tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/* -*- linux-c -*- ------------------------------------------------------- *
2 *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 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.h
13 *
14 * Header file for the real-mode video probing code
15 */
16
17#ifndef BOOT_VIDEO_H
18#define BOOT_VIDEO_H
19
20#include <linux/types.h>
21
22/* Enable autodetection of SVGA adapters and modes. */
23#undef CONFIG_VIDEO_SVGA
24
25/* Enable autodetection of VESA modes */
26#define CONFIG_VIDEO_VESA
27
28/* Retain screen contents when switching modes */
29#define CONFIG_VIDEO_RETAIN
30
31/* Force 400 scan lines for standard modes (hack to fix bad BIOS behaviour */
32#undef CONFIG_VIDEO_400_HACK
33
34/* This code uses an extended set of video mode numbers. These include:
35 * Aliases for standard modes
36 * NORMAL_VGA (-1)
37 * EXTENDED_VGA (-2)
38 * ASK_VGA (-3)
39 * Video modes numbered by menu position -- NOT RECOMMENDED because of lack
40 * of compatibility when extending the table. These are between 0x00 and 0xff.
41 */
42#define VIDEO_FIRST_MENU 0x0000
43
44/* Standard BIOS video modes (BIOS number + 0x0100) */
45#define VIDEO_FIRST_BIOS 0x0100
46
47/* VESA BIOS video modes (VESA number + 0x0200) */
48#define VIDEO_FIRST_VESA 0x0200
49
50/* Video7 special modes (BIOS number + 0x0900) */
51#define VIDEO_FIRST_V7 0x0900
52
53/* Special video modes */
54#define VIDEO_FIRST_SPECIAL 0x0f00
55#define VIDEO_80x25 0x0f00
56#define VIDEO_8POINT 0x0f01
57#define VIDEO_80x43 0x0f02
58#define VIDEO_80x28 0x0f03
59#define VIDEO_CURRENT_MODE 0x0f04
60#define VIDEO_80x30 0x0f05
61#define VIDEO_80x34 0x0f06
62#define VIDEO_80x60 0x0f07
63#define VIDEO_GFX_HACK 0x0f08
64#define VIDEO_LAST_SPECIAL 0x0f09
65
66/* Video modes given by resolution */
67#define VIDEO_FIRST_RESOLUTION 0x1000
68
69/* The "recalculate timings" flag */
70#define VIDEO_RECALC 0x8000
71
72/* Define DO_STORE according to CONFIG_VIDEO_RETAIN */
73#ifdef CONFIG_VIDEO_RETAIN
74void store_screen(void);
75#define DO_STORE() store_screen()
76#else
77#define DO_STORE() ((void)0)
78#endif /* CONFIG_VIDEO_RETAIN */
79
80/*
81 * Mode table structures
82 */
83
84struct mode_info {
85 u16 mode; /* Mode number (vga= style) */
86 u16 x, y; /* Width, height */
87 u16 depth; /* Bits per pixel, 0 for text mode */
88};
89
90struct card_info {
91 const char *card_name;
92 int (*set_mode)(struct mode_info *mode);
93 int (*probe)(void);
94 struct mode_info *modes;
95 int nmodes; /* Number of probed modes so far */
96 int unsafe; /* Probing is unsafe, only do after "scan" */
97 u16 xmode_first; /* Unprobed modes to try to call anyway */
98 u16 xmode_n; /* Size of unprobed mode range */
99};
100
101#define __videocard struct card_info __attribute__((section(".videocards")))
102extern struct card_info video_cards[], video_cards_end[];
103
104int mode_defined(u16 mode); /* video.c */
105
106/* Basic video information */
107#define ADAPTER_CGA 0 /* CGA/MDA/HGC */
108#define ADAPTER_EGA 1
109#define ADAPTER_VGA 2
110
111extern int adapter;
112extern u16 video_segment;
113extern int force_x, force_y; /* Don't query the BIOS for cols/rows */
114extern int do_restore; /* Restore screen contents */
115extern int graphic_mode; /* Graphics mode with linear frame buffer */
116
117/*
118 * int $0x10 is notorious for touching registers it shouldn't.
119 * gcc doesn't like %ebp being clobbered, so define it as a push/pop
120 * sequence here.
121 *
122 * A number of systems, including the original PC can clobber %bp in
123 * certain circumstances, like when scrolling. There exists at least
124 * one Trident video card which could clobber DS under a set of
125 * circumstances that we are unlikely to encounter (scrolling when
126 * using an extended graphics mode of more than 800x600 pixels), but
127 * it's cheap insurance to deal with that here.
128 */
129#define INT10 "pushl %%ebp; pushw %%ds; int $0x10; popw %%ds; popl %%ebp"
130
131/* Accessing VGA indexed registers */
132static inline u8 in_idx(u16 port, u8 index)
133{
134 outb(index, port);
135 return inb(port+1);
136}
137
138static inline void out_idx(u8 v, u16 port, u8 index)
139{
140 outw(index+(v << 8), port);
141}
142
143/* Writes a value to an indexed port and then reads the port again */
144static inline u8 tst_idx(u8 v, u16 port, u8 index)
145{
146 out_idx(port, index, v);
147 return in_idx(port, index);
148}
149
150/* Get the I/O port of the VGA CRTC */
151u16 vga_crtc(void); /* video-vga.c */
152
153#endif /* BOOT_VIDEO_H */