summaryrefslogtreecommitdiffstats
path: root/IntelFrameworkPkg/Include/Protocol/LegacyBios.h
blob: 88f598044a5c886d5e81be81c7b071dd9e1a8b9d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
/** @file
  The EFI Legacy BIOS Protocol is used to abstract legacy Option ROM usage
  under EFI and Legacy OS boot.  This file also includes all the related
  COMPATIBILIY16 structures and defintions.

  Note: The names for EFI_IA32_REGISTER_SET elements were picked to follow
  well known naming conventions.

  Thunk is the code that switches from 32-bit protected environment into the 16-bit real-mode
	environment. Reverse thunk is the code that does the opposite.

Copyright (c) 2007 - 2010, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials are licensed and made available under 
the terms and conditions of the BSD License that accompanies this distribution.  
The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php.                                          
    
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

  @par Revision Reference:
  This protocol is defined in Framework for EFI Compatibility Support Module spec
  Version 0.97.

**/

#ifndef _EFI_LEGACY_BIOS_H_
#define _EFI_LEGACY_BIOS_H_

///
/// 
///
#pragma pack(1)

typedef UINT8                       SERIAL_MODE;
typedef UINT8                       PARALLEL_MODE;

#define EFI_COMPATIBILITY16_TABLE_SIGNATURE SIGNATURE_32 ('I', 'F', 'E', '$')

///
/// There is a table located within the traditional BIOS in either the 0xF000:xxxx or 0xE000:xxxx
/// physical address range. It is located on a 16-byte boundary and provides the physical address of the
/// entry point for the Compatibility16 functions. These functions provide the platform-specific
/// information that is required by the generic EfiCompatibility code. The functions are invoked via
/// thunking by using EFI_LEGACY_BIOS_PROTOCOL.FarCall86() with the 32-bit physical
/// entry point.
///
typedef struct {
  ///
  /// The string "$EFI" denotes the start of the EfiCompatibility table. Byte 0 is "I," byte
  /// 1 is "F," byte 2 is "E," and byte 3 is "$" and is normally accessed as a DWORD or UINT32.
  ///
  UINT32                            Signature;
  
  ///
  /// The value required such that byte checksum of TableLength equals zero.
  ///
  UINT8                             TableChecksum;
  
  ///
  /// The length of this table.
  ///
  UINT8                             TableLength;
  
  ///
  /// The major EFI revision for which this table was generated.
  /// 
  UINT8                             EfiMajorRevision;
  
  ///
  /// The minor EFI revision for which this table was generated.
  ///
  UINT8                             EfiMinorRevision;
  
  ///
  /// The major revision of this table.
  ///
  UINT8                             TableMajorRevision;
  
  ///
  /// The minor revision of this table.
  ///
  UINT8                             TableMinorRevision;
  
  ///
  /// Reserved for future usage.
  ///
  UINT16                            Reserved;
  
  ///
  /// The segment of the entry point within the traditional BIOS for Compatibility16 functions.
  ///
  UINT16                            Compatibility16CallSegment;
  
  ///
  /// The offset of the entry point within the traditional BIOS for Compatibility16 functions.
  ///
  UINT16                            Compatibility16CallOffset;
  
  ///
  /// The segment of the entry point within the traditional BIOS for EfiCompatibility 
  /// to invoke the PnP installation check.
  ///
  UINT16                            PnPInstallationCheckSegment;
  
  ///
  /// The Offset of the entry point within the traditional BIOS for EfiCompatibility 
  /// to invoke the PnP installation check.
  ///
  UINT16                            PnPInstallationCheckOffset;
  
  ///
  /// EFI system resources table. Type EFI_SYSTEM_TABLE is defined in the IntelPlatform 
  ///Innovation Framework for EFI Driver Execution Environment Core Interface Specification (DXE CIS).
  ///
  UINT32                            EfiSystemTable; 
  
  ///
  /// The address of an OEM-provided identifier string. The string is null terminated.
  ///
  UINT32                            OemIdStringPointer;
  
  ///
  /// The 32-bit physical address where ACPI RSD PTR is stored within the traditional
  /// BIOS. The remained of the ACPI tables are located at their EFI addresses. The size
  /// reserved is the maximum for ACPI 2.0. The EfiCompatibility will fill in the ACPI
  /// RSD PTR with either the ACPI 1.0b or 2.0 values.
  ///
  UINT32                            AcpiRsdPtrPointer;
  
  ///
  /// The OEM revision number. Usage is undefined but provided for OEM module usage.
  ///
  UINT16                            OemRevision;
  
  ///
  /// The 32-bit physical address where INT15 E820 data is stored within the traditional
  /// BIOS. The EfiCompatibility code will fill in the E820Pointer value and copy the
  /// data to the indicated area.
  ///
  UINT32                            E820Pointer;
  
  ///
  /// The length of the E820 data and is filled in by the EfiCompatibility code.
  ///
  UINT32                            E820Length;
  
  ///
  /// The 32-bit physical address where the $PIR table is stored in the traditional BIOS.
  /// The EfiCompatibility code will fill in the IrqRoutingTablePointer value and
  /// copy the data to the indicated area.
  ///
  UINT32                            IrqRoutingTablePointer;
  
  ///
  /// The length of the $PIR table and is filled in by the EfiCompatibility code.
  ///
  UINT32                            IrqRoutingTableLength;
  
  ///
  /// The 32-bit physical address where the MP table is stored in the traditional BIOS.
  /// The EfiCompatibility code will fill in the MpTablePtr value and copy the data 
  /// to the indicated area.
  ///
  UINT32                            MpTablePtr;
  
  ///
  /// The length of the MP table and is filled in by the EfiCompatibility code.
  ///
  UINT32                            MpTableLength;
  
  ///
  /// The segment of the OEM-specific INT table/code.
  /// 
  UINT16                            OemIntSegment;
  
  ///
  /// The offset of the OEM-specific INT table/code.
  ///
  UINT16                            OemIntOffset;
  
  ///
  /// The segment of the OEM-specific 32-bit table/code.
  ///
  UINT16                            Oem32Segment;
  
  ///
  /// The offset of the OEM-specific 32-bit table/code.
  ///
  UINT16                            Oem32Offset;
  
  ///
  /// The segment of the OEM-specific 16-bit table/code.
  ///
  UINT16                            Oem16Segment;
  
  ///
  /// The offset of the OEM-specific 16-bit table/code.
  ///
  UINT16                            Oem16Offset;
  
  ///
  /// The segment of the TPM binary passed to 16-bit CSM.
  ///
  UINT16                            TpmSegment;
  
  ///
  /// The offset of the TPM binary passed to 16-bit CSM.
  ///
  UINT16                            TpmOffset;
  
