arch/x86/boot/video.h

   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 */