2 This module contains EBC support routines that are customized based on
5 Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
6 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"
18 #include "EbcSupport.h"
21 Given raw bytes of Itanium based code, format them into a bundle and
24 @param MemPtr pointer to memory location to write the bundles
26 @param Template 5-bit template.
27 @param Slot0 Instruction slot 0 data for the bundle.
28 @param Slot1 Instruction slot 1 data for the bundle.
29 @param Slot2 Instruction slot 2 data for the bundle.
31 @retval EFI_INVALID_PARAMETER Pointer is not aligned
32 @retval EFI_INVALID_PARAMETER No more than 5 bits in template
33 @retval EFI_INVALID_PARAMETER More than 41 bits used in code
34 @retval EFI_SUCCESS All data is written.
47 Pushes a 64 bit unsigned value to the VM stack.
49 @param VmPtr The pointer to current VM context.
50 @param Arg The value to be pushed.
60 // Advance the VM stack down, and then copy the argument to the stack.
63 VmPtr
->Gpr
[0] -= sizeof (UINT64
);
64 *(UINT64
*) VmPtr
->Gpr
[0] = Arg
;
68 Begin executing an EBC image. The address of the entry point is passed
69 in via a processor register, so we'll need to make a call to get the
72 This is a thunk function. Microsoft x64 compiler only provide fast_call
73 calling convention, so the first four arguments are passed by rcx, rdx,
74 r8, and r9, while other arguments are passed in stack.
76 @param Arg1 The 1st argument.
77 @param ... The variable arguments list.
79 @return The value returned by the EBC application we're going to run.
90 // Create a new VM context on the stack
113 // Get the EBC entry point from the processor register. Make sure you don't
114 // call any functions before this or you could mess up the register the
115 // entry point is passed in.
117 Addr
= EbcLLGetEbcEntryPoint ();
119 // Need the args off the stack.
121 VA_START (List
, Arg1
);
122 Arg2
= VA_ARG (List
, UINT64
);
123 Arg3
= VA_ARG (List
, UINT64
);
124 Arg4
= VA_ARG (List
, UINT64
);
125 Arg5
= VA_ARG (List
, UINT64
);
126 Arg6
= VA_ARG (List
, UINT64
);
127 Arg7
= VA_ARG (List
, UINT64
);
128 Arg8
= VA_ARG (List
, UINT64
);
129 Arg9
= VA_ARG (List
, UINT64
);
130 Arg10
= VA_ARG (List
, UINT64
);
131 Arg11
= VA_ARG (List
, UINT64
);
132 Arg12
= VA_ARG (List
, UINT64
);
133 Arg13
= VA_ARG (List
, UINT64
);
134 Arg14
= VA_ARG (List
, UINT64
);
135 Arg15
= VA_ARG (List
, UINT64
);
136 Arg16
= VA_ARG (List
, UINT64
);
139 // Now clear out our context
141 ZeroMem ((VOID
*) &VmContext
, sizeof (VM_CONTEXT
));
143 // Set the VM instruction pointer to the correct location in memory.
145 VmContext
.Ip
= (VMIP
) Addr
;
147 // Initialize the stack pointer for the EBC. Get the current system stack
148 // pointer and adjust it down by the max needed for the interpreter.
151 // NOTE: Eventually we should have the interpreter allocate memory
152 // for stack space which it will use during its execution. This
153 // would likely improve performance because the interpreter would
154 // no longer be required to test each memory access and adjust
155 // those reading from the stack gap.
157 // For IPF, the stack looks like (assuming 10 args passed)
159 // arg9 (Bottom of high stack)
160 // [ stack gap for interpreter execution ]
161 // [ magic value for detection of stack corruption ]
162 // arg8 (Top of low stack)
165 // [ 64-bit return address ]
167 // If the EBC accesses memory in the stack gap, then we assume that it's
168 // actually trying to access args9 and greater. Therefore we need to
169 // adjust memory accesses in this region to point above the stack gap.
172 // Now adjust the EBC stack pointer down to leave a gap for interpreter
173 // execution. Then stuff a magic value there.
