com32/lib/sys/vesa/initvesa.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 1999-2008 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   Permission is hereby granted, free of charge, to any person
   6  *   obtaining a copy of this software and associated documentation
   7  *   files (the "Software"), to deal in the Software without
   8  *   restriction, including without limitation the rights to use,
   9  *   copy, modify, merge, publish, distribute, sublicense, and/or
  10  *   sell copies of the Software, and to permit persons to whom
  11  *   the Software is furnished to do so, subject to the following
  12  *   conditions:
  13  *
  14  *   The above copyright notice and this permission notice shall
  15  *   be included in all copies or substantial portions of the Software.
  16  *
  17  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  19  *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20  *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  21  *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  22  *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24  *   OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  * ----------------------------------------------------------------------- */
  27
  28 /*
  29  * initvesa.c
  30  *
  31  * Query the VESA BIOS and select a 640x480x32 mode with local mapping
  32  * support, if one exists.
  33  */
  34
  35 #include <inttypes.h>
  36 #include <com32.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <sys/fpu.h>
  40 #include "vesa.h"
  41 #include "video.h"
  42 #include "fill.h"
  43 #include "debug.h"
  44
  45 struct vesa_info __vesa_info;
  46
  47 struct vesa_char *__vesacon_text_display;
  48
  49 int __vesacon_font_height, __vesacon_text_rows;
  50 enum vesa_pixel_format __vesacon_pixel_format = PXF_NONE;
  51 unsigned int __vesacon_bytes_per_pixel;
  52 uint8_t __vesacon_graphics_font[FONT_MAX_CHARS][FONT_MAX_HEIGHT];
  53
  54 uint32_t __vesacon_background[VIDEO_Y_SIZE][VIDEO_X_SIZE];
  55
  56 static void unpack_font(uint8_t *dst, uint8_t *src, int height)
  57 {
  58   int i;
  59
  60   for (i = 0; i < FONT_MAX_CHARS; i++) {
  61     memcpy(dst, src, height);
  62     memset(dst+height, 0, FONT_MAX_HEIGHT-height);
  63
  64     dst += FONT_MAX_HEIGHT;
  65     src += height;
  66   }
  67 }
  68
  69 static int __constfunc is_power_of_2(unsigned int x)
  70 {
  71   return x && !(x & (x-1));
  72 }
  73
  74 static int vesacon_paged_mode_ok(const struct vesa_mode_info *mi)
  75 {
  76   int i;
  77
  78   if (!is_power_of_2(mi->win_size) ||
  79       !is_power_of_2(mi->win_grain) ||
  80       mi->win_grain > mi->win_size)
  81     return 0;                   /* Impossible... */
  82
  83   for (i = 0; i < 2; i++) {
  84     if ((mi->win_attr[i] & 0x05) == 0x05 && mi->win_seg[i])
  85       return 1;                 /* Usable window */
  86   }
  87
  88   return 0;                     /* Nope... */
  89 }
  90
  91 static int vesacon_set_mode(void)
  92 {
  93   com32sys_t rm;
  94   uint8_t *rom_font;
  95   uint16_t mode, bestmode, *mode_ptr;
  96   struct vesa_general_info *gi;
  97   struct vesa_mode_info *mi;
  98   enum vesa_pixel_format pxf, bestpxf;
  99
 100   /* Allocate space in the bounce buffer for these structures */
 101   gi = &((struct vesa_info *)__com32.cs_bounce)->gi;
 102   mi = &((struct vesa_info *)__com32.cs_bounce)->mi;
 103
 104   debug("Hello, World!\r\n");
 105
 106   memset(&rm, 0, sizeof rm);
 107   memset(gi, 0, sizeof *gi);
 108
 109   gi->signature = VBE2_MAGIC;   /* Get VBE2 extended data */
 110   rm.eax.w[0] = 0x4F00;         /* Get SVGA general information */
 111   rm.edi.w[0] = OFFS(gi);
 112   rm.es      = SEG(gi);
 113   __intcall(0x10, &rm, &rm);
 114
 115   if ( rm.eax.w[0] != 0x004F )
 116     return 1;                   /* Function call failed */
 117   if ( gi->signature != VESA_MAGIC )
 118     return 2;                   /* No magic */
 119   if ( gi->version < 0x0102 )
 120     return 3;                   /* VESA 1.2+ required */
 121
 122   /* Copy general info */
 123   memcpy(&__vesa_info.gi, gi, sizeof *gi);
 124
 125   /* Search for a 640x480 mode with a suitable color and memory model... */
 126
 127   mode_ptr = GET_PTR(gi->video_mode_ptr);
 128   bestmode = 0;
 129   bestpxf  = PXF_NONE;
 130
 131   while ((mode = *mode_ptr++) != 0xFFFF) {
 132     mode &= 0x1FF;              /* The rest are attributes of sorts */
 133
 134     debug("Found mode: 0x%04x\r\n", mode);
 135
 136     memset(mi, 0, sizeof *mi);
 137     rm.eax.w[0] = 0x4F01;       /* Get SVGA mode information */
 138     rm.ecx.w[0] = mode;
 139     rm.edi.w[0] = OFFS(mi);
 140     rm.es  = SEG(mi);
 141     __intcall(0x10, &rm, &rm);
 142
 143     /* Must be a supported mode */
 144     if ( rm.eax.w[0] != 0x004f )
 145       continue;
 146
 147     debug("mode_attr 0x%04x, h_res = %4d, v_res = %4d, bpp = %2d, layout = %d (%d,%d,%d)\r\n",
 148           mi->mode_attr, mi->h_res, mi->v_res, mi->bpp, mi->memory_layout,
 149           mi->rpos, mi->gpos, mi->bpos);
 150
 151     /* Must be an LFB color graphics mode supported by the hardware.
