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-vesa.c 13 * 14 * VESA text modes 15 */ 16 17 #include "boot.h" 18 #include "video.h" 19 #include "vesa.h" 20 21 /* VESA information */ 22 static struct vesa_general_info vginfo; 23 static struct vesa_mode_info vminfo; 24 25 __videocard video_vesa; 26 27 static void vesa_store_mode_params_graphics(void); 28 29 static int vesa_probe(void) 30 { 31 #if defined(CONFIG_VIDEO_VESA) || defined(CONFIG_FIRMWARE_EDID) 32 u16 ax, cx, di; 33 u16 mode; 34 addr_t mode_ptr; 35 struct mode_info *mi; 36 int nmodes = 0; 37 38 video_vesa.modes = GET_HEAP(struct mode_info, 0); 39 40 ax = 0x4f00; 41 di = (size_t)&vginfo; 42 asm(INT10 43 : "+a" (ax), "+D" (di), "=m" (vginfo) 44 : : "ebx", "ecx", "edx", "esi"); 45 46 if (ax != 0x004f || 47 vginfo.signature != VESA_MAGIC || 48 vginfo.version < 0x0102) 49 return 0; /* Not present */ 50 #endif /* CONFIG_VIDEO_VESA || CONFIG_FIRMWARE_EDID */ 51 #ifdef CONFIG_VIDEO_VESA 52 set_fs(vginfo.video_mode_ptr.seg); 53 mode_ptr = vginfo.video_mode_ptr.off; 54 55 while ((mode = rdfs16(mode_ptr)) != 0xffff) { 56 mode_ptr += 2; 57 58 if (!heap_free(sizeof(struct mode_info))) 59 break; /* Heap full, can't save mode info */ 60 61 if (mode & ~0x1ff) 62 continue; 63 64 memset(&vminfo, 0, sizeof vminfo); /* Just in case... */ 65 66 ax = 0x4f01; 67 cx = mode; 68 di = (size_t)&vminfo; 69 asm(INT10 70 : "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo) 71 : : "ebx", "edx", "esi"); 72 73 if (ax != 0x004f) 74 continue; 75 76 if ((vminfo.mode_attr & 0x15) == 0x05) { 77 /* Text Mode, TTY BIOS supported, 78 supported by hardware */ 79 mi = GET_HEAP(struct mode_info, 1); 80 mi->mode = mode + VIDEO_FIRST_VESA; 81 mi->depth = 0; /* text */ 82 mi->x = vminfo.h_res; 83 mi->y = vminfo.v_res; 84 nmodes++; 85 } else if ((vminfo.mode_attr & 0x99) == 0x99 && 86 (vminfo.memory_layout == 4 || 87 vminfo.memory_layout == 6) && 88 vminfo.memory_planes == 1) { 89 #ifdef CONFIG_FB 90 /* Graphics mode, color, linear frame buffer 91 supported. Only register the mode if 92 if framebuffer is configured, however, 93 otherwise the user will be left without a screen. 94 We don't require CONFIG_FB_VESA, however, since 95 some of the other framebuffer drivers can use 96 this mode-setting, too. */ 97 mi = GET_HEAP(struct mode_info, 1); 98 mi->mode = mode + VIDEO_FIRST_VESA; 99 mi->depth = vminfo.bpp; 100 mi->x = vminfo.h_res; 101 mi->y = vminfo.v_res; 102 nmodes++; 103 #endif 104 } 105 } 106 107 return nmodes; 108 #else 109 return 0; 110 #endif /* CONFIG_VIDEO_VESA */ 111 } 112 113 static int vesa_set_mode(struct mode_info *mode) 114 { 115 u16 ax, bx, cx, di; 116 int is_graphic; 117 u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA; 118 119 memset(&vminfo, 0, sizeof vminfo); /* Just in case... */ 120 121 ax = 0x4f01; 122 cx = vesa_mode; 123 di = (size_t)&vminfo; 124 asm(INT10 125 : "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo) 126 : : "ebx", "edx", "esi"); 127 128 if (ax != 0x004f) 129 return -1; 130 131 if ((vminfo.mode_attr & 0x15) == 0x05) { 132 /* It's a supported text mode */ 133 is_graphic = 0; 134 } else if ((vminfo.mode_attr & 0x99) == 0x99) { 135 /* It's a graphics mode with linear frame buffer */ 136 is_graphic = 1; 137 vesa_mode |= 0x4000; /* Request linear frame buffer */ 138 } else { 139 return -1; /* Invalid mode */ 140 } 141 142 143 ax = 0x4f02; 144 bx = vesa_mode; 145 di = 0; 146 asm volatile(INT10 147 : "+a" (ax), "+b" (bx), "+D" (di) 148 : : "ecx", "edx", "esi"); 149 150 if (ax != 0x004f) 151 return -1; 152 153 graphic_mode = is_graphic; 154 if (!is_graphic) { 155 /* Text mode */ 156 force_x = mode->x; 157 force_y = mode->y; 158 do_restore = 1; 159 } else { 160 /* Graphics mode */ 161 vesa_store_mode_params_graphics(); 162 } 163 164 return 0; 165 } 166 167 168 /* Switch DAC to 8-bit mode */ 169 static void vesa_dac_set_8bits(void) 170 { 171 u8 dac_size = 6; 172 173 /* If possible, switch the DAC to 8-bit mode */ 174 if (vginfo.capabilities & 1) { 175 u16 ax, bx; 176 177 ax = 0x4f08; 178 bx = 0x0800; 179 asm volatile(INT10 180 : "+a" (ax), "+b" (bx) 181 : : "ecx", "edx", "esi", "edi"); 182 183 if (ax == 0x004f) 184 dac_size = bx >> 8; 185 } 186 187 /* Set the color sizes to the DAC size, and offsets to 0 */ 188 boot_params.screen_info.red_size = dac_size; 189 boot_params.screen_info.green_size = dac_size; 190 boot_params.screen_info.blue_size = dac_size; 191 boot_params.screen_info.rsvd_size = dac_size; 192 193 boot_params.screen_info.red_pos = 0; 194 boot_params.screen_info.green_pos = 0; 195 boot_params.screen_info.blue_pos = 0; 196 boot_params.screen_info.rsvd_pos = 0; 197 } 198 199 /* Save the VESA protected mode info */ 200 static void vesa_store_pm_info(void) 201 { 202 u16 ax, bx, di, es; 203 204 ax = 0x4f0a; 205 bx = di = 0; 206 asm("pushw %%es; "INT10"; movw %%es,%0; popw %%es" 207 : "=d" (es), "+a" (ax), "+b" (bx), "+D" (di) 208 : : "ecx", "esi"); 209 210 if (ax != 0x004f) 211 return; 212 213 boot_params.screen_info.vesapm_seg = es; 214 boot_params.screen_info.vesapm_off = di; 215 } 216 217 /* 218 * Save video mode parameters for graphics mode 219 */ 220 static void vesa_store_mode_params_graphics(void) 221 { 222 /* Tell the kernel we're in VESA graphics mode */ 223 boot_params.screen_info.orig_video_isVGA = 0x23; 224 225 /* Mode parameters */ 226 boot_params.screen_info.vesa_attributes = vminfo.mode_attr; 227 boot_params.screen_info.lfb_linelength = vminfo.logical_scan; 228 boot_params.screen_info.lfb_width = vminfo.h_res; 229 boot_params.screen_info.lfb_height = vminfo.v_res; 230 boot_params.screen_info.lfb_depth = vminfo.bpp; 231 boot_params.screen_info.pages = vminfo.image_planes; 232 boot_params.screen_info.lfb_base = vminfo.lfb_ptr; 233 memcpy(&boot_params.screen_info.red_size, 234 &vminfo.rmask, 8); 235 236 /* General parameters */ 237 boot_params.screen_info.lfb_size = vginfo.total_memory; 238 239 if (vminfo.bpp <= 8) 240 vesa_dac_set_8bits(); 241 242 vesa_store_pm_info(); 243 } 244 245 /* 246 * Save EDID information for the kernel; this is invoked, separately, 247 * after mode-setting. 248 */ 249 void vesa_store_edid(void) 250 { 251 #ifdef CONFIG_FIRMWARE_EDID 252 u16 ax, bx, cx, dx, di; 253 254 /* Apparently used as a nonsense token... */ 255 memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info); 256 257 if (vginfo.version < 0x0200) 258 return; /* EDID requires VBE 2.0+ */ 259 260 ax = 0x4f15; /* VBE DDC */ 261 bx = 0x0000; /* Report DDC capabilities */ 262 cx = 0; /* Controller 0 */ 263 di = 0; /* ES:DI must be 0 by spec */ 264 265 /* Note: The VBE DDC spec is different from the main VESA spec; 266 we genuinely have to assume all registers are destroyed here. */ 267 268 asm("pushw %%es; movw %2,%%es; "INT10"; popw %%es" 269 : "+a" (ax), "+b" (bx) 270 : "c" (cx), "D" (di) 271 : "esi"); 272 273 if (ax != 0x004f) 274 return; /* No EDID */ 275 276 /* BH = time in seconds to transfer EDD information */ 277 /* BL = DDC level supported */ 278 279 ax = 0x4f15; /* VBE DDC */ 280 bx = 0x0001; /* Read EDID */ 281 cx = 0; /* Controller 0 */ 282 dx = 0; /* EDID block number */ 283 di =(size_t) &boot_params.edid_info; /* (ES:)Pointer to block */ 284 asm(INT10 285 : "+a" (ax), "+b" (bx), "+d" (dx), "=m" (boot_params.edid_info) 286 : "c" (cx), "D" (di) 287 : "esi"); 288 #endif /* CONFIG_FIRMWARE_EDID */ 289 } 290 291 __videocard video_vesa = 292 { 293 .card_name = "VESA", 294 .probe = vesa_probe, 295 .set_mode = vesa_set_mode, 296 .xmode_first = VIDEO_FIRST_VESA, 297 .xmode_n = 0x200, 298 }; 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