176 Status
= GetEBCStack((EFI_HANDLE
)(UINTN
)-1, &VmContext
.StackPool
, &StackIndex
);
177 if (EFI_ERROR(Status
)) {
180 VmContext
.StackTop
= (UINT8
*)VmContext
.StackPool
+ (STACK_REMAIN_SIZE
);
181 VmContext
.Gpr
[0] = (UINT64
) ((UINT8
*)VmContext
.StackPool
+ STACK_POOL_SIZE
);
182 VmContext
.HighStackBottom
= (UINTN
) VmContext
.Gpr
[0];
183 VmContext
.Gpr
[0] -= sizeof (UINTN
);
186 PushU64 (&VmContext
, (UINT64
) VM_STACK_KEY_VALUE
);
187 VmContext
.StackMagicPtr
= (UINTN
*) VmContext
.Gpr
[0];
188 VmContext
.LowStackTop
= (UINTN
) VmContext
.Gpr
[0];
190 // Push the EBC arguments on the stack. Does not matter that they may not
193 PushU64 (&VmContext
, Arg16
);
194 PushU64 (&VmContext
, Arg15
);
195 PushU64 (&VmContext
, Arg14
);
196 PushU64 (&VmContext
, Arg13
);
197 PushU64 (&VmContext
, Arg12
);
198 PushU64 (&VmContext
, Arg11
);
199 PushU64 (&VmContext
, Arg10
);
200 PushU64 (&VmContext
, Arg9
);
201 PushU64 (&VmContext
, Arg8
);
202 PushU64 (&VmContext
, Arg7
);
203 PushU64 (&VmContext
, Arg6
);
204 PushU64 (&VmContext
, Arg5
);
205 PushU64 (&VmContext
, Arg4
);
206 PushU64 (&VmContext
, Arg3
);
207 PushU64 (&VmContext
, Arg2
);
208 PushU64 (&VmContext
, Arg1
);
210 // Push a bogus return address on the EBC stack because the
211 // interpreter expects one there. For stack alignment purposes on IPF,
212 // EBC return addresses are always 16 bytes. Push a bogus value as well.
214 PushU64 (&VmContext
, 0);
215 PushU64 (&VmContext
, 0xDEADBEEFDEADBEEF);
216 VmContext
.StackRetAddr
= (UINT64
) VmContext
.Gpr
[0];
218 // Begin executing the EBC code
220 EbcExecute (&VmContext
);
222 // Return the value in R[7] unless there was an error
224 ReturnEBCStack(StackIndex
);
225 return (UINT64
) VmContext
.Gpr
[7];
230 Begin executing an EBC image. The address of the entry point is passed
231 in via a processor register, so we'll need to make a call to get the
234 @param ImageHandle image handle for the EBC application we're executing
235 @param SystemTable standard system table passed into an driver's entry
238 @return The value returned by the EBC application we're going to run.
243 ExecuteEbcImageEntryPoint (
244 IN EFI_HANDLE ImageHandle
,
245 IN EFI_SYSTEM_TABLE
*SystemTable
249 // Create a new VM context on the stack
251 VM_CONTEXT VmContext
;
257 // Get the EBC entry point from the processor register. Make sure you don't
258 // call any functions before this or you could mess up the register the
259 // entry point is passed in.
261 Addr
= EbcLLGetEbcEntryPoint ();
264 // Now clear out our context
266 ZeroMem ((VOID
*) &VmContext
, sizeof (VM_CONTEXT
));
269 // Save the image handle so we can track the thunks created for this image
271 VmContext
.ImageHandle
= ImageHandle
;
272 VmContext
.SystemTable
= SystemTable
;
275 // Set the VM instruction pointer to the correct location in memory.
277 VmContext
.Ip
= (VMIP
) Addr
;
280 // Get the stack pointer. This is the bottom of the upper stack.
