VirtualBox

source: vbox/trunk/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-RegSetXcr0.asm@ 95532

Last change on this file since 95532 was 95372, checked in by vboxsync, 3 years ago

ValKit/bs3kit: Some more work on extended CPU/FPU state management. bugref:9898

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 2.5 KB
Line 
1; $Id: bs3-cmn-RegSetXcr0.asm 95372 2022-06-26 00:27:49Z vboxsync $
2;; @file
3; BS3Kit - Bs3RegSetXcr0
4;
5
6;
7; Copyright (C) 2007-2022 Oracle Corporation
8;
9; This file is part of VirtualBox Open Source Edition (OSE), as
10; available from http://www.virtualbox.org. This file is free software;
11; you can redistribute it and/or modify it under the terms of the GNU
12; General Public License (GPL) as published by the Free Software
13; Foundation, in version 2 as it comes in the "COPYING" file of the
14; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16;
17; The contents of this file may alternatively be used under the terms
18; of the Common Development and Distribution License Version 1.0
19; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20; VirtualBox OSE distribution, in which case the provisions of the
21; CDDL are applicable instead of those of the GPL.
22;
23; You may elect to license modified versions of this file under the
24; terms and conditions of either the GPL or the CDDL or both.
25;
26
27%include "bs3kit-template-header.mac"
28
29
30BS3_EXTERN_CMN Bs3Syscall
31%if TMPL_BITS == 16
32BS3_EXTERN_DATA16 g_bBs3CurrentMode
33%endif
34TMPL_BEGIN_TEXT
35
36
37;;
38; @cproto BS3_CMN_PROTO_STUB(void, Bs3RegSetXcr0,(uint64_t uValue));
39;
40; @param uValue The value to set.
41
42; @remarks Does not require 20h of parameter scratch space in 64-bit mode.
43;
44; @uses No GPRs.
45;
46BS3_PROC_BEGIN_CMN Bs3RegSetXcr0, BS3_PBC_HYBRID_SAFE
47 push xBP
48 mov xBP, xSP
49 push sSI
50 push sDX
51 push sAX
52
53 ; Load the value
54%if TMPL_BITS == 64
55 mov eax, ecx
56 mov rdx, rcx
57 shr rdx, 32
58%else
59 mov sAX, [xBP + xCB + cbCurRetAddr]
60 mov sDX, [xBP + xCB + cbCurRetAddr + 4]
61%endif
62
63%if TMPL_BITS == 16
64 ; If V8086 mode we have to go thru a syscall.
65 test byte [BS3_DATA16_WRT(g_bBs3CurrentMode)], BS3_MODE_CODE_V86
66 jnz .via_system_call
67 cmp byte [BS3_DATA16_WRT(g_bBs3CurrentMode)], BS3_MODE_RM
68 je .direct_access
69%endif
70 ; If not in ring-0, we have to make a system call.
71 mov si, ss
72 and si, X86_SEL_RPL
73 jnz .via_system_call
74
75.direct_access:
76 push sCX
77 xor ecx, ecx
78 xsetbv
79 pop sCX
80 jmp .return
81
82.via_system_call:
83 xchg esi, eax
84 mov xAX, BS3_SYSCALL_SET_XCR0
85 call Bs3Syscall
86
87.return:
88 pop sAX
89 pop sDX
90 pop sSI
91 pop xBP
92 BS3_HYBRID_RET
93BS3_PROC_END_CMN Bs3RegSetXcr0
94
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