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Updated BaseLib for THUNK functions and some CPU functions

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git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@158 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
bxing
2006-05-15 11:14:20 +00:00
parent 7c28d0e095
commit 97d92bdaf0
9 changed files with 664 additions and 256 deletions
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153
MdePkg/Library/BaseLib/x86Thunk.c
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@@ -14,6 +14,35 @@
**/
//
// Byte packed structure for a segment descriptor in a GDT/LDT
//
typedef union {
struct {
UINT32 LimitLow:16;
UINT32 BaseLow:16;
UINT32 BaseMid:8;
UINT32 Type:4;
UINT32 S:1;
UINT32 DPL:2;
UINT32 P:1;
UINT32 LimitHigh:4;
UINT32 AVL:1;
UINT32 L:1;
UINT32 DB:1;
UINT32 G:1;
UINT32 BaseHigh:8;
} Bits;
UINT64 Uint64;
} IA32_SEGMENT_DESCRIPTOR;
extern CONST UINT8 m16Start;
extern CONST UINT16 m16Size;
extern CONST UINT16 mThunk16Attr;
extern CONST UINT16 m16Gdt;
extern CONST UINT16 m16GdtrBase;
extern CONST UINT16 mTransition;
/**
Invokes 16-bit code in big real mode and returns the updated register set.
@@ -22,7 +51,7 @@
on the real mode stack and the starting address of the save area is returned.
@param RegisterSet Values of registers before invocation of 16-bit code.
@param Patch Pointer to the area following the 16-bit code.
@param Transition Pointer to the transition code under 1MB.
@return The pointer to a IA32_REGISTER_SET structure containing the updated
register values.
@@ -31,9 +60,44 @@
IA32_REGISTER_SET *
InternalAsmThunk16 (
IN IA32_REGISTER_SET *RegisterSet,
IN OUT VOID *Patch
IN OUT VOID *Transition
);
/**
Retrieves the properties for 16-bit thunk functions.
Computes the size of the buffer and stack below 1MB required to use the
AsmPrepareThunk16(), AsmThunk16() and AsmPrepareAndThunk16() functions. This
buffer size is returned in RealModeBufferSize, and the stack size is returned
in ExtraStackSize. If parameters are passed to the 16-bit real mode code,
then the actual minimum stack size is ExtraStackSize plus the maximum number
of bytes that need to be passed to the 16-bit real mode code.
If RealModeBufferSize is NULL, then ASSERT().
If ExtraStackSize is NULL, then ASSERT().
@param RealModeBufferSize A pointer to the size of the buffer below 1MB
required to use the 16-bit thunk functions.
@param ExtraStackSize A pointer to the extra size of stack below 1MB
that the 16-bit thunk functions require for
temporary storage in the transition to and from
16-bit real mode.
**/
VOID
EFIAPI
AsmGetThunk16Properties (
OUT UINT32 *RealModeBufferSize,
OUT UINT32 *ExtraStackSize
)
{
ASSERT (RealModeBufferSize != NULL);
ASSERT (ExtraStackSize != NULL);
*RealModeBufferSize = m16Size;
*ExtraStackSize = sizeof (IA32_DWORD_REGS) + 8;
}
/**
Prepares all structures a code required to use AsmThunk16().
@@ -51,7 +115,64 @@ AsmPrepareThunk16 (
OUT THUNK_CONTEXT *ThunkContext
)
{
IA32_SEGMENT_DESCRIPTOR *RealModeGdt;
ASSERT (ThunkContext != NULL);
ASSERT ((UINTN)ThunkContext->RealModeBuffer < 0x100000);
ASSERT (ThunkContext->RealModeBufferSize >= m16Size);
ASSERT ((UINTN)ThunkContext->RealModeBuffer + m16Size <= 0x100000);
ASSERT (((UINTN)ThunkContext->RealModeBuffer & 0x0f) == 0);
CopyMem (ThunkContext->RealModeBuffer, &m16Start, m16Size);
//
// Point RealModeGdt to the GDT to be used in transition
//
// RealModeGdt[0]: Reserved as NULL descriptor
// RealModeGdt[1]: Code Segment
// RealModeGdt[2]: Data Segment
// RealModeGdt[3]: Call Gate
//
RealModeGdt = (IA32_SEGMENT_DESCRIPTOR*)(
(UINTN)ThunkContext->RealModeBuffer + m16Gdt);
//
// Update Code & Data Segment Descriptor
//
RealModeGdt[1].Bits.BaseLow =
(UINT32)(UINTN)ThunkContext->RealModeBuffer & ~0xf;
RealModeGdt[1].Bits.BaseMid =
(UINT32)(UINTN)ThunkContext->RealModeBuffer >> 16;
//
// Update transition code entry point offset
//
*(UINT32*)((UINTN)ThunkContext->RealModeBuffer + mTransition) +=
(UINT32)(UINTN)ThunkContext->RealModeBuffer & 0xf;
//
// Update Segment Limits for both Code and Data Segment Descriptors
//
if ((ThunkContext->ThunkAttributes & THUNK_ATTRIBUTE_BIG_REAL_MODE) == 0) {
//
// Set segment limits to 64KB
//
RealModeGdt[1].Bits.LimitHigh = 0;
RealModeGdt[1].Bits.G = 0;
RealModeGdt[2].Bits.LimitHigh = 0;
RealModeGdt[2].Bits.G = 0;
}
//
// Update GDTBASE for this thunk context
//
*(VOID**)((UINTN)ThunkContext->RealModeBuffer + m16GdtrBase) = RealModeGdt;
//
// Update Thunk Attributes
//
*(UINT32*)((UINTN)ThunkContext->RealModeBuffer + mThunk16Attr) =
ThunkContext->ThunkAttributes;
}
/**
@@ -74,28 +195,20 @@ AsmThunk16 (
IN OUT THUNK_CONTEXT *ThunkContext
)
{
UINT16 *Patch;
IA32_REGISTER_SET *UpdatedRegs;
ASSERT (ThunkContext != NULL);
ASSERT ((UINTN)ThunkContext->RealModeBuffer < 0x100000);
ASSERT (ThunkContext->RealModeBufferSize >= m16Size);
ASSERT ((UINTN)ThunkContext->RealModeBuffer + m16Size <= 0x100000);
ASSERT (((UINTN)ThunkContext->RealModeBuffer & 0x0f) == 0);
Patch = (UINT16*)(
(UINTN)ThunkContext->RealModeCode +
ThunkContext->RealModeCodeSize
);
UpdatedRegs = InternalAsmThunk16 (
ThunkContext->RealModeState,
ThunkContext->RealModeBuffer
);
//
// 0x9a66 is the OpCode of far call with an operand size override.
//
*Patch = 0x9a66;
//
// CopyMem() here copies the updated register values back to RealModeState
//
CopyMem (
&ThunkContext->RealModeState,
InternalAsmThunk16 (&ThunkContext->RealModeState, Patch + 1),
sizeof (ThunkContext->RealModeState)
);
CopyMem (ThunkContext->RealModeState, UpdatedRegs, sizeof (*UpdatedRegs));
}
/**