1 files changed, 99 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/asm/ASMWrMsr.asm b/src/VBox/Runtime/common/asm/ASMWrMsr.asm
new file mode 100644
index 00000000..d1a9d422
--- /dev/null
+++ b/src/VBox/Runtime/common/asm/ASMWrMsr.asm
@@ -0,0 +1,99 @@
+; $Id: ASMWrMsr.asm $
+;; @file
+; IPRT - ASMWrMsr().
+;
+
+;
+; Copyright (C) 2013-2022 Oracle and/or its affiliates.
+;
+; This file is part of VirtualBox base platform packages, as
+; available from https://www.virtualbox.org.
+;
+; This program is free software; you can redistribute it and/or
+; modify it under the terms of the GNU General Public License
+; as published by the Free Software Foundation, in version 3 of the
+; License.
+;
+; This program is distributed in the hope that it will be useful, but
+; WITHOUT ANY WARRANTY; without even the implied warranty of
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+; General Public License for more details.
+;
+; You should have received a copy of the GNU General Public License
+; along with this program; if not, see <https://www.gnu.org/licenses>.
+;
+; The contents of this file may alternatively be used under the terms
+; of the Common Development and Distribution License Version 1.0
+; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
+; in the VirtualBox 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.
+;
+; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
+;
+
+;*******************************************************************************
+;* 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    uValue  msc=rdx, gcc=rsi, x86=[ebp+12]  The 64-bit value to write.
+;
+RT_BEGINPROC ASMWrMsr
+%ifdef ASM_CALL64_MSC
+        mov     rdi, rdx
+        mov     eax, edx
+        shr     rdx, 32
+        wrmsr
+        ret
+
+%elifdef ASM_CALL64_GCC
+        mov     ecx, edi
+        mov     eax, esi
+        mov     rdx, rsi
+        shr     edx, 32
+        wrmsr
+        ret
+
+%elif ARCH_BITS == 32
+        push    ebp
+        mov     ebp, esp
+        push    edi
+        mov     ecx, [ebp + 8]
+        mov     eax, [ebp + 12]
+        mov     edx, [ebp + 16]
+        wrmsr
+        pop     edi
+        leave
+        ret
+
+%elif ARCH_BITS == 16
+        push    bp
+        mov     bp, sp
+        push    eax
+        push    ecx
+        push    edx
+
+        mov     ecx, [bp + 04h]
+        mov     eax, [bp + 08h]
+        mov     edx, [bp + 0ch]
+        wrmsr
+
+        pop     edx
+        pop     ecx
+        pop     eax
+        leave
+        ret
+%else
+ %error "Undefined arch?"
+%endif
+ENDPROC ASMWrMsr
+