sent fewer bytes than planned.
                 Fix-up the length field of the packet.  */

	      /* FIXME: will fail if new len is a shorter string than 
		 old len.  */

              plen += hexnumstr (plen, (ULONGEST) i);
              *plen++ = ':';
            }
	}
      else
	{
	  for (i = 0; i < todo; i++)
	    {
	      *p++ = tohex ((myaddr[i] >> 4) & 0xf);
	      *p++ = tohex (myaddr[i] & 0xf);
	    }
	  *p = '\0';
	}

      putpkt_binary (buf, (int) (p - buf));
      getpkt (buf, 0);

      if (buf[0] == 'E')
	{
	  /* There is no correspondance between what the remote protocol uses
	     for errors and errno codes.  We would like a cleaner way of
	     representing errors (big enough to include errno codes, bfd_error
	     codes, and others).  But for now just return EIO.  */
	  errno = EIO;
	  return 0;
	}

      /* Increment by i, not by todo, in case escape chars 
	 caused us to send fewer bytes than we'd planned.  */
      myaddr  += i;
      memaddr += i;
      len     -= i;
    }
  return origlen;
}

/* Read memory data directly from the remote machine.
   This does not use the data cache; the data cache uses this.
   MEMADDR is the address in the remote memory space.
   MYADDR is the address of the buffer in our space.
   LEN is the number of bytes.

   Returns number of bytes transferred, or 0 for error.  */

static int
remote_read_bytes (memaddr, myaddr, len)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
{
  int max_buf_size;		/* Max size of packet output buffer */
  int origlen;

  /* Chop the transfer down if necessary */

  max_buf_size = min (remote_write_size, PBUFSIZ);
  if (remote_register_buf_size != 0)
    max_buf_size = min (max_buf_size, remote_register_buf_size);

  origlen = len;
  while (len > 0)
    {
      char buf[PBUFSIZ];
      char *p;
      int todo;
      int i;

      todo = min (len, max_buf_size / 2); /* num bytes that will fit */

      /* construct "m"<memaddr>","<len>" */
      /* sprintf (buf, "m%lx,%x", (unsigned long) memaddr, todo); */
      memaddr = remote_address_masked (memaddr);
      p = buf;
      *p++ = 'm';
      p += hexnumstr (p, (ULONGEST) memaddr);
      *p++ = ',';
      p += hexnumstr (p, (ULONGEST) todo);
      *p = '\0';

      putpkt (buf);
      getpkt (buf, 0);

      if (buf[0] == 'E')
	{
	  /* There is no correspondance between what the remote protocol uses
	     for errors and errno codes.  We would like a cleaner way of
	     representing errors (big enough to include errno codes, bfd_error
	     codes, and others).  But for now just return EIO.  */
	  errno = EIO;
	  return 0;
	}

  /* Reply describes memory byte by byte,
     each byte encoded as two hex characters.  */

      p = buf;
      for (i = 0; i < todo; i++)
	{
	  if (p[0] == 0 || p[1] == 0)
	    /* Reply is short.  This means that we were able to read
	       only part of what we wanted to.  */
	    return i + (origlen - len);
	  myaddr[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
	  p += 2;
	}
      myaddr += todo;
      memaddr += todo;
      len -= todo;
    }
  return origlen;
}

/* Read or write LEN bytes from inferior memory at MEMADDR,
   transferring to or from debugger address BUFFER.  Write to inferior if
   SHOULD_WRITE is nonzero.  Returns length of data written or read; 0
   for error.  */

#ifndef REMOTE_TRANSLATE_XFER_ADDRESS
#define REMOTE_TRANSLATE_XFER_ADDRESS(MEM_ADDR, MEM_LEN, TARG_ADDR, TARG_LEN) \
   (*(TARG_ADDR) = (MEM_ADDR), *(TARG_LEN) = (MEM_LEN))
#endif

/* ARGSUSED */
static int
remote_xfer_memory (mem_addr, buffer, mem_len, should_write, target)
     CORE_ADDR mem_addr;
     char *buffer;
     int mem_len;
     int should_write;
     struct target_ops *target;			/* ignored */
{
  CORE_ADDR targ_addr;
  int targ_len;
  REMOTE_TRANSLATE_XFER_ADDRESS (mem_addr, mem_len, &targ_addr, &targ_len);
  if (targ_len <= 0)
    return 0;

  return dcache_xfer_memory (remote_dcache, targ_addr, buffer,
			     targ_len, should_write);
}

