summaryrefslogtreecommitdiffstats
path: root/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-RegSetDrX.asm
blob: eeddad92c28d05117ce81745b9e84dc043b7b726 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
; $Id: bs3-cmn-RegSetDrX.asm $
;; @file
; BS3Kit - Bs3RegSetDrX
;

;
; Copyright (C) 2007-2019 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.
;

%include "bs3kit-template-header.mac"


BS3_EXTERN_CMN Bs3Panic
BS3_EXTERN_CMN Bs3Syscall
%if TMPL_BITS == 16
BS3_EXTERN_DATA16 g_bBs3CurrentMode
%endif
TMPL_BEGIN_TEXT

;TONLY16 CPU 386

;;
; @cproto   BS3_CMN_PROTO_STUB(void, Bs3RegSetDrX,(uint8_t iReg, RTCCUINTXREG uValue));
;
; @returns  Register value.
; @param    iRegister   The source register
; @param    uValue      The new Value.

; @remarks  Does not require 20h of parameter scratch space in 64-bit mode.
;
; @uses     No GPRs.
;
BS3_PROC_BEGIN_CMN Bs3RegSetDrX, BS3_PBC_HYBRID_SAFE
        BS3_CALL_CONV_PROLOG 2
        push    xBP
        mov     xBP, xSP
        push    sSI
        push    xDX

        mov     sSI, [xBP + xCB + cbCurRetAddr + xCB]

%if TMPL_BITS == 16
        ; If V8086 mode we have to go thru a syscall.
        test    byte [BS3_DATA16_WRT(g_bBs3CurrentMode)], BS3_MODE_CODE_V86
        jnz     .via_system_call
        cmp     byte [BS3_DATA16_WRT(g_bBs3CurrentMode)], BS3_MODE_RM
        je      .direct_access
%endif
        ; If not in ring-0, we have to make a system call.
        mov     dx, ss
        and     dx, X86_SEL_RPL
        jnz     .via_system_call

.direct_access:
        ; Switch (iRegister)
        mov     dl, [xBP + xCB + cbCurRetAddr]
        cmp     dl, 6
        jz      .set_dr6
        cmp     dl, 7
        jz      .set_dr7
        cmp     dl, 0
        jz      .set_dr0
        cmp     dl, 1
        jz      .set_dr1
        cmp     dl, 2
        jz      .set_dr2
        cmp     dl, 3
        jz      .set_dr3
        cmp     dl, 4
        jz      .set_dr4
        cmp     dl, 5
        jz      .set_dr5

        call    Bs3Panic

.set_dr0:
        mov     dr0, sSI
        jmp     .return
.set_dr1:
        mov     dr1, sSI
        jmp     .return
.set_dr2:
        mov     dr2, sSI
        jmp     .return
.set_dr3:
        mov     dr3, sSI
        jmp     .return
.set_dr4:
        mov     dr4, sSI
        jmp     .return
.set_dr5:
        mov     dr5, sSI
        jmp     .return
.set_dr7:
        mov     dr7, sSI
        jmp     .return
.set_dr6:
        mov     dr6, sSI
        jmp     .return

.via_system_call:
        mov     dl, [xBP + xCB + cbCurRetAddr]
        push    xAX
        mov     xAX, BS3_SYSCALL_SET_DRX
        call    Bs3Syscall
        pop     xAX

.return:
        pop     xDX
        pop     sSI
        pop     xBP
        BS3_CALL_CONV_EPILOG 2
        BS3_HYBRID_RET
BS3_PROC_END_CMN   Bs3RegSetDrX