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