283 Status
= GetEBCStack(ImageHandle
, &VmContext
.StackPool
, &StackIndex
);
284 if (EFI_ERROR(Status
)) {
287 VmContext
.StackTop
= (UINT8
*)VmContext
.StackPool
+ (STACK_REMAIN_SIZE
);
288 VmContext
.Gpr
[0] = (UINT64
) ((UINT8
*)VmContext
.StackPool
+ STACK_POOL_SIZE
);
289 VmContext
.HighStackBottom
= (UINTN
) VmContext
.Gpr
[0];
290 VmContext
.Gpr
[0] -= sizeof (UINTN
);
294 // Allocate stack space for the interpreter. Then put a magic value
295 // at the bottom so we can detect stack corruption.
297 PushU64 (&VmContext
, (UINT64
) VM_STACK_KEY_VALUE
);
298 VmContext
.StackMagicPtr
= (UINTN
*) (UINTN
) VmContext
.Gpr
[0];
301 // When we thunk to external native code, we copy the last 8 qwords from
302 // the EBC stack into the processor registers, and adjust the stack pointer
303 // up. If the caller is not passing 8 parameters, then we've moved the
304 // stack pointer up into the stack gap. If this happens, then the caller
305 // can mess up the stack gap contents (in particular our magic value).
306 // Therefore, leave another gap below the magic value. Pick 10 qwords down,
307 // just as a starting point.
309 VmContext
.Gpr
[0] -= 10 * sizeof (UINT64
);
312 // Align the stack pointer such that after pushing the system table,
313 // image handle, and return address on the stack, it's aligned on a 16-byte
314 // boundary as required for IPF.
316 VmContext
.Gpr
[0] &= (INT64
)~0x0f;
317 VmContext
.LowStackTop
= (UINTN
) VmContext
.Gpr
[0];
319 // Simply copy the image handle and system table onto the EBC stack.
320 // Greatly simplifies things by not having to spill the args
322 PushU64 (&VmContext
, (UINT64
) SystemTable
);
323 PushU64 (&VmContext
, (UINT64
) ImageHandle
);
326 // Interpreter assumes 64-bit return address is pushed on the stack.
327 // IPF does not do this so pad the stack accordingly. Also, a
328 // "return address" is 16 bytes as required for IPF stack alignments.
330 PushU64 (&VmContext
, (UINT64
) 0);
331 PushU64 (&VmContext
, (UINT64
) 0x1234567887654321);
332 VmContext
.StackRetAddr
= (UINT64
) VmContext
.Gpr
[0];
335 // Begin executing the EBC code
337 EbcExecute (&VmContext
);
340 // Return the value in R[7] unless there was an error
342 ReturnEBCStack(StackIndex
);
343 return (UINT64
) VmContext
.Gpr
[7];
348 Create thunks for an EBC image entry point, or an EBC protocol service.
350 @param ImageHandle Image handle for the EBC image. If not null, then
351 we're creating a thunk for an image entry point.
352 @param EbcEntryPoint Address of the EBC code that the thunk is to call
353 @param Thunk Returned thunk we create here
354 @param Flags Flags indicating options for creating the thunk
356 @retval EFI_SUCCESS The thunk was created successfully.
357 @retval EFI_INVALID_PARAMETER The parameter of EbcEntryPoint is not 16-bit
359 @retval EFI_OUT_OF_RESOURCES There is not enough memory to created the EBC
361 @retval EFI_BUFFER_TOO_SMALL EBC_THUNK_SIZE is not larger enough.
366 IN EFI_HANDLE ImageHandle
,
367 IN VOID
*EbcEntryPoint
,
375 UINT64 Code
[3]; // Code in a bundle
376 UINT64 RegNum
; // register number for MOVL
377 UINT64 BitI
; // bits of MOVL immediate data
378 UINT64 BitIc
; // bits of MOVL immediate data
379 UINT64 BitImm5c
; // bits of MOVL immediate data
380 UINT64 BitImm9d
; // bits of MOVL immediate data
381 UINT64 BitImm7b
; // bits of MOVL immediate data
382 UINT64 Br
; // branch register for loading and jumping
388 // Check alignment of pointer to EBC code, which must always be aligned
389 // on a 2-byte boundary.