   
#if 0
/* Enable after 4.12.  */

void
remote_search (len, data, mask, startaddr, increment, lorange, hirange
	       addr_found, data_found)
     int len;
     char *data;
     char *mask;
     CORE_ADDR startaddr;
     int increment;
     CORE_ADDR lorange;
     CORE_ADDR hirange;
     CORE_ADDR *addr_found;
     char *data_found;
{
  if (increment == -4 && len == 4)
    {
      long mask_long, data_long;
      long data_found_long;
      CORE_ADDR addr_we_found;
      char buf[PBUFSIZ];
      long returned_long[2];
      char *p;

      mask_long = extract_unsigned_integer (mask, len);
      data_long = extract_unsigned_integer (data, len);
      sprintf (buf, "t%x:%x,%x", startaddr, data_long, mask_long);
      putpkt (buf);
      getpkt (buf, 0);
      if (buf[0] == '\0')
	{
	  /* The stub doesn't support the 't' request.  We might want to
	     remember this fact, but on the other hand the stub could be
	     switched on us.  Maybe we should remember it only until
	     the next "target remote".  */
	  generic_search (len, data, mask, startaddr, increment, lorange,
			  hirange, addr_found, data_found);
	  return;
	}

      if (buf[0] == 'E')
	/* There is no correspondance between what the remote protocol uses
	   for errors and errno codes.  We would like a cleaner way of
	   representing errors (big enough to include errno codes, bfd_error
	   codes, and others).  But for now just use EIO.  */
	memory_error (EIO, startaddr);
      p = buf;
      addr_we_found = 0;
      while (*p != '\0' && *p != ',')
	addr_we_found = (addr_we_found << 4) + fromhex (*p++);
      if (*p == '\0')
	error ("Protocol error: short return for search");

      data_found_long = 0;
      while (*p != '\0' && *p != ',')
	data_found_long = (data_found_long << 4) + fromhex (*p++);
      /* Ignore anything after this comma, for future extensions.  */

      if (addr_we_found < lorange || addr_we_found >= hirange)
	{
	  *addr_found = 0;
	  return;
	}

      *addr_found = addr_we_found;
      *data_found = store_unsigned_integer (data_we_found, len);
      return;
    }
  generic_search (len, data, mask, startaddr, increment, lorange,
		  hirange, addr_found, data_found);
}
#endif /* 0 */

static void
remote_files_info (ignore)
     struct target_ops *ignore;
{
  puts_filtered ("Debugging a target over a serial line.\n");
}

/* Stuff for dealing with the packets which are part of this protocol.
   See comment at top of file for details.  */

/* Read a single character from the remote end, masking it down to 7 bits. */

static int
readchar (timeout)
     int timeout;
{
  int ch;

  ch = SERIAL_READCHAR (remote_desc, timeout);

  switch (ch)
    {
    case SERIAL_EOF:
      error ("Remote connection closed");
    case SERIAL_ERROR:
      perror_with_name ("Remote communication error");
    case SERIAL_TIMEOUT:
      return ch;
    default:
      return ch & 0x7f;
    }
}

/* Send the command in BUF to the remote machine, and read the reply
   into BUF.  Report an error if we get an error reply.  */

static void
remote_send (buf)
     char *buf;
{
  putpkt (buf);
  getpkt (buf, 0);

  if (buf[0] == 'E')
    error ("Remote failure reply: %s", buf);
}

/* Display a null-terminated packet on stdout, for debugging, using C
   string notation.  */

static void
print_packet (buf)
     char *buf;
{
  puts_filtered ("\"");
  while (*buf)
    gdb_printchar (*buf++, gdb_stdout, '"');
  puts_filtered ("\"");
}

int
putpkt (buf)
     char *buf;
{
  return putpkt_binary (buf, strlen (buf));
}

/* Send a packet to the remote machine, with error checking.  The data
   of the packet is in BUF.  The string in BUF can be at most  PBUFSIZ - 5
   to account for the $, # and checksum, and for a possible /0 if we are
   debugging (remote_debug) and want to print the sent packet as a string */

static int
putpkt_binary (buf, cnt)
     char *buf;
     int cnt;
{
  int i;
  unsigned char csum = 0;
  char buf2[PBUFSIZ];
  int ch;
  int tcount = 0;
  char *p;

  /* Copy the packet into buffer BUF2, encapsulating it
     and giving it a checksum.  */

  if (cnt > (int) sizeof (buf2) - 5)		/* Prosanity check */
    abort ();

  p = buf2;
  *p++ = '$';

  for (i = 0; i < cnt; i++)
    {
      csum += buf[i];
      *p++ = buf[i];
    }
  *p++ = '#';
  *p++ = tohex ((csum >> 4) & 0xf);
  *p++ = tohex (csum & 0xf);

