arch/x86/boot/video-vesa.c

   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         vginfo.signature = VBE2_MAGIC;
  41
  42         ax = 0x4f00;
  43         di = (size_t)&vginfo;
  44         asm(INT10
  45             : "+a" (ax), "+D" (di), "=m" (vginfo)
  46             : : "ebx", "ecx", "edx", "esi");
  47
  48         if (ax != 0x004f ||
  49             vginfo.signature != VESA_MAGIC ||
  50             vginfo.version < 0x0102)
  51                 return 0;       /* Not present */
  52 #endif /* CONFIG_VIDEO_VESA || CONFIG_FIRMWARE_EDID */
  53 #ifdef CONFIG_VIDEO_VESA
  54         set_fs(vginfo.video_mode_ptr.seg);
  55         mode_ptr = vginfo.video_mode_ptr.off;
  56
  57         while ((mode = rdfs16(mode_ptr)) != 0xffff) {
  58                 mode_ptr += 2;
  59
  60                 if (!heap_free(sizeof(struct mode_info)))
  61                         break;  /* Heap full, can't save mode info */
  62
  63                 if (mode & ~0x1ff)
  64                         continue;
  65
  66                 memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
  67
  68                 ax = 0x4f01;
  69                 cx = mode;
  70                 di = (size_t)&vminfo;
  71                 asm(INT10
  72                     : "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
  73                     : : "ebx", "edx", "esi");
  74
  75                 if (ax != 0x004f)
  76                         continue;
  77
  78                 if ((vminfo.mode_attr & 0x15) == 0x05) {
  79                         /* Text Mode, TTY BIOS supported,
  80                            supported by hardware */
  81                         mi = GET_HEAP(struct mode_info, 1);
  82                         mi->mode = mode + VIDEO_FIRST_VESA;
  83                         mi->x    = vminfo.h_res;
  84                         mi->y    = vminfo.v_res;
  85                         nmodes++;
  86                 } else if ((vminfo.mode_attr & 0x99) == 0x99) {
  87 #ifdef CONFIG_FB
  88                         /* Graphics mode, color, linear frame buffer
  89                            supported -- register the mode but hide from
  90                            the menu.  Only do this if framebuffer is
  91                            configured, however, otherwise the user will
  92                            be left without a screen. */
  93                         mi = GET_HEAP(struct mode_info, 1);
  94                         mi->mode = mode + VIDEO_FIRST_VESA;
  95                         mi->x = mi->y = 0;
  96                         nmodes++;
  97 #endif
  98                 }
  99         }
 100
 101         return nmodes;
 102 #else
 103         return 0;
 104 #endif /* CONFIG_VIDEO_VESA */
 105 }
 106
 107 static int vesa_set_mode(struct mode_info *mode)
 108 {
 109         u16 ax, bx, cx, di;
 110         int is_graphic;
 111         u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
 112
 113         memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
 114
 115         ax = 0x4f01;
 116         cx = vesa_mode;
 117         di = (size_t)&vminfo;
 118         asm(INT10
 119             : "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
 120             : : "ebx", "edx", "esi");
 121
 122         if (ax != 0x004f)
 123                 return -1;
 124
 125         if ((vminfo.mode_attr & 0x15) == 0x05) {
 126                 /* It's a supported text mode */
 127                 is_graphic = 0;
 128         } else if ((vminfo.mode_attr & 0x99) == 0x99) {
 129                 /* It's a graphics mode with linear frame buffer */
 130                 is_graphic = 1;
 131                 vesa_mode |= 0x4000; /* Request linear frame buffer */
 132         } else {
 133                 return -1;      /* Invalid mode */
 134         }
 135
 136
 137         ax = 0x4f02;
 138         bx = vesa_mode;
 139         di = 0;
 140         asm volatile(INT10
 141                      : "+a" (ax), "+b" (bx), "+D" (di)
 142                      : : "ecx", "edx", "esi");
 143
 144         if (ax != 0x004f)
 145                 return -1;
 146
 147         graphic_mode = is_graphic;
 148         if (!is_graphic) {
 149                 /* Text mode */
 150                 force_x = mode->x;
 151                 force_y = mode->y;
 152                 do_restore = 1;
 153         } else {
 154                 /* Graphics mode */
 155                 vesa_store_mode_params_graphics();
 156         }
 157
 158         return 0;
 159 }
 160
 161
 162 /* Switch DAC to 8-bit mode */
 163 static void vesa_dac_set_8bits(void)
 164 {
 165         u8 dac_size = 6;
 166
