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
|
# SPDX-License-Identifier: GPL-2.0
# Select 32 or 64 bit
config 64BIT
bool "64-bit kernel" if "$(ARCH)" = "x86"
default "$(ARCH)" != "i386"
help
Say yes to build a 64-bit kernel - formerly known as x86_64
Say no to build a 32-bit kernel - formerly known as i386
config X86_32
def_bool y
depends on !64BIT
# Options that are inherently 32-bit kernel only:
select ARCH_WANT_IPC_PARSE_VERSION
select CLKSRC_I8253
select CLONE_BACKWARDS
select GENERIC_VDSO_32
select HAVE_DEBUG_STACKOVERFLOW
select KMAP_LOCAL
select MODULES_USE_ELF_REL
select OLD_SIGACTION
select ARCH_SPLIT_ARG64
config X86_64
def_bool y
depends on 64BIT
# Options that are inherently 64-bit kernel only:
select ARCH_HAS_GIGANTIC_PAGE
select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
select ARCH_USE_CMPXCHG_LOCKREF
select HAVE_ARCH_SOFT_DIRTY
select MODULES_USE_ELF_RELA
select NEED_DMA_MAP_STATE
select SWIOTLB
select ARCH_HAS_ELFCORE_COMPAT
select ZONE_DMA32
config FORCE_DYNAMIC_FTRACE
def_bool y
depends on X86_32
depends on FUNCTION_TRACER
select DYNAMIC_FTRACE
help
We keep the static function tracing (!DYNAMIC_FTRACE) around
in order to test the non static function tracing in the
generic code, as other architectures still use it. But we
only need to keep it around for x86_64. No need to keep it
for x86_32. For x86_32, force DYNAMIC_FTRACE.
#
# Arch settings
#
# ( Note that options that are marked 'if X86_64' could in principle be
# ported to 32-bit as well. )
#
config X86
def_bool y
#
# Note: keep this list sorted alphabetically
#
select ACPI_LEGACY_TABLES_LOOKUP if ACPI
select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
select ARCH_32BIT_OFF_T if X86_32
select ARCH_CLOCKSOURCE_INIT
select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_CACHE_LINE_SIZE
select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_EARLY_DEBUG if KGDB
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FAST_MULTIPLIER
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_KCOV if X86_64
select ARCH_HAS_MEM_ENCRYPT
select ARCH_HAS_MEMBARRIER_SYNC_CORE
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
select ARCH_HAS_PMEM_API if X86_64
select ARCH_HAS_PTE_DEVMAP if X86_64
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
select ARCH_HAS_COPY_MC if X86_64
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_SET_DIRECT_MAP
select ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_HAS_STRICT_MODULE_RWX
select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
select ARCH_HAS_SYSCALL_WRAPPER
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAS_VM_GET_PAGE_PROT
select ARCH_HAS_DEBUG_WX
select ARCH_HAS_ZONE_DMA_SET if EXPERT
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_MIGHT_HAVE_PC_SERIO
select ARCH_STACKWALK
select ARCH_SUPPORTS_ACPI
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64
select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
select ARCH_SUPPORTS_LTO_CLANG
select ARCH_SUPPORTS_LTO_CLANG_THIN
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_MEMTEST
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
select ARCH_USE_SYM_ANNOTATIONS
select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
select ARCH_WANTS_DYNAMIC_TASK_STRUCT
select ARCH_WANTS_NO_INSTR
select ARCH_WANT_GENERAL_HUGETLB
select ARCH_WANT_HUGE_PMD_SHARE
select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP if X86_64
select ARCH_WANT_LD_ORPHAN_WARN
select ARCH_WANTS_THP_SWAP if X86_64
select ARCH_HAS_PARANOID_L1D_FLUSH
select BUILDTIME_TABLE_SORT
select CLKEVT_I8253
select CLOCKSOURCE_VALIDATE_LAST_CYCLE
select CLOCKSOURCE_WATCHDOG
select DCACHE_WORD_ACCESS
select DYNAMIC_SIGFRAME
select EDAC_ATOMIC_SCRUB
select EDAC_SUPPORT
select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
select GENERIC_CLOCKEVENTS_MIN_ADJUST
select GENERIC_CMOS_UPDATE
select GENERIC_CPU_AUTOPROBE
select GENERIC_CPU_VULNERABILITIES
select GENERIC_EARLY_IOREMAP
select GENERIC_ENTRY
select GENERIC_IOMAP
select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
select GENERIC_IRQ_MIGRATION if SMP
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_RESERVATION_MODE
select GENERIC_IRQ_SHOW
select GENERIC_PENDING_IRQ if SMP
select GENERIC_PTDUMP
select GENERIC_SMP_IDLE_THREAD
select GENERIC_TIME_VSYSCALL
select GENERIC_GETTIMEOFDAY
select GENERIC_VDSO_TIME_NS
select GUP_GET_PTE_LOW_HIGH if X86_PAE
select HARDIRQS_SW_RESEND
select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
select HAVE_ACPI_APEI if ACPI
select HAVE_ACPI_APEI_NMI if ACPI
select HAVE_ALIGNED_STRUCT_PAGE if SLUB
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
select HAVE_ARCH_HUGE_VMALLOC if X86_64
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN if X86_64
select HAVE_ARCH_KASAN_VMALLOC if X86_64
select HAVE_ARCH_KFENCE
select HAVE_ARCH_KGDB
select HAVE_ARCH_MMAP_RND_BITS if MMU
select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
select HAVE_ARCH_PREL32_RELOCATIONS
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_THREAD_STRUCT_WHITELIST
select HAVE_ARCH_STACKLEAK
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD
select HAVE_ARCH_VMAP_STACK if X86_64
select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
select HAVE_ARCH_WITHIN_STACK_FRAMES
select HAVE_ASM_MODVERSIONS
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
select HAVE_CONTEXT_TRACKING if X86_64
select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING
select HAVE_C_RECORDMCOUNT
select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
select HAVE_BUILDTIME_MCOUNT_SORT
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64
select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
select HAVE_SAMPLE_FTRACE_DIRECT if X86_64
select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64
select HAVE_EBPF_JIT
select HAVE_EFFICIENT_UNALIGNED_ACCESS
select HAVE_EISA
select HAVE_EXIT_THREAD
select HAVE_FAST_GUP
select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE)
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS
select HAVE_HW_BREAKPOINT
select HAVE_IOREMAP_PROT
select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
select HAVE_IRQ_TIME_ACCOUNTING
select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_LZ4
select HAVE_KERNEL_LZMA
select HAVE_KERNEL_LZO
select HAVE_KERNEL_XZ
select HAVE_KERNEL_ZSTD
select HAVE_KPROBES
select HAVE_KPROBES_ON_FTRACE
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_KRETPROBES
select HAVE_RETHOOK
select HAVE_KVM
select HAVE_LIVEPATCH if X86_64
select HAVE_MIXED_BREAKPOINTS_REGS
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_MOVE_PMD
select HAVE_MOVE_PUD
select HAVE_NOINSTR_HACK if HAVE_OBJTOOL
select HAVE_NMI
select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL
select HAVE_OBJTOOL if X86_64
select HAVE_OPTPROBES
select HAVE_PCSPKR_PLATFORM
select HAVE_PERF_EVENTS
select HAVE_PERF_EVENTS_NMI
select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
select HAVE_PCI
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
select HAVE_POSIX_CPU_TIMERS_TASK_WORK
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION
select HAVE_FUNCTION_ARG_ACCESS_API
select HAVE_SETUP_PER_CPU_AREA
select HAVE_SOFTIRQ_ON_OWN_STACK
select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
select HAVE_STACK_VALIDATION if HAVE_OBJTOOL
select HAVE_STATIC_CALL
select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL
select HAVE_PREEMPT_DYNAMIC_CALL
select HAVE_RSEQ
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL
select HAVE_UNSTABLE_SCHED_CLOCK
select HAVE_USER_RETURN_NOTIFIER
select HAVE_GENERIC_VDSO
select HOTPLUG_SMT if SMP
select IRQ_FORCED_THREADING
select NEED_PER_CPU_EMBED_FIRST_CHUNK
select NEED_PER_CPU_PAGE_FIRST_CHUNK
select NEED_SG_DMA_LENGTH
select PCI_DOMAINS if PCI
select PCI_LOCKLESS_CONFIG if PCI
select PERF_EVENTS
select RTC_LIB
select RTC_MC146818_LIB
select SPARSE_IRQ
select SRCU
select SYSCTL_EXCEPTION_TRACE
select THREAD_INFO_IN_TASK
select TRACE_IRQFLAGS_SUPPORT
select USER_STACKTRACE_SUPPORT
select VIRT_TO_BUS
select HAVE_ARCH_KCSAN if X86_64
select X86_FEATURE_NAMES if PROC_FS
select PROC_PID_ARCH_STATUS if PROC_FS
select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX
imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
config INSTRUCTION_DECODER
def_bool y
depends on KPROBES || PERF_EVENTS || UPROBES
config OUTPUT_FORMAT
string
default "elf32-i386" if X86_32
default "elf64-x86-64" if X86_64
config LOCKDEP_SUPPORT
def_bool y
config STACKTRACE_SUPPORT
def_bool y
config MMU
def_bool y
config ARCH_MMAP_RND_BITS_MIN
default 28 if 64BIT
default 8
config ARCH_MMAP_RND_BITS_MAX
default 32 if 64BIT
default 16
config ARCH_MMAP_RND_COMPAT_BITS_MIN
default 8
config ARCH_MMAP_RND_COMPAT_BITS_MAX
default 16
config SBUS
bool
config GENERIC_ISA_DMA
def_bool y
depends on ISA_DMA_API
config GENERIC_BUG
def_bool y
depends on BUG
select GENERIC_BUG_RELATIVE_POINTERS if X86_64
config GENERIC_BUG_RELATIVE_POINTERS
bool
config ARCH_MAY_HAVE_PC_FDC
def_bool y
depends on ISA_DMA_API
config GENERIC_CALIBRATE_DELAY
def_bool y
config ARCH_HAS_CPU_RELAX
def_bool y
config ARCH_HIBERNATION_POSSIBLE
def_bool y
config ARCH_NR_GPIO
int
default 1024 if X86_64
default 512
config ARCH_SUSPEND_POSSIBLE
def_bool y
config AUDIT_ARCH
def_bool y if X86_64
config KASAN_SHADOW_OFFSET
hex
depends on KASAN
default 0xdffffc0000000000
config HAVE_INTEL_TXT
def_bool y
depends on INTEL_IOMMU && ACPI
config X86_32_SMP
def_bool y
depends on X86_32 && SMP
config X86_64_SMP
def_bool y
depends on X86_64 && SMP
config ARCH_SUPPORTS_UPROBES
def_bool y
config FIX_EARLYCON_MEM
def_bool y
config DYNAMIC_PHYSICAL_MASK
bool
config PGTABLE_LEVELS
int
default 5 if X86_5LEVEL
default 4 if X86_64
default 3 if X86_PAE
default 2
config CC_HAS_SANE_STACKPROTECTOR
bool
default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
help
We have to make sure stack protector is unconditionally disabled if
the compiler produces broken code or if it does not let us control
the segment on 32-bit kernels.
menu "Processor type and features"
config SMP
bool "Symmetric multi-processing support"
help
This enables support for systems with more than one CPU. If you have
a system with only one CPU, say N. If you have a system with more
than one CPU, say Y.