  /* Send it over and over until we get a positive ack.  */

  while (1)
    {
      int started_error_output = 0;

      if (remote_debug)
	{
	  *p = '\0';
	  printf_unfiltered ("Sending packet: %s...", buf2);
	  gdb_flush (gdb_stdout);
	}
      if (SERIAL_WRITE (remote_desc, buf2, p - buf2))
	perror_with_name ("putpkt: write failed");

      /* read until either a timeout occurs (-2) or '+' is read */
      while (1)
	{
	  ch = readchar (remote_timeout);

 	  if (remote_debug)
	    {
	      switch (ch)
		{
		case '+':
		case SERIAL_TIMEOUT:
		case '$':
		  if (started_error_output)
		    {
		      putchar_unfiltered ('\n');
		      started_error_output = 0;
		    }
		}
	    }

	  switch (ch)
	    {
	    case '+':
	      if (remote_debug)
		printf_unfiltered ("Ack\n");
	      return 1;
	    case SERIAL_TIMEOUT:
	      tcount ++;
	      if (tcount > 3)
		return 0;
	      break;		/* Retransmit buffer */
	    case '$':
	      {
		char junkbuf[PBUFSIZ];

	      /* It's probably an old response, and we're out of sync.
		 Just gobble up the packet and ignore it.  */
		getpkt (junkbuf, 0);
		continue;		/* Now, go look for + */
	      }
	    default:
	      if (remote_debug)
		{
		  if (!started_error_output)
		    {
		      started_error_output = 1;
		      printf_unfiltered ("putpkt: Junk: ");
		    }
		  putchar_unfiltered (ch & 0177);
		}
	      continue;
	    }
	  break;		/* Here to retransmit */
	}

#if 0
      /* This is wrong.  If doing a long backtrace, the user should be
	 able to get out next time we call QUIT, without anything as
	 violent as interrupt_query.  If we want to provide a way out of
	 here without getting to the next QUIT, it should be based on
	 hitting ^C twice as in remote_wait.  */
      if (quit_flag)
	{
	  quit_flag = 0;
	  interrupt_query ();
	}
#endif
    }
}

/* Come here after finding the start of the frame.  Collect the rest
   into BUF, verifying the checksum, length, and handling run-length
   compression.  Returns 0 on any error, 1 on success.  */

static int
read_frame (buf)
     char *buf;
{
  unsigned char csum;
  char *bp;
  int c;

  csum = 0;
  bp = buf;

  while (1)
    {
      c = readchar (remote_timeout);

      switch (c)
	{
	case SERIAL_TIMEOUT:
	  if (remote_debug)
	    puts_filtered ("Timeout in mid-packet, retrying\n");
	  return 0;
	case '$':
	  if (remote_debug)
	    puts_filtered ("Saw new packet start in middle of old one\n");
	  return 0;		/* Start a new packet, count retries */
	case '#':
	  {
	    unsigned char pktcsum;

	    *bp = '\000';

	    pktcsum = fromhex (readchar (remote_timeout)) << 4;
	    pktcsum |= fromhex (readchar (remote_timeout));

	    if (csum == pktcsum)
	      return 1;

	    if (remote_debug) 
	      {
		printf_filtered ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=",
				 pktcsum, csum);
		puts_filtered (buf);
		puts_filtered ("\n");
	      }
	    return 0;
	  }
	case '*':		/* Run length encoding */
	  csum += c;
	  c = readchar (remote_timeout);
	  csum += c;
	  c = c - ' ' + 3;	/* Compute repeat count */


	  if (c > 0 && c < 255 && bp + c - 1 < buf + PBUFSIZ - 1)
	    {
	      memset (bp, *(bp - 1), c);
	      bp += c;
	      continue;
	    }

	  *bp = '\0';
	  printf_filtered ("Repeat count %d too large for buffer: ", c);
	  puts_filtered (buf);
	  puts_filtered ("\n");
	  return 0;

	default:
	  if (bp < buf + PBUFSIZ - 1)
	    {
	      *bp++ = c;
	      csum += c;
	      continue;
	    }

	  *bp = '\0';
	  puts_filtered ("Remote packet too long: ");
	  puts_filtered (buf);
	  puts_filtered ("\n");

	  return 0;
	}
    }
}

/* Read a packet from the remote machine, with error checking, and
   store it in BUF.  BUF is expected to be of size PBUFSIZ.  If
   FOREVER, wait forever rather than timing out; this is used while
   the target is executing user code.  */

void
getpkt (buf, forever)
     char *buf;
     int forever;
{
  int c;
  int tries;
  int timeout;
  int val;

  strcpy (buf,"timeout");

  if (forever)
    {
      timeout = watchdog > 0 ? watchdog : -1;
    }

  else
    timeout = remote_timeout;