391 if ((UINT32
) (UINTN
) EbcEntryPoint
& 0x01) {
392 return EFI_INVALID_PARAMETER
;
395 // Allocate memory for the thunk. Make the (most likely incorrect) assumption
396 // that the returned buffer is not aligned, so round up to the next
399 Size
= EBC_THUNK_SIZE
+ EBC_THUNK_ALIGNMENT
- 1;
401 Ptr
= AllocatePool (Size
);
404 return EFI_OUT_OF_RESOURCES
;
407 // Save the start address of the buffer.
412 // Make sure it's aligned for code execution. If not, then
415 if ((UINT32
) (UINTN
) Ptr
& (EBC_THUNK_ALIGNMENT
- 1)) {
416 Ptr
= (UINT8
*) (((UINTN
) Ptr
+ (EBC_THUNK_ALIGNMENT
- 1)) &~ (UINT64
) (EBC_THUNK_ALIGNMENT
- 1));
419 // Return the pointer to the thunk to the caller to user as the
420 // image entry point.
422 *Thunk
= (VOID
*) Ptr
;
425 // Clear out the thunk entry
426 // ZeroMem(Ptr, Size);
428 // For IPF, when you do a call via a function pointer, the function pointer
429 // actually points to a function descriptor which consists of a 64-bit
430 // address of the function, followed by a 64-bit gp for the function being
431 // called. See the the Software Conventions and Runtime Architecture Guide
433 // So first off in our thunk, create a descriptor for our actual thunk code.
434 // This means we need to create a pointer to the thunk code (which follows
435 // the descriptor we're going to create), followed by the gp of the Vm
436 // interpret function we're going to eventually execute.
438 Data64Ptr
= (UINT64
*) Ptr
;
441 // Write the function's entry point (which is our thunk code that follows
442 // this descriptor we're creating).
444 *Data64Ptr
= (UINT64
) (Data64Ptr
+ 2);
446 // Get the gp from the descriptor for EbcInterpret and stuff it in our thunk
449 *(Data64Ptr
+ 1) = *(UINT64
*) ((UINT64
*) (UINTN
) EbcInterpret
+ 1);
451 // Advance our thunk data pointer past the descriptor. Since the
452 // descriptor consists of 16 bytes, the pointer is still aligned for
453 // IPF code execution (on 16-byte boundary).
455 Ptr
+= sizeof (UINT64
) * 2;
458 // *************************** MAGIC BUNDLE ********************************
460 // Write magic code bundle for: movl r8 = 0xca112ebcca112ebc to help the VM
461 // to recognize it is a thunk.
463 Addr
= (UINT64
) 0xCA112EBCCA112EBC;
466 // Now generate the code bytes. First is nop.m 0x0
468 Code
[0] = OPCODE_NOP
;
471 // Next is simply Addr[62:22] (41 bits) of the address
473 Code
[1] = RShiftU64 (Addr
, 22) & 0x1ffffffffff;
476 // Extract bits from the address for insertion into the instruction
479 BitI
= RShiftU64 (Addr
, 63) & 0x01;
483 BitIc
= RShiftU64 (Addr
, 21) & 0x01;
485 // imm5c = Addr[20:16] for 5 bits
487 BitImm5c
= RShiftU64 (Addr
, 16) & 0x1F;
489 // imm9d = Addr[15:7] for 9 bits
491 BitImm9d
= RShiftU64 (Addr
, 7) & 0x1FF;
493 // imm7b = Addr[6:0] for 7 bits
495 BitImm7b
= Addr
& 0x7F;
498 // The EBC entry point will be put into r8, so r8 can be used here
499 // temporary. R8 is general register and is auto-serialized.