  ///
  /// A pointer to a string identifying the independent BIOS vendor.
  ///
  UINT32                            IbvPointer;
  
  ///
  /// This field is NULL for all systems not supporting PCI Express. This field is the base
  /// value of the start of the PCI Express memory-mapped configuration registers and
  /// must be filled in prior to EfiCompatibility code issuing the Compatibility16 function
  /// Compatibility16InitializeYourself().
  /// Compatibility16InitializeYourself() is defined in Compatability16
  /// Functions.
  ///
  UINT32                            PciExpressBase;
  
  ///
  /// Maximum PCI bus number assigned.
  ///
  UINT8                             LastPciBus;
} EFI_COMPATIBILITY16_TABLE;

///
/// Functions provided by the CSM binary which communicate between the EfiCompatibility 
/// and Compatability16 code.
///
/// Inconsistent with the specification here: 
/// The member's name started with "Compatibility16" [defined in Intel Framework 
/// Compatibility Support Module Specification / 0.97 version] 
/// has been changed to "Legacy16" since keeping backward compatible.
///
typedef enum {
  ///
  /// Causes the Compatibility16 code to do any internal initialization required.
  /// Input:
  ///   AX = Compatibility16InitializeYourself
  ///   ES:BX = Pointer to EFI_TO_COMPATIBILITY16_INIT_TABLE
  /// Return:
  ///   AX = Return Status codes
  ///
  Legacy16InitializeYourself    = 0x0000,
  
  ///
  /// Causes the Compatibility16 BIOS to perform any drive number translations to match the boot sequence.
  /// Input:
  ///   AX = Compatibility16UpdateBbs
  ///   ES:BX = Pointer to EFI_TO_COMPATIBILITY16_BOOT_TABLE
  /// Return:
  ///   AX = Returned status codes
  ///
  Legacy16UpdateBbs             = 0x0001,
  
  ///
  /// Allows the Compatibility16 code to perform any final actions before booting. The Compatibility16
  /// code is read/write.
  /// Input:
  ///   AX = Compatibility16PrepareToBoot
  ///   ES:BX = Pointer to EFI_TO_COMPATIBILITY16_BOOT_TABLE structure  
  /// Return:
  ///   AX = Returned status codes
  ///
  Legacy16PrepareToBoot         = 0x0002,
  
  ///
  /// Causes the Compatibility16 BIOS to boot. The Compatibility16 code is Read/Only.
  /// Input:
  ///   AX = Compatibility16Boot
  /// Output:
  ///   AX = Returned status codes
  ///
  Legacy16Boot                  = 0x0003,
  
  ///
  /// Allows the Compatibility16 code to get the last device from which a boot was attempted. This is
  /// stored in CMOS and is the priority number of the last attempted boot device.
  /// Input:
  ///   AX = Compatibility16RetrieveLastBootDevice
  /// Output:
  ///   AX = Returned status codes
  ///   BX = Priority number of the boot device.
  ///
  Legacy16RetrieveLastBootDevice = 0x0004,
  
  ///
  /// Allows the Compatibility16 code rehook INT13, INT18, and/or INT19 after dispatching a legacy OpROM.
  /// Input:
  ///   AX = Compatibility16DispatchOprom
  ///   ES:BX = Pointer to EFI_DISPATCH_OPROM_TABLE
  /// Output:
  ///   AX = Returned status codes
  ///   BX = Number of non-BBS-compliant devices found. Equals 0 if BBS compliant.
  ///
  Legacy16DispatchOprom         = 0x0005,
  
  ///
  /// Finds a free area in the 0xFxxxx or 0xExxxx region of the specified length and returns the address
  /// of that region.
  /// Input:
  ///   AX = Compatibility16GetTableAddress
  ///   BX = Allocation region
  ///       00 = Allocate from either 0xE0000 or 0xF0000 64 KB blocks.
  ///       Bit 0 = 1 Allocate from 0xF0000 64 KB block
  ///       Bit 1 = 1 Allocate from 0xE0000 64 KB block
  ///   CX = Requested length in bytes.
  ///   DX = Required address alignment. Bit mapped. First non-zero bit from the right is the alignment.
  /// Output:
  ///   AX = Returned status codes
  ///   DS:BX = Address of the region
  ///
  Legacy16GetTableAddress       = 0x0006,
  
  ///
  /// Enables the EfiCompatibility module to do any nonstandard processing of keyboard LEDs or state.
  /// Input:
  ///   AX = Compatibility16SetKeyboardLeds
  ///   CL = LED status.
  ///     Bit 0  Scroll Lock 0 = Off
  ///     Bit 1  NumLock
  ///     Bit 2  Caps Lock
  /// Output:
  ///     AX = Returned status codes
  ///
  Legacy16SetKeyboardLeds       = 0x0007,
  
  ///
  /// Enables the EfiCompatibility module to install an interrupt handler for PCI mass media devices that
  /// do not have an OpROM associated with them. An example is SATA.
  /// Input:
  ///   AX = Compatibility16InstallPciHandler
  ///   ES:BX = Pointer to EFI_LEGACY_INSTALL_PCI_HANDLER structure
  /// Output:
  ///   AX = Returned status codes
  ///
  Legacy16InstallPciHandler     = 0x0008
} EFI_COMPATIBILITY_FUNCTIONS;


///
/// EFI_DISPATCH_OPROM_TABLE
///
typedef struct {
  UINT16  PnPInstallationCheckSegment;  ///< A pointer to the PnpInstallationCheck data structure.
  UINT16  PnPInstallationCheckOffset;   ///< A pointer to the PnpInstallationCheck data structure.
  UINT16  OpromSegment;                 ///< The segment where the OpROM was placed. Offset is assumed to be 3.
  UINT8   PciBus;                       ///< The PCI bus.
  UINT8   PciDeviceFunction;            ///< The PCI device * 0x08 | PCI function.
  UINT8   NumberBbsEntries;             ///< The number of valid BBS table entries upon entry and exit. The IBV code may
                                        ///< increase this number, if BBS-compliant devices also hook INTs in order to force the
                                        ///< OpROM BIOS Setup to be executed.
  UINT32  BbsTablePointer;              ///< A pointer to the BBS table.
  UINT16  RuntimeSegment;               ///< The segment where the OpROM can be relocated to. If this value is 0x0000, this
                                        ///< means that the relocation of this run time code is not supported.
                                        ///< Inconsistent with specification here: 
                                        ///< The member's name "OpromDestinationSegment" [defined in Intel Framework Compatibility Support Module Specification / 0.97 version] 
                                        ///< has been changed to "RuntimeSegment" since keeping backward compatible.

