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audk/MdeModulePkg/Universal/EbcDxe/Ia32/EbcSupport.c

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/*++
Copyright (c) 2006, Intel Corporation
All rights reserved. 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.
Module Name:
EbcSupport.c
Abstract:
This module contains EBC support routines that are customized based on
the target processor.
--*/
#include "EbcInt.h"
#include "EbcExecute.h"
//
// NOTE: This is the stack size allocated for the interpreter
// when it executes an EBC image. The requirements can change
// based on whether or not a debugger is present, and other
// platform-specific configurations.
//
#define VM_STACK_SIZE (1024 * 4)
#define EBC_THUNK_SIZE 32
#define STACK_REMAIN_SIZE (1024 * 4)
VOID
EbcLLCALLEX (
IN VM_CONTEXT *VmPtr,
IN UINTN FuncAddr,
IN UINTN NewStackPointer,
IN VOID *FramePtr,
IN UINT8 Size
)
/*++
Routine Description:
This function is called to execute an EBC CALLEX instruction.
The function check the callee's content to see whether it is common native
code or a thunk to another piece of EBC code.
If the callee is common native code, use EbcLLCAllEXASM to manipulate,
otherwise, set the VM->IP to target EBC code directly to avoid another VM
be startup which cost time and stack space.
Arguments:
VmPtr - Pointer to a VM context.
FuncAddr - Callee's address
NewStackPointer - New stack pointer after the call
FramePtr - New frame pointer after the call
Size - The size of call instruction
Returns:
None.
--*/
{
UINTN IsThunk;
UINTN TargetEbcAddr;
IsThunk = 1;
TargetEbcAddr = 0;
//
// Processor specific code to check whether the callee is a thunk to EBC.
//
if (*((UINT8 *)FuncAddr) != 0xB8) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 1) != 0xBC) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 2) != 0x2E) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 3) != 0x11) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 4) != 0xCA) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 5) != 0xB8) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 10) != 0xB9) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 15) != 0xFF) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 16) != 0xE1) {
IsThunk = 0;
goto Action;
}
TargetEbcAddr = ((UINTN)(*((UINT8 *)FuncAddr + 9)) << 24) + ((UINTN)(*((UINT8 *)FuncAddr + 8)) << 16) +
((UINTN)(*((UINT8 *)FuncAddr + 7)) << 8) + ((UINTN)(*((UINT8 *)FuncAddr + 6)));
Action:
if (IsThunk == 1){
//
// The callee is a thunk to EBC, adjust the stack pointer down 16 bytes and
// put our return address and frame pointer on the VM stack.
// Then set the VM's IP to new EBC code.
//
VmPtr->R[0] -= 8;
VmWriteMemN (VmPtr, (UINTN) VmPtr->R[0], (UINTN) FramePtr);
VmPtr->FramePtr = (VOID *) (UINTN) VmPtr->R[0];
VmPtr->R[0] -= 8;
VmWriteMem64 (VmPtr, (UINTN) VmPtr->R[0], (UINT64) (UINTN) (VmPtr->Ip + Size));
VmPtr->Ip = (VMIP) (UINTN) TargetEbcAddr;
} else {
//
// The callee is not a thunk to EBC, call native code.
//
EbcLLCALLEXNative (FuncAddr, NewStackPointer, FramePtr);
//
// Get return value and advance the IP.
//
VmPtr->R[7] = EbcLLGetReturnValue ();
VmPtr->Ip += Size;
}
}
STATIC
UINT64
EbcInterpret (
IN OUT UINTN Arg1,
IN OUT UINTN Arg2,
IN OUT UINTN Arg3,
IN OUT UINTN Arg4,
IN OUT UINTN Arg5,
IN OUT UINTN Arg6,
IN OUT UINTN Arg7,
IN OUT UINTN Arg8,
IN OUT UINTN Arg9,
IN OUT UINTN Arg10,
IN OUT UINTN Arg11,
IN OUT UINTN Arg12,
IN OUT UINTN Arg13,
IN OUT UINTN Arg14,
IN OUT UINTN Arg15,
IN OUT UINTN Arg16
)
/*++
Routine Description:
Begin executing an EBC image. The address of the entry point is passed
in via a processor register, so we'll need to make a call to get the
value.
Arguments:
None. Since we're called from a fixed up thunk (which we want to keep
small), our only so-called argument is the EBC entry point passed in
to us in a processor register.
Returns:
The value returned by the EBC application we're going to run.
--*/
{
//
// Create a new VM context on the stack
//
VM_CONTEXT VmContext;
UINTN Addr;
EFI_STATUS Status;
UINTN StackIndex;
//
// Get the EBC entry point from the processor register.
