arch/x86/boot/video.h

   1 /* -*- linux-c -*- ------------------------------------------------------- *
   2  *
   3  *   Copyright (C) 1991, 1992 Linus Torvalds
   4  *   Copyright 2007 rPath, Inc. - All Rights Reserved
   5  *
   6  *   This file is part of the Linux kernel, and is made available under
   7  *   the terms of the GNU General Public License version 2.
   8  *
   9  * ----------------------------------------------------------------------- */
  10
  11 /*
  12  * arch/i386/boot/video.h
  13  *
  14  * Header file for the real-mode video probing code
  15  */
  16
  17 #ifndef BOOT_VIDEO_H
  18 #define BOOT_VIDEO_H
  19
  20 #include <linux/types.h>
  21
  22 /* Enable autodetection of SVGA adapters and modes. */
  23 #undef CONFIG_VIDEO_SVGA
  24
  25 /* Enable autodetection of VESA modes */
  26 #define CONFIG_VIDEO_VESA
  27
  28 /* Retain screen contents when switching modes */
  29 #define CONFIG_VIDEO_RETAIN
  30
  31 /* Force 400 scan lines for standard modes (hack to fix bad BIOS behaviour */
  32 #undef CONFIG_VIDEO_400_HACK
  33
  34 /* This code uses an extended set of video mode numbers. These include:
  35  * Aliases for standard modes
  36  *      NORMAL_VGA (-1)
  37  *      EXTENDED_VGA (-2)
  38  *      ASK_VGA (-3)
  39  * Video modes numbered by menu position -- NOT RECOMMENDED because of lack
  40  * of compatibility when extending the table. These are between 0x00 and 0xff.
  41  */
  42 #define VIDEO_FIRST_MENU 0x0000
  43
  44 /* Standard BIOS video modes (BIOS number + 0x0100) */
  45 #define VIDEO_FIRST_BIOS 0x0100
  46
  47 /* VESA BIOS video modes (VESA number + 0x0200) */
  48 #define VIDEO_FIRST_VESA 0x0200
  49
  50 /* Video7 special modes (BIOS number + 0x0900) */
  51 #define VIDEO_FIRST_V7 0x0900
  52
  53 /* Special video modes */
  54 #define VIDEO_FIRST_SPECIAL 0x0f00
  55 #define VIDEO_80x25 0x0f00
  56 #define VIDEO_8POINT 0x0f01
  57 #define VIDEO_80x43 0x0f02
  58 #define VIDEO_80x28 0x0f03
  59 #define VIDEO_CURRENT_MODE 0x0f04
  60 #define VIDEO_80x30 0x0f05
  61 #define VIDEO_80x34 0x0f06
  62 #define VIDEO_80x60 0x0f07
  63 #define VIDEO_GFX_HACK 0x0f08
  64 #define VIDEO_LAST_SPECIAL 0x0f09
  65
  66 /* Video modes given by resolution */
  67 #define VIDEO_FIRST_RESOLUTION 0x1000
  68
  69 /* The "recalculate timings" flag */
  70 #define VIDEO_RECALC 0x8000
  71
  72 /* Define DO_STORE according to CONFIG_VIDEO_RETAIN */
  73 #ifdef CONFIG_VIDEO_RETAIN
  74 void store_screen(void);
  75 #define DO_STORE() store_screen()
  76 #else
  77 #define DO_STORE() ((void)0)
  78 #endif /* CONFIG_VIDEO_RETAIN */
  79
  80 /*
  81  * Mode table structures
  82  */
  83
  84 struct mode_info {
  85         u16 mode;               /* Mode number (vga= style) */
  86         u16 x, y;               /* Width, height */
  87         u16 depth;              /* Bits per pixel, 0 for text mode */
  88 };
  89
  90 struct card_info {
  91         const char *card_name;
  92         int (*set_mode)(struct mode_info *mode);
  93         int (*probe)(void);
  94         struct mode_info *modes;
  95         int nmodes;             /* Number of probed modes so far */
  96         int unsafe;             /* Probing is unsafe, only do after "scan" */
  97         u16 xmode_first;        /* Unprobed modes to try to call anyway */
  98         u16 xmode_n;            /* Size of unprobed mode range */
  99 };
 100
 101 #define __videocard struct card_info __attribute__((section(".videocards")))
 102 extern struct card_info video_cards[], video_cards_end[];
 103
 104 int mode_defined(u16 mode);     /* video.c */
 105
 106 /* Basic video information */
 107 #define ADAPTER_CGA     0       /* CGA/MDA/HGC */
 108 #define ADAPTER_EGA     1
 109 #define ADAPTER_VGA     2
 110
 111 extern int adapter;
 112 extern u16 video_segment;
 113 extern int force_x, force_y;    /* Don't query the BIOS for cols/rows */
 114 extern int do_restore;          /* Restore screen contents */
 115 extern int graphic_mode;        /* Graphics mode with linear frame buffer */
 116
 117 /*
 118  * int $0x10 is notorious for touching registers it shouldn't.
 119  * gcc doesn't like %ebp being clobbered, so define it as a push/pop
 120  * sequence here.
 121  *
 122  * A number of systems, including the original PC can clobber %bp in
 123  * certain circumstances, like when scrolling.  There exists at least
 124  * one Trident video card which could clobber DS under a set of
 125  * circumstances that we are unlikely to encounter (scrolling when
 126  * using an extended graphics mode of more than 800x600 pixels), but
 127  * it's cheap insurance to deal with that here.
 128  */
 129 #define INT10 "pushl %%ebp; pushw %%ds; int $0x10; popw %%ds; popl %%ebp"
 130
 131 /* Accessing VGA indexed registers */
 132 static inline u8 in_idx(u16 port, u8 index)
 133 {
 134         outb(index, port);
 135         return inb(port+1);
 136 }
 137
 138 static inline void out_idx(u8 v, u16 port, u8 index)
 139 {
 140         outw(index+(v << 8), port);
 141 }
 142
 143 /* Writes a value to an indexed port and then reads the port again */
 144 static inline u8 tst_idx(u8 v, u16 port, u8 index)
 145 {
 146         out_idx(port, index, v);
 147         return in_idx(port, index);
 148 }
 149
 150 /* Get the I/O port of the VGA CRTC */
 151 u16 vga_crtc(void);             /* video-vga.c */
 152
 153 #endif /* BOOT_VIDEO_H */