If you say N here, the kernel will run on uni- and multiprocessor
machines, but will use only one CPU of a multiprocessor machine. If
you say Y here, the kernel will run on many, but not all,
uniprocessor machines. On a uniprocessor machine, the kernel
will run faster if you say N here.
Note that if you say Y here and choose architecture "586" or
"Pentium" under "Processor family", the kernel will not work on 486
architectures. Similarly, multiprocessor kernels for the "PPro"
architecture may not work on all Pentium based boards.
People using multiprocessor machines who say Y here should also say
Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
Management" code will be disabled if you say Y here.
See also <file:Documentation/x86/i386/IO-APIC.rst>,
<file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
<http://www.tldp.org/docs.html#howto>.
If you don't know what to do here, say N.
config X86_FEATURE_NAMES
bool "Processor feature human-readable names" if EMBEDDED
default y
help
This option compiles in a table of x86 feature bits and corresponding
names. This is required to support /proc/cpuinfo and a few kernel
messages. You can disable this to save space, at the expense of
making those few kernel messages show numeric feature bits instead.
If in doubt, say Y.
config X86_X2APIC
bool "Support x2apic"
depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
help
This enables x2apic support on CPUs that have this feature.
This allows 32-bit apic IDs (so it can support very large systems),
and accesses the local apic via MSRs not via mmio.
If you don't know what to do here, say N.
config X86_MPPARSE
bool "Enable MPS table" if ACPI
default y
depends on X86_LOCAL_APIC
help
For old smp systems that do not have proper acpi support. Newer systems
(esp with 64bit cpus) with acpi support, MADT and DSDT will override it
config GOLDFISH
def_bool y
depends on X86_GOLDFISH
config RETPOLINE
bool "Avoid speculative indirect branches in kernel"
select OBJTOOL if HAVE_OBJTOOL
default y
help
Compile kernel with the retpoline compiler options to guard against
kernel-to-user data leaks by avoiding speculative indirect
branches. Requires a compiler with -mindirect-branch=thunk-extern
support for full protection. The kernel may run slower.
config CC_HAS_SLS
def_bool $(cc-option,-mharden-sls=all)
config SLS
bool "Mitigate Straight-Line-Speculation"
depends on CC_HAS_SLS && X86_64
select OBJTOOL if HAVE_OBJTOOL
default n
help
Compile the kernel with straight-line-speculation options to guard
against straight line speculation. The kernel image might be slightly
larger.
config X86_CPU_RESCTRL
bool "x86 CPU resource control support"
depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
select KERNFS
select PROC_CPU_RESCTRL if PROC_FS
help
Enable x86 CPU resource control support.
Provide support for the allocation and monitoring of system resources
usage by the CPU.
Intel calls this Intel Resource Director Technology
(Intel(R) RDT). More information about RDT can be found in the
Intel x86 Architecture Software Developer Manual.
AMD calls this AMD Platform Quality of Service (AMD QoS).
More information about AMD QoS can be found in the AMD64 Technology
Platform Quality of Service Extensions manual.
Say N if unsure.
if X86_32
config X86_BIGSMP
bool "Support for big SMP systems with more than 8 CPUs"
depends on SMP
help
This option is needed for the systems that have more than 8 CPUs.
config X86_EXTENDED_PLATFORM
bool "Support for extended (non-PC) x86 platforms"
default y
help
If you disable this option then the kernel will only support
standard PC platforms. (which covers the vast majority of
systems out there.)
If you enable this option then you'll be able to select support
for the following (non-PC) 32 bit x86 platforms:
Goldfish (Android emulator)
AMD Elan
RDC R-321x SoC
SGI 320/540 (Visual Workstation)
STA2X11-based (e.g. Northville)
Moorestown MID devices
If you have one of these systems, or if you want to build a
generic distribution kernel, say Y here - otherwise say N.
endif # X86_32
if X86_64
config X86_EXTENDED_PLATFORM
bool "Support for extended (non-PC) x86 platforms"
default y
help
If you disable this option then the kernel will only support
standard PC platforms. (which covers the vast majority of
systems out there.)
If you enable this option then you'll be able to select support
for the following (non-PC) 64 bit x86 platforms:
Numascale NumaChip
ScaleMP vSMP
SGI Ultraviolet
If you have one of these systems, or if you want to build a
generic distribution kernel, say Y here - otherwise say N.
endif # X86_64
# This is an alphabetically sorted list of 64 bit extended platforms
# Please maintain the alphabetic order if and when there are additions
config X86_NUMACHIP
bool "Numascale NumaChip"
depends on X86_64
depends on X86_EXTENDED_PLATFORM
depends on NUMA
depends on SMP
depends on X86_X2APIC
depends on PCI_MMCONFIG
help
Adds support for Numascale NumaChip large-SMP systems. Needed to
enable more than ~168 cores.
If you don't have one of these, you should say N here.
config X86_VSMP
bool "ScaleMP vSMP"
select HYPERVISOR_GUEST
select PARAVIRT
depends on X86_64 && PCI
depends on X86_EXTENDED_PLATFORM
depends on SMP
help
Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
supposed to run on these EM64T-based machines. Only choose this option
if you have one of these machines.
config X86_UV
bool "SGI Ultraviolet"
depends on X86_64
depends on X86_EXTENDED_PLATFORM
depends on NUMA
depends on EFI
depends on KEXEC_CORE
depends on X86_X2APIC
depends on PCI
help
This option is needed in order to support SGI Ultraviolet systems.
If you don't have one of these, you should say N here.
# Following is an alphabetically sorted list of 32 bit extended platforms
# Please maintain the alphabetic order if and when there are additions
config X86_GOLDFISH
bool "Goldfish (Virtual Platform)"
depends on X86_EXTENDED_PLATFORM
help
Enable support for the Goldfish virtual platform used primarily
for Android development. Unless you are building for the Android
Goldfish emulator say N here.
config X86_INTEL_CE
bool "CE4100 TV platform"
depends on PCI
depends on PCI_GODIRECT
depends on X86_IO_APIC
depends on X86_32
depends on X86_EXTENDED_PLATFORM
select X86_REBOOTFIXUPS
select OF
select OF_EARLY_FLATTREE
help
Select for the Intel CE media processor (CE4100) SOC.
This option compiles in support for the CE4100 SOC for settop
boxes and media devices.
config X86_INTEL_MID
bool "Intel MID platform support"
depends on X86_EXTENDED_PLATFORM
depends on X86_PLATFORM_DEVICES
depends on PCI
depends on X86_64 || (PCI_GOANY && X86_32)
depends on X86_IO_APIC
select I2C
select DW_APB_TIMER
select INTEL_SCU_PCI
help
Select to build a kernel capable of supporting Intel MID (Mobile
Internet Device) platform systems which do not have the PCI legacy
interfaces. If you are building for a PC class system say N here.
Intel MID platforms are based on an Intel processor and chipset which
consume less power than most of the x86 derivatives.
config X86_INTEL_QUARK
bool "Intel Quark platform support"
depends on X86_32
depends on X86_EXTENDED_PLATFORM
depends on X86_PLATFORM_DEVICES
depends on X86_TSC
depends on PCI
depends on PCI_GOANY
depends on X86_IO_APIC
select IOSF_MBI
select INTEL_IMR
select COMMON_CLK
help
Select to include support for Quark X1000 SoC.
Say Y here if you have a Quark based system such as the Arduino
compatible Intel Galileo.
config X86_INTEL_LPSS
bool "Intel Low Power Subsystem Support"
depends on X86 && ACPI && PCI
select COMMON_CLK
select PINCTRL
select IOSF_MBI
help
Select to build support for Intel Low Power Subsystem such as
found on Intel Lynxpoint PCH. Selecting this option enables
things like clock tree (common clock framework) and pincontrol
which are needed by the LPSS peripheral drivers.
config X86_AMD_PLATFORM_DEVICE
bool "AMD ACPI2Platform devices support"
depends on ACPI
select COMMON_CLK
select PINCTRL
help
Select to interpret AMD specific ACPI device to platform device
such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
implemented under PINCTRL subsystem.
config IOSF_MBI
tristate "Intel SoC IOSF Sideband support for SoC platforms"
depends on PCI
help
This option enables sideband register access support for Intel SoC
platforms. On these platforms the IOSF sideband is used in lieu of
MSR's for some register accesses, mostly but not limited to thermal
and power. Drivers may query the availability of this device to
determine if they need the sideband in order to work on these
platforms. The sideband is available on the following SoC products.
This list is not meant to be exclusive.
- BayTrail
- Braswell
- Quark
You should say Y if you are running a kernel on one of these SoC's.
config IOSF_MBI_DEBUG
bool "Enable IOSF sideband access through debugfs"
depends on IOSF_MBI && DEBUG_FS
help
Select this option to expose the IOSF sideband access registers (MCR,
MDR, MCRX) through debugfs to write and read register information from
different units on the SoC. This is most useful for obtaining device
state information for debug and analysis. As this is a general access
mechanism, users of this option would have specific knowledge of the
device they want to access.
If you don't require the option or are in doubt, say N.
config X86_RDC321X
bool "RDC R-321x SoC"
depends on X86_32
depends on X86_EXTENDED_PLATFORM
select M486
select X86_REBOOTFIXUPS
help
This option is needed for RDC R-321x system-on-chip, also known
as R-8610-(G).
If you don't have one of these chips, you should say N here.
config X86_32_NON_STANDARD
bool "Support non-standard 32-bit SMP architectures"
depends on X86_32 && SMP
depends on X86_EXTENDED_PLATFORM
help
This option compiles in the bigsmp and STA2X11 default
subarchitectures. It is intended for a generic binary
kernel. If you select them all, kernel will probe it one by
one and will fallback to default.
# Alphabetically sorted list of Non standard 32 bit platforms
config X86_SUPPORTS_MEMORY_FAILURE
def_bool y
# MCE code calls memory_failure():
depends on X86_MCE
# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
depends on X86_64 || !SPARSEMEM
select ARCH_SUPPORTS_MEMORY_FAILURE
config STA2X11
bool "STA2X11 Companion Chip Support"
depends on X86_32_NON_STANDARD && PCI
select SWIOTLB
select MFD_STA2X11
select GPIOLIB
help
This adds support for boards based on the STA2X11 IO-Hub,
a.k.a. "ConneXt". The chip is used in place of the standard
PC chipset, so all "standard" peripherals are missing. If this
option is selected the kernel will still be able to boot on
standard PC machines.
config X86_32_IRIS
tristate "Eurobraille/Iris poweroff module"
depends on X86_32
help
The Iris machines from EuroBraille do not have APM or ACPI support
to shut themselves down properly. A special I/O sequence is
needed to do so, which is what this module does at
kernel shutdown.