} EFI_DISPATCH_OPROM_TABLE;

///
/// EFI_TO_COMPATIBILITY16_INIT_TABLE
///
typedef struct {
  ///
  /// Starting address of memory under 1 MB. The ending address is assumed to be 640 KB or 0x9FFFF.
  ///
  UINT32                            BiosLessThan1MB;
  
  ///
  /// The starting address of the high memory block.
  ///
  UINT32                            HiPmmMemory;
  
  ///
  /// The length of high memory block.
  ///
  UINT32                            HiPmmMemorySizeInBytes;
  
  ///
  /// The segment of the reverse thunk call code.
  ///
  UINT16                            ReverseThunkCallSegment;
  
  ///
  /// The offset of the reverse thunk call code.
  ///
  UINT16                            ReverseThunkCallOffset;
  
  ///
  /// The number of E820 entries copied to the Compatibility16 BIOS.
  ///
  UINT32                            NumberE820Entries;
  
  ///
  /// The amount of usable memory above 1 MB, e.g., E820 type 1 memory.
  ///
  UINT32                            OsMemoryAbove1Mb;
  
  ///
  /// The start of thunk code in main memory. Memory cannot be used by BIOS or PMM.
  ///
  UINT32                            ThunkStart;
  
  ///
  /// The size of the thunk code.
  ///
  UINT32                            ThunkSizeInBytes;
  
  ///
  /// Starting address of memory under 1 MB.
  ///
  UINT32                            LowPmmMemory;
  
  ///
  /// The length of low Memory block.
  ///
  UINT32                            LowPmmMemorySizeInBytes;
} EFI_TO_COMPATIBILITY16_INIT_TABLE;

///
/// DEVICE_PRODUCER_SERIAL.
///
typedef struct {
  UINT16                            Address;    ///< I/O address assigned to the serial port.
  UINT8                             Irq;        ///< IRQ assigned to the serial port.
  SERIAL_MODE                       Mode;       ///< Mode of serial port. Values are defined below.
} DEVICE_PRODUCER_SERIAL;

///
/// DEVICE_PRODUCER_SERIAL's modes.
///@{
#define DEVICE_SERIAL_MODE_NORMAL               0x00
#define DEVICE_SERIAL_MODE_IRDA                 0x01
#define DEVICE_SERIAL_MODE_ASK_IR               0x02
#define DEVICE_SERIAL_MODE_DUPLEX_HALF          0x00
#define DEVICE_SERIAL_MODE_DUPLEX_FULL          0x10
///@)

///
/// DEVICE_PRODUCER_PARALLEL.
///
typedef struct {
  UINT16                            Address;  ///< I/O address assigned to the parallel port.
  UINT8                             Irq;      ///< IRQ assigned to the parallel port.
  UINT8                             Dma;      ///< DMA assigned to the parallel port.
  PARALLEL_MODE                     Mode;     ///< Mode of the parallel port. Values are defined below.
} DEVICE_PRODUCER_PARALLEL;

///
/// DEVICE_PRODUCER_PARALLEL's modes.
///@{
#define DEVICE_PARALLEL_MODE_MODE_OUTPUT_ONLY   0x00
#define DEVICE_PARALLEL_MODE_MODE_BIDIRECTIONAL 0x01
#define DEVICE_PARALLEL_MODE_MODE_EPP           0x02
#define DEVICE_PARALLEL_MODE_MODE_ECP           0x03
///@}

///
/// DEVICE_PRODUCER_FLOPPY
///
typedef struct {
  UINT16                            Address;          ///< I/O address assigned to the floppy.
  UINT8                             Irq;              ///< IRQ assigned to the floppy.
  UINT8                             Dma;              ///< DMA assigned to the floppy.
  UINT8                             NumberOfFloppy;   ///< Number of floppies in the system.
} DEVICE_PRODUCER_FLOPPY;

///
/// LEGACY_DEVICE_FLAGS
///
typedef struct {
  UINT32                            A20Kybd : 1;      ///< A20 controller by keyboard controller.
  UINT32                            A20Port90 : 1;    ///< A20 controlled by port 0x92.
  UINT32                            Reserved : 30;    ///< Reserved for future usage.
} LEGACY_DEVICE_FLAGS;

///
/// DEVICE_PRODUCER_DATA_HEADER
///
typedef struct {
  DEVICE_PRODUCER_SERIAL            Serial[4];      ///< Data for serial port x. Type DEVICE_PRODUCER_SERIAL is defined below.
  DEVICE_PRODUCER_PARALLEL          Parallel[3];    ///< Data for parallel port x. Type DEVICE_PRODUCER_PARALLEL is defined below.
  DEVICE_PRODUCER_FLOPPY            Floppy;         ///< Data for floppy. Type DEVICE_PRODUCER_FLOPPY is defined below.
  UINT8                             MousePresent;   ///< Flag to indicate if mouse is present.
  LEGACY_DEVICE_FLAGS               Flags;          ///< Miscellaneous Boolean state information passed to CSM.
} DEVICE_PRODUCER_DATA_HEADER;

///
/// ATAPI_IDENTIFY
///
typedef struct {
  UINT16                            Raw[256];     ///< Raw data from the IDE IdentifyDrive command.
} ATAPI_IDENTIFY;

///
/// HDD_INFO
///
typedef struct {
  ///
  /// Status of IDE device. Values are defined below. There is one HDD_INFO structure
  /// per IDE controller. The IdentifyDrive is per drive. Index 0 is master and index
  /// 1 is slave.
  ///
  UINT16                            Status;   
  
  ///
  /// PCI bus of IDE controller.
  ///
  UINT32                            Bus;
  
  ///
  /// PCI device of IDE controller.
  ///
  UINT32                            Device;
  
  ///
  /// PCI function of IDE controller.
  ///
  UINT32                            Function;
  
  ///
  /// Command ports base address.
  ///
  UINT16                            CommandBaseAddress;
  
  ///
  /// Control ports base address.
  ///
  UINT16                            ControlBaseAddress;
  
  ///
  /// Bus master address.
  ///
  UINT16                            BusMasterAddress;
  
  UINT8                             HddIrq;
  
  ///
  /// Data that identifies the drive data; one per possible attached drive.
  ///
  ATAPI_IDENTIFY                    IdentifyDrive[2];
} HDD_INFO;

///
/// HDD_INFO status bits
///
#define HDD_PRIMARY               0x01
#define HDD_SECONDARY             0x02
#define HDD_MASTER_ATAPI_CDROM    0x04
#define HDD_SLAVE_ATAPI_CDROM     0x08
#define HDD_MASTER_IDE            0x20
#define HDD_SLAVE_IDE             0x40
#define HDD_MASTER_ATAPI_ZIPDISK  0x10
#define HDD_SLAVE_ATAPI_ZIPDISK   0x80

///
/// BBS_STATUS_FLAGS;\.
///
typedef struct {
  UINT16                            OldPosition : 4;    ///< Prior priority.
  UINT16                            Reserved1 : 4;      ///< Reserved for future use.
  UINT16                            Enabled : 1;        ///< If 0, ignore this entry.
  UINT16                            Failed : 1;         ///< 0 = Not known if boot failure occurred.
                                                        ///< 1 = Boot attempted failed.
  
