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  * VESA text modes
  13  */
  14
  15 #include "boot.h"
  16 #include "video.h"
  17 #include "vesa.h"
  18
  19 /* VESA information */
  20 static struct vesa_general_info vginfo;
  21 static struct vesa_mode_info vminfo;
  22
  23 __videocard video_vesa;
  24
  25 #ifndef _WAKEUP
  26 static void vesa_store_mode_params_graphics(void);
  27 #else /* _WAKEUP */
  28 static inline void vesa_store_mode_params_graphics(void) {}
  29 #endif /* _WAKEUP */
  30
  31 static int vesa_probe(void)
  32 {
  33 #if defined(CONFIG_VIDEO_VESA) || defined(CONFIG_FIRMWARE_EDID)
  34         u16 ax, cx, di;
  35         u16 mode;
  36         addr_t mode_ptr;
  37         struct mode_info *mi;
  38         int nmodes = 0;
  39
  40         video_vesa.modes = GET_HEAP(struct mode_info, 0);
  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->depth = 0; /* text */
  84                         mi->x     = vminfo.h_res;
  85                         mi->y     = vminfo.v_res;
  86                         nmodes++;
  87                 } else if ((vminfo.mode_attr & 0x99) == 0x99 &&
  88                            (vminfo.memory_layout == 4 ||
  89                             vminfo.memory_layout == 6) &&
  90                            vminfo.memory_planes == 1) {
  91 #ifdef CONFIG_FB
  92                         /* Graphics mode, color, linear frame buffer
  93                            supported.  Only register the mode if
  94                            if framebuffer is configured, however,
  95                            otherwise the user will be left without a screen.
  96                            We don't require CONFIG_FB_VESA, however, since
  97                            some of the other framebuffer drivers can use
  98                            this mode-setting, too. */
  99                         mi = GET_HEAP(struct mode_info, 1);
 100                         mi->mode = mode + VIDEO_FIRST_VESA;
 101                         mi->depth = vminfo.bpp;
 102                         mi->x = vminfo.h_res;
 103                         mi->y = vminfo.v_res;
 104                         nmodes++;
 105 #endif
 106                 }
 107         }
 108
 109         return nmodes;
 110 #else
 111         return 0;
 112 #endif /* CONFIG_VIDEO_VESA */
 113 }
 114
 115 static int vesa_set_mode(struct mode_info *mode)
 116 {
 117         u16 ax, bx, cx, di;
 118         int is_graphic;
 119         u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
 120
 121         memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
 122
 123         ax = 0x4f01;
 124         cx = vesa_mode;
 125         di = (size_t)&vminfo;
 126         asm(INT10
 127             : "+a" (ax), "+c" (cx), "+D" (di), "=m" (vminfo)
 128             : : "ebx", "edx", "esi");
 129
 130         if (ax != 0x004f)
 131                 return -1;
 132
 133         if ((vminfo.mode_attr & 0x15) == 0x05) {
 134                 /* It's a supported text mode */
 135                 is_graphic = 0;
 136         } else if ((vminfo.mode_attr & 0x99) == 0x99) {
 137                 /* It's a graphics mode with linear frame buffer */
 138                 is_graphic = 1;
 139                 vesa_mode |= 0x4000; /* Request linear frame buffer */
 140         } else {
 141                 return -1;      /* Invalid mode */
 142         }
 143
 144
 145         ax = 0x4f02;
 146         bx = vesa_mode;
 147         di = 0;
 148         asm volatile(INT10
 149                      : "+a" (ax), "+b" (bx), "+D" (di)
 150                      : : "ecx", "edx", "esi");
 151
 152         if (ax != 0x004f)
 153                 return -1;
 154
 155         graphic_mode = is_graphic;
 156         if (!is_graphic) {
 157                 /* Text mode */
 158                 force_x = mode->x;
 159                 force_y = mode->y;
 160                 do_restore = 1;
 161         } else {
 162                 /* Graphics mode */
 163                 vesa_store_mode_params_graphics();
 164         }
 165
 166         return 0;
 167 }
 168
 169
 170 #ifndef _WAKEUP
 171
 172 /* Switch DAC to 8-bit mode */
 173 static void vesa_dac_set_8bits(void)
 174 {
 175         u8 dac_size = 6;
 176
 177         /* If possible, switch the DAC to 8-bit mode */
 178         if (vginfo.capabilities & 1) {
 179                 u16 ax, bx;
 180
 181                 ax = 0x4f08;
 182                 bx = 0x0800;
 183                 asm volatile(INT10