504 // Next is jumbled data, including opcode and rest of address
506 Code
[2] = LShiftU64 (BitImm7b
, 13);
507 Code
[2] = Code
[2] | LShiftU64 (0x00, 20); // vc
508 Code
[2] = Code
[2] | LShiftU64 (BitIc
, 21);
509 Code
[2] = Code
[2] | LShiftU64 (BitImm5c
, 22);
510 Code
[2] = Code
[2] | LShiftU64 (BitImm9d
, 27);
511 Code
[2] = Code
[2] | LShiftU64 (BitI
, 36);
512 Code
[2] = Code
[2] | LShiftU64 ((UINT64
)MOVL_OPCODE
, 37);
513 Code
[2] = Code
[2] | LShiftU64 ((RegNum
& 0x7F), 6);
515 WriteBundle ((VOID
*) Ptr
, 0x05, Code
[0], Code
[1], Code
[2]);
518 // *************************** FIRST BUNDLE ********************************
520 // Write code bundle for: movl r8 = EBC_ENTRY_POINT so we pass
521 // the ebc entry point in to the interpreter function via a processor
523 // Note -- we could easily change this to pass in a pointer to a structure
524 // that contained, among other things, the EBC image's entry point. But
525 // for now pass it directly.
528 Addr
= (UINT64
) EbcEntryPoint
;
531 // Now generate the code bytes. First is nop.m 0x0
533 Code
[0] = OPCODE_NOP
;
536 // Next is simply Addr[62:22] (41 bits) of the address
538 Code
[1] = RShiftU64 (Addr
, 22) & 0x1ffffffffff;
541 // Extract bits from the address for insertion into the instruction
544 BitI
= RShiftU64 (Addr
, 63) & 0x01;
548 BitIc
= RShiftU64 (Addr
, 21) & 0x01;
550 // imm5c = Addr[20:16] for 5 bits
552 BitImm5c
= RShiftU64 (Addr
, 16) & 0x1F;
554 // imm9d = Addr[15:7] for 9 bits
556 BitImm9d
= RShiftU64 (Addr
, 7) & 0x1FF;
558 // imm7b = Addr[6:0] for 7 bits
560 BitImm7b
= Addr
& 0x7F;
563 // Put the EBC entry point in r8, which is the location of the return value
569 // Next is jumbled data, including opcode and rest of address
571 Code
[2] = LShiftU64 (BitImm7b
, 13);
572 Code
[2] = Code
[2] | LShiftU64 (0x00, 20); // vc
573 Code
[2] = Code
[2] | LShiftU64 (BitIc
, 21);
574 Code
[2] = Code
[2] | LShiftU64 (BitImm5c
, 22);
575 Code
[2] = Code
[2] | LShiftU64 (BitImm9d
, 27);
576 Code
[2] = Code
[2] | LShiftU64 (BitI
, 36);
577 Code
[2] = Code
[2] | LShiftU64 ((UINT64
)MOVL_OPCODE
, 37);
578 Code
[2] = Code
[2] | LShiftU64 ((RegNum
& 0x7F), 6);
580 WriteBundle ((VOID
*) Ptr
, 0x05, Code
[0], Code
[1], Code
[2]);
583 // *************************** NEXT BUNDLE *********************************
585 // Write code bundle for:
586 // movl rx = offset_of(EbcInterpret|ExecuteEbcImageEntryPoint)
588 // Advance pointer to next bundle, then compute the offset from this bundle
589 // to the address of the entry point of the interpreter.