  ///
  /// State of media present.
  ///   00 = No bootable media is present in the device.
  ///   01 = Unknown if a bootable media present.
  ///   10 = Media is present and appears bootable.
  ///   11 = Reserved.
  ///
  UINT16                            MediaPresent : 2;
  UINT16                            Reserved2 : 4;      ///< Reserved for future use.
} BBS_STATUS_FLAGS;

///
/// BBS_TABLE, device type values & boot priority values.
///
typedef struct {
  ///
  /// The boot priority for this boot device. Values are defined below.
  ///
  UINT16                            BootPriority;
  
  ///
  /// The PCI bus for this boot device.
  ///
  UINT32                            Bus;
  
  ///
  /// The PCI device for this boot device.
  ///
  UINT32                            Device;
  
  ///
  /// The PCI function for the boot device.
  ///
  UINT32                            Function;
  
  ///
  /// The PCI class for this boot device.
  ///
  UINT8                             Class;
  
  ///
  /// The PCI Subclass for this boot device.
  ///
  UINT8                             SubClass;
  
  ///
  /// Segment:offset address of an ASCIIZ description string describing the manufacturer.
  ///
  UINT16                            MfgStringOffset;
  
  ///
  /// Segment:offset address of an ASCIIZ description string describing the manufacturer.
  ///  
  UINT16                            MfgStringSegment;
  
  ///
  /// BBS device type. BBS device types are defined below.
  ///
  UINT16                            DeviceType;
  
  ///
  /// Status of this boot device. Type BBS_STATUS_FLAGS is defined below.
  ///
  BBS_STATUS_FLAGS                  StatusFlags;
  
  ///
  /// Segment:Offset address of boot loader for IPL devices or install INT13 handler for
  /// BCV devices.
  ///
  UINT16                            BootHandlerOffset;
  
  ///
  /// Segment:Offset address of boot loader for IPL devices or install INT13 handler for
  /// BCV devices.
  ///  
  UINT16                            BootHandlerSegment;
  
  ///
  /// Segment:offset address of an ASCIIZ description string describing this device.
  ///
  UINT16                            DescStringOffset;

  ///
  /// Segment:offset address of an ASCIIZ description string describing this device.
  ///
  UINT16                            DescStringSegment;
  
  ///
  /// Reserved.
  ///
  UINT32                            InitPerReserved;
  
  ///
  /// The use of these fields is IBV dependent. They can be used to flag that an OpROM
  /// has hooked the specified IRQ. The OpROM may be BBS compliant as some SCSI
  /// BBS-compliant OpROMs also hook IRQ vectors in order to run their BIOS Setup
  ///
  UINT32                            AdditionalIrq13Handler;
  
  ///
  /// The use of these fields is IBV dependent. They can be used to flag that an OpROM
  /// has hooked the specified IRQ. The OpROM may be BBS compliant as some SCSI
  /// BBS-compliant OpROMs also hook IRQ vectors in order to run their BIOS Setup
  ///  
  UINT32                            AdditionalIrq18Handler;
  
  ///
  /// The use of these fields is IBV dependent. They can be used to flag that an OpROM
  /// has hooked the specified IRQ. The OpROM may be BBS compliant as some SCSI
  /// BBS-compliant OpROMs also hook IRQ vectors in order to run their BIOS Setup
  ///  
  UINT32                            AdditionalIrq19Handler;
  
  ///
  /// The use of these fields is IBV dependent. They can be used to flag that an OpROM
  /// has hooked the specified IRQ. The OpROM may be BBS compliant as some SCSI
  /// BBS-compliant OpROMs also hook IRQ vectors in order to run their BIOS Setup
  ///  
  UINT32                            AdditionalIrq40Handler;
  UINT8                             AssignedDriveNumber;
  UINT32                            AdditionalIrq41Handler;
  UINT32                            AdditionalIrq46Handler;
  UINT32                            IBV1;
  UINT32                            IBV2;
} BBS_TABLE;

///
/// BBS device type values
///@{
#define BBS_FLOPPY              0x01
#define BBS_HARDDISK            0x02
#define BBS_CDROM               0x03
#define BBS_PCMCIA              0x04
#define BBS_USB                 0x05
#define BBS_EMBED_NETWORK       0x06
#define BBS_BEV_DEVICE          0x80
#define BBS_UNKNOWN             0xff
///@}

///
/// BBS boot priority values
///@{
#define BBS_DO_NOT_BOOT_FROM    0xFFFC
#define BBS_LOWEST_PRIORITY     0xFFFD
#define BBS_UNPRIORITIZED_ENTRY 0xFFFE
#define BBS_IGNORE_ENTRY        0xFFFF
///@}

///
/// SMM_ATTRIBUTES
///
typedef struct {
  ///
  /// Access mechanism used to generate the soft SMI. Defined types are below. The other
  /// values are reserved for future usage.
  ///
  UINT16                            Type : 3;
  
  ///
  /// The size of "port" in bits. Defined values are below.
  ///
  UINT16                            PortGranularity : 3;
  
  ///
  /// The size of data in bits. Defined values are below.
  ///
  UINT16                            DataGranularity : 3;
  
  ///
  /// Reserved for future use.
  ///
  UINT16                            Reserved : 7;
} SMM_ATTRIBUTES;

///
/// SMM_ATTRIBUTES type values.
///@{
#define STANDARD_IO       0x00
#define STANDARD_MEMORY   0x01
///@}

///
/// SMM_ATTRIBUTES port size constants.
///@{
#define PORT_SIZE_8       0x00
#define PORT_SIZE_16      0x01
#define PORT_SIZE_32      0x02
#define PORT_SIZE_64      0x03
///@}

///
/// SMM_ATTRIBUTES data size constants.
///@{
#define DATA_SIZE_8       0x00
#define DATA_SIZE_16      0x01
#define DATA_SIZE_32      0x02
#define DATA_SIZE_64      0x03
///@}

///
/// SMM_FUNCTION & relating constants.
///
typedef struct {
  UINT16                            Function : 15;
  UINT16                            Owner : 1;
} SMM_FUNCTION;

///
/// SMM_FUNCTION Function constants.
///@{
#define INT15_D042        0x0000
#define GET_USB_BOOT_INFO 0x0001
#define DMI_PNP_50_57     0x0002
///@}

///
/// SMM_FUNCTION Owner constants.
///@{
#define STANDARD_OWNER    0x0
#define OEM_OWNER         0x1
///@}