 184                              : "+a" (ax), "+b" (bx)
 185                              : : "ecx", "edx", "esi", "edi");
 186
 187                 if (ax == 0x004f)
 188                         dac_size = bx >> 8;
 189         }
 190
 191         /* Set the color sizes to the DAC size, and offsets to 0 */
 192         boot_params.screen_info.red_size = dac_size;
 193         boot_params.screen_info.green_size = dac_size;
 194         boot_params.screen_info.blue_size = dac_size;
 195         boot_params.screen_info.rsvd_size = dac_size;
 196
 197         boot_params.screen_info.red_pos = 0;
 198         boot_params.screen_info.green_pos = 0;
 199         boot_params.screen_info.blue_pos = 0;
 200         boot_params.screen_info.rsvd_pos = 0;
 201 }
 202
 203 /* Save the VESA protected mode info */
 204 static void vesa_store_pm_info(void)
 205 {
 206         u16 ax, bx, di, es;
 207
 208         ax = 0x4f0a;
 209         bx = di = 0;
 210         asm("pushw %%es; "INT10"; movw %%es,%0; popw %%es"
 211             : "=d" (es), "+a" (ax), "+b" (bx), "+D" (di)
 212             : : "ecx", "esi");
 213
 214         if (ax != 0x004f)
 215                 return;
 216
 217         boot_params.screen_info.vesapm_seg = es;
 218         boot_params.screen_info.vesapm_off = di;
 219 }
 220
 221 /*
 222  * Save video mode parameters for graphics mode
 223  */
 224 static void vesa_store_mode_params_graphics(void)
 225 {
 226         /* Tell the kernel we're in VESA graphics mode */
 227         boot_params.screen_info.orig_video_isVGA = 0x23;
 228
 229         /* Mode parameters */
 230         boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
 231         boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
 232         boot_params.screen_info.lfb_width = vminfo.h_res;
 233         boot_params.screen_info.lfb_height = vminfo.v_res;
 234         boot_params.screen_info.lfb_depth = vminfo.bpp;
 235         boot_params.screen_info.pages = vminfo.image_planes;
 236         boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
 237         memcpy(&boot_params.screen_info.red_size,
 238                &vminfo.rmask, 8);
 239
 240         /* General parameters */
 241         boot_params.screen_info.lfb_size = vginfo.total_memory;
 242
 243         if (vminfo.bpp <= 8)
 244                 vesa_dac_set_8bits();
 245
 246         vesa_store_pm_info();
 247 }
 248
 249 /*
 250  * Save EDID information for the kernel; this is invoked, separately,
 251  * after mode-setting.
 252  */
 253 void vesa_store_edid(void)
 254 {
 255 #ifdef CONFIG_FIRMWARE_EDID
 256         u16 ax, bx, cx, dx, di;
 257
 258         /* Apparently used as a nonsense token... */
 259         memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info);
 260
 261         if (vginfo.version < 0x0200)
 262                 return;         /* EDID requires VBE 2.0+ */
 263
 264         ax = 0x4f15;            /* VBE DDC */
 265         bx = 0x0000;            /* Report DDC capabilities */
 266         cx = 0;                 /* Controller 0 */
 267         di = 0;                 /* ES:DI must be 0 by spec */
 268
 269         /* Note: The VBE DDC spec is different from the main VESA spec;
 270            we genuinely have to assume all registers are destroyed here. */
 271
 272         asm("pushw %%es; movw %2,%%es; "INT10"; popw %%es"
 273             : "+a" (ax), "+b" (bx)
 274             :  "c" (cx), "D" (di)
 275             : "esi");
 276
 277         if (ax != 0x004f)
 278                 return;         /* No EDID */
 279
 280         /* BH = time in seconds to transfer EDD information */
 281         /* BL = DDC level supported */
 282
 283         ax = 0x4f15;            /* VBE DDC */
 284         bx = 0x0001;            /* Read EDID */
 285         cx = 0;                 /* Controller 0 */
 286         dx = 0;                 /* EDID block number */
 287         di =(size_t) &boot_params.edid_info; /* (ES:)Pointer to block */
 288         asm(INT10
 289             : "+a" (ax), "+b" (bx), "+d" (dx), "=m" (boot_params.edid_info)
 290             : "c" (cx), "D" (di)
 291             : "esi");
 292 #endif /* CONFIG_FIRMWARE_EDID */
 293 }
 294
 295 #endif /* not _WAKEUP */
 296
 297 __videocard video_vesa =
 298 {
 299         .card_name      = "VESA",
 300         .probe          = vesa_probe,
 301         .set_mode       = vesa_set_mode,
 302         .xmode_first    = VIDEO_FIRST_VESA,
 303         .xmode_n        = 0x200,
 304 };