This is only for Iris machines from EuroBraille.
If unused, say N.
config SCHED_OMIT_FRAME_POINTER
def_bool y
prompt "Single-depth WCHAN output"
depends on X86
help
Calculate simpler /proc/<PID>/wchan values. If this option
is disabled then wchan values will recurse back to the
caller function. This provides more accurate wchan values,
at the expense of slightly more scheduling overhead.
If in doubt, say "Y".
menuconfig HYPERVISOR_GUEST
bool "Linux guest support"
help
Say Y here to enable options for running Linux under various hyper-
visors. This option enables basic hypervisor detection and platform
setup.
If you say N, all options in this submenu will be skipped and
disabled, and Linux guest support won't be built in.
if HYPERVISOR_GUEST
config PARAVIRT
bool "Enable paravirtualization code"
depends on HAVE_STATIC_CALL
help
This changes the kernel so it can modify itself when it is run
under a hypervisor, potentially improving performance significantly
over full virtualization. However, when run without a hypervisor
the kernel is theoretically slower and slightly larger.
config PARAVIRT_XXL
bool
config PARAVIRT_DEBUG
bool "paravirt-ops debugging"
depends on PARAVIRT && DEBUG_KERNEL
help
Enable to debug paravirt_ops internals. Specifically, BUG if
a paravirt_op is missing when it is called.
config PARAVIRT_SPINLOCKS
bool "Paravirtualization layer for spinlocks"
depends on PARAVIRT && SMP
help
Paravirtualized spinlocks allow a pvops backend to replace the
spinlock implementation with something virtualization-friendly
(for example, block the virtual CPU rather than spinning).
It has a minimal impact on native kernels and gives a nice performance
benefit on paravirtualized KVM / Xen kernels.
If you are unsure how to answer this question, answer Y.
config X86_HV_CALLBACK_VECTOR
def_bool n
source "arch/x86/xen/Kconfig"
config KVM_GUEST
bool "KVM Guest support (including kvmclock)"
depends on PARAVIRT
select PARAVIRT_CLOCK
select ARCH_CPUIDLE_HALTPOLL
select X86_HV_CALLBACK_VECTOR
default y
help
This option enables various optimizations for running under the KVM
hypervisor. It includes a paravirtualized clock, so that instead
of relying on a PIT (or probably other) emulation by the
underlying device model, the host provides the guest with
timing infrastructure such as time of day, and system time
config ARCH_CPUIDLE_HALTPOLL
def_bool n
prompt "Disable host haltpoll when loading haltpoll driver"
help
If virtualized under KVM, disable host haltpoll.
config PVH
bool "Support for running PVH guests"
help
This option enables the PVH entry point for guest virtual machines
as specified in the x86/HVM direct boot ABI.
config PARAVIRT_TIME_ACCOUNTING
bool "Paravirtual steal time accounting"
depends on PARAVIRT
help
Select this option to enable fine granularity task steal time
accounting. Time spent executing other tasks in parallel with
the current vCPU is discounted from the vCPU power. To account for
that, there can be a small performance impact.
If in doubt, say N here.
config PARAVIRT_CLOCK
bool
config JAILHOUSE_GUEST
bool "Jailhouse non-root cell support"
depends on X86_64 && PCI
select X86_PM_TIMER
help
This option allows to run Linux as guest in a Jailhouse non-root
cell. You can leave this option disabled if you only want to start
Jailhouse and run Linux afterwards in the root cell.
config ACRN_GUEST
bool "ACRN Guest support"
depends on X86_64
select X86_HV_CALLBACK_VECTOR
help
This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
a flexible, lightweight reference open-source hypervisor, built with
real-time and safety-criticality in mind. It is built for embedded
IOT with small footprint and real-time features. More details can be
found in https://projectacrn.org/.
config INTEL_TDX_GUEST
bool "Intel TDX (Trust Domain Extensions) - Guest Support"
depends on X86_64 && CPU_SUP_INTEL
depends on X86_X2APIC
select ARCH_HAS_CC_PLATFORM
select X86_MEM_ENCRYPT
select X86_MCE
help
Support running as a guest under Intel TDX. Without this support,
the guest kernel can not boot or run under TDX.
TDX includes memory encryption and integrity capabilities
which protect the confidentiality and integrity of guest
memory contents and CPU state. TDX guests are protected from
some attacks from the VMM.
endif # HYPERVISOR_GUEST
source "arch/x86/Kconfig.cpu"
config HPET_TIMER
def_bool X86_64
prompt "HPET Timer Support" if X86_32
help
Use the IA-PC HPET (High Precision Event Timer) to manage
time in preference to the PIT and RTC, if a HPET is
present.
HPET is the next generation timer replacing legacy 8254s.
The HPET provides a stable time base on SMP
systems, unlike the TSC, but it is more expensive to access,
as it is off-chip. The interface used is documented
in the HPET spec, revision 1.
You can safely choose Y here. However, HPET will only be
activated if the platform and the BIOS support this feature.
Otherwise the 8254 will be used for timing services.
Choose N to continue using the legacy 8254 timer.
config HPET_EMULATE_RTC
def_bool y
depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
# Mark as expert because too many people got it wrong.
# The code disables itself when not needed.
config DMI
default y
select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
bool "Enable DMI scanning" if EXPERT
help
Enabled scanning of DMI to identify machine quirks. Say Y
here unless you have verified that your setup is not
affected by entries in the DMI blacklist. Required by PNP
BIOS code.
config GART_IOMMU
bool "Old AMD GART IOMMU support"
select DMA_OPS
select IOMMU_HELPER
select SWIOTLB
depends on X86_64 && PCI && AMD_NB
help
Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
GART based hardware IOMMUs.
The GART supports full DMA access for devices with 32-bit access
limitations, on systems with more than 3 GB. This is usually needed
for USB, sound, many IDE/SATA chipsets and some other devices.
Newer systems typically have a modern AMD IOMMU, supported via
the CONFIG_AMD_IOMMU=y config option.
In normal configurations this driver is only active when needed:
there's more than 3 GB of memory and the system contains a
32-bit limited device.
If unsure, say Y.
config BOOT_VESA_SUPPORT
bool
help
If true, at least one selected framebuffer driver can take advantage
of VESA video modes set at an early boot stage via the vga= parameter.
config MAXSMP
bool "Enable Maximum number of SMP Processors and NUMA Nodes"
depends on X86_64 && SMP && DEBUG_KERNEL
select CPUMASK_OFFSTACK
help
Enable maximum number of CPUS and NUMA Nodes for this architecture.
If unsure, say N.
#
# The maximum number of CPUs supported:
#
# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
# and which can be configured interactively in the
# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
#
# The ranges are different on 32-bit and 64-bit kernels, depending on
# hardware capabilities and scalability features of the kernel.
#
# ( If MAXSMP is enabled we just use the highest possible value and disable
# interactive configuration. )
#
config NR_CPUS_RANGE_BEGIN
int
default NR_CPUS_RANGE_END if MAXSMP
default 1 if !SMP
default 2
config NR_CPUS_RANGE_END
int
depends on X86_32
default 64 if SMP && X86_BIGSMP
default 8 if SMP && !X86_BIGSMP
default 1 if !SMP
config NR_CPUS_RANGE_END
int
depends on X86_64
default 8192 if SMP && CPUMASK_OFFSTACK
default 512 if SMP && !CPUMASK_OFFSTACK
default 1 if !SMP
config NR_CPUS_DEFAULT
int
depends on X86_32
default 32 if X86_BIGSMP
default 8 if SMP
default 1 if !SMP
config NR_CPUS_DEFAULT
int
depends on X86_64
default 8192 if MAXSMP
default 64 if SMP
default 1 if !SMP
config NR_CPUS
int "Maximum number of CPUs" if SMP && !MAXSMP
range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
default NR_CPUS_DEFAULT
help
This allows you to specify the maximum number of CPUs which this
kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
supported value is 8192, otherwise the maximum value is 512. The
minimum value which makes sense is 2.
This is purely to save memory: each supported CPU adds about 8KB
to the kernel image.
config SCHED_CLUSTER
bool "Cluster scheduler support"
depends on SMP
default y
help
Cluster scheduler support improves the CPU scheduler's decision
making when dealing with machines that have clusters of CPUs.
Cluster usually means a couple of CPUs which are placed closely
by sharing mid-level caches, last-level cache tags or internal
busses.
config SCHED_SMT
def_bool y if SMP
config SCHED_MC
def_bool y
prompt "Multi-core scheduler support"
depends on SMP
help
Multi-core scheduler support improves the CPU scheduler's decision
making when dealing with multi-core CPU chips at a cost of slightly
increased overhead in some places. If unsure say N here.
config SCHED_MC_PRIO
bool "CPU core priorities scheduler support"
depends on SCHED_MC && CPU_SUP_INTEL
select X86_INTEL_PSTATE
select CPU_FREQ
default y
help
Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
core ordering determined at manufacturing time, which allows
certain cores to reach higher turbo frequencies (when running
single threaded workloads) than others.
Enabling this kernel feature teaches the scheduler about
the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
scheduler's CPU selection logic accordingly, so that higher
overall system performance can be achieved.
This feature will have no effect on CPUs without this feature.
If unsure say Y here.
config UP_LATE_INIT
def_bool y
depends on !SMP && X86_LOCAL_APIC
config X86_UP_APIC
bool "Local APIC support on uniprocessors" if !PCI_MSI
default PCI_MSI
depends on X86_32 && !SMP && !X86_32_NON_STANDARD
help
A local APIC (Advanced Programmable Interrupt Controller) is an
integrated interrupt controller in the CPU. If you have a single-CPU
system which has a processor with a local APIC, you can say Y here to
enable and use it. If you say Y here even though your machine doesn't
have a local APIC, then the kernel will still run with no slowdown at
all. The local APIC supports CPU-generated self-interrupts (timer,
performance counters), and the NMI watchdog which detects hard
lockups.
config X86_UP_IOAPIC
bool "IO-APIC support on uniprocessors"
depends on X86_UP_APIC
help
An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
SMP-capable replacement for PC-style interrupt controllers. Most
SMP systems and many recent uniprocessor systems have one.
