1 files changed, 79 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/asm/ASMWrMsrEx.asm b/src/VBox/Runtime/common/asm/ASMWrMsrEx.asm
new file mode 100644
index 00000000..ee5c6a46
--- /dev/null
+++ b/src/VBox/Runtime/common/asm/ASMWrMsrEx.asm
@@ -0,0 +1,79 @@
+; $Id: ASMWrMsrEx.asm $
+;; @file
+; IPRT - ASMWrMsrEx().
+;
+
+;
+; Copyright (C) 2013-2020 Oracle Corporation
+;
+; This file is part of VirtualBox Open Source Edition (OSE), as
+; available from http://www.virtualbox.org. This file is free software;
+; you can redistribute it and/or modify it under the terms of the GNU
+; General Public License (GPL) as published by the Free Software
+; Foundation, in version 2 as it comes in the "COPYING" file of the
+; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+;
+; The contents of this file may alternatively be used under the terms
+; of the Common Development and Distribution License Version 1.0
+; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+; VirtualBox OSE distribution, in which case the provisions of the
+; CDDL are applicable instead of those of the GPL.
+;
+; You may elect to license modified versions of this file under the
+; terms and conditions of either the GPL or the CDDL or both.
+;
+
+;*******************************************************************************
+;* Header Files                                                                *
+;*******************************************************************************
+%include "iprt/asmdefs.mac"
+
+BEGINCODE
+
+;;
+; Special version of ASMRdMsr that allow specifying the rdi value.
+;
+; @param    uMsr    msc=rcx, gcc=rdi, x86=[ebp+8]   The MSR to read.
+; @param    uXDI    msc=rdx, gcc=rsi, x86=[ebp+12]  The EDI/RDI value.
+; @param    uValue  msc=r8,  gcc=rdx, x86=[ebp+16]  The 64-bit value to write.
+;
+BEGINPROC_EXPORTED ASMWrMsrEx
+%ifdef ASM_CALL64_MSC
+proc_frame ASMWrMsrEx_DupWarningHack
+        push    rdi
+        [pushreg rdi]
+[endprolog]
+        and     ecx, ecx                ; serious paranoia
+        mov     rdi, rdx
+        mov     eax, r8d
+        mov     rdx, r8
+        shr     rdx, 32
+        wrmsr
+        pop     rdi
+        ret
+endproc_frame
+%elifdef ASM_CALL64_GCC
+        mov     ecx, edi
+        mov     rdi, rsi
+        mov     eax, edx
+        shr     edx, 32
+        wrmsr
+        ret
+%elifdef RT_ARCH_X86
+        push    ebp
+        mov     ebp, esp
+        push    edi
+        mov     ecx, [ebp + 8]
+        mov     edi, [esp + 12]
+        mov     eax, [esp + 16]
+        mov     edx, [esp + 20]
+        wrmsr
+        pop     edi
+        leave
+        ret
+%else
+ %error "Undefined arch?"
+%endif
+ENDPROC ASMWrMsrEx
+