///
/// This structure assumes both port and data sizes are 1. SmmAttribute must be
/// properly to reflect that assumption.
///
typedef struct {
  ///
  /// Describes the access mechanism, SmmPort, and SmmData sizes. Type
  /// SMM_ATTRIBUTES is defined below.
  ///
  SMM_ATTRIBUTES                    SmmAttributes;
  
  ///
  /// Function Soft SMI is to perform. Type SMM_FUNCTION is defined below.
  ///
  SMM_FUNCTION                      SmmFunction;
  
  ///
  /// SmmPort size depends upon SmmAttributes and ranges from2 bytes to 16 bytes.
  ///
  UINT8                             SmmPort;
  
  ///
  /// SmmData size depends upon SmmAttributes and ranges from2 bytes to 16 bytes.
  ///
  UINT8                             SmmData;
} SMM_ENTRY;

///
/// SMM_TABLE
///
typedef struct {
  UINT16                            NumSmmEntries;    ///< Number of entries represented by SmmEntry.
  SMM_ENTRY                         SmmEntry;         ///< One entry per function. Type SMM_ENTRY is defined below.
} SMM_TABLE;

///
/// UDC_ATTRIBUTES
///
typedef struct {
  ///
  /// This bit set indicates that the ServiceAreaData is valid.
  ///
  UINT8                             DirectoryServiceValidity : 1;
  
  ///
  /// This bit set indicates to use the Reserve Area Boot Code Address (RACBA) only if
  /// DirectoryServiceValidity is 0.
  ///
  UINT8                             RabcaUsedFlag : 1;
  
  ///
  /// This bit set indicates to execute hard disk diagnostics.
  ///
  UINT8                             ExecuteHddDiagnosticsFlag : 1;
  
  ///
  /// Reserved for future use. Set to 0.
  ///
  UINT8                             Reserved : 5;
} UDC_ATTRIBUTES;

///
/// UD_TABLE
///
typedef struct {
  ///
  /// This field contains the bit-mapped attributes of the PARTIES information. Type
  /// UDC_ATTRIBUTES is defined below.
  ///
  UDC_ATTRIBUTES                    Attributes;
  
  ///
  /// This field contains the zero-based device on which the selected
  /// ServiceDataArea is present. It is 0 for master and 1 for the slave device.  
  ///
  UINT8                             DeviceNumber;
  
  ///
  /// This field contains the zero-based index into the BbsTable for the parent device.
  /// This index allows the user to reference the parent device information such as PCI
  /// bus, device function.
  ///
  UINT8                             BbsTableEntryNumberForParentDevice;
  
  ///
  /// This field contains the zero-based index into the BbsTable for the boot entry.
  ///
  UINT8                             BbsTableEntryNumberForBoot;
  
  ///
  /// This field contains the zero-based index into the BbsTable for the HDD diagnostics entry.
  ///
  UINT8                             BbsTableEntryNumberForHddDiag;
  
  ///
  /// The raw Beer data.
  ///
  UINT8                             BeerData[128];
  
  ///
  /// The raw data of selected service area.
  ///
  UINT8                             ServiceAreaData[64];
} UD_TABLE;

#define EFI_TO_LEGACY_MAJOR_VERSION 0x02
#define EFI_TO_LEGACY_MINOR_VERSION 0x00
#define MAX_IDE_CONTROLLER          8

///
/// EFI_TO_COMPATIBILITY16_BOOT_TABLE
///
typedef struct {
  UINT16                            MajorVersion;                 ///< The EfiCompatibility major version number.
  UINT16                            MinorVersion;                 ///< The EfiCompatibility minor version number.
  UINT32                            AcpiTable;                    ///< The location of the RSDT ACPI table. < 4G range.
  UINT32                            SmbiosTable;                  ///< The location of the SMBIOS table in EFI memory. < 4G range.
  UINT32                            SmbiosTableLength;
  //
  // Legacy SIO state
  //
  DEVICE_PRODUCER_DATA_HEADER       SioData;                      ///< Standard traditional device information.
  UINT16                            DevicePathType;               ///< The default boot type.
  UINT16                            PciIrqMask;                   ///< Mask of which IRQs have been assigned to PCI.
  UINT32                            NumberE820Entries;            ///< Number of E820 entries. The number can change from the
                                                                  ///< Compatibility16InitializeYourself() function.
  //
  // Controller & Drive Identify[2] per controller information
  //
  HDD_INFO                          HddInfo[MAX_IDE_CONTROLLER];  ///< Hard disk drive information, including raw Identify Drive data.
  UINT32                            NumberBbsEntries;             ///< Number of entries in the BBS table
  UINT32                            BbsTable;                     ///< A pointer to the BBS table. Type BBS_TABLE is defined below.
  UINT32                            SmmTable;                     ///< A pointer to the SMM table. Type SMM_TABLE is defined below.
  UINT32                            OsMemoryAbove1Mb;             ///< The amount of usable memory above 1 MB, i.e. E820 type 1 memory. This value can
                                                                  ///< differ from the value in EFI_TO_COMPATIBILITY16_INIT_TABLE as more
                                                                  ///< memory may have been discovered.
  UINT32                            UnconventionalDeviceTable;    ///< Information to boot off an unconventional device like a PARTIES partition. Type
                                                                  ///< UD_TABLE is defined below.
} EFI_TO_COMPATIBILITY16_BOOT_TABLE;

///
/// EFI_LEGACY_INSTALL_PCI_HANDLER
///
typedef struct {
  UINT8                             PciBus;             ///< The PCI bus of the device.
  UINT8                             PciDeviceFun;       ///< The PCI device in bits 7:3 and function in bits 2:0.
  UINT8                             PciSegment;         ///< The PCI segment of the device.
  UINT8                             PciClass;           ///< The PCI class code of the device.
  UINT8                             PciSubclass;        ///< The PCI subclass code of the device.
  UINT8                             PciInterface;       ///< The PCI interface code of the device.
  //
  // Primary section
  //
  UINT8                             PrimaryIrq;         ///< The primary device IRQ.
  UINT8                             PrimaryReserved;    ///< Reserved.
  UINT16                            PrimaryControl;     ///< The primary device control I/O base.
  UINT16                            PrimaryBase;        ///< The primary device I/O base.
  UINT16                            PrimaryBusMaster;   ///< The primary device bus master I/O base.
  //
  // Secondary Section
  //
  UINT8                             SecondaryIrq;       ///< The secondary device IRQ.
  UINT8                             SecondaryReserved;  ///< Reserved.
  UINT16                            SecondaryControl;   ///< The secondary device control I/O base.
  UINT16                            SecondaryBase;      ///< The secondary device I/O base.
  UINT16                            SecondaryBusMaster; ///< The secondary device bus master I/O base.
} EFI_LEGACY_INSTALL_PCI_HANDLER;

//
// Restore default pack value
//
#pragma pack()

#define EFI_LEGACY_BIOS_PROTOCOL_GUID \
  { \
    0xdb9a1e3d, 0x45cb, 0x4abb, {0x85, 0x3b, 0xe5, 0x38, 0x7f, 0xdb, 0x2e, 0x2d } \
  }

typedef struct _EFI_LEGACY_BIOS_PROTOCOL EFI_LEGACY_BIOS_PROTOCOL;

///
/// Flags returned by CheckPciRom().
///
#define NO_ROM            0x00
#define ROM_FOUND         0x01
#define VALID_LEGACY_ROM  0x02
#define ROM_WITH_CONFIG   0x04     ///< Not defined in the Framework CSM Specification.