If you have a single-CPU system with an IO-APIC, you can say Y here
to use it. If you say Y here even though your machine doesn't have
an IO-APIC, then the kernel will still run with no slowdown at all.
config X86_LOCAL_APIC
def_bool y
depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
select IRQ_DOMAIN_HIERARCHY
select PCI_MSI_IRQ_DOMAIN if PCI_MSI
config X86_IO_APIC
def_bool y
depends on X86_LOCAL_APIC || X86_UP_IOAPIC
config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
bool "Reroute for broken boot IRQs"
depends on X86_IO_APIC
help
This option enables a workaround that fixes a source of
spurious interrupts. This is recommended when threaded
interrupt handling is used on systems where the generation of
superfluous "boot interrupts" cannot be disabled.
Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
entry in the chipset's IO-APIC is masked (as, e.g. the RT
kernel does during interrupt handling). On chipsets where this
boot IRQ generation cannot be disabled, this workaround keeps
the original IRQ line masked so that only the equivalent "boot
IRQ" is delivered to the CPUs. The workaround also tells the
kernel to set up the IRQ handler on the boot IRQ line. In this
way only one interrupt is delivered to the kernel. Otherwise
the spurious second interrupt may cause the kernel to bring
down (vital) interrupt lines.
Only affects "broken" chipsets. Interrupt sharing may be
increased on these systems.
config X86_MCE
bool "Machine Check / overheating reporting"
select GENERIC_ALLOCATOR
default y
help
Machine Check support allows the processor to notify the
kernel if it detects a problem (e.g. overheating, data corruption).
The action the kernel takes depends on the severity of the problem,
ranging from warning messages to halting the machine.
config X86_MCELOG_LEGACY
bool "Support for deprecated /dev/mcelog character device"
depends on X86_MCE
help
Enable support for /dev/mcelog which is needed by the old mcelog
userspace logging daemon. Consider switching to the new generation
rasdaemon solution.
config X86_MCE_INTEL
def_bool y
prompt "Intel MCE features"
depends on X86_MCE && X86_LOCAL_APIC
help
Additional support for intel specific MCE features such as
the thermal monitor.
config X86_MCE_AMD
def_bool y
prompt "AMD MCE features"
depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
help
Additional support for AMD specific MCE features such as
the DRAM Error Threshold.
config X86_ANCIENT_MCE
bool "Support for old Pentium 5 / WinChip machine checks"
depends on X86_32 && X86_MCE
help
Include support for machine check handling on old Pentium 5 or WinChip
systems. These typically need to be enabled explicitly on the command
line.
config X86_MCE_THRESHOLD
depends on X86_MCE_AMD || X86_MCE_INTEL
def_bool y
config X86_MCE_INJECT
depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
tristate "Machine check injector support"
help
Provide support for injecting machine checks for testing purposes.
If you don't know what a machine check is and you don't do kernel
QA it is safe to say n.
source "arch/x86/events/Kconfig"
config X86_LEGACY_VM86
bool "Legacy VM86 support"
depends on X86_32
help
This option allows user programs to put the CPU into V8086
mode, which is an 80286-era approximation of 16-bit real mode.
Some very old versions of X and/or vbetool require this option
for user mode setting. Similarly, DOSEMU will use it if
available to accelerate real mode DOS programs. However, any
recent version of DOSEMU, X, or vbetool should be fully
functional even without kernel VM86 support, as they will all
fall back to software emulation. Nevertheless, if you are using
a 16-bit DOS program where 16-bit performance matters, vm86
mode might be faster than emulation and you might want to
enable this option.
Note that any app that works on a 64-bit kernel is unlikely to
need this option, as 64-bit kernels don't, and can't, support
V8086 mode. This option is also unrelated to 16-bit protected
mode and is not needed to run most 16-bit programs under Wine.
Enabling this option increases the complexity of the kernel
and slows down exception handling a tiny bit.
If unsure, say N here.
config VM86
bool
default X86_LEGACY_VM86
config X86_16BIT
bool "Enable support for 16-bit segments" if EXPERT
default y
depends on MODIFY_LDT_SYSCALL
help
This option is required by programs like Wine to run 16-bit
protected mode legacy code on x86 processors. Disabling
this option saves about 300 bytes on i386, or around 6K text
plus 16K runtime memory on x86-64,
config X86_ESPFIX32
def_bool y
depends on X86_16BIT && X86_32
config X86_ESPFIX64
def_bool y
depends on X86_16BIT && X86_64
config X86_VSYSCALL_EMULATION
bool "Enable vsyscall emulation" if EXPERT
default y
depends on X86_64
help
This enables emulation of the legacy vsyscall page. Disabling
it is roughly equivalent to booting with vsyscall=none, except
that it will also disable the helpful warning if a program
tries to use a vsyscall. With this option set to N, offending
programs will just segfault, citing addresses of the form
0xffffffffff600?00.
This option is required by many programs built before 2013, and
care should be used even with newer programs if set to N.
Disabling this option saves about 7K of kernel size and
possibly 4K of additional runtime pagetable memory.
config X86_IOPL_IOPERM
bool "IOPERM and IOPL Emulation"
default y
help
This enables the ioperm() and iopl() syscalls which are necessary
for legacy applications.
Legacy IOPL support is an overbroad mechanism which allows user
space aside of accessing all 65536 I/O ports also to disable
interrupts. To gain this access the caller needs CAP_SYS_RAWIO
capabilities and permission from potentially active security
modules.
The emulation restricts the functionality of the syscall to
only allowing the full range I/O port access, but prevents the
ability to disable interrupts from user space which would be
granted if the hardware IOPL mechanism would be used.
config TOSHIBA
tristate "Toshiba Laptop support"
depends on X86_32
help
This adds a driver to safely access the System Management Mode of
the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
not work on models with a Phoenix BIOS. The System Management Mode
is used to set the BIOS and power saving options on Toshiba portables.
For information on utilities to make use of this driver see the
Toshiba Linux utilities web site at:
<http://www.buzzard.org.uk/toshiba/>.
Say Y if you intend to run this kernel on a Toshiba portable.
Say N otherwise.
config X86_REBOOTFIXUPS
bool "Enable X86 board specific fixups for reboot"
depends on X86_32
help
This enables chipset and/or board specific fixups to be done
in order to get reboot to work correctly. This is only needed on
some combinations of hardware and BIOS. The symptom, for which
this config is intended, is when reboot ends with a stalled/hung
system.
Currently, the only fixup is for the Geode machines using
CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Say Y if you want to enable the fixup. Currently, it's safe to
enable this option even if you don't need it.
Say N otherwise.
config MICROCODE
bool "CPU microcode loading support"
default y
depends on CPU_SUP_AMD || CPU_SUP_INTEL
help
If you say Y here, you will be able to update the microcode on
Intel and AMD processors. The Intel support is for the IA32 family,
e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
AMD support is for families 0x10 and later. You will obviously need
the actual microcode binary data itself which is not shipped with
the Linux kernel.
The preferred method to load microcode from a detached initrd is described
in Documentation/x86/microcode.rst. For that you need to enable
CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
initrd for microcode blobs.
In addition, you can build the microcode into the kernel. For that you
need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
config option.
config MICROCODE_INTEL
bool "Intel microcode loading support"
depends on CPU_SUP_INTEL && MICROCODE
default MICROCODE
help
This options enables microcode patch loading support for Intel
processors.
For the current Intel microcode data package go to
<https://downloadcenter.intel.com> and search for
'Linux Processor Microcode Data File'.
config MICROCODE_AMD
bool "AMD microcode loading support"
depends on CPU_SUP_AMD && MICROCODE
help
If you select this option, microcode patch loading support for AMD
processors will be enabled.
config MICROCODE_LATE_LOADING
bool "Late microcode loading (DANGEROUS)"
default n
depends on MICROCODE
help
Loading microcode late, when the system is up and executing instructions
is a tricky business and should be avoided if possible. Just the sequence
of synchronizing all cores and SMT threads is one fragile dance which does
not guarantee that cores might not softlock after the loading. Therefore,
use this at your own risk. Late loading taints the kernel too.
config X86_MSR
tristate "/dev/cpu/*/msr - Model-specific register support"
help
This device gives privileged processes access to the x86
Model-Specific Registers (MSRs). It is a character device with
major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
MSR accesses are directed to a specific CPU on multi-processor
systems.
config X86_CPUID
tristate "/dev/cpu/*/cpuid - CPU information support"
help
This device gives processes access to the x86 CPUID instruction to
be executed on a specific processor. It is a character device
with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
/dev/cpu/31/cpuid.
choice
prompt "High Memory Support"
default HIGHMEM4G
depends on X86_32
config NOHIGHMEM
bool "off"
help
Linux can use up to 64 Gigabytes of physical memory on x86 systems.
However, the address space of 32-bit x86 processors is only 4
Gigabytes large. That means that, if you have a large amount of
physical memory, not all of it can be "permanently mapped" by the
kernel. The physical memory that's not permanently mapped is called
"high memory".
If you are compiling a kernel which will never run on a machine with
more than 1 Gigabyte total physical RAM, answer "off" here (default
choice and suitable for most users). This will result in a "3GB/1GB"
split: 3GB are mapped so that each process sees a 3GB virtual memory
space and the remaining part of the 4GB virtual memory space is used
by the kernel to permanently map as much physical memory as
possible.
If the machine has between 1 and 4 Gigabytes physical RAM, then
answer "4GB" here.
If more than 4 Gigabytes is used then answer "64GB" here. This
selection turns Intel PAE (Physical Address Extension) mode on.
PAE implements 3-level paging on IA32 processors. PAE is fully
supported by Linux, PAE mode is implemented on all recent Intel
processors (Pentium Pro and better). NOTE: If you say "64GB" here,
then the kernel will not boot on CPUs that don't support PAE!
The actual amount of total physical memory will either be
auto detected or can be forced by using a kernel command line option
such as "mem=256M". (Try "man bootparam" or see the documentation of
your boot loader (lilo or loadlin) about how to pass options to the
kernel at boot time.)
If unsure, say "off".
config HIGHMEM4G
bool "4GB"
help
Select this if you have a 32-bit processor and between 1 and 4
gigabytes of physical RAM.
config HIGHMEM64G
bool "64GB"
depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
select X86_PAE
help
Select this if you have a 32-bit processor and more than 4
gigabytes of physical RAM.
endchoice
choice
prompt "Memory split" if EXPERT
default VMSPLIT_3G
depends on X86_32
help
Select the desired split between kernel and user memory.
If the address range available to the kernel is less than the
physical memory installed, the remaining memory will be available
as "high memory". Accessing high memory is a little more costly
than low memory, as it needs to be mapped into the kernel first.
Note that increasing the kernel address space limits the range
available to user programs, making the address space there
tighter. Selecting anything other than the default 3G/1G split
will also likely make your kernel incompatible with binary-only
kernel modules.
