2 This module contains EBC support routines that are customized based on
3 the target x64 processor.
5 Copyright (c) 2006, Intel Corporation
6 All rights reserved. This program and the accompanying materials
7 are licensed and made available under the terms and conditions of the BSD License
8 which accompanies this distribution. The full text of the license may be found at
9 http://opensource.org/licenses/bsd-license.php
11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
17 #include "EbcExecute.h"
20 // NOTE: This is the stack size allocated for the interpreter
21 // when it executes an EBC image. The requirements can change
22 // based on whether or not a debugger is present, and other
23 // platform-specific configurations.
25 #define VM_STACK_SIZE (1024 * 8)
26 #define EBC_THUNK_SIZE 64
28 #define STACK_REMAIN_SIZE (1024 * 4)
32 Pushes a 64 bit unsigned value to the VM stack.
34 @param VmPtr The pointer to current VM context.
35 @param Arg The value to be pushed.
46 // Advance the VM stack down, and then copy the argument to the stack.
49 VmPtr
->R
[0] -= sizeof (UINT64
);
50 *(UINT64
*) VmPtr
->R
[0] = Arg
;
56 Begin executing an EBC image. The address of the entry point is passed
57 in via a processor register, so we'll need to make a call to get the
60 This is a thunk function. Microsoft x64 compiler only provide fast_call
61 calling convention, so the first four arguments are passed by rcx, rdx,
62 r8, and r9, while other arguments are passed in stack.
64 @param Arg1 The 1st argument.
65 @param Arg2 The 2nd argument.
66 @param Arg3 The 3rd argument.
67 @param Arg4 The 4th argument.
68 @param Arg5 The 5th argument.
69 @param Arg6 The 6th argument.
70 @param Arg7 The 7th argument.
71 @param Arg8 The 8th argument.
72 @param Arg9 The 9th argument.
73 @param Arg10 The 10th argument.
74 @param Arg11 The 11th argument.
75 @param Arg12 The 12th argument.
76 @param Arg13 The 13th argument.
77 @param Arg14 The 14th argument.
78 @param Arg15 The 15th argument.
79 @param Arg16 The 16th argument.
81 @return The value returned by the EBC application we're going to run.
106 // Create a new VM context on the stack
108 VM_CONTEXT VmContext
;
114 // Get the EBC entry point from the processor register.
115 // Don't call any function before getting the EBC entry
116 // point because this will collab the return register.
118 Addr
= EbcLLGetEbcEntryPoint ();
121 // Now clear out our context
123 ZeroMem ((VOID
*) &VmContext
, sizeof (VM_CONTEXT
));
126 // Set the VM instruction pointer to the correct location in memory.
128 VmContext
.Ip
= (VMIP
) Addr
;
131 // Initialize the stack pointer for the EBC. Get the current system stack
132 // pointer and adjust it down by the max needed for the interpreter.
134 Addr
= EbcLLGetStackPointer ();
137 // Adjust the VM's stack pointer down.
140 Status
= GetEBCStack((EFI_HANDLE
)(UINTN
)-1, &VmContext
.StackPool
, &StackIndex
);
141 if (EFI_ERROR(Status
)) {
144 VmContext
.StackTop
= (UINT8
*)VmContext
.StackPool
+ (STACK_REMAIN_SIZE
);
145 VmContext
.R
[0] = (UINT64
) ((UINT8
*)VmContext
.StackPool
+ STACK_POOL_SIZE
);
146 VmContext
.HighStackBottom
= (UINTN
) VmContext
.R
[0];
147 VmContext
.R
[0] -= sizeof (UINTN
);
150 // Align the stack on a natural boundary.
152 VmContext
.R
[0] &= ~(sizeof (UINTN
) - 1);
155 // Put a magic value in the stack gap, then adjust down again.
157 *(UINTN
*) (UINTN
) (VmContext
.R
[0]) = (UINTN
) VM_STACK_KEY_VALUE
;
158 VmContext
.StackMagicPtr
= (UINTN
*) (UINTN
) VmContext
.R
[0];
161 // The stack upper to LowStackTop is belong to the VM.
