xref: /openbmc/linux/arch/x86/boot/video.h (revision 0545810f)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* -*- linux-c -*- ------------------------------------------------------- *
3  *
4  *   Copyright (C) 1991, 1992 Linus Torvalds
5  *   Copyright 2007 rPath, Inc. - All Rights Reserved
6  *
7  * ----------------------------------------------------------------------- */
8 
9 /*
10  * Header file for the real-mode video probing code
11  */
12 
13 #ifndef BOOT_VIDEO_H
14 #define BOOT_VIDEO_H
15 
16 #include <linux/types.h>
17 
18 /*
19  * This code uses an extended set of video mode numbers. These include:
20  * Aliases for standard modes
21  *      NORMAL_VGA (-1)
22  *      EXTENDED_VGA (-2)
23  *      ASK_VGA (-3)
24  * Video modes numbered by menu position -- NOT RECOMMENDED because of lack
25  * of compatibility when extending the table. These are between 0x00 and 0xff.
26  */
27 #define VIDEO_FIRST_MENU 0x0000
28 
29 /* Standard BIOS video modes (BIOS number + 0x0100) */
30 #define VIDEO_FIRST_BIOS 0x0100
31 
32 /* VESA BIOS video modes (VESA number + 0x0200) */
33 #define VIDEO_FIRST_VESA 0x0200
34 
35 /* Video7 special modes (BIOS number + 0x0900) */
36 #define VIDEO_FIRST_V7 0x0900
37 
38 /* Special video modes */
39 #define VIDEO_FIRST_SPECIAL 0x0f00
40 #define VIDEO_80x25 0x0f00
41 #define VIDEO_8POINT 0x0f01
42 #define VIDEO_80x43 0x0f02
43 #define VIDEO_80x28 0x0f03
44 #define VIDEO_CURRENT_MODE 0x0f04
45 #define VIDEO_80x30 0x0f05
46 #define VIDEO_80x34 0x0f06
47 #define VIDEO_80x60 0x0f07
48 #define VIDEO_GFX_HACK 0x0f08
49 #define VIDEO_LAST_SPECIAL 0x0f09
50 
51 /* Video modes given by resolution */
52 #define VIDEO_FIRST_RESOLUTION 0x1000
53 
54 /* The "recalculate timings" flag */
55 #define VIDEO_RECALC 0x8000
56 
57 void store_screen(void);
58 #define DO_STORE() store_screen()
59 
60 /*
61  * Mode table structures
62  */
63 
64 struct mode_info {
65 	u16 mode;		/* Mode number (vga= style) */
66 	u16 x, y;		/* Width, height */
67 	u16 depth;		/* Bits per pixel, 0 for text mode */
68 };
69 
70 struct card_info {
71 	const char *card_name;
72 	int (*set_mode)(struct mode_info *mode);
73 	int (*probe)(void);
74 	struct mode_info *modes;
75 	int nmodes;		/* Number of probed modes so far */
76 	int unsafe;		/* Probing is unsafe, only do after "scan" */
77 	u16 xmode_first;	/* Unprobed modes to try to call anyway */
78 	u16 xmode_n;		/* Size of unprobed mode range */
79 };
80 
81 #define __videocard struct card_info __section(".videocards") __attribute__((used))
82 extern struct card_info video_cards[], video_cards_end[];
83 
84 int mode_defined(u16 mode);	/* video.c */
85 
86 /* Basic video information */
87 #define ADAPTER_CGA	0	/* CGA/MDA/HGC */
88 #define ADAPTER_EGA	1
89 #define ADAPTER_VGA	2
90 
91 extern int adapter;
92 extern int force_x, force_y;	/* Don't query the BIOS for cols/rows */
93 extern int do_restore;		/* Restore screen contents */
94 extern int graphic_mode;	/* Graphics mode with linear frame buffer */
95 
96 /* Accessing VGA indexed registers */
97 static inline u8 in_idx(u16 port, u8 index)
98 {
99 	outb(index, port);
100 	return inb(port+1);
101 }
102 
103 static inline void out_idx(u8 v, u16 port, u8 index)
104 {
105 	outw(index+(v << 8), port);
106 }
107 
108 /* Writes a value to an indexed port and then reads the port again */
109 static inline u8 tst_idx(u8 v, u16 port, u8 index)
110 {
111 	out_idx(port, index, v);
112 	return in_idx(port, index);
113 }
114 
115 /* Get the I/O port of the VGA CRTC */
116 u16 vga_crtc(void);		/* video-vga.c */
117 
118 #endif /* BOOT_VIDEO_H */
119