xref: /openbmc/linux/arch/x86/boot/video.h (revision 95e9fd10)
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 /*
21  * This code uses an extended set of video mode numbers. These include:
22  * Aliases for standard modes
23  *      NORMAL_VGA (-1)
24  *      EXTENDED_VGA (-2)
25  *      ASK_VGA (-3)
26  * Video modes numbered by menu position -- NOT RECOMMENDED because of lack
27  * of compatibility when extending the table. These are between 0x00 and 0xff.
28  */
29 #define VIDEO_FIRST_MENU 0x0000
30 
31 /* Standard BIOS video modes (BIOS number + 0x0100) */
32 #define VIDEO_FIRST_BIOS 0x0100
33 
34 /* VESA BIOS video modes (VESA number + 0x0200) */
35 #define VIDEO_FIRST_VESA 0x0200
36 
37 /* Video7 special modes (BIOS number + 0x0900) */
38 #define VIDEO_FIRST_V7 0x0900
39 
40 /* Special video modes */
41 #define VIDEO_FIRST_SPECIAL 0x0f00
42 #define VIDEO_80x25 0x0f00
43 #define VIDEO_8POINT 0x0f01
44 #define VIDEO_80x43 0x0f02
45 #define VIDEO_80x28 0x0f03
46 #define VIDEO_CURRENT_MODE 0x0f04
47 #define VIDEO_80x30 0x0f05
48 #define VIDEO_80x34 0x0f06
49 #define VIDEO_80x60 0x0f07
50 #define VIDEO_GFX_HACK 0x0f08
51 #define VIDEO_LAST_SPECIAL 0x0f09
52 
53 /* Video modes given by resolution */
54 #define VIDEO_FIRST_RESOLUTION 0x1000
55 
56 /* The "recalculate timings" flag */
57 #define VIDEO_RECALC 0x8000
58 
59 void store_screen(void);
60 #define DO_STORE() store_screen()
61 
62 /*
63  * Mode table structures
64  */
65 
66 struct mode_info {
67 	u16 mode;		/* Mode number (vga= style) */
68 	u16 x, y;		/* Width, height */
69 	u16 depth;		/* Bits per pixel, 0 for text mode */
70 };
71 
72 struct card_info {
73 	const char *card_name;
74 	int (*set_mode)(struct mode_info *mode);
75 	int (*probe)(void);
76 	struct mode_info *modes;
77 	int nmodes;		/* Number of probed modes so far */
78 	int unsafe;		/* Probing is unsafe, only do after "scan" */
79 	u16 xmode_first;	/* Unprobed modes to try to call anyway */
80 	u16 xmode_n;		/* Size of unprobed mode range */
81 };
82 
83 #define __videocard struct card_info __attribute__((section(".videocards")))
84 extern struct card_info video_cards[], video_cards_end[];
85 
86 int mode_defined(u16 mode);	/* video.c */
87 
88 /* Basic video information */
89 #define ADAPTER_CGA	0	/* CGA/MDA/HGC */
90 #define ADAPTER_EGA	1
91 #define ADAPTER_VGA	2
92 
93 extern int adapter;
94 extern u16 video_segment;
95 extern int force_x, force_y;	/* Don't query the BIOS for cols/rows */
96 extern int do_restore;		/* Restore screen contents */
97 extern int graphic_mode;	/* Graphics mode with linear frame buffer */
98 
99 /* Accessing VGA indexed registers */
100 static inline u8 in_idx(u16 port, u8 index)
101 {
102 	outb(index, port);
103 	return inb(port+1);
104 }
105 
106 static inline void out_idx(u8 v, u16 port, u8 index)
107 {
108 	outw(index+(v << 8), port);
109 }
110 
111 /* Writes a value to an indexed port and then reads the port again */
112 static inline u8 tst_idx(u8 v, u16 port, u8 index)
113 {
114 	out_idx(port, index, v);
115 	return in_idx(port, index);
116 }
117 
118 /* Get the I/O port of the VGA CRTC */
119 u16 vga_crtc(void);		/* video-vga.c */
120 
121 #endif /* BOOT_VIDEO_H */
122