1 files changed, 66 insertions, 0 deletions
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c
new file mode 100644
index 0000000..c45d5d4
--- /dev/null
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c
@@ -0,0 +1,66 @@
+/** @file
+  This code fills in BDA (0x400) and EBDA (pointed to by 0x4xx)
+  information. There is support for doing initializeation before
+  Legacy16 is loaded and before a legacy boot is attempted.
+
+Copyright (c) 2006 - 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 which 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.
+
+**/
+
+#include "LegacyBiosInterface.h"
+
+/**
+  Fill in the standard BDA and EBDA stuff before Legacy16 load
+
+  @param  Private     Legacy BIOS Instance data
+
+  @retval EFI_SUCCESS It should always work.
+
+**/
+EFI_STATUS
+LegacyBiosInitBda (
+  IN  LEGACY_BIOS_INSTANCE    *Private
+  )
+{
+  BDA_STRUC *Bda;
+  UINT8     *Ebda;
+
+  Bda   = (BDA_STRUC *) ((UINTN) 0x400);
+  Ebda  = (UINT8 *) ((UINTN) 0x9fc00);
+
+  ZeroMem (Bda, 0x100);
+  ZeroMem (Ebda, 0x400);
+  //
+  // 640k-1k for EBDA
+  //
+  Bda->MemSize        = 0x27f;
+  Bda->KeyHead        = 0x1e;
+  Bda->KeyTail        = 0x1e;
+  Bda->FloppyData     = 0x00;
+  Bda->FloppyTimeout  = 0xff;
+
+  Bda->KeyStart       = 0x001E;
+  Bda->KeyEnd         = 0x003E;
+  Bda->KeyboardStatus = 0x10;
+  Bda->Ebda           = 0x9fc0;
+
+  //
+  // Move LPT time out here and zero out LPT4 since some SCSI OPROMS
+  // use this as scratch pad (LPT4 is Reserved)
+  //
+  Bda->Lpt1_2Timeout  = 0x1414;
+  Bda->Lpt3_4Timeout  = 0x1400;
+
+  *Ebda               = 0x01;
+
+  return EFI_SUCCESS;
+}