Commit | Line | Data |
---|---|---|
e44b7b75 PM |
1 | /* -*- linux-c -*- ------------------------------------------------------- * |
2 | * | |
3 | * Copyright (C) 1991, 1992 Linus Torvalds | |
4 | * Copyright 2007-2008 rPath, Inc. - All Rights Reserved | |
5 | * | |
6 | * This file is part of the Linux kernel, and is made available under | |
7 | * the terms of the GNU General Public License version 2. | |
8 | * | |
9 | * ----------------------------------------------------------------------- */ | |
10 | ||
11 | /* | |
12 | * arch/i386/boot/video-mode.c | |
13 | * | |
14 | * Set the video mode. This is separated out into a different | |
15 | * file in order to be shared with the ACPI wakeup code. | |
16 | */ | |
17 | ||
18 | #include "boot.h" | |
19 | #include "video.h" | |
20 | #include "vesa.h" | |
21 | ||
22 | /* | |
23 | * Common variables | |
24 | */ | |
25 | int adapter; /* 0=CGA/MDA/HGC, 1=EGA, 2=VGA+ */ | |
26 | u16 video_segment; | |
27 | int force_x, force_y; /* Don't query the BIOS for cols/rows */ | |
28 | ||
29 | int do_restore; /* Screen contents changed during mode flip */ | |
30 | int graphic_mode; /* Graphic mode with linear frame buffer */ | |
31 | ||
32 | /* Probe the video drivers and have them generate their mode lists. */ | |
33 | void probe_cards(int unsafe) | |
34 | { | |
35 | struct card_info *card; | |
36 | static u8 probed[2]; | |
37 | ||
38 | if (probed[unsafe]) | |
39 | return; | |
40 | ||
41 | probed[unsafe] = 1; | |
42 | ||
43 | for (card = video_cards; card < video_cards_end; card++) { | |
44 | if (card->unsafe == unsafe) { | |
45 | if (card->probe) | |
46 | card->nmodes = card->probe(); | |
47 | else | |
48 | card->nmodes = 0; | |
49 | } | |
50 | } | |
51 | } | |
52 | ||
53 | /* Test if a mode is defined */ | |
54 | int mode_defined(u16 mode) | |
55 | { | |
56 | struct card_info *card; | |
57 | struct mode_info *mi; | |
58 | int i; | |
59 | ||
60 | for (card = video_cards; card < video_cards_end; card++) { | |
61 | mi = card->modes; | |
62 | for (i = 0; i < card->nmodes; i++, mi++) { | |
63 | if (mi->mode == mode) | |
64 | return 1; | |
65 | } | |
66 | } | |
67 | ||
68 | return 0; | |
69 | } | |
70 | ||
71 | /* Set mode (without recalc) */ | |
72 | static int raw_set_mode(u16 mode, u16 *real_mode) | |
73 | { | |
74 | int nmode, i; | |
75 | struct card_info *card; | |
76 | struct mode_info *mi; | |
77 | ||
78 | /* Drop the recalc bit if set */ | |
79 | mode &= ~VIDEO_RECALC; | |
80 | ||
81 | /* Scan for mode based on fixed ID, position, or resolution */ | |
82 | nmode = 0; | |
83 | for (card = video_cards; card < video_cards_end; card++) { | |
84 | mi = card->modes; | |
85 | for (i = 0; i < card->nmodes; i++, mi++) { | |
86 | int visible = mi->x || mi->y; | |
87 | ||
88 | if ((mode == nmode && visible) || | |
89 | mode == mi->mode || | |
90 | mode == (mi->y << 8)+mi->x) { | |
91 | *real_mode = mi->mode; | |
92 | return card->set_mode(mi); | |
93 | } | |
94 | ||
95 | if (visible) | |
96 | nmode++; | |
97 | } | |
98 | } | |
99 | ||
100 | /* Nothing found? Is it an "exceptional" (unprobed) mode? */ | |
101 | for (card = video_cards; card < video_cards_end; card++) { | |
102 | if (mode >= card->xmode_first && | |
103 | mode < card->xmode_first+card->xmode_n) { | |
104 | struct mode_info mix; | |
105 | *real_mode = mix.mode = mode; | |
106 | mix.x = mix.y = 0; | |
107 | return card->set_mode(&mix); | |
108 | } | |
109 | } | |
110 | ||
111 | /* Otherwise, failure... */ | |
112 | return -1; | |
113 | } | |
114 | ||
115 | /* | |
116 | * Recalculate the vertical video cutoff (hack!) | |
117 | */ | |
118 | static void vga_recalc_vertical(void) | |
119 | { | |
120 | unsigned int font_size, rows; | |
121 | u16 crtc; | |
122 | u8 pt, ov; | |
123 | ||
124 | set_fs(0); | |
125 | font_size = rdfs8(0x485); /* BIOS: font size (pixels) */ | |
126 | rows = force_y ? force_y : rdfs8(0x484)+1; /* Text rows */ | |
127 | ||
128 | rows *= font_size; /* Visible scan lines */ | |
129 | rows--; /* ... minus one */ | |
130 | ||
131 | crtc = vga_crtc(); | |
132 | ||
133 | pt = in_idx(crtc, 0x11); | |
134 | pt &= ~0x80; /* Unlock CR0-7 */ | |
135 | out_idx(pt, crtc, 0x11); | |
136 | ||
137 | out_idx((u8)rows, crtc, 0x12); /* Lower height register */ | |
138 | ||
139 | ov = in_idx(crtc, 0x07); /* Overflow register */ | |
140 | ov &= 0xbd; | |
141 | ov |= (rows >> (8-1)) & 0x02; | |
142 | ov |= (rows >> (9-6)) & 0x40; | |
143 | out_idx(ov, crtc, 0x07); | |
144 | } | |
145 | ||
146 | /* Set mode (with recalc if specified) */ | |
147 | int set_mode(u16 mode) | |
148 | { | |
149 | int rv; | |
150 | u16 real_mode; | |
151 | ||
152 | /* Very special mode numbers... */ | |
153 | if (mode == VIDEO_CURRENT_MODE) | |
154 | return 0; /* Nothing to do... */ | |
155 | else if (mode == NORMAL_VGA) | |
156 | mode = VIDEO_80x25; | |
157 | else if (mode == EXTENDED_VGA) | |
158 | mode = VIDEO_8POINT; | |
159 | ||
160 | rv = raw_set_mode(mode, &real_mode); | |
161 | if (rv) | |
162 | return rv; | |
163 | ||
164 | if (mode & VIDEO_RECALC) | |
165 | vga_recalc_vertical(); | |
166 | ||
167 | /* Save the canonical mode number for the kernel, not | |
168 | an alias, size specification or menu position */ | |
169 | #ifndef _WAKEUP | |
170 | boot_params.hdr.vid_mode = real_mode; | |
171 | #endif | |
172 | return 0; | |
173 | } |