#define MAX_TRIES 3

  for (tries = 1; tries <= MAX_TRIES; tries++)
    {
      /* This can loop forever if the remote side sends us characters
	 continuously, but if it pauses, we'll get a zero from readchar
	 because of timeout.  Then we'll count that as a retry.  */

      /* Note that we will only wait forever prior to the start of a packet.
	 After that, we expect characters to arrive at a brisk pace.  They
	 should show up within remote_timeout intervals.  */

      do
	{
	  c = readchar (timeout);

	  if (c == SERIAL_TIMEOUT)
	    {
	      if (forever)	/* Watchdog went off.  Kill the target. */
		{
		  target_mourn_inferior ();
		  error ("Watchdog has expired.  Target detached.\n");
		}
	      if (remote_debug)
		puts_filtered ("Timed out.\n");
	      goto retry;
	    }
	}
      while (c != '$');

      /* We've found the start of a packet, now collect the data.  */

      val = read_frame (buf);

      if (val == 1)
	{
	  if (remote_debug)
	    fprintf_unfiltered (gdb_stdout, "Packet received: %s\n", buf);
	  SERIAL_WRITE (remote_desc, "+", 1);
	  return;
	}

      /* Try the whole thing again.  */
    retry:
      SERIAL_WRITE (remote_desc, "-", 1);
    }

  /* We have tried hard enough, and just can't receive the packet.  Give up. */

  printf_unfiltered ("Ignoring packet error, continuing...\n");
  SERIAL_WRITE (remote_desc, "+", 1);
}

static void
remote_kill ()
{
  /* For some mysterious reason, wait_for_inferior calls kill instead of
     mourn after it gets TARGET_WAITKIND_SIGNALLED.  Work around it.  */
  if (kill_kludge)
    {
      kill_kludge = 0;
      target_mourn_inferior ();
      return;
    }

  /* Use catch_errors so the user can quit from gdb even when we aren't on
     speaking terms with the remote system.  */
  catch_errors ((catch_errors_ftype*) putpkt, "k", "", RETURN_MASK_ERROR);

  /* Don't wait for it to die.  I'm not really sure it matters whether
     we do or not.  For the existing stubs, kill is a noop.  */
  target_mourn_inferior ();
}

static void
remote_mourn ()
{
  remote_mourn_1 (&remote_ops);
}

static void
extended_remote_mourn ()
{
  /* We do _not_ want to mourn the target like this; this will
     remove the extended remote target  from the target stack,
     and the next time the user says "run" it'll fail. 

     FIXME: What is the right thing to do here?  */
#if 0
  remote_mourn_1 (&extended_remote_ops);
#endif
}

/* Worker function for remote_mourn.  */
static void
remote_mourn_1 (target)
     struct target_ops *target;
{
  unpush_target (target);
  generic_mourn_inferior ();
}

/* In the extended protocol we want to be able to do things like
   "run" and have them basically work as expected.  So we need
   a special create_inferior function. 

   FIXME: One day add support for changing the exec file
   we're debugging, arguments and an environment.  */

static void
extended_remote_create_inferior (exec_file, args, env)
     char *exec_file;
     char *args;
     char **env;
{
  /* Rip out the breakpoints; we'll reinsert them after restarting
     the remote server.  */
  remove_breakpoints ();

  /* Now restart the remote server.  */
  extended_remote_restart ();

  /* Now put the breakpoints back in.  This way we're safe if the
     restart function works via a unix fork on the remote side.  */
  insert_breakpoints ();

  /* Clean up from the last time we were running.  */
  clear_proceed_status ();

  /* Let the remote process run.  */
  proceed (-1, TARGET_SIGNAL_0, 0);
}


/* On some machines, e.g. 68k, we may use a different breakpoint instruction
   than other targets; in those use REMOTE_BREAKPOINT instead of just
   BREAKPOINT.  Also, bi-endian targets may define LITTLE_REMOTE_BREAKPOINT
   and BIG_REMOTE_BREAKPOINT.  If none of these are defined, we just call
   the standard routines that are in mem-break.c.  */

/* FIXME, these ought to be done in a more dynamic fashion.  For instance,
   the choice of breakpoint instruction affects target program design and
   vice versa, and by making it user-tweakable, the special code here
   goes away and we need fewer special GDB configurations.  */

#if defined (LITTLE_REMOTE_BREAKPOINT) && defined (BIG_REMOTE_BREAKPOINT) && !defined(REMOTE_BREAKPOINT)
#define REMOTE_BREAKPOINT
#endif