//
Addr = EbcLLGetEbcEntryPoint ();
//
// Now clear out our context
//
ZeroMem ((VOID *) &VmContext, sizeof (VM_CONTEXT));
//
// Set the VM instruction pointer to the correct location in memory.
//
VmContext.Ip = (VMIP) Addr;
//
// Initialize the stack pointer for the EBC. Get the current system stack
// pointer and adjust it down by the max needed for the interpreter.
//
//
// Align the stack on a natural boundary
//
//
// Allocate stack pool
//
Status = GetEBCStack((EFI_HANDLE)-1, &VmContext.StackPool, &StackIndex);
if (EFI_ERROR(Status)) {
return Status;
}
VmContext.StackTop = (UINT8*)VmContext.StackPool + (STACK_REMAIN_SIZE);
VmContext.R[0] = (UINT64)(UINTN) ((UINT8*)VmContext.StackPool + STACK_POOL_SIZE);
VmContext.HighStackBottom = (UINTN)VmContext.R[0];
VmContext.R[0] &= ~(sizeof (UINTN) - 1);
VmContext.R[0] -= sizeof (UINTN);
//
// Put a magic value in the stack gap, then adjust down again
//
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) VM_STACK_KEY_VALUE;
VmContext.StackMagicPtr = (UINTN *) (UINTN) VmContext.R[0];
VmContext.LowStackTop = (UINTN) VmContext.R[0];
//
// For IA32, this is where we say our return address is
//
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg16;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg15;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg14;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg13;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg12;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg11;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg10;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg9;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg8;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg7;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg6;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg5;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg4;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg3;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg2;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) Arg1;
VmContext.R[0] -= 16;
VmContext.StackRetAddr = (UINT64) VmContext.R[0];
//
// We need to keep track of where the EBC stack starts. This way, if the EBC
// accesses any stack variables above its initial stack setting, then we know
// it's accessing variables passed into it, which means the data is on the
// VM's stack.
// When we're called, on the stack (high to low) we have the parameters, the
// return address, then the saved ebp. Save the pointer to the return address.
// EBC code knows that's there, so should look above it for function parameters.
// The offset is the size of locals (VMContext + Addr + saved ebp).
// Note that the interpreter assumes there is a 16 bytes of return address on
// the stack too, so adjust accordingly.
// VmContext.HighStackBottom = (UINTN)(Addr + sizeof (VmContext) + sizeof (Addr));
//
//
// Begin executing the EBC code
//
EbcExecute (&VmContext);
//
// Return the value in R[7] unless there was an error
//
ReturnEBCStack(StackIndex);
return (UINT64) VmContext.R[7];
}
STATIC
UINT64
ExecuteEbcImageEntryPoint (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
/*++
Routine Description:
Begin executing an EBC image. The address of the entry point is passed
in via a processor register, so we'll need to make a call to get the
value.
Arguments:
ImageHandle - image handle for the EBC application we're executing
SystemTable - standard system table passed into an driver's entry point
Returns:
The value returned by the EBC application we're going to run.
--*/
{
//
// Create a new VM context on the stack
//
VM_CONTEXT VmContext;
UINTN Addr;
EFI_STATUS Status;
UINTN StackIndex;
//
// Get the EBC entry point from the processor register. Make sure you don't
// call any functions before this or you could mess up the register the
// entry point is passed in.
//
Addr = EbcLLGetEbcEntryPoint ();
//
// Print(L"*** Thunked into EBC entry point - ImageHandle = 0x%X\n", (UINTN)ImageHandle);
// Print(L"EBC entry point is 0x%X\n", (UINT32)(UINTN)Addr);
//
// Now clear out our context
//
ZeroMem ((VOID *) &VmContext, sizeof (VM_CONTEXT));
//
// Save the image handle so we can track the thunks created for this image
//
VmContext.ImageHandle = ImageHandle;
VmContext.SystemTable = SystemTable;
//
// Set the VM instruction pointer to the correct location in memory.
//
VmContext.Ip = (VMIP) Addr;
//
// Initialize the stack pointer for the EBC. Get the current system stack
// pointer and adjust it down by the max needed for the interpreter.