///
/// The following macros do not appear in the Framework CSM Specification and 
/// are kept for backward compatibility only.  They convert 32-bit address (_Adr) 
/// to Segment:Offset 16-bit form.
///
///@{
#define EFI_SEGMENT(_Adr)     (UINT16) ((UINT16) (((UINTN) (_Adr)) >> 4) & 0xf000)
#define EFI_OFFSET(_Adr)      (UINT16) (((UINT16) ((UINTN) (_Adr))) & 0xffff)
///@}

#define CARRY_FLAG            0x01

///
/// EFI_EFLAGS_REG
///
typedef struct {
  UINT32 CF:1;
  UINT32 Reserved1:1;
  UINT32 PF:1;
  UINT32 Reserved2:1;
  UINT32 AF:1;
  UINT32 Reserved3:1;
  UINT32 ZF:1;
  UINT32 SF:1;
  UINT32 TF:1;
  UINT32 IF:1;
  UINT32 DF:1;
  UINT32 OF:1;
  UINT32 IOPL:2;
  UINT32 NT:1;
  UINT32 Reserved4:2;
  UINT32 VM:1;
  UINT32 Reserved5:14;
} EFI_EFLAGS_REG;

///
/// EFI_DWORD_REGS
///
typedef struct {
    UINT32           EAX;
    UINT32           EBX;
    UINT32           ECX;
    UINT32           EDX;
    UINT32           ESI;
    UINT32           EDI;
    EFI_EFLAGS_REG   EFlags;
    UINT16           ES;
    UINT16           CS;
    UINT16           SS;
    UINT16           DS;
    UINT16           FS;
    UINT16           GS;
    UINT32           EBP;
    UINT32           ESP;
} EFI_DWORD_REGS;

///
/// EFI_FLAGS_REG
///
typedef struct {
  UINT16     CF:1;
  UINT16     Reserved1:1;
  UINT16     PF:1;
  UINT16     Reserved2:1;
  UINT16     AF:1;
  UINT16     Reserved3:1;
  UINT16     ZF:1;
  UINT16     SF:1;
  UINT16     TF:1;
  UINT16     IF:1;
  UINT16     DF:1;
  UINT16     OF:1;
  UINT16     IOPL:2;
  UINT16     NT:1;
  UINT16     Reserved4:1;
} EFI_FLAGS_REG;

///
/// EFI_WORD_REGS
///
typedef struct {
    UINT16           AX;
    UINT16           ReservedAX;
    UINT16           BX;
    UINT16           ReservedBX;
    UINT16           CX;
    UINT16           ReservedCX;
    UINT16           DX;
    UINT16           ReservedDX;
    UINT16           SI;
    UINT16           ReservedSI;
    UINT16           DI;
    UINT16           ReservedDI;
    EFI_FLAGS_REG    Flags;
    UINT16           ReservedFlags;
    UINT16           ES;
    UINT16           CS;
    UINT16           SS;
    UINT16           DS;
    UINT16           FS;
    UINT16           GS;
    UINT16           BP;
    UINT16           ReservedBP;
    UINT16           SP;
    UINT16           ReservedSP;
} EFI_WORD_REGS;

///
/// EFI_BYTE_REGS
///
typedef struct {
    UINT8   AL, AH;
    UINT16  ReservedAX;
    UINT8   BL, BH;
    UINT16  ReservedBX;
    UINT8   CL, CH;
    UINT16  ReservedCX;
    UINT8   DL, DH;
    UINT16  ReservedDX;
} EFI_BYTE_REGS;

///
/// EFI_IA32_REGISTER_SET
///
typedef union {
  EFI_DWORD_REGS  E;
  EFI_WORD_REGS   X;
  EFI_BYTE_REGS   H;
} EFI_IA32_REGISTER_SET;

/**
  Thunk to 16-bit real mode and execute a software interrupt with a vector
  of BiosInt. Regs will contain the 16-bit register context on entry and
  exit.

  @param[in]     This      The protocol instance pointer.
  @param[in]     BiosInt   The processor interrupt vector to invoke.
  @param[in,out] Reg       Register contexted passed into (and returned) from thunk to
                           16-bit mode.

  @retval TRUE                Thunk completed with no BIOS errors in the target code. See Regs for status.  
  @retval FALSE                  There was a BIOS error in the target code.
**/
typedef
BOOLEAN
(EFIAPI *EFI_LEGACY_BIOS_INT86)(
  IN     EFI_LEGACY_BIOS_PROTOCOL  *This,
  IN     UINT8                     BiosInt,
  IN OUT EFI_IA32_REGISTER_SET     *Regs
  );

/**
  Thunk to 16-bit real mode and call Segment:Offset. Regs will contain the
  16-bit register context on entry and exit. Arguments can be passed on
  the Stack argument

  @param[in] This        The protocol instance pointer.
  @param[in] Segment     The segemnt of 16-bit mode call.
  @param[in] Offset      The offset of 16-bit mdoe call.
  @param[in] Reg         Register contexted passed into (and returned) from thunk to
                         16-bit mode.
  @param[in] Stack       The caller allocated stack used to pass arguments.
  @param[in] StackSize   The size of Stack in bytes.

  @retval FALSE                 Thunk completed with no BIOS errors in the target code.                                See Regs for status.  @retval TRUE                  There was a BIOS error in the target code.
**/
typedef
BOOLEAN
(EFIAPI *EFI_LEGACY_BIOS_FARCALL86)(
  IN EFI_LEGACY_BIOS_PROTOCOL  *This,
  IN UINT16                    Segment,
  IN UINT16                    Offset,
  IN EFI_IA32_REGISTER_SET     *Regs,
  IN VOID                      *Stack,
  IN UINTN                     StackSize
  );

/**
  Test to see if a legacy PCI ROM exists for this device. Optionally return
  the Legacy ROM instance for this PCI device.