#ifdef REMOTE_BREAKPOINT

/* If the target isn't bi-endian, just pretend it is.  */
#if !defined (LITTLE_REMOTE_BREAKPOINT) && !defined (BIG_REMOTE_BREAKPOINT)
#define LITTLE_REMOTE_BREAKPOINT REMOTE_BREAKPOINT
#define BIG_REMOTE_BREAKPOINT REMOTE_BREAKPOINT
#endif

static unsigned char big_break_insn[] = BIG_REMOTE_BREAKPOINT;
static unsigned char little_break_insn[] = LITTLE_REMOTE_BREAKPOINT;

#endif /* REMOTE_BREAKPOINT */

/* Insert a breakpoint on targets that don't have any better breakpoint
   support.  We read the contents of the target location and stash it,
   then overwrite it with a breakpoint instruction.  ADDR is the target
   location in the target machine.  CONTENTS_CACHE is a pointer to 
   memory allocated for saving the target contents.  It is guaranteed
   by the caller to be long enough to save sizeof BREAKPOINT bytes (this
   is accomplished via BREAKPOINT_MAX).  */

static int
remote_insert_breakpoint (addr, contents_cache)
     CORE_ADDR addr;
     char *contents_cache;
{
#ifdef REMOTE_BREAKPOINT
  int val;

  val = target_read_memory (addr, contents_cache, sizeof big_break_insn);

  if (val == 0)
    {
      if (TARGET_BYTE_ORDER == BIG_ENDIAN)
	val = target_write_memory (addr, (char *) big_break_insn,
				   sizeof big_break_insn);
      else
	val = target_write_memory (addr, (char *) little_break_insn,
				   sizeof little_break_insn);
    }

  return val;
#else
  return memory_insert_breakpoint (addr, contents_cache);
#endif /* REMOTE_BREAKPOINT */
}

static int
remote_remove_breakpoint (addr, contents_cache)
     CORE_ADDR addr;
     char *contents_cache;
{
#ifdef REMOTE_BREAKPOINT
  return target_write_memory (addr, contents_cache, sizeof big_break_insn);
#else
  return memory_remove_breakpoint (addr, contents_cache);
#endif /* REMOTE_BREAKPOINT */
}

/* Some targets are only capable of doing downloads, and afterwards
   they switch to the remote serial protocol.  This function provides
   a clean way to get from the download target to the remote target.
   It's basically just a wrapper so that we don't have to expose any
   of the internal workings of remote.c.

   Prior to calling this routine, you should shutdown the current
   target code, else you will get the "A program is being debugged
   already..." message.  Usually a call to pop_target() suffices.  */

void
push_remote_target (name, from_tty)
     char *name;
     int from_tty;
{
  printf_filtered ("Switching to remote protocol\n");
  remote_open (name, from_tty);
}

/* Other targets want to use the entire remote serial module but with
   certain remote_ops overridden. */

void
open_remote_target (name, from_tty, target, extended_p)
     char *name;
     int from_tty;
     struct target_ops *target;
     int extended_p;
{
  printf_filtered ("Selecting the %sremote protocol\n",
		   (extended_p ? "extended-" : ""));
  remote_open_1 (name, from_tty, target, extended_p);
}

/* Table used by the crc32 function to calcuate the checksum. */

static unsigned long crc32_table[256] = {0, 0};

static unsigned long
crc32 (buf, len, crc)
     unsigned char *buf;
     int len;
     unsigned int crc;
{
  if (! crc32_table[1])
    {
      /* Initialize the CRC table and the decoding table. */
      int i, j;
      unsigned int c;

      for (i = 0; i < 256; i++)
        {
          for (c = i << 24, j = 8; j > 0; --j)
            c = c & 0x80000000 ? (c << 1) ^ 0x04c11db7 : (c << 1);
          crc32_table[i] = c;
        }
    }

  while (len--)
    {
      crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *buf) & 255];
      buf++;
    }
  return crc;
}

/* compare-sections command

   With no arguments, compares each loadable section in the exec bfd
   with the same memory range on the target, and reports mismatches.
   Useful for verifying the image on the target against the exec file.
   Depends on the target understanding the new "qCRC:" request.  */

static void
compare_sections_command (args, from_tty)
     char *args;
     int from_tty;
{
  asection *s;
  unsigned long host_crc, target_crc;
  extern bfd *exec_bfd;
  struct cleanup *old_chain;
  char *tmp, *sectdata, *sectname, buf[PBUFSIZ];
  bfd_size_type size;
  bfd_vma lma;
  int matched = 0;
  int mismatched = 0;

