OvmfPkg: Replace BSD License with BSD+Patent License

[mirror_edk2.git] / OvmfPkg / Library / LoadLinuxLib / LinuxGdt.c

/** @file\r
  Initialize GDT for Linux.\r
\r
  Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "LoadLinuxLib.h"\r
\r
\r
//\r
// Local structure definitions\r
//\r
\r
#pragma pack (1)\r
\r
//\r
// Global Descriptor Entry structures\r
//\r
\r
typedef struct _GDT_ENTRY {\r
  UINT16 Limit15_0;\r
  UINT16 Base15_0;\r
  UINT8  Base23_16;\r
  UINT8  Type;\r
  UINT8  Limit19_16_and_flags;\r
  UINT8  Base31_24;\r
} GDT_ENTRY;\r
\r
typedef\r
struct _GDT_ENTRIES {\r
  GDT_ENTRY Null;\r
  GDT_ENTRY Null2;\r
  GDT_ENTRY Linear;\r
  GDT_ENTRY LinearCode;\r
  GDT_ENTRY TaskSegment;\r
  GDT_ENTRY Spare4;\r
  GDT_ENTRY Spare5;\r
} GDT_ENTRIES;\r
\r
#pragma pack ()\r
\r
STATIC GDT_ENTRIES *mGdt = NULL;\r
\r
//\r
// Global descriptor table (GDT) Template\r
//\r
STATIC GDT_ENTRIES GdtTemplate = {\r
  //\r
  // Null\r
  //\r
  {\r
    0x0,            // limit 15:0\r
    0x0,            // base 15:0\r
    0x0,            // base 23:16\r
    0x0,            // type\r
    0x0,            // limit 19:16, flags\r
    0x0,            // base 31:24\r
  },\r
  //\r
  // Null2\r
  //\r
  {\r
    0x0,            // limit 15:0\r
    0x0,            // base 15:0\r
    0x0,            // base 23:16\r
    0x0,            // type\r
    0x0,            // limit 19:16, flags\r
    0x0,            // base 31:24\r
  },\r
  //\r
  // Linear\r
  //\r
  {\r
    0x0FFFF,        // limit 0xFFFFF\r
    0x0,            // base 0\r
    0x0,\r
    0x09A,          // present, ring 0, data, expand-up, writable\r
    0x0CF,          // page-granular, 32-bit\r
    0x0,\r
  },\r
  //\r
  // LinearCode\r
  //\r
  {\r
    0x0FFFF,        // limit 0xFFFFF\r
    0x0,            // base 0\r
    0x0,\r
    0x092,          // present, ring 0, data, expand-up, writable\r
    0x0CF,          // page-granular, 32-bit\r
    0x0,\r
  },\r
  //\r
  // TaskSegment\r
  //\r
  {\r
    0x0,            // limit 0\r
    0x0,            // base 0\r
    0x0,\r
    0x089,          // ?\r
    0x080,          // ?\r
    0x0,\r
  },\r
  //\r
  // Spare4\r
  //\r
  {\r
    0x0,            // limit 0\r
    0x0,            // base 0\r
    0x0,\r
    0x0,            // present, ring 0, data, expand-up, writable\r
    0x0,            // page-granular, 32-bit\r
    0x0,\r
  },\r
  //\r
  // Spare5\r
  //\r
  {\r
    0x0,            // limit 0\r
    0x0,            // base 0\r
    0x0,\r
    0x0,            // present, ring 0, data, expand-up, writable\r
    0x0,            // page-granular, 32-bit\r
    0x0,\r
  },\r
};\r
\r
/**\r
  Initialize Global Descriptor Table.\r
\r
**/\r
VOID\r
InitLinuxDescriptorTables (\r
  VOID\r
  )\r
{\r
  //\r
  // Allocate Runtime Data for the GDT\r
  //\r
  mGdt = AllocateRuntimePool (sizeof (GdtTemplate) + 8);\r
  ASSERT (mGdt != NULL);\r
  mGdt = ALIGN_POINTER (mGdt, 8);\r
\r
  //\r
  // Initialize all GDT entries\r
  //\r
  CopyMem (mGdt, &GdtTemplate, sizeof (GdtTemplate));\r
\r
}\r
\r
/**\r
  Initialize Global Descriptor Table.\r
\r
**/\r
VOID\r
SetLinuxDescriptorTables (\r
  VOID\r
  )\r
{\r
  IA32_DESCRIPTOR GdtPtr;\r
  IA32_DESCRIPTOR IdtPtr;\r
\r
  //\r
  // Write GDT register\r
  //\r
  GdtPtr.Base = (UINT32)(UINTN)(VOID*) mGdt;\r
  GdtPtr.Limit = (UINT16) (sizeof (GdtTemplate) - 1);\r
  AsmWriteGdtr (&GdtPtr);\r
\r
  IdtPtr.Base = (UINT32) 0;\r
  IdtPtr.Limit = (UINT16) 0;\r
  AsmWriteIdtr (&IdtPtr);\r
}\r
\r