163 VmContext
.LowStackTop
= (UINTN
) VmContext
.R
[0];
166 // For the worst case, assume there are 4 arguments passed in registers, store
167 // them to VM's stack.
169 PushU64 (&VmContext
, (UINT64
) Arg16
);
170 PushU64 (&VmContext
, (UINT64
) Arg15
);
171 PushU64 (&VmContext
, (UINT64
) Arg14
);
172 PushU64 (&VmContext
, (UINT64
) Arg13
);
173 PushU64 (&VmContext
, (UINT64
) Arg12
);
174 PushU64 (&VmContext
, (UINT64
) Arg11
);
175 PushU64 (&VmContext
, (UINT64
) Arg10
);
176 PushU64 (&VmContext
, (UINT64
) Arg9
);
177 PushU64 (&VmContext
, (UINT64
) Arg8
);
178 PushU64 (&VmContext
, (UINT64
) Arg7
);
179 PushU64 (&VmContext
, (UINT64
) Arg6
);
180 PushU64 (&VmContext
, (UINT64
) Arg5
);
181 PushU64 (&VmContext
, (UINT64
) Arg4
);
182 PushU64 (&VmContext
, (UINT64
) Arg3
);
183 PushU64 (&VmContext
, (UINT64
) Arg2
);
184 PushU64 (&VmContext
, (UINT64
) Arg1
);
187 // Interpreter assumes 64-bit return address is pushed on the stack.
188 // The x64 does not do this so pad the stack accordingly.
190 PushU64 (&VmContext
, (UINT64
) 0);
191 PushU64 (&VmContext
, (UINT64
) 0x1234567887654321ULL
);
194 // For x64, this is where we say our return address is
196 VmContext
.StackRetAddr
= (UINT64
) VmContext
.R
[0];
199 // We need to keep track of where the EBC stack starts. This way, if the EBC
200 // accesses any stack variables above its initial stack setting, then we know
201 // it's accessing variables passed into it, which means the data is on the
203 // When we're called, on the stack (high to low) we have the parameters, the
204 // return address, then the saved ebp. Save the pointer to the return address.
205 // EBC code knows that's there, so should look above it for function parameters.
206 // The offset is the size of locals (VMContext + Addr + saved ebp).
207 // Note that the interpreter assumes there is a 16 bytes of return address on
208 // the stack too, so adjust accordingly.
209 // VmContext.HighStackBottom = (UINTN)(Addr + sizeof (VmContext) + sizeof (Addr));
213 // Begin executing the EBC code
215 EbcExecute (&VmContext
);
218 // Return the value in R[7] unless there was an error
220 ReturnEBCStack(StackIndex
);
221 return (UINT64
) VmContext
.R
[7];
226 Begin executing an EBC image. The address of the entry point is passed
227 in via a processor register, so we'll need to make a call to get the
230 @param ImageHandle image handle for the EBC application we're executing
231 @param SystemTable standard system table passed into an driver's entry
234 @return The value returned by the EBC application we're going to run.
239 ExecuteEbcImageEntryPoint (
240 IN EFI_HANDLE ImageHandle
,
241 IN EFI_SYSTEM_TABLE
*SystemTable
245 // Create a new VM context on the stack
247 VM_CONTEXT VmContext
;
253 // Get the EBC entry point from the processor register. Make sure you don't
254 // call any functions before this or you could mess up the register the
255 // entry point is passed in.
257 Addr
= EbcLLGetEbcEntryPoint ();
260 // Now clear out our context
262 ZeroMem ((VOID
*) &VmContext
, sizeof (VM_CONTEXT
));
265 // Save the image handle so we can track the thunks created for this image
267 VmContext
.ImageHandle
= ImageHandle
;
268 VmContext
.SystemTable
= SystemTable
;
271 // Set the VM instruction pointer to the correct location in memory.
273 VmContext
.Ip
= (VMIP
) Addr
;
276 // Initialize the stack pointer for the EBC. Get the current system stack
277 // pointer and adjust it down by the max needed for the interpreter.
