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         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 };