VirtualBox

source: vbox/trunk/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-RegSetLdtr.asm@ 72138

Last change on this file since 72138 was 72138, checked in by vboxsync, 7 years ago

bs3kit: Made the CRx & DRx getters and setters work from rings other than ring-0. Added getters and setters for TR and LDTR.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 2.2 KB
Line 
1; $Id: bs3-cmn-RegSetLdtr.asm 72138 2018-05-07 13:03:51Z vboxsync $
2;; @file
3; BS3Kit - Bs3RegSetLdtr
4;
5
6;
7; Copyright (C) 2007-2018 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
34BS3_EXTERN_SYSTEM16 Bs3Gdt
35TMPL_BEGIN_TEXT
36
37
38;;
39; @cproto BS3_CMN_PROTO_STUB(void, Bs3RegSetLdtr,(uint16_t uValue));
40;
41; @param uValue The value to set.
42
43; @remarks Does not require 20h of parameter scratch space in 64-bit mode.
44;
45; @uses No GPRs.
46;
47BS3_PROC_BEGIN_CMN Bs3RegSetLdtr, BS3_PBC_HYBRID_SAFE
48 BS3_CALL_CONV_PROLOG 1
49 push xBP
50 mov xBP, xSP
51 push xDX
52 push xAX
53
54 mov dx, [xBP + xCB + cbCurRetAddr]
55
56%if TMPL_BITS == 16
57 ; If V8086 mode we have to go thru a syscall.
58 test byte [BS3_DATA16_WRT(g_bBs3CurrentMode)], BS3_MODE_CODE_V86
59 jnz .via_system_call
60%endif
61 ; If not in ring-0, we have to make a system call.
62 mov ax, ss
63 and ax, X86_SEL_RPL
64 jnz .via_system_call
65
66 ; Load it.
67 lldt dx
68 jmp .return
69
70.via_system_call:
71 mov ax, BS3_SYSCALL_SET_LDTR
72 call Bs3Syscall
73
74.return:
75 pop xAX
76 pop xDX
77 pop xBP
78 BS3_CALL_CONV_EPILOG 1
79 BS3_HYBRID_RET
80BS3_PROC_END_CMN Bs3RegSetLdtr
81
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