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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
; FreeDOS DISPLAY: HWInit.ASM
;
; ===================================================================
;
; Hardware dependant initialisation routines for DISPLAY, and
; table with the supported hardware
;
; WWW: http://www.freedos.org/
;
; ===================================================================
;
; =====================================================================
;
; Tables
;
; . . . . . line that rules
HardwareTables:
DB "EGA",0,0,0,0,0
DB "EGA "
DW EGAInit
DW 0
DB "EGA 8",0,0,0
DB "EGA "
DW EGAInit
DW 1
DB "LCD",0,0,0,0,0
DB "EGA "
DW EGAInit
DW 1
DB "EGA 14",0,0
DB "EGA "
DW EGAInit
DW 2
DB "VGA",0,0,0,0,0
DB "EGA "
DW EGAInit
DW 3
DB 0 ; end of table
; =====================================================================
;
; Initialisation routines for EGA/VGA
;
; . . . . . line that rules
tblDCC DB NO,MDA,CGA,NO,EGA,EGA,NO,VGA,VGA,NO,MCGA,MCGA,MCGA
; Fn: TestAdapter
; In: (none)
; Out: AL Video adapter type
; Note: No VESA check yet.
; Author: Ilya V. Vasilyev
TestAdapter:
mov ax,1a00H ; Call DCC
int 10H
cmp al,1aH
jnz taNoDCC
; Now we know, that have PS/2 Video BIOS.
; Active adapter code is now in BL register
cmp bl,0cH
ja taNoDCC
sub bh,bh
mov al,[tblDCC+bx]
cmp al,bh
jnz taKnowAdapter
taNoDCC:
mov bl,10H ; Get Configuration Information
mov ah,12H ; Alternate Select
int 10H
mov al,EGA
cmp bl,10H
jnz taKnowAdapter ; if bh<>0, EGA_MONO
int 11H ; EquipList
and al,30H
cmp al,30H
mov al,MDA
jz taKnowAdapter
mov al,CGA
taKnowAdapter:
mov [bAdapter],al
ret
; Fn: EGAInit
; In: AX: parameter from table
; 0: "EGA" (use adapter type to determine)
; 1: "EGA 8", "LCD" (8x8 only)
; 2: "EGA 14" (8x8,814 only)
; 3: "VGA" (8x8,8x14,8x16)
; NO OTHERS ARE SUPPORTED
; Out: AL Video adapter type
; FCarry: set on error (not found, or initialisation error)
; DX: offset to an error string
; NOTE: bMaxHWcpNumber: should detect the maximum number of HW CPs, if I
; knew of a way to get this info from ARABIC/HEBREW
; wHardCPs: no default codepages specified
;
EGAInit: mov [cs:wMinFontSize],ax
;****** Test the adapter: exit if CGA
call TestAdapter
mov [cs:bAdapter], al
cmp al,CGA
ja ComputeSubfont
mov dx,errAcient ; driver requires EGA or better
stc
ret
;****** Compute the minimum subfont number (AL=bAdapter)
ComputeSubfont:
mov cx,[cs:wMinFontSize]
test cx,0ffffh ; if parameter non-null, it is
jnz EGAInitEnd ; the minimum subfont number
mov cx,1
cmp al,EGA ; remember: AL=adapter
jb MinimumComputed
inc cx
cmp al,VGA
jb MinimumComputed
inc cx
MinimumComputed:
mov [cs:wMinFontSize],cx
;****** Exit successfuly: update the resident procs and exit
EGAInitEnd:
mov WORD [cs:pRefreshHWcp], EGAHSelect
mov WORD [cs:pRefreshSWcp], EGASSelect
clc
ret
|