  if (!exec_bfd)
    error ("command cannot be used without an exec file");
  if (!current_target.to_shortname ||
      strcmp (current_target.to_shortname, "remote") != 0)
    error ("command can only be used with remote target");

  for (s = exec_bfd->sections; s; s = s->next) 
    {
      if (!(s->flags & SEC_LOAD))
	continue;	/* skip non-loadable section */

      size = bfd_get_section_size_before_reloc (s);
      if (size == 0)
	continue;	/* skip zero-length section */

      sectname = (char *) bfd_get_section_name (exec_bfd, s);
      if (args && strcmp (args, sectname) != 0)
	continue;	/* not the section selected by user */

      matched = 1;	/* do this section */
      lma = s->lma;
      /* FIXME: assumes lma can fit into long */
      sprintf (buf, "qCRC:%lx,%lx", (long) lma, (long) size);
      putpkt (buf);

      /* be clever; compute the host_crc before waiting for target reply */
      sectdata = xmalloc (size);
      old_chain = make_cleanup (free, sectdata);
      bfd_get_section_contents (exec_bfd, s, sectdata, 0, size);
      host_crc = crc32 ((unsigned char *) sectdata, size, 0xffffffff);

      getpkt (buf, 0);
      if (buf[0] == 'E')
	error ("target memory fault, section %s, range 0x%08x -- 0x%08x",
	       sectname, lma, lma + size);
      if (buf[0] != 'C')
	error ("remote target does not support this operation");

      for (target_crc = 0, tmp = &buf[1]; *tmp; tmp++)
	target_crc = target_crc * 16 + fromhex (*tmp);

      printf_filtered ("Section %s, range 0x%08x -- 0x%08x: ",
		       sectname, lma, lma + size);
      if (host_crc == target_crc)
	printf_filtered ("matched.\n");
      else
       {
	 printf_filtered ("MIS-MATCHED!\n");
	 mismatched++;
       }

      do_cleanups (old_chain);
    }
  if (mismatched > 0)
    warning ("One or more sections of the remote executable does not match\n\
the loaded file\n");
  if (args && !matched)
    printf_filtered ("No loaded section named '%s'.\n", args);
}

static int
remote_query (query_type, buf, outbuf, bufsiz)
     int query_type;
     char *buf;
     char *outbuf;
     int *bufsiz;
{
  int i;
  char buf2[PBUFSIZ];
  char *p2 = &buf2[0];
  char *p = buf;

  if (! bufsiz)
    error ("null pointer to remote bufer size specified");

  /* minimum outbuf size is PBUFSIZ - if bufsiz is not large enough let 
     the caller know and return what the minimum size is   */
  /* Note: a zero bufsiz can be used to query the minimum buffer size */
  if ( *bufsiz < PBUFSIZ )
    {
      *bufsiz = PBUFSIZ;
      return -1;
    }

  /* except for querying the minimum buffer size, target must be open */
  if (! remote_desc)
    error ("remote query is only available after target open");

  /* we only take uppercase letters as query types, at least for now */
  if ( (query_type < 'A') || (query_type > 'Z') )
    error ("invalid remote query type");

  if (! buf)
    error ("null remote query specified");

  if (! outbuf)
    error ("remote query requires a buffer to receive data");

  outbuf[0] = '\0';

  *p2++ = 'q';
  *p2++ = query_type;

  /* we used one buffer char for the remote protocol q command and another
     for the query type.  As the remote protocol encapsulation uses 4 chars
     plus one extra in case we are debugging (remote_debug),
     we have PBUFZIZ - 7 left to pack the query string */
  i = 0;
  while ( buf[i] && (i < (PBUFSIZ - 8)) )
    {
      /* bad caller may have sent forbidden characters */
      if ( (!isprint(buf[i])) || (buf[i] == '$') || (buf[i] == '#') )
        error ("illegal characters in query string");

      *p2++ = buf[i];
      i++;
    }
  *p2 = buf[i];

  if ( buf[i] )
    error ("query larger than available buffer");

  i = putpkt (buf2);
  if ( i < 0 ) return i;

  getpkt (outbuf, 0);

  return 0;
}

static void
packet_command (args, from_tty)
     char *args;
     int from_tty;
{
  char buf[PBUFSIZ];

  if (! remote_desc)
    error ("command can only be used with remote target");

  if (! args)
    error ("remote-packet command requires packet text as argument");

  puts_filtered ("sending: ");
  print_packet (args);
  puts_filtered ("\n");
  putpkt (args);

  getpkt (buf, 0);
  puts_filtered ("received: ");
  print_packet (buf);
  puts_filtered ("\n");
}