279 Addr
= EbcLLGetStackPointer ();
281 Status
= GetEBCStack(ImageHandle
, &VmContext
.StackPool
, &StackIndex
);
282 if (EFI_ERROR(Status
)) {
285 VmContext
.StackTop
= (UINT8
*)VmContext
.StackPool
+ (STACK_REMAIN_SIZE
);
286 VmContext
.R
[0] = (UINT64
) ((UINT8
*)VmContext
.StackPool
+ STACK_POOL_SIZE
);
287 VmContext
.HighStackBottom
= (UINTN
) VmContext
.R
[0];
288 VmContext
.R
[0] -= sizeof (UINTN
);
292 // Put a magic value in the stack gap, then adjust down again
294 *(UINTN
*) (UINTN
) (VmContext
.R
[0]) = (UINTN
) VM_STACK_KEY_VALUE
;
295 VmContext
.StackMagicPtr
= (UINTN
*) (UINTN
) VmContext
.R
[0];
298 // Align the stack on a natural boundary
299 VmContext
.R
[0] &= ~(sizeof(UINTN
) - 1);
301 VmContext
.LowStackTop
= (UINTN
) VmContext
.R
[0];
304 // Simply copy the image handle and system table onto the EBC stack.
305 // Greatly simplifies things by not having to spill the args.
307 PushU64 (&VmContext
, (UINT64
) SystemTable
);
308 PushU64 (&VmContext
, (UINT64
) ImageHandle
);
311 // VM pushes 16-bytes for return address. Simulate that here.
313 PushU64 (&VmContext
, (UINT64
) 0);
314 PushU64 (&VmContext
, (UINT64
) 0x1234567887654321ULL
);
317 // For x64, this is where we say our return address is
319 VmContext
.StackRetAddr
= (UINT64
) VmContext
.R
[0];
322 // Entry function needn't access high stack context, simply
323 // put the stack pointer here.
327 // Begin executing the EBC code
329 EbcExecute (&VmContext
);
332 // Return the value in R[7] unless there was an error
334 ReturnEBCStack(StackIndex
);
335 return (UINT64
) VmContext
.R
[7];
340 Create thunks for an EBC image entry point, or an EBC protocol service.
342 @param ImageHandle Image handle for the EBC image. If not null, then
343 we're creating a thunk for an image entry point.
344 @param EbcEntryPoint Address of the EBC code that the thunk is to call
345 @param Thunk Returned thunk we create here
346 @param Flags Flags indicating options for creating the thunk
348 @retval EFI_SUCCESS The thunk was created successfully.
349 @retval EFI_INVALID_PARAMETER The parameter of EbcEntryPoint is not 16-bit
351 @retval EFI_OUT_OF_RESOURCES There is not enough memory to created the EBC
353 @retval EFI_BUFFER_TOO_SMALL EBC_THUNK_SIZE is not larger enough.
358 IN EFI_HANDLE ImageHandle
,
359 IN VOID
*EbcEntryPoint
,
372 // Check alignment of pointer to EBC code
374 if ((UINT32
) (UINTN
) EbcEntryPoint
& 0x01) {
375 return EFI_INVALID_PARAMETER
;
378 Size
= EBC_THUNK_SIZE
;
381 Ptr
= AllocatePool (Size
);
384 return EFI_OUT_OF_RESOURCES
;
387 // Print(L"Allocate TH: 0x%X\n", (UINT32)Ptr);
389 // Save the start address so we can add a pointer to it to a list later.
394 // Give them the address of our buffer we're going to fix up
396 *Thunk
= (VOID
*) Ptr
;
399 // Add a magic code here to help the VM recognize the thunk..
400 // mov rax, ca112ebccall2ebch => 48 B8 BC 2E 11 CA BC 2E 11 CA
408 Addr
= (UINT64
) 0xCA112EBCCA112EBCULL
;
409 for (Index
= 0; Index
< sizeof (Addr
); Index
++) {
410 *Ptr
= (UINT8
) (UINTN
) Addr
;
417 // Add code bytes to load up a processor register with the EBC entry point.