//
//
// Allocate stack pool
//
Status = GetEBCStack(ImageHandle, &VmContext.StackPool, &StackIndex);
if (EFI_ERROR(Status)) {
return Status;
}
VmContext.StackTop = (UINT8*)VmContext.StackPool + (STACK_REMAIN_SIZE);
VmContext.R[0] = (UINT64)(UINTN) ((UINT8*)VmContext.StackPool + STACK_POOL_SIZE);
VmContext.HighStackBottom = (UINTN)VmContext.R[0];
VmContext.R[0] -= sizeof (UINTN);
//
// Put a magic value in the stack gap, then adjust down again
//
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) VM_STACK_KEY_VALUE;
VmContext.StackMagicPtr = (UINTN *) (UINTN) VmContext.R[0];
//
// Align the stack on a natural boundary
// VmContext.R[0] &= ~(sizeof(UINTN) - 1);
//
VmContext.LowStackTop = (UINTN) VmContext.R[0];
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) SystemTable;
VmContext.R[0] -= sizeof (UINTN);
*(UINTN *) (UINTN) (VmContext.R[0]) = (UINTN) ImageHandle;
VmContext.R[0] -= 16;
VmContext.StackRetAddr = (UINT64) VmContext.R[0];
//
// VM pushes 16-bytes for return address. Simulate that here.
//
//
// Begin executing the EBC code
//
EbcExecute (&VmContext);
//
// Return the value in R[7] unless there was an error
//
return (UINT64) VmContext.R[7];
}
EFI_STATUS
EbcCreateThunks (
IN EFI_HANDLE ImageHandle,
IN VOID *EbcEntryPoint,
OUT VOID **Thunk,
IN UINT32 Flags
)
/*++
Routine Description:
Create an IA32 thunk for the given EBC entry point.
Arguments:
ImageHandle - Handle of image for which this thunk is being created
EbcEntryPoint - Address of the EBC code that the thunk is to call
Thunk - Returned thunk we create here
Returns:
Standard EFI status.
--*/
{
UINT8 *Ptr;
UINT8 *ThunkBase;
UINT32 I;
UINT32 Addr;
INT32 Size;
INT32 ThunkSize;
//
// Check alignment of pointer to EBC code
//
if ((UINT32) (UINTN) EbcEntryPoint & 0x01) {
return EFI_INVALID_PARAMETER;
}
Size = EBC_THUNK_SIZE;
ThunkSize = Size;
Ptr = AllocatePool (Size);
if (Ptr == NULL) {
return EFI_OUT_OF_RESOURCES;
}
//
// Print(L"Allocate TH: 0x%X\n", (UINT32)Ptr);
//
// Save the start address so we can add a pointer to it to a list later.
//
ThunkBase = Ptr;
//
// Give them the address of our buffer we're going to fix up
//
*Thunk = (VOID *) Ptr;
//
// Add a magic code here to help the VM recognize the thunk..
// mov eax, 0xca112ebc => B8 BC 2E 11 CA
//
*Ptr = 0xB8;
Ptr++;
Size--;
Addr = (UINT32) 0xCA112EBC;
for (I = 0; I < sizeof (Addr); I++) {
*Ptr = (UINT8) (UINTN) Addr;
Addr >>= 8;
Ptr++;
Size--;
}
//
// Add code bytes to load up a processor register with the EBC entry point.
// mov eax, 0xaa55aa55 => B8 55 AA 55 AA
// The first 8 bytes of the thunk entry is the address of the EBC
// entry point.
//
*Ptr = 0xB8;
Ptr++;
Size--;
Addr = (UINT32) EbcEntryPoint;
for (I = 0; I < sizeof (Addr); I++) {
*Ptr = (UINT8) (UINTN) Addr;
Addr >>= 8;
Ptr++;
Size--;
}
//
// Stick in a load of ecx with the address of appropriate VM function.
// mov ecx 12345678h => 0xB9 0x78 0x56 0x34 0x12
//
if (Flags & FLAG_THUNK_ENTRY_POINT) {
Addr = (UINT32) (UINTN) ExecuteEbcImageEntryPoint;
} else {
Addr = (UINT32) (UINTN) EbcInterpret;
}
//
// MOV ecx
//
*Ptr = 0xB9;
Ptr++;
Size--;
for (I = 0; I < sizeof (Addr); I++) {
*Ptr = (UINT8) Addr;
Addr >>= 8;
Ptr++;
Size--;
}
//
// Stick in jump opcode bytes for jmp ecx => 0xFF 0xE1
//
*Ptr = 0xFF;
Ptr++;
Size--;
*Ptr = 0xE1;
Size--;
//
// Double check that our defined size is ok (application error)
//
if (Size < 0) {
ASSERT (FALSE);
return EFI_BUFFER_TOO_SMALL;
}
//
// Add the thunk to the list for this image. Do this last since the add
// function flushes the cache for us.
//
EbcAddImageThunk (ImageHandle, (VOID *) ThunkBase, ThunkSize);
return EFI_SUCCESS;
}
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