 167         /* If possible, switch the DAC to 8-bit mode */
 168         if (vginfo.capabilities & 1) {
 169                 u16 ax, bx;
 170
 171                 ax = 0x4f08;
 172                 bx = 0x0800;
 173                 asm volatile(INT10
 174                              : "+a" (ax), "+b" (bx)
 175                              : : "ecx", "edx", "esi", "edi");
 176
 177                 if (ax == 0x004f)
 178                         dac_size = bx >> 8;
 179         }
 180
 181         /* Set the color sizes to the DAC size, and offsets to 0 */
 182         boot_params.screen_info.red_size = dac_size;
 183         boot_params.screen_info.green_size = dac_size;
 184         boot_params.screen_info.blue_size = dac_size;
 185         boot_params.screen_info.rsvd_size = dac_size;
 186
 187         boot_params.screen_info.red_pos = 0;
 188         boot_params.screen_info.green_pos = 0;
 189         boot_params.screen_info.blue_pos = 0;
 190         boot_params.screen_info.rsvd_pos = 0;
 191 }
 192
 193 /* Save the VESA protected mode info */
 194 static void vesa_store_pm_info(void)
 195 {
 196         u16 ax, bx, di, es;
 197
 198         ax = 0x4f0a;
 199         bx = di = 0;
 200         asm("pushw %%es; "INT10"; movw %%es,%0; popw %%es"
 201             : "=d" (es), "+a" (ax), "+b" (bx), "+D" (di)
 202             : : "ecx", "esi");
 203
 204         if (ax != 0x004f)
 205                 return;
 206
 207         boot_params.screen_info.vesapm_seg = es;
 208         boot_params.screen_info.vesapm_off = di;
 209 }
 210
 211 /*
 212  * Save video mode parameters for graphics mode
 213  */
 214 static void vesa_store_mode_params_graphics(void)
 215 {
 216         /* Tell the kernel we're in VESA graphics mode */
 217         boot_params.screen_info.orig_video_isVGA = 0x23;
 218
 219         /* Mode parameters */
 220         boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
 221         boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
 222         boot_params.screen_info.lfb_width = vminfo.h_res;
 223         boot_params.screen_info.lfb_height = vminfo.v_res;
 224         boot_params.screen_info.lfb_depth = vminfo.bpp;
 225         boot_params.screen_info.pages = vminfo.image_planes;
 226         boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
 227         memcpy(&boot_params.screen_info.red_size,
 228                &vminfo.rmask, 8);
 229
 230         /* General parameters */
 231         boot_params.screen_info.lfb_size = vginfo.total_memory;
 232
 233         if (vminfo.bpp <= 8)
 234                 vesa_dac_set_8bits();
 235
 236         vesa_store_pm_info();
 237 }
 238
 239 /*
 240  * Save EDID information for the kernel; this is invoked, separately,
 241  * after mode-setting.
 242  */
 243 void vesa_store_edid(void)
 244 {
 245 #ifdef CONFIG_FIRMWARE_EDID
 246         u16 ax, bx, cx, dx, di;
 247
 248         /* Apparently used as a nonsense token... */
 249         memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info);
 250
 251         if (vginfo.version < 0x0200)
 252                 return;         /* EDID requires VBE 2.0+ */
 253
 254         ax = 0x4f15;            /* VBE DDC */
 255         bx = 0x0000;            /* Report DDC capabilities */
 256         cx = 0;                 /* Controller 0 */
 257         di = 0;                 /* ES:DI must be 0 by spec */
 258
 259         /* Note: The VBE DDC spec is different from the main VESA spec;
 260            we genuinely have to assume all registers are destroyed here. */
 261
 262         asm("pushw %%es; movw %2,%%es; "INT10"; popw %%es"
 263             : "+a" (ax), "+b" (bx)
 264             :  "c" (cx), "D" (di)
 265             : "esi");
 266
 267         if (ax != 0x004f)
 268                 return;         /* No EDID */
 269
 270         /* BH = time in seconds to transfer EDD information */
 271         /* BL = DDC level supported */
 272
 273         ax = 0x4f15;            /* VBE DDC */
 274         bx = 0x0001;            /* Read EDID */
 275         cx = 0;                 /* Controller 0 */
 276         dx = 0;                 /* EDID block number */
 277         di =(size_t) &boot_params.edid_info; /* (ES:)Pointer to block */
 278         asm(INT10
 279             : "+a" (ax), "+b" (bx), "+d" (dx), "=m" (boot_params.edid_info)
 280             : "c" (cx), "D" (di)
 281             : "esi");
 282 #endif /* CONFIG_FIRMWARE_EDID */
 283 }
 284
 285 __videocard video_vesa =
 286 {
 287         .card_name      = "VESA",
 288         .probe          = vesa_probe,
 289         .set_mode       = vesa_set_mode,
 290         .xmode_first    = VIDEO_FIRST_VESA,
 291         .xmode_n        = 0x200,
 292 };