955723bd63
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@5258 6f19259b-4bc3-4df7-8a09-765794883524
134 lines
3.8 KiB
ArmAsm
134 lines
3.8 KiB
ArmAsm
#/** @file
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#
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# This code provides low level routines that support the Virtual Machine
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# for option ROMs.
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#
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# Copyright (c) 2007 - 2008, Intel Corporation. <BR>
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# All rights reserved. This program and the accompanying materials
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# are licensed and made available under the terms and conditions of the BSD License
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# which accompanies this distribution. The full text of the license may be found at
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# http://opensource.org/licenses/bsd-license.php
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#
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# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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#
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#**/
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#---------------------------------------------------------------------------
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# Equate files needed.
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#---------------------------------------------------------------------------
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#---------------------------------------------------------------------------
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##GenericPostSegment SEGMENT USE16
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#---------------------------------------------------------------------------
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#****************************************************************************
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# EbcLLCALLEX
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#
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# This function is called to execute an EBC CALLEX instruction.
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# This instruction requires that we thunk out to external native
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# code. For x64, we switch stacks, copy the arguments to the stack
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# and jump to the specified function.
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# On return, we restore the stack pointer to its original location.
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#
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# Destroys no working registers.
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#****************************************************************************
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.global _CopyMem;
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# VOID EbcLLCALLEXNative(UINTN FuncAddr, UINTN NewStackPointer, VOID *FramePtr)
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.global _EbcLLCALLEXNative;
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_EbcLLCALLEXNative:
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push %rbp
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push %rbx
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mov %rsp, %rbp
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# Function prolog
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# Copy FuncAddr to a preserved register.
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mov %rcx, %rbx
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# Set stack pointer to new value
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sub %r8, %rdx
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sub %rsp, %r8
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mov %rsp, %rcx
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sub %rsp, 0x20
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call _CopyMem
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add %rsp, 0x20
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# Considering the worst case, load 4 potiential arguments
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# into registers.
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mov (%rsp), %rcx
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mov 8(%rsp), %rdx
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mov 10(%rsp), %r8
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mov 18(%rsp), %r9
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# Now call the external routine
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call *%rbx
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# Function epilog
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mov %rbp, %rsp
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pop %rbx
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pop %rbp
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ret
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# UINTN EbcLLGetEbcEntryPoint(VOID);
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# Routine Description:
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# The VM thunk code stuffs an EBC entry point into a processor
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# register. Since we can't use inline assembly to get it from
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# the interpreter C code, stuff it into the return value
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# register and return.
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#
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# Arguments:
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# None.
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#
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# Returns:
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# The contents of the register in which the entry point is passed.
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#
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.global _EbcLLGetEbcEntryPoint;
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_EbcLLGetEbcEntryPoint:
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ret
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#/*++
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#
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#Routine Description:
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#
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# Return the caller's value of the stack pointer.
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#
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#Arguments:
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#
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# None.
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#
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#Returns:
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#
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# The current value of the stack pointer for the caller. We
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# adjust it by 4 here because when they called us, the return address
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# is put on the stack, thereby lowering it by 4 bytes.
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#
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#--*/
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# UINTN EbcLLGetStackPointer()
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.global _EbcLLGetStackPointer;
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_EbcLLGetStackPointer:
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mov %rsp, %rax
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# Stack adjusted by this much when we were called,
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# For this function, it's 4.
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add $4, %rax
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ret
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.global _EbcLLGetReturnValue;
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_EbcLLGetReturnValue:
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# UINT64 EbcLLGetReturnValue(VOID);
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# Routine Description:
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# When EBC calls native, on return the VM has to stuff the return
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# value into a VM register. It's assumed here that the value is still
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# in the register, so simply return and the caller should get the
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# return result properly.
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#
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# Arguments:
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# None.
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#
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# Returns:
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# The unmodified value returned by the native code.
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#
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ret
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