If you are not absolutely sure what you are doing, leave this
option alone!
config VMSPLIT_3G
bool "3G/1G user/kernel split"
config VMSPLIT_3G_OPT
depends on !X86_PAE
bool "3G/1G user/kernel split (for full 1G low memory)"
config VMSPLIT_2G
bool "2G/2G user/kernel split"
config VMSPLIT_2G_OPT
depends on !X86_PAE
bool "2G/2G user/kernel split (for full 2G low memory)"
config VMSPLIT_1G
bool "1G/3G user/kernel split"
endchoice
config PAGE_OFFSET
hex
default 0xB0000000 if VMSPLIT_3G_OPT
default 0x80000000 if VMSPLIT_2G
default 0x78000000 if VMSPLIT_2G_OPT
default 0x40000000 if VMSPLIT_1G
default 0xC0000000
depends on X86_32
config HIGHMEM
def_bool y
depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
config X86_PAE
bool "PAE (Physical Address Extension) Support"
depends on X86_32 && !HIGHMEM4G
select PHYS_ADDR_T_64BIT
select SWIOTLB
help
PAE is required for NX support, and furthermore enables
larger swapspace support for non-overcommit purposes. It
has the cost of more pagetable lookup overhead, and also
consumes more pagetable space per process.
config X86_5LEVEL
bool "Enable 5-level page tables support"
default y
select DYNAMIC_MEMORY_LAYOUT
select SPARSEMEM_VMEMMAP
depends on X86_64
help
5-level paging enables access to larger address space:
upto 128 PiB of virtual address space and 4 PiB of
physical address space.
It will be supported by future Intel CPUs.
A kernel with the option enabled can be booted on machines that
support 4- or 5-level paging.
See Documentation/x86/x86_64/5level-paging.rst for more
information.
Say N if unsure.
config X86_DIRECT_GBPAGES
def_bool y
depends on X86_64
help
Certain kernel features effectively disable kernel
linear 1 GB mappings (even if the CPU otherwise
supports them), so don't confuse the user by printing
that we have them enabled.
config X86_CPA_STATISTICS
bool "Enable statistic for Change Page Attribute"
depends on DEBUG_FS
help
Expose statistics about the Change Page Attribute mechanism, which
helps to determine the effectiveness of preserving large and huge
page mappings when mapping protections are changed.
config X86_MEM_ENCRYPT
select ARCH_HAS_FORCE_DMA_UNENCRYPTED
select DYNAMIC_PHYSICAL_MASK
select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
def_bool n
config AMD_MEM_ENCRYPT
bool "AMD Secure Memory Encryption (SME) support"
depends on X86_64 && CPU_SUP_AMD
select DMA_COHERENT_POOL
select ARCH_USE_MEMREMAP_PROT
select INSTRUCTION_DECODER
select ARCH_HAS_CC_PLATFORM
select X86_MEM_ENCRYPT
help
Say yes to enable support for the encryption of system memory.
This requires an AMD processor that supports Secure Memory
Encryption (SME).
config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
bool "Activate AMD Secure Memory Encryption (SME) by default"
depends on AMD_MEM_ENCRYPT
help
Say yes to have system memory encrypted by default if running on
an AMD processor that supports Secure Memory Encryption (SME).
If set to Y, then the encryption of system memory can be
deactivated with the mem_encrypt=off command line option.
If set to N, then the encryption of system memory can be
activated with the mem_encrypt=on command line option.
# Common NUMA Features
config NUMA
bool "NUMA Memory Allocation and Scheduler Support"
depends on SMP
depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
default y if X86_BIGSMP
select USE_PERCPU_NUMA_NODE_ID
help
Enable NUMA (Non-Uniform Memory Access) support.
The kernel will try to allocate memory used by a CPU on the
local memory controller of the CPU and add some more
NUMA awareness to the kernel.
For 64-bit this is recommended if the system is Intel Core i7
(or later), AMD Opteron, or EM64T NUMA.
For 32-bit this is only needed if you boot a 32-bit
kernel on a 64-bit NUMA platform.
Otherwise, you should say N.
config AMD_NUMA
def_bool y
prompt "Old style AMD Opteron NUMA detection"
depends on X86_64 && NUMA && PCI
help
Enable AMD NUMA node topology detection. You should say Y here if
you have a multi processor AMD system. This uses an old method to
read the NUMA configuration directly from the builtin Northbridge
of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
which also takes priority if both are compiled in.
config X86_64_ACPI_NUMA
def_bool y
prompt "ACPI NUMA detection"
depends on X86_64 && NUMA && ACPI && PCI
select ACPI_NUMA
help
Enable ACPI SRAT based node topology detection.
config NUMA_EMU
bool "NUMA emulation"
depends on NUMA
help
Enable NUMA emulation. A flat machine will be split
into virtual nodes when booted with "numa=fake=N", where N is the
number of nodes. This is only useful for debugging.
config NODES_SHIFT
int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
range 1 10
default "10" if MAXSMP
default "6" if X86_64
default "3"
depends on NUMA
help
Specify the maximum number of NUMA Nodes available on the target
system. Increases memory reserved to accommodate various tables.
config ARCH_FLATMEM_ENABLE
def_bool y
depends on X86_32 && !NUMA
config ARCH_SPARSEMEM_ENABLE
def_bool y
depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
select SPARSEMEM_STATIC if X86_32
select SPARSEMEM_VMEMMAP_ENABLE if X86_64
config ARCH_SPARSEMEM_DEFAULT
def_bool X86_64 || (NUMA && X86_32)
config ARCH_SELECT_MEMORY_MODEL
def_bool y
depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
config ARCH_MEMORY_PROBE
bool "Enable sysfs memory/probe interface"
depends on MEMORY_HOTPLUG
help
This option enables a sysfs memory/probe interface for testing.
See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
If you are unsure how to answer this question, answer N.
config ARCH_PROC_KCORE_TEXT
def_bool y
depends on X86_64 && PROC_KCORE
config ILLEGAL_POINTER_VALUE
hex
default 0 if X86_32
default 0xdead000000000000 if X86_64
config X86_PMEM_LEGACY_DEVICE
bool
config X86_PMEM_LEGACY
tristate "Support non-standard NVDIMMs and ADR protected memory"
depends on PHYS_ADDR_T_64BIT
depends on BLK_DEV
select X86_PMEM_LEGACY_DEVICE
select NUMA_KEEP_MEMINFO if NUMA
select LIBNVDIMM
help
Treat memory marked using the non-standard e820 type of 12 as used
by the Intel Sandy Bridge-EP reference BIOS as protected memory.
The kernel will offer these regions to the 'pmem' driver so
they can be used for persistent storage.
Say Y if unsure.
config HIGHPTE
bool "Allocate 3rd-level pagetables from highmem"
depends on HIGHMEM
help
The VM uses one page table entry for each page of physical memory.
For systems with a lot of RAM, this can be wasteful of precious
low memory. Setting this option will put user-space page table
entries in high memory.
config X86_CHECK_BIOS_CORRUPTION
bool "Check for low memory corruption"
help
Periodically check for memory corruption in low memory, which
is suspected to be caused by BIOS. Even when enabled in the
configuration, it is disabled at runtime. Enable it by
setting "memory_corruption_check=1" on the kernel command
line. By default it scans the low 64k of memory every 60
seconds; see the memory_corruption_check_size and
memory_corruption_check_period parameters in
Documentation/admin-guide/kernel-parameters.rst to adjust this.
When enabled with the default parameters, this option has
almost no overhead, as it reserves a relatively small amount
of memory and scans it infrequently. It both detects corruption
and prevents it from affecting the running system.
It is, however, intended as a diagnostic tool; if repeatable
BIOS-originated corruption always affects the same memory,
you can use memmap= to prevent the kernel from using that
memory.
config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
bool "Set the default setting of memory_corruption_check"
depends on X86_CHECK_BIOS_CORRUPTION
default y
help
Set whether the default state of memory_corruption_check is
on or off.
config MATH_EMULATION
bool
depends on MODIFY_LDT_SYSCALL
prompt "Math emulation" if X86_32 && (M486SX || MELAN)
help
Linux can emulate a math coprocessor (used for floating point
operations) if you don't have one. 486DX and Pentium processors have
a math coprocessor built in, 486SX and 386 do not, unless you added
a 487DX or 387, respectively. (The messages during boot time can
give you some hints here ["man dmesg"].) Everyone needs either a
coprocessor or this emulation.
If you don't have a math coprocessor, you need to say Y here; if you
say Y here even though you have a coprocessor, the coprocessor will
be used nevertheless. (This behavior can be changed with the kernel
command line option "no387", which comes handy if your coprocessor
is broken. Try "man bootparam" or see the documentation of your boot
loader (lilo or loadlin) about how to pass options to the kernel at
boot time.) This means that it is a good idea to say Y here if you
intend to use this kernel on different machines.
More information about the internals of the Linux math coprocessor
emulation can be found in <file:arch/x86/math-emu/README>.
If you are not sure, say Y; apart from resulting in a 66 KB bigger
kernel, it won't hurt.
config MTRR
def_bool y
prompt "MTRR (Memory Type Range Register) support" if EXPERT
help
On Intel P6 family processors (Pentium Pro, Pentium II and later)
the Memory Type Range Registers (MTRRs) may be used to control
processor access to memory ranges. This is most useful if you have
a video (VGA) card on a PCI or AGP bus. Enabling write-combining
allows bus write transfers to be combined into a larger transfer
before bursting over the PCI/AGP bus. This can increase performance
of image write operations 2.5 times or more. Saying Y here creates a
/proc/mtrr file which may be used to manipulate your processor's
MTRRs. Typically the X server should use this.
This code has a reasonably generic interface so that similar
control registers on other processors can be easily supported
as well:
The Cyrix 6x86, 6x86MX and M II processors have Address Range
Registers (ARRs) which provide a similar functionality to MTRRs. For
these, the ARRs are used to emulate the MTRRs.
The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
write-combining. All of these processors are supported by this code
and it makes sense to say Y here if you have one of them.
Saying Y here also fixes a problem with buggy SMP BIOSes which only
set the MTRRs for the boot CPU and not for the secondary CPUs. This
can lead to all sorts of problems, so it's good to say Y here.
You can safely say Y even if your machine doesn't have MTRRs, you'll
just add about 9 KB to your kernel.
See <file:Documentation/x86/mtrr.rst> for more information.
config MTRR_SANITIZER
def_bool y
prompt "MTRR cleanup support"
depends on MTRR
help
Convert MTRR layout from continuous to discrete, so X drivers can
add writeback entries.
Can be disabled with disable_mtrr_cleanup on the kernel command line.
The largest mtrr entry size for a continuous block can be set with
mtrr_chunk_size.
If unsure, say Y.
config MTRR_SANITIZER_ENABLE_DEFAULT
int "MTRR cleanup enable value (0-1)"
range 0 1
default "0"
depends on MTRR_SANITIZER
help
Enable mtrr cleanup default value
config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
int "MTRR cleanup spare reg num (0-7)"
range 0 7
default "1"
depends on MTRR_SANITIZER
help
mtrr cleanup spare entries default, it can be changed via
mtrr_spare_reg_nr=N on the kernel command line.
config X86_PAT
def_bool y
prompt "x86 PAT support" if EXPERT
depends on MTRR
help
Use PAT attributes to setup page level cache control.
