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