diff options
Diffstat (limited to 'MdePkg/Library/BaseLib/X86Thunk.c')
| -rw-r--r-- | MdePkg/Library/BaseLib/X86Thunk.c | 268 |
1 files changed, 0 insertions, 268 deletions
diff --git a/MdePkg/Library/BaseLib/X86Thunk.c b/MdePkg/Library/BaseLib/X86Thunk.c deleted file mode 100644 index dac1d19374..0000000000 --- a/MdePkg/Library/BaseLib/X86Thunk.c +++ /dev/null @@ -1,268 +0,0 @@ -/** @file
- Real Mode Thunk Functions for IA32 and x64.
-
- Copyright (c) 2006 - 2012, 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 "BaseLibInternals.h"
-
-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.
-
- This function transfers control to the 16-bit code specified by CS:EIP using
- the stack specified by SS:ESP in RegisterSet. The updated registers are saved
- 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 Transition The pointer to the transition code under 1MB.
-
- @return The pointer to a IA32_REGISTER_SET structure containing the updated
- register values.
-
-**/
-IA32_REGISTER_SET *
-EFIAPI
-InternalAsmThunk16 (
- IN IA32_REGISTER_SET *RegisterSet,
- 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;
-
- //
- // Extra 4 bytes for return address, and another 4 bytes for mode transition
- //
- *ExtraStackSize = sizeof (IA32_DWORD_REGS) + 8;
-}
-
-/**
- Prepares all structures a code required to use AsmThunk16().
-
- Prepares all structures and code required to use AsmThunk16().
-
- This interface is limited to be used in either physical mode or virtual modes with paging enabled where the
- virtual to physical mappings for ThunkContext.RealModeBuffer is mapped 1:1.
-
- If ThunkContext is NULL, then ASSERT().
-
- @param ThunkContext A pointer to the context structure that describes the
- 16-bit real mode code to call.
-
-**/
-VOID
-EFIAPI
-AsmPrepareThunk16 (
- IN 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);
-
- 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;
-}
-
-/**
- Transfers control to a 16-bit real mode entry point and returns the results.
-
- Transfers control to a 16-bit real mode entry point and returns the results.
- AsmPrepareThunk16() must be called with ThunkContext before this function is used.
- This function must be called with interrupts disabled.
-
- The register state from the RealModeState field of ThunkContext is restored just prior
- to calling the 16-bit real mode entry point. This includes the EFLAGS field of RealModeState,
- which is used to set the interrupt state when a 16-bit real mode entry point is called.
- Control is transferred to the 16-bit real mode entry point specified by the CS and Eip fields of RealModeState.
- The stack is initialized to the SS and ESP fields of RealModeState. Any parameters passed to
- the 16-bit real mode code must be populated by the caller at SS:ESP prior to calling this function.
- The 16-bit real mode entry point is invoked with a 16-bit CALL FAR instruction,
- so when accessing stack contents, the 16-bit real mode code must account for the 16-bit segment
- and 16-bit offset of the return address that were pushed onto the stack. The 16-bit real mode entry
- point must exit with a RETF instruction. The register state is captured into RealModeState immediately
- after the RETF instruction is executed.
-
- If EFLAGS specifies interrupts enabled, or any of the 16-bit real mode code enables interrupts,
- or any of the 16-bit real mode code makes a SW interrupt, then the caller is responsible for making sure
- the IDT at address 0 is initialized to handle any HW or SW interrupts that may occur while in 16-bit real mode.
-
- If EFLAGS specifies interrupts enabled, or any of the 16-bit real mode code enables interrupts,
- then the caller is responsible for making sure the 8259 PIC is in a state compatible with 16-bit real mode.
- This includes the base vectors, the interrupt masks, and the edge/level trigger mode.
-
- If THUNK_ATTRIBUTE_BIG_REAL_MODE is set in the ThunkAttributes field of ThunkContext, then the user code
- is invoked in big real mode. Otherwise, the user code is invoked in 16-bit real mode with 64KB segment limits.
-
- If neither THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 nor THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL are set in
- ThunkAttributes, then it is assumed that the user code did not enable the A20 mask, and no attempt is made to
- disable the A20 mask.
-
- If THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 is set and THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL is clear in
- ThunkAttributes, then attempt to use the INT 15 service to disable the A20 mask. If this INT 15 call fails,
- then attempt to disable the A20 mask by directly accessing the 8042 keyboard controller I/O ports.
-
- If THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 is clear and THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL is set in
- ThunkAttributes, then attempt to disable the A20 mask by directly accessing the 8042 keyboard controller I/O ports.
-
- If ThunkContext is NULL, then ASSERT().
- If AsmPrepareThunk16() was not previously called with ThunkContext, then ASSERT().
- If both THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 and THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL are set in
- ThunkAttributes, then ASSERT().
-
- This interface is limited to be used in either physical mode or virtual modes with paging enabled where the
- virtual to physical mappings for ThunkContext.RealModeBuffer is mapped 1:1.
-
- @param ThunkContext A pointer to the context structure that describes the
- 16-bit real mode code to call.
-
-**/
-VOID
-EFIAPI
-AsmThunk16 (
- IN OUT THUNK_CONTEXT *ThunkContext
- )
-{
- IA32_REGISTER_SET *UpdatedRegs;
-
- ASSERT (ThunkContext != NULL);
- ASSERT ((UINTN)ThunkContext->RealModeBuffer < 0x100000);
- ASSERT (ThunkContext->RealModeBufferSize >= m16Size);
- ASSERT ((UINTN)ThunkContext->RealModeBuffer + m16Size <= 0x100000);
- ASSERT (((ThunkContext->ThunkAttributes & (THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 | THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL)) != \
- (THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 | THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL)));
-
- UpdatedRegs = InternalAsmThunk16 (
- ThunkContext->RealModeState,
- ThunkContext->RealModeBuffer
- );
-
- CopyMem (ThunkContext->RealModeState, UpdatedRegs, sizeof (*UpdatedRegs));
-}
-
-/**
- Prepares all structures and code for a 16-bit real mode thunk, transfers
- control to a 16-bit real mode entry point, and returns the results.
-
- Prepares all structures and code for a 16-bit real mode thunk, transfers
- control to a 16-bit real mode entry point, and returns the results. If the
- caller only need to perform a single 16-bit real mode thunk, then this
- service should be used. If the caller intends to make more than one 16-bit
- real mode thunk, then it is more efficient if AsmPrepareThunk16() is called
- once and AsmThunk16() can be called for each 16-bit real mode thunk.
-
- This interface is limited to be used in either physical mode or virtual modes with paging enabled where the
- virtual to physical mappings for ThunkContext.RealModeBuffer is mapped 1:1.
-
- See AsmPrepareThunk16() and AsmThunk16() for the detailed description and ASSERT() conditions.
-
- @param ThunkContext A pointer to the context structure that describes the
- 16-bit real mode code to call.
-
-**/
-VOID
-EFIAPI
-AsmPrepareAndThunk16 (
- IN OUT THUNK_CONTEXT *ThunkContext
- )
-{
- AsmPrepareThunk16 (ThunkContext);
- AsmThunk16 (ThunkContext);
-}
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