PATs are the modern equivalents of MTRRs and are much more
flexible than MTRRs.
Say N here if you see bootup problems (boot crash, boot hang,
spontaneous reboots) or a non-working video driver.
If unsure, say Y.
config ARCH_USES_PG_UNCACHED
def_bool y
depends on X86_PAT
config ARCH_RANDOM
def_bool y
prompt "x86 architectural random number generator" if EXPERT
help
Enable the x86 architectural RDRAND instruction
(Intel Bull Mountain technology) to generate random numbers.
If supported, this is a high bandwidth, cryptographically
secure hardware random number generator.
config X86_UMIP
def_bool y
prompt "User Mode Instruction Prevention" if EXPERT
help
User Mode Instruction Prevention (UMIP) is a security feature in
some x86 processors. If enabled, a general protection fault is
issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
executed in user mode. These instructions unnecessarily expose
information about the hardware state.
The vast majority of applications do not use these instructions.
For the very few that do, software emulation is provided in
specific cases in protected and virtual-8086 modes. Emulated
results are dummy.
config CC_HAS_IBT
# GCC >= 9 and binutils >= 2.29
# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
# Clang/LLVM >= 14
# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
(CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
$(as-instr,endbr64)
config X86_KERNEL_IBT
prompt "Indirect Branch Tracking"
bool
depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
depends on !LD_IS_LLD || LLD_VERSION >= 140000
select OBJTOOL
help
Build the kernel with support for Indirect Branch Tracking, a
hardware support course-grain forward-edge Control Flow Integrity
protection. It enforces that all indirect calls must land on
an ENDBR instruction, as such, the compiler will instrument the
code with them to make this happen.
In addition to building the kernel with IBT, seal all functions that
are not indirect call targets, avoiding them ever becoming one.
This requires LTO like objtool runs and will slow down the build. It
does significantly reduce the number of ENDBR instructions in the
kernel image.
config X86_INTEL_MEMORY_PROTECTION_KEYS
prompt "Memory Protection Keys"
def_bool y
# Note: only available in 64-bit mode
depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
select ARCH_USES_HIGH_VMA_FLAGS
select ARCH_HAS_PKEYS
help
Memory Protection Keys provides a mechanism for enforcing
page-based protections, but without requiring modification of the
page tables when an application changes protection domains.
For details, see Documentation/core-api/protection-keys.rst
If unsure, say y.
choice
prompt "TSX enable mode"
depends on CPU_SUP_INTEL
default X86_INTEL_TSX_MODE_OFF
help
Intel's TSX (Transactional Synchronization Extensions) feature
allows to optimize locking protocols through lock elision which
can lead to a noticeable performance boost.
On the other hand it has been shown that TSX can be exploited
to form side channel attacks (e.g. TAA) and chances are there
will be more of those attacks discovered in the future.
Therefore TSX is not enabled by default (aka tsx=off). An admin
might override this decision by tsx=on the command line parameter.
Even with TSX enabled, the kernel will attempt to enable the best
possible TAA mitigation setting depending on the microcode available
for the particular machine.
This option allows to set the default tsx mode between tsx=on, =off
and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
details.
Say off if not sure, auto if TSX is in use but it should be used on safe
platforms or on if TSX is in use and the security aspect of tsx is not
relevant.
config X86_INTEL_TSX_MODE_OFF
bool "off"
help
TSX is disabled if possible - equals to tsx=off command line parameter.
config X86_INTEL_TSX_MODE_ON
bool "on"
help
TSX is always enabled on TSX capable HW - equals the tsx=on command
line parameter.
config X86_INTEL_TSX_MODE_AUTO
bool "auto"
help
TSX is enabled on TSX capable HW that is believed to be safe against
side channel attacks- equals the tsx=auto command line parameter.
endchoice
config X86_SGX
bool "Software Guard eXtensions (SGX)"
depends on X86_64 && CPU_SUP_INTEL
depends on CRYPTO=y
depends on CRYPTO_SHA256=y
select SRCU
select MMU_NOTIFIER
select NUMA_KEEP_MEMINFO if NUMA
select XARRAY_MULTI
help
Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
that can be used by applications to set aside private regions of code
and data, referred to as enclaves. An enclave's private memory can
only be accessed by code running within the enclave. Accesses from
outside the enclave, including other enclaves, are disallowed by
hardware.
If unsure, say N.
config EFI
bool "EFI runtime service support"
depends on ACPI
select UCS2_STRING
select EFI_RUNTIME_WRAPPERS
select ARCH_USE_MEMREMAP_PROT
help
This enables the kernel to use EFI runtime services that are
available (such as the EFI variable services).
This option is only useful on systems that have EFI firmware.
In addition, you should use the latest ELILO loader available
at <http://elilo.sourceforge.net> in order to take advantage
of EFI runtime services. However, even with this option, the
resultant kernel should continue to boot on existing non-EFI
platforms.
config EFI_STUB
bool "EFI stub support"
depends on EFI
depends on $(cc-option,-mabi=ms) || X86_32
select RELOCATABLE
help
This kernel feature allows a bzImage to be loaded directly
by EFI firmware without the use of a bootloader.
See Documentation/admin-guide/efi-stub.rst for more information.
config EFI_MIXED
bool "EFI mixed-mode support"
depends on EFI_STUB && X86_64
help
Enabling this feature allows a 64-bit kernel to be booted
on a 32-bit firmware, provided that your CPU supports 64-bit
mode.
Note that it is not possible to boot a mixed-mode enabled
kernel via the EFI boot stub - a bootloader that supports
the EFI handover protocol must be used.
If unsure, say N.
source "kernel/Kconfig.hz"
config KEXEC
bool "kexec system call"
select KEXEC_CORE
help
kexec is a system call that implements the ability to shutdown your
current kernel, and to start another kernel. It is like a reboot
but it is independent of the system firmware. And like a reboot
you can start any kernel with it, not just Linux.
The name comes from the similarity to the exec system call.
It is an ongoing process to be certain the hardware in a machine
is properly shutdown, so do not be surprised if this code does not
initially work for you. As of this writing the exact hardware
interface is strongly in flux, so no good recommendation can be
made.
config KEXEC_FILE
bool "kexec file based system call"
select KEXEC_CORE
select BUILD_BIN2C
depends on X86_64
depends on CRYPTO=y
depends on CRYPTO_SHA256=y
help
This is new version of kexec system call. This system call is
file based and takes file descriptors as system call argument
for kernel and initramfs as opposed to list of segments as
accepted by previous system call.
config ARCH_HAS_KEXEC_PURGATORY
def_bool KEXEC_FILE
config KEXEC_SIG
bool "Verify kernel signature during kexec_file_load() syscall"
depends on KEXEC_FILE
help
This option makes the kexec_file_load() syscall check for a valid
signature of the kernel image. The image can still be loaded without
a valid signature unless you also enable KEXEC_SIG_FORCE, though if
there's a signature that we can check, then it must be valid.
In addition to this option, you need to enable signature
verification for the corresponding kernel image type being
loaded in order for this to work.
config KEXEC_SIG_FORCE
bool "Require a valid signature in kexec_file_load() syscall"
depends on KEXEC_SIG
help
This option makes kernel signature verification mandatory for
the kexec_file_load() syscall.
config KEXEC_BZIMAGE_VERIFY_SIG
bool "Enable bzImage signature verification support"
depends on KEXEC_SIG
depends on SIGNED_PE_FILE_VERIFICATION
select SYSTEM_TRUSTED_KEYRING
help
Enable bzImage signature verification support.
config CRASH_DUMP
bool "kernel crash dumps"
depends on X86_64 || (X86_32 && HIGHMEM)
help
Generate crash dump after being started by kexec.
This should be normally only set in special crash dump kernels
which are loaded in the main kernel with kexec-tools into
a specially reserved region and then later executed after
a crash by kdump/kexec. The crash dump kernel must be compiled
to a memory address not used by the main kernel or BIOS using
PHYSICAL_START, or it must be built as a relocatable image
(CONFIG_RELOCATABLE=y).
For more details see Documentation/admin-guide/kdump/kdump.rst
config KEXEC_JUMP
bool "kexec jump"
depends on KEXEC && HIBERNATION
help
Jump between original kernel and kexeced kernel and invoke
code in physical address mode via KEXEC
config PHYSICAL_START
hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
default "0x1000000"
help
This gives the physical address where the kernel is loaded.
If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
bzImage will decompress itself to above physical address and
run from there. Otherwise, bzImage will run from the address where
it has been loaded by the boot loader and will ignore above physical
address.
In normal kdump cases one does not have to set/change this option
as now bzImage can be compiled as a completely relocatable image
(CONFIG_RELOCATABLE=y) and be used to load and run from a different
address. This option is mainly useful for the folks who don't want
to use a bzImage for capturing the crash dump and want to use a
vmlinux instead. vmlinux is not relocatable hence a kernel needs
to be specifically compiled to run from a specific memory area
(normally a reserved region) and this option comes handy.
So if you are using bzImage for capturing the crash dump,
leave the value here unchanged to 0x1000000 and set
CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
for capturing the crash dump change this value to start of
the reserved region. In other words, it can be set based on
the "X" value as specified in the "crashkernel=YM@XM"
command line boot parameter passed to the panic-ed
kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
for more details about crash dumps.
Usage of bzImage for capturing the crash dump is recommended as
one does not have to build two kernels. Same kernel can be used
as production kernel and capture kernel. Above option should have
gone away after relocatable bzImage support is introduced. But it
is present because there are users out there who continue to use
vmlinux for dump capture. This option should go away down the
line.
Don't change this unless you know what you are doing.
config RELOCATABLE
bool "Build a relocatable kernel"
default y
help
This builds a kernel image that retains relocation information
so it can be loaded someplace besides the default 1MB.
The relocations tend to make the kernel binary about 10% larger,
but are discarded at runtime.
One use is for the kexec on panic case where the recovery kernel
must live at a different physical address than the primary
kernel.
Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
it has been loaded at and the compile time physical address
(CONFIG_PHYSICAL_START) is used as the minimum location.
config RANDOMIZE_BASE
bool "Randomize the address of the kernel image (KASLR)"
depends on RELOCATABLE
default y
help
In support of Kernel Address Space Layout Randomization (KASLR),
this randomizes the physical address at which the kernel image
is decompressed and the virtual address where the kernel
image is mapped, as a security feature that deters exploit
attempts relying on knowledge of the location of kernel
code internals.
On 64-bit, the kernel physical and virtual addresses are
randomized separately. The physical address will be anywhere
between 16MB and the top of physical memory (up to 64TB). The
virtual address will be randomized from 16MB up to 1GB (9 bits
of entropy). Note that this also reduces the memory space
available to kernel modules from 1.5GB to 1GB.