#if 0
/* --------- UNIT_TEST for THREAD oriented PACKETS ------------------------- */

static void display_thread_info PARAMS ((struct gdb_ext_thread_info *info));

static void threadset_test_cmd PARAMS ((char *cmd, int tty));

static void threadalive_test PARAMS ((char *cmd, int tty));

static void threadlist_test_cmd PARAMS ((char *cmd, int tty));

int get_and_display_threadinfo PARAMS ((threadref *ref));

static void threadinfo_test_cmd PARAMS ((char *cmd, int tty));

static int thread_display_step PARAMS ((threadref *ref, void *context));

static void threadlist_update_test_cmd PARAMS ((char *cmd, int tty));

static void init_remote_threadtests PARAMS ((void));

#define SAMPLE_THREAD  0x05060708  /* Truncated 64 bit threadid */

static void
threadset_test_cmd (cmd, tty)
     char *cmd;
     int tty;
{
  int sample_thread = SAMPLE_THREAD;

  printf_filtered ("Remote threadset test\n");
  set_thread (sample_thread, 1);
}


static void
threadalive_test (cmd, tty)
     char *cmd;
     int tty;
{
  int sample_thread = SAMPLE_THREAD;

  if (remote_thread_alive (sample_thread))
    printf_filtered ("PASS: Thread alive test\n");
  else
    printf_filtered ("FAIL: Thread alive test\n");
}

void output_threadid PARAMS ((char *title, threadref * ref));

void
output_threadid (title, ref)
     char *title;
     threadref *ref;
{
  char hexid[20];

  pack_threadid (&hexid[0], ref);	/* Convert threead id into hex */
  hexid[16] = 0;
  printf_filtered ("%s  %s\n", title, (&hexid[0]));
}

static void
threadlist_test_cmd (cmd, tty)
     char *cmd;
     int tty;
{
  int startflag = 1;
  threadref nextthread;
  int done, result_count;
  threadref threadlist[3];

  printf_filtered ("Remote Threadlist test\n");
  if (!remote_get_threadlist (startflag, &nextthread, 3, &done,
			      &result_count, &threadlist[0]))
    printf_filtered ("FAIL: threadlist test\n");
  else
    {
      threadref *scan = threadlist;
      threadref *limit = scan + result_count;

      while (scan < limit)
	output_threadid (" thread ", scan++);
    }
}

void
display_thread_info (info)
     struct gdb_ext_thread_info *info;
{
  output_threadid ("Threadid: ", &info->threadid);
  printf_filtered ("Name: %s\n ", info->shortname);
  printf_filtered ("State: %s\n", info->display);
  printf_filtered ("other: %s\n\n", info->more_display);
}

int
get_and_display_threadinfo (ref)
     threadref *ref;
{
  int result;
  int set;
  struct gdb_ext_thread_info threadinfo;

  set = TAG_THREADID | TAG_EXISTS | TAG_THREADNAME
    | TAG_MOREDISPLAY | TAG_DISPLAY;
  if (0 != (result = remote_get_threadinfo (ref, set, &threadinfo)))
    display_thread_info (&threadinfo);
  return result;
}

static void
threadinfo_test_cmd (cmd, tty)
     char *cmd;
     int tty;
{
  int athread = SAMPLE_THREAD;
  threadref thread;
  int set;

  int_to_threadref (&thread, athread);
  printf_filtered ("Remote Threadinfo test\n");
  if (!get_and_display_threadinfo (&thread))
    printf_filtered ("FAIL cannot get thread info\n");
}

static int
thread_display_step (ref, context)
     threadref *ref;
     void *context;
{
  /* output_threadid(" threadstep ",ref); *//* simple test */
  return get_and_display_threadinfo (ref);
}

static void
threadlist_update_test_cmd (cmd, tty)
     char *cmd;
     int tty;
{
  printf_filtered ("Remote Threadlist update test\n");
  remote_threadlist_iterator (thread_display_step, 0, CRAZY_MAX_THREADS);
}

static void
init_remote_threadtests (void)
{
  add_com ("tlist", class_obscure, threadlist_test_cmd,
     "Fetch and print the remote list of thread identifiers, one pkt only");
  add_com ("tinfo", class_obscure, threadinfo_test_cmd,
	   "Fetch and display info about one thread");
  add_com ("tset", class_obscure, threadset_test_cmd,
	   "Test setting to a different thread");
  add_com ("tupd", class_obscure, threadlist_update_test_cmd,
	   "Iterate through updating all remote thread info");
  add_com ("talive", class_obscure, threadalive_test,
	   " Remote thread alive test ");
}

