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 */
in_idx(u16 port,u8 index)97  static inline u8 in_idx(u16 port, u8 index)
98  {
99  	outb(index, port);
100  	return inb(port+1);
101  }
102  
out_idx(u8 v,u16 port,u8 index)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 */
tst_idx(u8 v,u16 port,u8 index)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