  @param[in]  This        The protocol instance pointer.
  @param[in]  PciHandle   The PCI PC-AT OPROM from this devices ROM BAR will be loaded
  @param[out] RomImage    Return the legacy PCI ROM for this device.
  @param[out] RomSize     The size of ROM Image.
  @param[out] Flags       Indicates if ROM found and if PC-AT. Multiple bits can be set as follows:
                            - 00 = No ROM.
                            - 01 = ROM Found.
                            - 02 = ROM is a valid legacy ROM.

  @retval EFI_SUCCESS       The Legacy Option ROM availible for this device
  @retval EFI_UNSUPPORTED   The Legacy Option ROM is not supported.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_CHECK_ROM)(
  IN  EFI_LEGACY_BIOS_PROTOCOL  *This,
  IN  EFI_HANDLE                PciHandle,
  OUT VOID                      **RomImage, OPTIONAL
  OUT UINTN                     *RomSize, OPTIONAL
  OUT UINTN                     *Flags
  );

/**
  Load a legacy PC-AT OPROM on the PciHandle device. Return information
  about how many disks were added by the OPROM and the shadow address and
  size. DiskStart & DiskEnd are INT 13h drive letters. Thus 0x80 is C:

  @param[in]  This               The protocol instance pointer.
  @param[in]  PciHandle          The PCI PC-AT OPROM from this devices ROM BAR will be loaded.
                                 This value is NULL if RomImage is non-NULL. This is the normal
                                 case.
  @param[in]  RomImage           A PCI PC-AT ROM image. This argument is non-NULL if there is
                                 no hardware associated with the ROM and thus no PciHandle,
                                 otherwise is must be NULL.
                                 Example is PXE base code.
  @param[out] Flags              The type of ROM discovered. Multiple bits can be set, as follows:
                                   - 00 = No ROM.
                                   - 01 = ROM found.
                                   - 02 = ROM is a valid legacy ROM.
  @param[out] DiskStart          The disk number of first device hooked by the ROM. If DiskStart
                                 is the same as DiskEnd no disked were hooked.
  @param[out] DiskEnd            disk number of the last device hooked by the ROM.
  @param[out] RomShadowAddress   Shadow address of PC-AT ROM.
  @param[out] RomShadowSize      Size of RomShadowAddress in bytes.

  @retval EFI_SUCCESS             Thunk completed, see Regs for status.
  @retval EFI_INVALID_PARAMETER   PciHandle not found

**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_INSTALL_ROM)(
  IN  EFI_LEGACY_BIOS_PROTOCOL  *This,
  IN  EFI_HANDLE                PciHandle,
  IN  VOID                      **RomImage,
  OUT UINTN                     *Flags,
  OUT UINT8                     *DiskStart, OPTIONAL
  OUT UINT8                     *DiskEnd, OPTIONAL
  OUT VOID                      **RomShadowAddress, OPTIONAL
  OUT UINT32                    *ShadowedRomSize OPTIONAL
  );

/**
  This function attempts to traditionally boot the specified BootOption. If the EFI context has
  been compromised, this function will not return. This procedure is not used for loading an EFI-aware
  OS off a traditional device. The following actions occur:
  - Get EFI SMBIOS data structures, convert them to a traditional format, and copy to
    Compatibility16.
  - Get a pointer to ACPI data structures and copy the Compatibility16 RSD PTR to F0000 block.
  - Find the traditional SMI handler from a firmware volume and register the traditional SMI
    handler with the EFI SMI handler.
  - Build onboard IDE information and pass this information to the Compatibility16 code.
  - Make sure all PCI Interrupt Line registers are programmed to match 8259.
  - Reconfigure SIO devices from EFI mode (polled) into traditional mode (interrupt driven).
  - Shadow all PCI ROMs.
  - Set up BDA and EBDA standard areas before the legacy boot.
  - Construct the Compatibility16 boot memory map and pass it to the Compatibility16 code.
  - Invoke the Compatibility16 table function Compatibility16PrepareToBoot(). This
    invocation causes a thunk into the Compatibility16 code, which sets all appropriate internal
    data structures. The boot device list is a parameter.
  - Invoke the Compatibility16 Table function Compatibility16Boot(). This invocation
    causes a thunk into the Compatibility16 code, which does an INT19.
  - If the Compatibility16Boot() function returns, then the boot failed in a graceful
    manner--meaning that the EFI code is still valid. An ungraceful boot failure causes a reset because the state
    of EFI code is unknown.

  @param[in] This             The protocol instance pointer.
  @param[in] BootOption       The EFI Device Path from BootXXXX variable.
  @param[in] LoadOptionSize   The size of LoadOption in size.
  @param[in] LoadOption       LThe oadOption from BootXXXX variable.

  @retval EFI_DEVICE_ERROR      Failed to boot from any boot device and memory is uncorrupted.                                Note: This function normally does not returns. It will either boot the                                OS or reset the system if memory has been "corrupted" by loading                                a boot sector and passing control to it.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_BOOT)(
  IN EFI_LEGACY_BIOS_PROTOCOL  *This,
  IN BBS_BBS_DEVICE_PATH       *BootOption,
  IN UINT32                    LoadOptionsSize,
  IN VOID                      *LoadOptions
  );

/**
  This function takes the Leds input parameter and sets/resets the BDA accordingly. 
  Leds is also passed to Compatibility16 code, in case any special processing is required. 
  This function is normally called from EFI Setup drivers that handle user-selectable
  keyboard options such as boot with NUM LOCK on/off. This function does not
  touch the keyboard or keyboard LEDs but only the BDA.

  @param[in] This   The protocol instance pointer.
  @param[in] Leds   The status of current Scroll, Num & Cap lock LEDS:
                      - Bit 0 is Scroll Lock 0 = Not locked.
                      - Bit 1 is Num Lock.
                      - Bit 2 is Caps Lock.

  @retval EFI_SUCCESS   The BDA was updated successfully.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_UPDATE_KEYBOARD_LED_STATUS)(
  IN EFI_LEGACY_BIOS_PROTOCOL  *This,
  IN UINT8                     Leds
  );

/**
  Retrieve legacy BBS info and assign boot priority.

  @param[in]     This       The protocol instance pointer.
  @param[out]    HddCount   The number of HDD_INFO structures.
  @param[out]    HddInfo    Onboard IDE controller information.
  @param[out]    BbsCount   The number of BBS_TABLE structures.
  @param[in,out] BbsTable   Points to List of BBS_TABLE.

  @retval EFI_SUCCESS   Tables were returned.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_GET_BBS_INFO)(
  IN     EFI_LEGACY_BIOS_PROTOCOL  *This,
  OUT    UINT16                    *HddCount,
  OUT    HDD_INFO                  **HddInfo,
  OUT    UINT16                    *BbsCount,
  IN OUT BBS_TABLE                 **BbsTable
  );

/**
  Assign drive number to legacy HDD drives prior to booting an EFI
  aware OS so the OS can access drives without an EFI driver.

