arch/x86/boot/video-vga.c

   1 /* -*- linux-c -*- ------------------------------------------------------- *
   2  *
   3  *   Copyright (C) 1991, 1992 Linus Torvalds
   4  *   Copyright 2007 rPath, Inc. - All Rights Reserved
   5  *   Copyright 2009 Intel Corporation; author H. Peter Anvin
   6  *
   7  *   This file is part of the Linux kernel, and is made available under
   8  *   the terms of the GNU General Public License version 2.
   9  *
  10  * ----------------------------------------------------------------------- */
  11
  12 /*
  13  * Common all-VGA modes
  14  */
  15
  16 #include "boot.h"
  17 #include "video.h"
  18
  19 static struct mode_info vga_modes[] = {
  20         { VIDEO_80x25,  80, 25, 0 },
  21         { VIDEO_8POINT, 80, 50, 0 },
  22         { VIDEO_80x43,  80, 43, 0 },
  23         { VIDEO_80x28,  80, 28, 0 },
  24         { VIDEO_80x30,  80, 30, 0 },
  25         { VIDEO_80x34,  80, 34, 0 },
  26         { VIDEO_80x60,  80, 60, 0 },
  27 };
  28
  29 static struct mode_info ega_modes[] = {
  30         { VIDEO_80x25,  80, 25, 0 },
  31         { VIDEO_8POINT, 80, 43, 0 },
  32 };
  33
  34 static struct mode_info cga_modes[] = {
  35         { VIDEO_80x25,  80, 25, 0 },
  36 };
  37
  38 static __videocard video_vga;
  39
  40 /* Set basic 80x25 mode */
  41 static u8 vga_set_basic_mode(void)
  42 {
  43         struct biosregs ireg, oreg;
  44         u16 ax;
  45         u8 rows;
  46         u8 mode;
  47
  48         initregs(&ireg);
  49
  50 #ifdef CONFIG_VIDEO_400_HACK
  51         if (adapter >= ADAPTER_VGA) {
  52                 ireg.ax = 0x1202;
  53                 ireg.bx = 0x0030;
  54                 intcall(0x10, &ireg, NULL);
  55         }
  56 #endif
  57
  58         ax = 0x0f00;
  59         intcall(0x10, &ireg, &oreg);
  60         mode = oreg.al;
  61
  62         set_fs(0);
  63         rows = rdfs8(0x484);    /* rows minus one */
  64
  65 #ifndef CONFIG_VIDEO_400_HACK
  66         if ((oreg.ax == 0x5003 || oreg.ax == 0x5007) &&
  67             (rows == 0 || rows == 24))
  68                 return mode;
  69 #endif
  70
  71         if (mode != 3 && mode != 7)
  72                 mode = 3;
  73
  74         /* Set the mode */
  75         ireg.ax = mode;         /* AH=0: set mode */
  76         intcall(0x10, &ireg, NULL);
  77         do_restore = 1;
  78         return mode;
  79 }
  80
  81 static void vga_set_8font(void)
  82 {
  83         /* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
  84         struct biosregs ireg;
  85
  86         initregs(&ireg);
  87
  88         /* Set 8x8 font */
  89         ireg.ax = 0x1112;
  90         /* ireg.bl = 0; */
  91         intcall(0x10, &ireg, NULL);
  92
  93         /* Use alternate print screen */
  94         ireg.ax = 0x1200;
  95         ireg.bl = 0x20;
  96         intcall(0x10, &ireg, NULL);
  97
  98         /* Turn off cursor emulation */
  99         ireg.ax = 0x1201;
 100         ireg.bl = 0x34;
 101         intcall(0x10, &ireg, NULL);
 102
 103         /* Cursor is scan lines 6-7 */
 104         ireg.ax = 0x0100;
 105         ireg.cx = 0x0607;
 106         intcall(0x10, &ireg, NULL);
 107 }
 108
 109 static void vga_set_14font(void)
 110 {
 111         /* Set 9x14 font - 80x28 on VGA */
 112         struct biosregs ireg;
 113
 114         initregs(&ireg);
 115
 116         /* Set 9x14 font */
 117         ireg.ax = 0x1111;
 118         /* ireg.bl = 0; */
 119         intcall(0x10, &ireg, NULL);
 120
 121         /* Turn off cursor emulation */
 122         ireg.ax = 0x1201;
 123         ireg.bl = 0x34;
 124         intcall(0x10, &ireg, NULL);
 125
 126         /* Cursor is scan lines 11-12 */
 127         ireg.ax = 0x0100;
 128         ireg.cx = 0x0b0c;
 129         intcall(0x10, &ireg, NULL);
 130 }
 131
 132 static void vga_set_80x43(void)
 133 {
 134         /* Set 80x43 mode on VGA (not EGA) */
 135         struct biosregs ireg;
 136
 137         initregs(&ireg);
 138
 139         /* Set 350 scans */
 140         ireg.ax = 0x1201;
 141         ireg.bl = 0x30;
 142         intcall(0x10, &ireg, NULL);
 143
 144         /* Reset video mode */
 145         ireg.ax = 0x0003;
 146         intcall(0x10, &ireg, NULL);
 147
 148         vga_set_8font();
 149 }
 150
 151 /* I/O address of the VGA CRTC */
 152 u16 vga_crtc(void)
 153 {
 154         return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
 155 }
 156
 157 static void vga_set_480_scanlines(void)
 158 {
 159         u16 crtc;               /* CRTC base address */
 160         u8  csel;               /* CRTC miscellaneous output register */
 161