On 32-bit, the kernel physical and virtual addresses are
randomized together. They will be randomized from 16MB up to
512MB (8 bits of entropy).
Entropy is generated using the RDRAND instruction if it is
supported. If RDTSC is supported, its value is mixed into
the entropy pool as well. If neither RDRAND nor RDTSC are
supported, then entropy is read from the i8254 timer. The
usable entropy is limited by the kernel being built using
2GB addressing, and that PHYSICAL_ALIGN must be at a
minimum of 2MB. As a result, only 10 bits of entropy are
theoretically possible, but the implementations are further
limited due to memory layouts.
If unsure, say Y.
# Relocation on x86 needs some additional build support
config X86_NEED_RELOCS
def_bool y
depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
config PHYSICAL_ALIGN
hex "Alignment value to which kernel should be aligned"
default "0x200000"
range 0x2000 0x1000000 if X86_32
range 0x200000 0x1000000 if X86_64
help
This value puts the alignment restrictions on physical address
where kernel is loaded and run from. Kernel is compiled for an
address which meets above alignment restriction.
If bootloader loads the kernel at a non-aligned address and
CONFIG_RELOCATABLE is set, kernel will move itself to nearest
address aligned to above value and run from there.
If bootloader loads the kernel at a non-aligned address and
CONFIG_RELOCATABLE is not set, kernel will ignore the run time
load address and decompress itself to the address it has been
compiled for and run from there. The address for which kernel is
compiled already meets above alignment restrictions. Hence the
end result is that kernel runs from a physical address meeting
above alignment restrictions.
On 32-bit this value must be a multiple of 0x2000. On 64-bit
this value must be a multiple of 0x200000.
Don't change this unless you know what you are doing.
config DYNAMIC_MEMORY_LAYOUT
bool
help
This option makes base addresses of vmalloc and vmemmap as well as
__PAGE_OFFSET movable during boot.
config RANDOMIZE_MEMORY
bool "Randomize the kernel memory sections"
depends on X86_64
depends on RANDOMIZE_BASE
select DYNAMIC_MEMORY_LAYOUT
default RANDOMIZE_BASE
help
Randomizes the base virtual address of kernel memory sections
(physical memory mapping, vmalloc & vmemmap). This security feature
makes exploits relying on predictable memory locations less reliable.
The order of allocations remains unchanged. Entropy is generated in
the same way as RANDOMIZE_BASE. Current implementation in the optimal
configuration have in average 30,000 different possible virtual
addresses for each memory section.
If unsure, say Y.
config RANDOMIZE_MEMORY_PHYSICAL_PADDING
hex "Physical memory mapping padding" if EXPERT
depends on RANDOMIZE_MEMORY
default "0xa" if MEMORY_HOTPLUG
default "0x0"
range 0x1 0x40 if MEMORY_HOTPLUG
range 0x0 0x40
help
Define the padding in terabytes added to the existing physical
memory size during kernel memory randomization. It is useful
for memory hotplug support but reduces the entropy available for
address randomization.
If unsure, leave at the default value.
config HOTPLUG_CPU
def_bool y
depends on SMP
config BOOTPARAM_HOTPLUG_CPU0
bool "Set default setting of cpu0_hotpluggable"
depends on HOTPLUG_CPU
help
Set whether default state of cpu0_hotpluggable is on or off.
Say Y here to enable CPU0 hotplug by default. If this switch
is turned on, there is no need to give cpu0_hotplug kernel
parameter and the CPU0 hotplug feature is enabled by default.
Please note: there are two known CPU0 dependencies if you want
to enable the CPU0 hotplug feature either by this switch or by
cpu0_hotplug kernel parameter.
First, resume from hibernate or suspend always starts from CPU0.
So hibernate and suspend are prevented if CPU0 is offline.
Second dependency is PIC interrupts always go to CPU0. CPU0 can not
offline if any interrupt can not migrate out of CPU0. There may
be other CPU0 dependencies.
Please make sure the dependencies are under your control before
you enable this feature.
Say N if you don't want to enable CPU0 hotplug feature by default.
You still can enable the CPU0 hotplug feature at boot by kernel
parameter cpu0_hotplug.
config DEBUG_HOTPLUG_CPU0
def_bool n
prompt "Debug CPU0 hotplug"
depends on HOTPLUG_CPU
help
Enabling this option offlines CPU0 (if CPU0 can be offlined) as
soon as possible and boots up userspace with CPU0 offlined. User
can online CPU0 back after boot time.
To debug CPU0 hotplug, you need to enable CPU0 offline/online
feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
compilation or giving cpu0_hotplug kernel parameter at boot.
If unsure, say N.
config COMPAT_VDSO
def_bool n
prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
depends on COMPAT_32
help
Certain buggy versions of glibc will crash if they are
presented with a 32-bit vDSO that is not mapped at the address
indicated in its segment table.
The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
the only released version with the bug, but OpenSUSE 9
contains a buggy "glibc 2.3.2".
The symptom of the bug is that everything crashes on startup, saying:
dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
Saying Y here changes the default value of the vdso32 boot
option from 1 to 0, which turns off the 32-bit vDSO entirely.
This works around the glibc bug but hurts performance.
If unsure, say N: if you are compiling your own kernel, you
are unlikely to be using a buggy version of glibc.
choice
prompt "vsyscall table for legacy applications"
depends on X86_64
default LEGACY_VSYSCALL_XONLY
help
Legacy user code that does not know how to find the vDSO expects
to be able to issue three syscalls by calling fixed addresses in
kernel space. Since this location is not randomized with ASLR,
it can be used to assist security vulnerability exploitation.
This setting can be changed at boot time via the kernel command
line parameter vsyscall=[emulate|xonly|none]. Emulate mode
is deprecated and can only be enabled using the kernel command
line.
On a system with recent enough glibc (2.14 or newer) and no
static binaries, you can say None without a performance penalty
to improve security.
If unsure, select "Emulate execution only".
config LEGACY_VSYSCALL_XONLY
bool "Emulate execution only"
help
The kernel traps and emulates calls into the fixed vsyscall
address mapping and does not allow reads. This
configuration is recommended when userspace might use the
legacy vsyscall area but support for legacy binary
instrumentation of legacy code is not needed. It mitigates
certain uses of the vsyscall area as an ASLR-bypassing
buffer.
config LEGACY_VSYSCALL_NONE
bool "None"
help
There will be no vsyscall mapping at all. This will
eliminate any risk of ASLR bypass due to the vsyscall
fixed address mapping. Attempts to use the vsyscalls
will be reported to dmesg, so that either old or
malicious userspace programs can be identified.
endchoice
config CMDLINE_BOOL
bool "Built-in kernel command line"
help
Allow for specifying boot arguments to the kernel at
build time. On some systems (e.g. embedded ones), it is
necessary or convenient to provide some or all of the
kernel boot arguments with the kernel itself (that is,
to not rely on the boot loader to provide them.)
To compile command line arguments into the kernel,
set this option to 'Y', then fill in the
boot arguments in CONFIG_CMDLINE.
Systems with fully functional boot loaders (i.e. non-embedded)
should leave this option set to 'N'.
config CMDLINE
string "Built-in kernel command string"
depends on CMDLINE_BOOL
default ""
help
Enter arguments here that should be compiled into the kernel
image and used at boot time. If the boot loader provides a
command line at boot time, it is appended to this string to
form the full kernel command line, when the system boots.
However, you can use the CONFIG_CMDLINE_OVERRIDE option to
change this behavior.
In most cases, the command line (whether built-in or provided
by the boot loader) should specify the device for the root
file system.
config CMDLINE_OVERRIDE
bool "Built-in command line overrides boot loader arguments"
depends on CMDLINE_BOOL && CMDLINE != ""
help
Set this option to 'Y' to have the kernel ignore the boot loader
command line, and use ONLY the built-in command line.
This is used to work around broken boot loaders. This should
be set to 'N' under normal conditions.
config MODIFY_LDT_SYSCALL
bool "Enable the LDT (local descriptor table)" if EXPERT
default y
help
Linux can allow user programs to install a per-process x86
Local Descriptor Table (LDT) using the modify_ldt(2) system
call. This is required to run 16-bit or segmented code such as
DOSEMU or some Wine programs. It is also used by some very old
threading libraries.
Enabling this feature adds a small amount of overhead to
context switches and increases the low-level kernel attack
surface. Disabling it removes the modify_ldt(2) system call.
Saying 'N' here may make sense for embedded or server kernels.
config STRICT_SIGALTSTACK_SIZE
bool "Enforce strict size checking for sigaltstack"
depends on DYNAMIC_SIGFRAME
help
For historical reasons MINSIGSTKSZ is a constant which became
already too small with AVX512 support. Add a mechanism to
enforce strict checking of the sigaltstack size against the
real size of the FPU frame. This option enables the check
by default. It can also be controlled via the kernel command
line option 'strict_sas_size' independent of this config
switch. Enabling it might break existing applications which
allocate a too small sigaltstack but 'work' because they
never get a signal delivered.
Say 'N' unless you want to really enforce this check.
source "kernel/livepatch/Kconfig"
endmenu
config ARCH_HAS_ADD_PAGES
def_bool y
depends on ARCH_ENABLE_MEMORY_HOTPLUG
config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
def_bool y
menu "Power management and ACPI options"
config ARCH_HIBERNATION_HEADER
def_bool y
depends on HIBERNATION
source "kernel/power/Kconfig"
source "drivers/acpi/Kconfig"
config X86_APM_BOOT
def_bool y
depends on APM
menuconfig APM
tristate "APM (Advanced Power Management) BIOS support"
depends on X86_32 && PM_SLEEP
help
APM is a BIOS specification for saving power using several different
techniques. This is mostly useful for battery powered laptops with
APM compliant BIOSes. If you say Y here, the system time will be
reset after a RESUME operation, the /proc/apm device will provide
battery status information, and user-space programs will receive
notification of APM "events" (e.g. battery status change).
If you select "Y" here, you can disable actual use of the APM
BIOS by passing the "apm=off" option to the kernel at boot time.
Note that the APM support is almost completely disabled for
machines with more than one CPU.
In order to use APM, you will need supporting software. For location
and more information, read <file:Documentation/power/apm-acpi.rst>
and the Battery Powered Linux mini-HOWTO, available from
<http://www.tldp.org/docs.html#howto>.
This driver does not spin down disk drives (see the hdparm(8)
manpage ("man 8 hdparm") for that), and it doesn't turn off
VESA-compliant "green" monitors.
This driver does not support the TI 4000M TravelMate and the ACER
486/DX4/75 because they don't have compliant BIOSes. Many "green"
desktop machines also don't have compliant BIOSes, and this driver
may cause those machines to panic during the boot phase.