  @param[in]  This       The protocol instance pointer.
  @param[out] BbsCount   The number of BBS_TABLE structures
  @param[out] BbsTable   List of BBS entries

  @retval EFI_SUCCESS   Drive numbers assigned.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_PREPARE_TO_BOOT_EFI)(
  IN  EFI_LEGACY_BIOS_PROTOCOL  *This,
  OUT UINT16                    *BbsCount,
  OUT BBS_TABLE                 **BbsTable
  );

/**
  To boot from an unconventional device like parties and/or execute
  HDD diagnostics.

  @param[in]  This              The protocol instance pointer.
  @param[in]  Attributes        How to interpret the other input parameters.
  @param[in]  BbsEntry          The 0-based index into the BbsTable for the parent
                                device.
  @param[in]  BeerData          A pointer to the 128 bytes of ram BEER data.
  @param[in]  ServiceAreaData   A pointer to the 64 bytes of raw Service Area data. The
                                caller must provide a pointer to the specific Service
                                Area and not the start all Service Areas.

  @retval EFI_INVALID_PARAMETER   If error. Does NOT return if no error.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_BOOT_UNCONVENTIONAL_DEVICE)(
  IN EFI_LEGACY_BIOS_PROTOCOL  *This,
  IN UDC_ATTRIBUTES            Attributes,
  IN UINTN                     BbsEntry,
  IN VOID                      *BeerData,
  IN VOID                      *ServiceAreaData
  );

/**
  Shadow all legacy16 OPROMs that haven't been shadowed.
  Warning: Use this with caution. This routine disconnects all EFI
  drivers. If used externally, then  the caller must re-connect EFI
  drivers.
  
  @param[in]  This   The protocol instance pointer.
  
  @retval EFI_SUCCESS   OPROMs were shadowed.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_SHADOW_ALL_LEGACY_OPROMS)(
  IN EFI_LEGACY_BIOS_PROTOCOL  *This
  );

/**
  Get a region from the LegacyBios for S3 usage.

  @param[in]  This                  The protocol instance pointer.
  @param[in]  LegacyMemorySize      The size of required region.
  @param[in]  Region                The region to use.
                                    00 = Either 0xE0000 or 0xF0000 block.
                                      - Bit0 = 1 0xF0000 block.
                                      - Bit1 = 1 0xE0000 block.
  @param[in]  Alignment             Address alignment. Bit mapped. The first non-zero
                                    bit from right is alignment.
  @param[out] LegacyMemoryAddress   The Region Assigned

  @retval EFI_SUCCESS           The Region was assigned.
  @retval EFI_ACCESS_DENIED     The function was previously invoked.
  @retval Other                 The Region was not assigned.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_GET_LEGACY_REGION)(
  IN  EFI_LEGACY_BIOS_PROTOCOL  *This,
  IN  UINTN                     LegacyMemorySize,
  IN  UINTN                     Region,
  IN  UINTN                     Alignment,
  OUT VOID                      **LegacyMemoryAddress
  );

/**
  Get a region from the LegacyBios for Tiano usage. Can only be invoked once.

  @param[in]  This                        The protocol instance pointer.
  @param[in]  LegacyMemorySize            The size of data to copy.
  @param[in]  LegacyMemoryAddress         The Legacy Region destination address.
                                          Note: must be in region assigned by
                                          LegacyBiosGetLegacyRegion.
  @param[in]  LegacyMemorySourceAddress   The source of the data to copy.

  @retval EFI_SUCCESS           The Region assigned.
  @retval EFI_ACCESS_DENIED     Destination was outside an assigned region.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_COPY_LEGACY_REGION)(
  IN EFI_LEGACY_BIOS_PROTOCOL  *This,
  IN UINTN                     LegacyMemorySize,
  IN VOID                      *LegacyMemoryAddress,
  IN VOID                      *LegacyMemorySourceAddress
  );

///
/// Abstracts the traditional BIOS from the rest of EFI. The LegacyBoot()
/// member function allows the BDS to support booting a traditional OS.
/// EFI thunks drivers that make EFI bindings for BIOS INT services use
/// all the other member functions.
///
struct _EFI_LEGACY_BIOS_PROTOCOL {
  ///
  /// Performs traditional software INT. See the Int86() function description.
  ///
  EFI_LEGACY_BIOS_INT86                       Int86;
  
  ///
  /// Performs a far call into Compatibility16 or traditional OpROM code.
  ///
  EFI_LEGACY_BIOS_FARCALL86                   FarCall86;
  
  ///
  /// Checks if a traditional OpROM exists for this device.
  ///
  EFI_LEGACY_BIOS_CHECK_ROM                   CheckPciRom;
  
  ///
  /// Loads a traditional OpROM in traditional OpROM address space.
  ///
  EFI_LEGACY_BIOS_INSTALL_ROM                 InstallPciRom;
  
  ///
  /// Boots a traditional OS.
  ///
  EFI_LEGACY_BIOS_BOOT                        LegacyBoot;
  
  ///
  /// Updates BDA to reflect the current EFI keyboard LED status.
  ///
  EFI_LEGACY_BIOS_UPDATE_KEYBOARD_LED_STATUS  UpdateKeyboardLedStatus;
  
  ///
  /// Allows an external agent, such as BIOS Setup, to get the BBS data.
  ///
  EFI_LEGACY_BIOS_GET_BBS_INFO                GetBbsInfo;
  
  ///
  /// Causes all legacy OpROMs to be shadowed.
  ///
  EFI_LEGACY_BIOS_SHADOW_ALL_LEGACY_OPROMS    ShadowAllLegacyOproms;
  
  ///
  /// Performs all actions prior to boot. Used when booting an EFI-aware OS
  /// rather than a legacy OS.  
  ///
  EFI_LEGACY_BIOS_PREPARE_TO_BOOT_EFI         PrepareToBootEfi;
  
  ///
  /// Allows EFI to reserve an area in the 0xE0000 or 0xF0000 block.
  ///
  EFI_LEGACY_BIOS_GET_LEGACY_REGION           GetLegacyRegion;
  
  ///
  /// Allows EFI to copy data to the area specified by GetLegacyRegion.
  ///
  EFI_LEGACY_BIOS_COPY_LEGACY_REGION          CopyLegacyRegion;
  
  ///
  /// Allows the user to boot off an unconventional device such as a PARTIES partition.
  ///
  EFI_LEGACY_BIOS_BOOT_UNCONVENTIONAL_DEVICE  BootUnconventionalDevice;
};

extern EFI_GUID gEfiLegacyBiosProtocolGuid;

#endif