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Diffstat (limited to 'MdeModulePkg/Universal/EbcDxe/x64/EbcLowLevel.asm')
| -rw-r--r-- | MdeModulePkg/Universal/EbcDxe/x64/EbcLowLevel.asm | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/MdeModulePkg/Universal/EbcDxe/x64/EbcLowLevel.asm b/MdeModulePkg/Universal/EbcDxe/x64/EbcLowLevel.asm new file mode 100644 index 0000000..7b59e93 --- /dev/null +++ b/MdeModulePkg/Universal/EbcDxe/x64/EbcLowLevel.asm @@ -0,0 +1,154 @@ + page ,132
+ title VM ASSEMBLY LANGUAGE ROUTINES
+;****************************************************************************
+;*
+;* 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.
+;*
+;****************************************************************************
+;****************************************************************************
+; REV 1.0
+;****************************************************************************
+;
+; Rev Date Description
+; --- -------- ------------------------------------------------------------
+; 1.0 05/09/12 Initial creation of file.
+;
+;****************************************************************************
+
+;* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+; This code provides low level routines that support the Virtual Machine
+; for option ROMs.
+;* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+
+;---------------------------------------------------------------------------
+; Equate files needed.
+;---------------------------------------------------------------------------
+
+text SEGMENT
+
+;---------------------------------------------------------------------------
+;;GenericPostSegment SEGMENT USE16
+;---------------------------------------------------------------------------
+
+;****************************************************************************
+; EbcLLCALLEX
+;
+; This function is called to execute an EBC CALLEX instruction.
+; This instruction requires that we thunk out to external native
+; code. For x64, we switch stacks, copy the arguments to the stack
+; and jump to the specified function.
+; On return, we restore the stack pointer to its original location.
+;
+; Destroys no working registers.
+;****************************************************************************
+; VOID EbcLLCALLEXNative(UINTN FuncAddr, UINTN NewStackPointer, VOID *FramePtr)
+
+CopyMem PROTO Destination:PTR DWORD, Source:PTR DWORD, Count:DWORD
+
+
+EbcLLCALLEXNative PROC NEAR PUBLIC
+ push rbp
+ push rbx
+ mov rbp, rsp
+ ; Function prolog
+
+ ; Copy FuncAddr to a preserved register.
+ mov rbx, rcx
+
+ ; Set stack pointer to new value
+ sub r8, rdx
+ sub rsp, r8
+ mov rcx, rsp
+ sub rsp, 20h
+ call CopyMem
+ add rsp, 20h
+
+ ; Considering the worst case, load 4 potiential arguments
+ ; into registers.
+ mov rcx, qword ptr [rsp]
+ mov rdx, qword ptr [rsp+8h]
+ mov r8, qword ptr [rsp+10h]
+ mov r9, qword ptr [rsp+18h]
+
+ ; Now call the external routine
+ call rbx
+
+ ; Function epilog
+ mov rsp, rbp
+ pop rbx
+ pop rbp
+ ret
+EbcLLCALLEXNative ENDP
+
+
+; UINTN EbcLLGetEbcEntryPoint(VOID);
+; Routine Description:
+; The VM thunk code stuffs an EBC entry point into a processor
+; register. Since we can't use inline assembly to get it from
+; the interpreter C code, stuff it into the return value
+; register and return.
+;
+; Arguments:
+; None.
+;
+; Returns:
+; The contents of the register in which the entry point is passed.
+;
+EbcLLGetEbcEntryPoint PROC NEAR PUBLIC
+ ret
+EbcLLGetEbcEntryPoint ENDP
+
+;/*++
+;
+;Routine Description:
+;
+; Return the caller's value of the stack pointer.
+;
+;Arguments:
+;
+; None.
+;
+;Returns:
+;
+; The current value of the stack pointer for the caller. We
+; adjust it by 4 here because when they called us, the return address
+; is put on the stack, thereby lowering it by 4 bytes.
+;
+;--*/
+
+; UINTN EbcLLGetStackPointer()
+EbcLLGetStackPointer PROC NEAR PUBLIC
+ mov rax, rsp ; get current stack pointer
+ ; Stack adjusted by this much when we were called,
+ ; For this function, it's 4.
+ add rax, 4
+ ret
+EbcLLGetStackPointer ENDP
+
+; UINT64 EbcLLGetReturnValue(VOID);
+; Routine Description:
+; When EBC calls native, on return the VM has to stuff the return
+; value into a VM register. It's assumed here that the value is still
+; in the register, so simply return and the caller should get the
+; return result properly.
+;
+; Arguments:
+; None.
+;
+; Returns:
+; The unmodified value returned by the native code.
+;
+EbcLLGetReturnValue PROC NEAR PUBLIC
+ ret
+EbcLLGetReturnValue ENDP
+
+text ENDS
+END
+
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