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bcecde14 | 1 | /** @file\r |
2 | This code fills in BDA (0x400) and EBDA (pointed to by 0x4xx)\r | |
3 | information. There is support for doing initializeation before\r | |
4 | Legacy16 is loaded and before a legacy boot is attempted.\r | |
5 | \r | |
6 | Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>\r | |
7 | \r | |
8 | This program and the accompanying materials\r | |
9 | are licensed and made available under the terms and conditions\r | |
10 | of the BSD License which accompanies this distribution. The\r | |
11 | full text of the license may be found at\r | |
12 | http://opensource.org/licenses/bsd-license.php\r | |
13 | \r | |
14 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
15 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
16 | \r | |
17 | **/\r | |
18 | \r | |
19 | #include "LegacyBiosInterface.h"\r | |
20 | \r | |
21 | /**\r | |
22 | Fill in the standard BDA and EBDA stuff before Legacy16 load\r | |
23 | \r | |
24 | @param Private Legacy BIOS Instance data\r | |
25 | \r | |
26 | @retval EFI_SUCCESS It should always work.\r | |
27 | \r | |
28 | **/\r | |
29 | EFI_STATUS\r | |
30 | LegacyBiosInitBda (\r | |
31 | IN LEGACY_BIOS_INSTANCE *Private\r | |
32 | )\r | |
33 | {\r | |
34 | BDA_STRUC *Bda;\r | |
35 | UINT8 *Ebda;\r | |
36 | \r | |
37 | Bda = (BDA_STRUC *) ((UINTN) 0x400);\r | |
38 | Ebda = (UINT8 *) ((UINTN) 0x9fc00);\r | |
39 | \r | |
40 | ZeroMem (Bda, 0x100);\r | |
41 | ZeroMem (Ebda, 0x400);\r | |
42 | //\r | |
43 | // 640k-1k for EBDA\r | |
44 | //\r | |
45 | Bda->MemSize = 0x27f;\r | |
46 | Bda->KeyHead = 0x1e;\r | |
47 | Bda->KeyTail = 0x1e;\r | |
48 | Bda->FloppyData = 0x00;\r | |
49 | Bda->FloppyTimeout = 0xff;\r | |
50 | \r | |
51 | Bda->KeyStart = 0x001E;\r | |
52 | Bda->KeyEnd = 0x003E;\r | |
53 | Bda->KeyboardStatus = 0x10;\r | |
54 | Bda->Ebda = 0x9fc0;\r | |
55 | \r | |
56 | //\r | |
57 | // Move LPT time out here and zero out LPT4 since some SCSI OPROMS\r | |
58 | // use this as scratch pad (LPT4 is Reserved)\r | |
59 | //\r | |
60 | Bda->Lpt1_2Timeout = 0x1414;\r | |
61 | Bda->Lpt3_4Timeout = 0x1400;\r | |
62 | \r | |
63 | *Ebda = 0x01;\r | |
64 | \r | |
65 | return EFI_SUCCESS;\r | |
66 | }\r |