592 if ((Flags
& FLAG_THUNK_ENTRY_POINT
) != 0) {
593 Addr
= (UINT64
) ExecuteEbcImageEntryPoint
;
595 Addr
= (UINT64
) EbcInterpret
;
598 // Indirection on Itanium-based systems
600 Addr
= *(UINT64
*) Addr
;
603 // Now write the code to load the offset into a register
605 Code
[0] = OPCODE_NOP
;
608 // Next is simply Addr[62:22] (41 bits) of the address
610 Code
[1] = RShiftU64 (Addr
, 22) & 0x1ffffffffff;
613 // Extract bits from the address for insertion into the instruction
616 BitI
= RShiftU64 (Addr
, 63) & 0x01;
620 BitIc
= RShiftU64 (Addr
, 21) & 0x01;
622 // imm5c = Addr[20:16] for 5 bits
624 BitImm5c
= RShiftU64 (Addr
, 16) & 0x1F;
626 // imm9d = Addr[15:7] for 9 bits
628 BitImm9d
= RShiftU64 (Addr
, 7) & 0x1FF;
630 // imm7b = Addr[6:0] for 7 bits
632 BitImm7b
= Addr
& 0x7F;
635 // Put it in r31, a scratch register
640 // Next is jumbled data, including opcode and rest of address
642 Code
[2] = LShiftU64(BitImm7b
, 13);
643 Code
[2] = Code
[2] | LShiftU64 (0x00, 20); // vc
644 Code
[2] = Code
[2] | LShiftU64 (BitIc
, 21);
645 Code
[2] = Code
[2] | LShiftU64 (BitImm5c
, 22);
646 Code
[2] = Code
[2] | LShiftU64 (BitImm9d
, 27);
647 Code
[2] = Code
[2] | LShiftU64 (BitI
, 36);
648 Code
[2] = Code
[2] | LShiftU64 ((UINT64
)MOVL_OPCODE
, 37);
649 Code
[2] = Code
[2] | LShiftU64 ((RegNum
& 0x7F), 6);
651 WriteBundle ((VOID
*) Ptr
, 0x05, Code
[0], Code
[1], Code
[2]);
654 // *************************** NEXT BUNDLE *********************************
656 // Load branch register with EbcInterpret() function offset from the bundle
657 // address: mov b6 = RegNum
659 // See volume 3 page 4-29 of the Arch. Software Developer's Manual.
661 // Advance pointer to next bundle
664 Code
[0] = OPCODE_NOP
;
665 Code
[1] = OPCODE_NOP
;
666 Code
[2] = OPCODE_MOV_BX_RX
;
669 // Pick a branch register to use. Then fill in the bits for the branch
670 // register and user register (same user register as previous bundle).
673 Code
[2] |= LShiftU64 (Br
, 6);
674 Code
[2] |= LShiftU64 (RegNum
, 13);
675 WriteBundle ((VOID
*) Ptr
, 0x0d, Code
[0], Code
[1], Code
[2]);
678 // *************************** NEXT BUNDLE *********************************
680 // Now do the branch: (p0) br.cond.sptk.few b6
682 // Advance pointer to next bundle.
683 // Fill in the bits for the branch register (same reg as previous bundle)
686 Code
[0] = OPCODE_NOP
;
687 Code
[1] = OPCODE_NOP
;
688 Code
[2] = OPCODE_BR_COND_SPTK_FEW
;
689 Code
[2] |= LShiftU64 (Br
, 13);
690 WriteBundle ((VOID
*) Ptr
, 0x1d, Code
[0], Code
[1], Code
[2]);
693 // Add the thunk to our list of allocated thunks so we can do some cleanup
694 // when the image is unloaded. Do this last since the Add function flushes
695 // the instruction cache for us.
697 EbcAddImageThunk (ImageHandle
, (VOID
*) ThunkBase
, ThunkSize
);
707 Given raw bytes of Itanium based code, format them into a bundle and
710 @param MemPtr pointer to memory location to write the bundles
712 @param Template 5-bit template.
713 @param Slot0 Instruction slot 0 data for the bundle.
714 @param Slot1 Instruction slot 1 data for the bundle.
715 @param Slot2 Instruction slot 2 data for the bundle.
717 @retval EFI_INVALID_PARAMETER Pointer is not aligned
718 @retval EFI_INVALID_PARAMETER No more than 5 bits in template
719 @retval EFI_INVALID_PARAMETER More than 41 bits used in code
720 @retval EFI_SUCCESS All data is written.
738 // Verify pointer is aligned
740 if ((UINT64
) MemPtr
& 0xF) {
741 return EFI_INVALID_PARAMETER
;
744 // Verify no more than 5 bits in template
746 if ((Template
&~0x1F) != 0) {
747 return EFI_INVALID_PARAMETER
;
750 // Verify max of 41 bits used in code
752 if (((Slot0
| Slot1
| Slot2
) &~0x1ffffffffff) != 0) {
753 return EFI_INVALID_PARAMETER
;
756 Low64
= LShiftU64 (Slot1
, 46);
757 Low64
= Low64
| LShiftU64 (Slot0
, 5) | Template
;
759 High64
= RShiftU64 (Slot1
, 18);
760 High64
= High64
| LShiftU64 (Slot2
, 23);
763 // Now write it all out
765 BPtr
= (UINT8
*) MemPtr
;
766 for (Index
= 0; Index
< 8; Index
++) {
767 *BPtr
= (UINT8
) Low64
;
768 Low64
= RShiftU64 (Low64
, 8);
772 for (Index
= 0; Index
< 8; Index
++) {
773 *BPtr
= (UINT8
) High64
;
774 High64
= RShiftU64 (High64
, 8);
783 This function is called to execute an EBC CALLEX instruction.
784 The function check the callee's content to see whether it is common native
785 code or a thunk to another piece of EBC code.
