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
57void store_screen(void);
58#define DO_STORE() store_screen()
59
60/*
61 * Mode table structures
62 */
63
64struct 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
70struct 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))
82extern struct card_info video_cards[], video_cards_end[];
83
84int 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
91extern int adapter;
92extern int force_x, force_y;	/* Don't query the BIOS for cols/rows */
93extern int do_restore;		/* Restore screen contents */
94extern int graphic_mode;	/* Graphics mode with linear frame buffer */
95
96/* Accessing VGA indexed registers */
97static inline u8 in_idx(u16 port, u8 index)
98{
99	outb(index, port);
100	return inb(port+1);
101}
102
103static 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 */
109static 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 */
116u16 vga_crtc(void);		/* video-vga.c */
117
118#endif /* BOOT_VIDEO_H */
119