 162         crtc = vga_crtc();
 163
 164         out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */
 165         out_idx(0x0b, crtc, 0x06); /* Vertical total */
 166         out_idx(0x3e, crtc, 0x07); /* Vertical overflow */
 167         out_idx(0xea, crtc, 0x10); /* Vertical sync start */
 168         out_idx(0xdf, crtc, 0x12); /* Vertical display end */
 169         out_idx(0xe7, crtc, 0x15); /* Vertical blank start */
 170         out_idx(0x04, crtc, 0x16); /* Vertical blank end */
 171         csel = inb(0x3cc);
 172         csel &= 0x0d;
 173         csel |= 0xe2;
 174         outb(csel, 0x3c2);
 175 }
 176
 177 static void vga_set_vertical_end(int lines)
 178 {
 179         u16 crtc;               /* CRTC base address */
 180         u8  ovfw;               /* CRTC overflow register */
 181         int end = lines-1;
 182
 183         crtc = vga_crtc();
 184
 185         ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40);
 186
 187         out_idx(ovfw, crtc, 0x07); /* Vertical overflow */
 188         out_idx(end,  crtc, 0x12); /* Vertical display end */
 189 }
 190
 191 static void vga_set_80x30(void)
 192 {
 193         vga_set_480_scanlines();
 194         vga_set_vertical_end(30*16);
 195 }
 196
 197 static void vga_set_80x34(void)
 198 {
 199         vga_set_480_scanlines();
 200         vga_set_14font();
 201         vga_set_vertical_end(34*14);
 202 }
 203
 204 static void vga_set_80x60(void)
 205 {
 206         vga_set_480_scanlines();
 207         vga_set_8font();
 208         vga_set_vertical_end(60*8);
 209 }
 210
 211 static int vga_set_mode(struct mode_info *mode)
 212 {
 213         /* Set the basic mode */
 214         vga_set_basic_mode();
 215
 216         /* Override a possibly broken BIOS */
 217         force_x = mode->x;
 218         force_y = mode->y;
 219
 220         switch (mode->mode) {
 221         case VIDEO_80x25:
 222                 break;
 223         case VIDEO_8POINT:
 224                 vga_set_8font();
 225                 break;
 226         case VIDEO_80x43:
 227                 vga_set_80x43();
 228                 break;
 229         case VIDEO_80x28:
 230                 vga_set_14font();
 231                 break;
 232         case VIDEO_80x30:
 233                 vga_set_80x30();
 234                 break;
 235         case VIDEO_80x34:
 236                 vga_set_80x34();
 237                 break;
 238         case VIDEO_80x60:
 239                 vga_set_80x60();
 240                 break;
 241         }
 242
 243         return 0;
 244 }
 245
 246 /*
 247  * Note: this probe includes basic information required by all
 248  * systems.  It should be executed first, by making sure
 249  * video-vga.c is listed first in the Makefile.
 250  */
 251 static int vga_probe(void)
 252 {
 253         static const char *card_name[] = {
 254                 "CGA/MDA/HGC", "EGA", "VGA"
 255         };
 256         static struct mode_info *mode_lists[] = {
 257                 cga_modes,
 258                 ega_modes,
 259                 vga_modes,
 260         };
 261         static int mode_count[] = {
 262                 sizeof(cga_modes)/sizeof(struct mode_info),
 263                 sizeof(ega_modes)/sizeof(struct mode_info),
 264                 sizeof(vga_modes)/sizeof(struct mode_info),
 265         };
 266
 267         struct biosregs ireg, oreg;
 268
 269         initregs(&ireg);
 270
 271         ireg.ax = 0x1200;
 272         ireg.bl = 0x10;         /* Check EGA/VGA */
 273         intcall(0x10, &ireg, &oreg);
 274
 275 #ifndef _WAKEUP
 276         boot_params.screen_info.orig_video_ega_bx = oreg.bx;
 277 #endif
 278
 279         /* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
 280         if (oreg.bl != 0x10) {
 281                 /* EGA/VGA */
 282                 ireg.ax = 0x1a00;
 283                 intcall(0x10, &ireg, &oreg);
 284
 285                 if (oreg.al == 0x1a) {
 286                         adapter = ADAPTER_VGA;
 287 #ifndef _WAKEUP
 288                         boot_params.screen_info.orig_video_isVGA = 1;
 289 #endif
 290                 } else {
 291                         adapter = ADAPTER_EGA;
 292                 }
 293         } else {
 294                 adapter = ADAPTER_CGA;
 295         }
 296
 297         video_vga.modes = mode_lists[adapter];
 298         video_vga.card_name = card_name[adapter];
 299         return mode_count[adapter];
 300 }
 301
 302 static __videocard video_vga = {
 303         .card_name      = "VGA",
 304         .probe          = vga_probe,
 305         .set_mode       = vga_set_mode,
 306 };