786 If the callee is common native code, use EbcLLCAllEXASM to manipulate,
787 otherwise, set the VM->IP to target EBC code directly to avoid another VM
788 be startup which cost time and stack space.
790 @param VmPtr Pointer to a VM context.
791 @param FuncAddr Callee's address
792 @param NewStackPointer New stack pointer after the call
793 @param FramePtr New frame pointer after the call
794 @param Size The size of call instruction
799 IN VM_CONTEXT
*VmPtr
,
801 IN UINTN NewStackPointer
,
821 // FuncAddr points to the descriptor of the target instructions.
823 CalleeAddr
= *((UINT64
*)FuncAddr
);
826 // Processor specific code to check whether the callee is a thunk to EBC.
828 if (*((UINT64
*)CalleeAddr
) != 0xBCCA000100000005) {
832 if (*((UINT64
*)CalleeAddr
+ 1) != 0x697623C1004A112E) {
837 CodeOne18
= RShiftU64 (*((UINT64
*)CalleeAddr
+ 2), 46) & 0x3FFFF;
838 CodeOne23
= (*((UINT64
*)CalleeAddr
+ 3)) & 0x7FFFFF;
839 CodeTwoI
= RShiftU64 (*((UINT64
*)CalleeAddr
+ 3), 59) & 0x1;
840 CodeTwoIc
= RShiftU64 (*((UINT64
*)CalleeAddr
+ 3), 44) & 0x1;
841 CodeTwo7b
= RShiftU64 (*((UINT64
*)CalleeAddr
+ 3), 36) & 0x7F;
842 CodeTwo5c
= RShiftU64 (*((UINT64
*)CalleeAddr
+ 3), 45) & 0x1F;
843 CodeTwo9d
= RShiftU64 (*((UINT64
*)CalleeAddr
+ 3), 50) & 0x1FF;
845 TargetEbcAddr
= CodeTwo7b
;
846 TargetEbcAddr
= TargetEbcAddr
| LShiftU64 (CodeTwo9d
, 7);
847 TargetEbcAddr
= TargetEbcAddr
| LShiftU64 (CodeTwo5c
, 16);
848 TargetEbcAddr
= TargetEbcAddr
| LShiftU64 (CodeTwoIc
, 21);
849 TargetEbcAddr
= TargetEbcAddr
| LShiftU64 (CodeOne18
, 22);
850 TargetEbcAddr
= TargetEbcAddr
| LShiftU64 (CodeOne23
, 40);
851 TargetEbcAddr
= TargetEbcAddr
| LShiftU64 (CodeTwoI
, 63);
856 // The callee is a thunk to EBC, adjust the stack pointer down 16 bytes and
857 // put our return address and frame pointer on the VM stack.
858 // Then set the VM's IP to new EBC code.
861 VmWriteMemN (VmPtr
, (UINTN
) VmPtr
->Gpr
[0], (UINTN
) FramePtr
);
862 VmPtr
->FramePtr
= (VOID
*) (UINTN
) VmPtr
->Gpr
[0];
864 VmWriteMem64 (VmPtr
, (UINTN
) VmPtr
->Gpr
[0], (UINT64
) (VmPtr
->Ip
+ Size
));
866 VmPtr
->Ip
= (VMIP
) (UINTN
) TargetEbcAddr
;
869 // The callee is not a thunk to EBC, call native code,
870 // and get return value.
872 VmPtr
->Gpr
[7] = EbcLLCALLEXNative (FuncAddr
, NewStackPointer
, FramePtr
);