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 __attribute__((used,section(".videocards")))
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 */