Generally, if you don't have a battery in your machine, there isn't
much point in using this driver and you should say N. If you get
random kernel OOPSes or reboots that don't seem to be related to
anything, try disabling/enabling this option (or disabling/enabling
APM in your BIOS).
Some other things you should try when experiencing seemingly random,
"weird" problems:
1) make sure that you have enough swap space and that it is
enabled.
2) pass the "no-hlt" option to the kernel
3) switch on floating point emulation in the kernel and pass
the "no387" option to the kernel
4) pass the "floppy=nodma" option to the kernel
5) pass the "mem=4M" option to the kernel (thereby disabling
all but the first 4 MB of RAM)
6) make sure that the CPU is not over clocked.
7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
8) disable the cache from your BIOS settings
9) install a fan for the video card or exchange video RAM
10) install a better fan for the CPU
11) exchange RAM chips
12) exchange the motherboard.
To compile this driver as a module, choose M here: the
module will be called apm.
if APM
config APM_IGNORE_USER_SUSPEND
bool "Ignore USER SUSPEND"
help
This option will ignore USER SUSPEND requests. On machines with a
compliant APM BIOS, you want to say N. However, on the NEC Versa M
series notebooks, it is necessary to say Y because of a BIOS bug.
config APM_DO_ENABLE
bool "Enable PM at boot time"
help
Enable APM features at boot time. From page 36 of the APM BIOS
specification: "When disabled, the APM BIOS does not automatically
power manage devices, enter the Standby State, enter the Suspend
State, or take power saving steps in response to CPU Idle calls."
This driver will make CPU Idle calls when Linux is idle (unless this
feature is turned off -- see "Do CPU IDLE calls", below). This
should always save battery power, but more complicated APM features
will be dependent on your BIOS implementation. You may need to turn
this option off if your computer hangs at boot time when using APM
support, or if it beeps continuously instead of suspending. Turn
this off if you have a NEC UltraLite Versa 33/C or a Toshiba
T400CDT. This is off by default since most machines do fine without
this feature.
config APM_CPU_IDLE
depends on CPU_IDLE
bool "Make CPU Idle calls when idle"
help
Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
On some machines, this can activate improved power savings, such as
a slowed CPU clock rate, when the machine is idle. These idle calls
are made after the idle loop has run for some length of time (e.g.,
333 mS). On some machines, this will cause a hang at boot time or
whenever the CPU becomes idle. (On machines with more than one CPU,
this option does nothing.)
config APM_DISPLAY_BLANK
bool "Enable console blanking using APM"
help
Enable console blanking using the APM. Some laptops can use this to
turn off the LCD backlight when the screen blanker of the Linux
virtual console blanks the screen. Note that this is only used by
the virtual console screen blanker, and won't turn off the backlight
when using the X Window system. This also doesn't have anything to
do with your VESA-compliant power-saving monitor. Further, this
option doesn't work for all laptops -- it might not turn off your
backlight at all, or it might print a lot of errors to the console,
especially if you are using gpm.
config APM_ALLOW_INTS
bool "Allow interrupts during APM BIOS calls"
help
Normally we disable external interrupts while we are making calls to
the APM BIOS as a measure to lessen the effects of a badly behaving
BIOS implementation. The BIOS should reenable interrupts if it
needs to. Unfortunately, some BIOSes do not -- especially those in
many of the newer IBM Thinkpads. If you experience hangs when you
suspend, try setting this to Y. Otherwise, say N.
endif # APM
source "drivers/cpufreq/Kconfig"
source "drivers/cpuidle/Kconfig"
source "drivers/idle/Kconfig"
endmenu
menu "Bus options (PCI etc.)"
choice
prompt "PCI access mode"
depends on X86_32 && PCI
default PCI_GOANY
help
On PCI systems, the BIOS can be used to detect the PCI devices and
determine their configuration. However, some old PCI motherboards
have BIOS bugs and may crash if this is done. Also, some embedded
PCI-based systems don't have any BIOS at all. Linux can also try to
detect the PCI hardware directly without using the BIOS.
With this option, you can specify how Linux should detect the
PCI devices. If you choose "BIOS", the BIOS will be used,
if you choose "Direct", the BIOS won't be used, and if you
choose "MMConfig", then PCI Express MMCONFIG will be used.
If you choose "Any", the kernel will try MMCONFIG, then the
direct access method and falls back to the BIOS if that doesn't
work. If unsure, go with the default, which is "Any".
config PCI_GOBIOS
bool "BIOS"
config PCI_GOMMCONFIG
bool "MMConfig"
config PCI_GODIRECT
bool "Direct"
config PCI_GOOLPC
bool "OLPC XO-1"
depends on OLPC
config PCI_GOANY
bool "Any"
endchoice
config PCI_BIOS
def_bool y
depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
config PCI_DIRECT
def_bool y
depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
config PCI_MMCONFIG
bool "Support mmconfig PCI config space access" if X86_64
default y
depends on PCI && (ACPI || JAILHOUSE_GUEST)
depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
config PCI_OLPC
def_bool y
depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
config PCI_XEN
def_bool y
depends on PCI && XEN
config MMCONF_FAM10H
def_bool y
depends on X86_64 && PCI_MMCONFIG && ACPI
config PCI_CNB20LE_QUIRK
bool "Read CNB20LE Host Bridge Windows" if EXPERT
depends on PCI
help
Read the PCI windows out of the CNB20LE host bridge. This allows
PCI hotplug to work on systems with the CNB20LE chipset which do
not have ACPI.
There's no public spec for this chipset, and this functionality
is known to be incomplete.
You should say N unless you know you need this.
config ISA_BUS
bool "ISA bus support on modern systems" if EXPERT
help
Expose ISA bus device drivers and options available for selection and
configuration. Enable this option if your target machine has an ISA
bus. ISA is an older system, displaced by PCI and newer bus
architectures -- if your target machine is modern, it probably does
not have an ISA bus.
If unsure, say N.
# x86_64 have no ISA slots, but can have ISA-style DMA.
config ISA_DMA_API
bool "ISA-style DMA support" if (X86_64 && EXPERT)
default y
help
Enables ISA-style DMA support for devices requiring such controllers.
If unsure, say Y.
if X86_32
config ISA
bool "ISA support"
help
Find out whether you have ISA slots on your motherboard. ISA is the
name of a bus system, i.e. the way the CPU talks to the other stuff
inside your box. Other bus systems are PCI, EISA, MicroChannel
(MCA) or VESA. ISA is an older system, now being displaced by PCI;
newer boards don't support it. If you have ISA, say Y, otherwise N.
config SCx200
tristate "NatSemi SCx200 support"
help
This provides basic support for National Semiconductor's
(now AMD's) Geode processors. The driver probes for the
PCI-IDs of several on-chip devices, so its a good dependency
for other scx200_* drivers.
If compiled as a module, the driver is named scx200.
config SCx200HR_TIMER
tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
depends on SCx200
default y
help
This driver provides a clocksource built upon the on-chip
27MHz high-resolution timer. Its also a workaround for
NSC Geode SC-1100's buggy TSC, which loses time when the
processor goes idle (as is done by the scheduler). The
other workaround is idle=poll boot option.
config OLPC
bool "One Laptop Per Child support"
depends on !X86_PAE
select GPIOLIB
select OF
select OF_PROMTREE
select IRQ_DOMAIN
select OLPC_EC
help
Add support for detecting the unique features of the OLPC
XO hardware.
config OLPC_XO1_PM
bool "OLPC XO-1 Power Management"
depends on OLPC && MFD_CS5535=y && PM_SLEEP
help
Add support for poweroff and suspend of the OLPC XO-1 laptop.
config OLPC_XO1_RTC
bool "OLPC XO-1 Real Time Clock"
depends on OLPC_XO1_PM && RTC_DRV_CMOS
help
Add support for the XO-1 real time clock, which can be used as a
programmable wakeup source.
config OLPC_XO1_SCI
bool "OLPC XO-1 SCI extras"
depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
depends on INPUT=y
select POWER_SUPPLY
help
Add support for SCI-based features of the OLPC XO-1 laptop:
- EC-driven system wakeups
- Power button
- Ebook switch
- Lid switch
- AC adapter status updates
- Battery status updates
config OLPC_XO15_SCI
bool "OLPC XO-1.5 SCI extras"
depends on OLPC && ACPI
select POWER_SUPPLY
help
Add support for SCI-based features of the OLPC XO-1.5 laptop:
- EC-driven system wakeups
- AC adapter status updates
- Battery status updates
config ALIX
bool "PCEngines ALIX System Support (LED setup)"
select GPIOLIB
help
This option enables system support for the PCEngines ALIX.
At present this just sets up LEDs for GPIO control on
ALIX2/3/6 boards. However, other system specific setup should
get added here.
Note: You must still enable the drivers for GPIO and LED support
(GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
Note: You have to set alix.force=1 for boards with Award BIOS.
config NET5501
bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
select GPIOLIB
help
This option enables system support for the Soekris Engineering net5501.
config GEOS
bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
select GPIOLIB
depends on DMI
help
This option enables system support for the Traverse Technologies GEOS.
config TS5500
bool "Technologic Systems TS-5500 platform support"
depends on MELAN
select CHECK_SIGNATURE
select NEW_LEDS
select LEDS_CLASS
help
This option enables system support for the Technologic Systems TS-5500.
endif # X86_32
config AMD_NB
def_bool y
depends on CPU_SUP_AMD && PCI
endmenu
menu "Binary Emulations"
config IA32_EMULATION
bool "IA32 Emulation"
depends on X86_64
select ARCH_WANT_OLD_COMPAT_IPC
select BINFMT_ELF
select COMPAT_OLD_SIGACTION
help
Include code to run legacy 32-bit programs under a
64-bit kernel. You should likely turn this on, unless you're
100% sure that you don't have any 32-bit programs left.
config X86_X32_ABI
bool "x32 ABI for 64-bit mode"
depends on X86_64
# llvm-objcopy does not convert x86_64 .note.gnu.property or
# compressed debug sections to x86_x32 properly:
# https://github.com/ClangBuiltLinux/linux/issues/514
# https://github.com/ClangBuiltLinux/linux/issues/1141
depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
help
Include code to run binaries for the x32 native 32-bit ABI
for 64-bit processors. An x32 process gets access to the
full 64-bit register file and wide data path while leaving
pointers at 32 bits for smaller memory footprint.
config COMPAT_32
def_bool y
depends on IA32_EMULATION || X86_32
select HAVE_UID16
select OLD_SIGSUSPEND3
config COMPAT
def_bool y
depends on IA32_EMULATION || X86_X32_ABI
config COMPAT_FOR_U64_ALIGNMENT
def_bool y
depends on COMPAT
endmenu
config HAVE_ATOMIC_IOMAP
def_bool y
depends on X86_32
source "arch/x86/kvm/Kconfig"
source "arch/x86/Kconfig.assembler"
|