projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| 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 | |
| 2ea3576e JW |
40 | ACCESS_PAGE0_CODE (\r |
| 41 | ZeroMem (Bda, 0x100);\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 | );\r | |
| 64 | \r | |
| bcecde14 | 65 | ZeroMem (Ebda, 0x400);\r |
| 2ea3576e | 66 | *Ebda = 0x01;\r |
| d057d8c4 | 67 | \r |
| bcecde14 | 68 | return EFI_SUCCESS;\r |
| 69 | }\r |