#endif /* 0 */

static void
init_remote_ops ()
{
  remote_ops.to_shortname = "remote";		
  remote_ops.to_longname = "Remote serial target in gdb-specific protocol";
  remote_ops.to_doc = 
    "Use a remote computer via a serial line, using a gdb-specific protocol.\n\
Specify the serial device it is connected to (e.g. /dev/ttya).";  
  remote_ops.to_open = remote_open;		
  remote_ops.to_close = remote_close;		
  remote_ops.to_detach = remote_detach;
  remote_ops.to_resume = remote_resume;	
  remote_ops.to_wait = remote_wait;
  remote_ops.to_fetch_registers = remote_fetch_registers;
  remote_ops.to_store_registers = remote_store_registers;
  remote_ops.to_prepare_to_store = remote_prepare_to_store;
  remote_ops.to_xfer_memory = remote_xfer_memory;	
  remote_ops.to_files_info = remote_files_info;	
  remote_ops.to_insert_breakpoint = remote_insert_breakpoint;
  remote_ops.to_remove_breakpoint = remote_remove_breakpoint;
  remote_ops.to_kill = remote_kill;		
  remote_ops.to_load = generic_load;		
  remote_ops.to_mourn_inferior = remote_mourn;
  remote_ops.to_thread_alive = remote_thread_alive;
  remote_ops.to_find_new_threads = remote_find_new_threads;
  remote_ops.to_stop = remote_stop;
  remote_ops.to_query = remote_query;
  remote_ops.to_stratum = process_stratum;
  remote_ops.to_has_all_memory = 1;	
  remote_ops.to_has_memory = 1;	
  remote_ops.to_has_stack = 1;	
  remote_ops.to_has_registers = 1;	
  remote_ops.to_has_execution = 1;	
  remote_ops.to_has_thread_control = tc_schedlock; /* can lock scheduler */
  remote_ops.to_magic = OPS_MAGIC;	
}

/* Set up the extended remote vector by making a copy of the standard
   remote vector and adding to it.  */

static void
init_extended_remote_ops ()
{
  extended_remote_ops = remote_ops;

  extended_remote_ops.to_shortname = "extended-remote";	
  extended_remote_ops.to_longname = 
    "Extended remote serial target in gdb-specific protocol";
  extended_remote_ops.to_doc = 
    "Use a remote computer via a serial line, using a gdb-specific protocol.\n\
Specify the serial device it is connected to (e.g. /dev/ttya).",
  extended_remote_ops.to_open = extended_remote_open;	
  extended_remote_ops.to_create_inferior = extended_remote_create_inferior;
  extended_remote_ops.to_mourn_inferior = extended_remote_mourn;
} 

void
_initialize_remote ()
{
  /* runtime constants */
  remote_write_size = PBUFSIZ;

  init_remote_ops ();
  add_target (&remote_ops);

  init_extended_remote_ops ();
  add_target (&extended_remote_ops);

#if 0
  init_remote_threadtests ();
#endif

  add_cmd ("compare-sections", class_obscure, compare_sections_command, 
	   "Compare section data on target to the exec file.\n\
Argument is a single section name (default: all loaded sections).", 
	   &cmdlist);

  add_cmd ("packet", class_maintenance, packet_command,
	   "Send an arbitrary packet to a remote target.\n\
   maintenance packet TEXT\n\
If GDB is talking to an inferior via the GDB serial protocol, then\n\
this command sends the string TEXT to the inferior, and displays the\n\
response packet.  GDB supplies the initial `$' character, and the\n\
terminating `#' character and checksum.",
	   &maintenancelist);

  add_show_from_set 
    (add_set_cmd ("remotetimeout", no_class,
		  var_integer, (char *)&remote_timeout,
		  "Set timeout value for remote read.\n",
		  &setlist),
     &showlist);

  add_show_from_set 
    (add_set_cmd ("remotebreak", no_class,
		  var_integer, (char *)&remote_break,
		  "Set whether to send break if interrupted.\n",
		  &setlist),
     &showlist);

  add_show_from_set 
    (add_set_cmd ("remotewritesize", no_class,
		  var_integer, (char *)&remote_write_size,
		  "Set the maximum number of bytes per memory write packet.\n",
		  &setlist),
     &showlist);

  remote_address_size = TARGET_PTR_BIT;
  add_show_from_set 
    (add_set_cmd ("remoteaddresssize", class_obscure,
		  var_integer, (char *)&remote_address_size,
		  "Set the maximum size of the address (in bits) \
in a memory packet.\n",
		  &setlist),
     &showlist);  

  add_show_from_set 
    (add_set_cmd ("remotebinarydownload", no_class,
		  var_boolean, (char *) &remote_binary_download,
		  "Set binary downloads.\n", &setlist),
     &showlist);
}