418 // mov rax, 123456789abcdef0h => 48 B8 F0 DE BC 9A 78 56 34 12
419 // The first 8 bytes of the thunk entry is the address of the EBC
428 Addr
= (UINT64
) EbcEntryPoint
;
429 for (Index
= 0; Index
< sizeof (Addr
); Index
++) {
430 *Ptr
= (UINT8
) (UINTN
) Addr
;
437 // Stick in a load of ecx with the address of appropriate VM function.
438 // Using r11 because it's a volatile register and won't be used in this
440 // mov r11 123456789abcdef0h => 49 BB F0 DE BC 9A 78 56 34 12
442 if (Flags
& FLAG_THUNK_ENTRY_POINT
) {
443 Addr
= (UINTN
) ExecuteEbcImageEntryPoint
;
445 Addr
= (UINTN
) EbcInterpret
;
449 // mov r11 Addr => 0x49 0xBB
457 for (Index
= 0; Index
< sizeof (Addr
); Index
++) {
464 // Stick in jump opcode bytes for jmp r11 => 0x41 0xFF 0xE3
476 // Double check that our defined size is ok (application error)
480 return EFI_BUFFER_TOO_SMALL
;
483 // Add the thunk to the list for this image. Do this last since the add
484 // function flushes the cache for us.
486 EbcAddImageThunk (ImageHandle
, (VOID
*) ThunkBase
, ThunkSize
);
493 This function is called to execute an EBC CALLEX instruction.
494 The function check the callee's content to see whether it is common native
495 code or a thunk to another piece of EBC code.
496 If the callee is common native code, use EbcLLCAllEXASM to manipulate,
497 otherwise, set the VM->IP to target EBC code directly to avoid another VM
498 be startup which cost time and stack space.
500 @param VmPtr Pointer to a VM context.
501 @param FuncAddr Callee's address
502 @param NewStackPointer New stack pointer after the call
503 @param FramePtr New frame pointer after the call
504 @param Size The size of call instruction
509 IN VM_CONTEXT
*VmPtr
,
511 IN UINTN NewStackPointer
,
523 // Processor specific code to check whether the callee is a thunk to EBC.
525 if (*((UINT8
*)FuncAddr
) != 0x48) {
529 if (*((UINT8
*)FuncAddr
+ 1) != 0xB8) {
533 if (*((UINT8
*)FuncAddr
+ 2) != 0xBC) {
537 if (*((UINT8
*)FuncAddr
+ 3) != 0x2E) {
541 if (*((UINT8
*)FuncAddr
+ 4) != 0x11) {
545 if (*((UINT8
*)FuncAddr
+ 5) != 0xCA) {
549 if (*((UINT8
*)FuncAddr
+ 6) != 0xBC) {
553 if (*((UINT8
*)FuncAddr
+ 7) != 0x2E) {
557 if (*((UINT8
*)FuncAddr
+ 8) != 0x11) {
561 if (*((UINT8
*)FuncAddr
+ 9) != 0xCA) {
565 if (*((UINT8
*)FuncAddr
+ 10) != 0x48) {
569 if (*((UINT8
*)FuncAddr
+ 11) != 0xB8) {
574 CopyMem (&TargetEbcAddr
, (UINT8
*)FuncAddr
+ 12, 8);
579 // The callee is a thunk to EBC, adjust the stack pointer down 16 bytes and
580 // put our return address and frame pointer on the VM stack.
581 // Then set the VM's IP to new EBC code.
584 VmWriteMemN (VmPtr
, (UINTN
) VmPtr
->R
[0], (UINTN
) FramePtr
);
585 VmPtr
->FramePtr
= (VOID
*) (UINTN
) VmPtr
->R
[0];
587 VmWriteMem64 (VmPtr
, (UINTN
) VmPtr
->R
[0], (UINT64
) (VmPtr
->Ip
+ Size
));
589 VmPtr
->Ip
= (VMIP
) (UINTN
) TargetEbcAddr
;
592 // The callee is not a thunk to EBC, call native code.
594 EbcLLCALLEXNative (FuncAddr
, NewStackPointer
, FramePtr
);
597 // Get return value and advance the IP.
599 VmPtr
->R
[7] = EbcLLGetReturnValue ();