 152
 153       The bits tested are:
 154        4 - graphics mode
 155        3 - color mode
 156        1 - mode information available (mandatory in VBE 1.2+)
 157        0 - mode supported by hardware
 158     */
 159     if ( (mi->mode_attr & 0x001b) != 0x001b )
 160       continue;
 161
 162     /* Must be 640x480 */
 163     if ( mi->h_res != VIDEO_X_SIZE || mi->v_res != VIDEO_Y_SIZE )
 164       continue;
 165
 166     /* We don't support multibank (interlaced memory) modes */
 167     /*
 168      *  Note: The Bochs VESA BIOS (vbe.c 1.58 2006/08/19) violates the
 169      * specification which states that banks == 1 for unbanked modes;
 170      * fortunately it does report bank_size == 0 for those.
 171      */
 172     if ( mi->banks > 1 && mi->bank_size ) {
 173       debug("bad: banks = %d, banksize = %d, pages = %d\r\n",
 174             mi->banks, mi->bank_size, mi->image_pages);
 175       continue;
 176     }
 177
 178     /* Must be either a flat-framebuffer mode, or be an acceptable
 179        paged mode */
 180     if ( !(mi->mode_attr & 0x0080) && !vesacon_paged_mode_ok(mi) ) {
 181       debug("bad: invalid paged mode\r\n");
 182       continue;
 183     }
 184
 185     /* Must either be a packed-pixel mode or a direct color mode
 186        (depending on VESA version ); must be a supported pixel format */
 187     pxf = PXF_NONE;             /* Not usable */
 188
 189     if (mi->bpp == 32 &&
 190         (mi->memory_layout == 4 ||
 191          (mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
 192           mi->bpos == 0)))
 193       pxf = PXF_BGRA32;
 194     else if (mi->bpp == 24 &&
 195              (mi->memory_layout == 4 ||
 196               (mi->memory_layout == 6 && mi->rpos == 16 && mi->gpos == 8 &&
 197                mi->bpos == 0)))
 198       pxf = PXF_BGR24;
 199     else if (mi->bpp == 16 &&
 200              (mi->memory_layout == 4 ||
 201               (mi->memory_layout == 6 && mi->rpos == 11 && mi->gpos == 5 &&
 202                mi->bpos == 0)))
 203       pxf = PXF_LE_RGB16_565;
 204     else if (mi->bpp == 15 &&
 205              (mi->memory_layout == 4 ||
 206               (mi->memory_layout == 6 && mi->rpos == 10 && mi->gpos == 5 &&
 207                mi->bpos == 0)))
 208       pxf = PXF_LE_RGB15_555;
 209
 210     if (pxf < bestpxf) {
 211       debug("Best mode so far, pxf = %d\r\n", pxf);
 212
 213       /* Best mode so far... */
 214       bestmode = mode;
 215       bestpxf  = pxf;
 216
 217       /* Copy mode info */
 218       memcpy(&__vesa_info.mi, mi, sizeof *mi);
 219     }
 220   }
 221
 222   if (bestpxf == PXF_NONE)
 223     return 4;                   /* No mode found */
 224
 225   mi = &__vesa_info.mi;
 226   mode = bestmode;
 227   __vesacon_bytes_per_pixel = (mi->bpp+7) >> 3;
 228   __vesacon_format_pixels = __vesacon_format_pixels_list[bestpxf];
 229
 230   /* Download the SYSLINUX- or BIOS-provided font */
 231   rm.eax.w[0] = 0x0018;         /* Query custom font */
 232   __intcall(0x22, &rm, &rm);
 233   if (!(rm.eflags.l & EFLAGS_CF) && rm.eax.b[0]) {
 234     __vesacon_font_height = rm.eax.b[0];
 235     rom_font = MK_PTR(rm.es, rm.ebx.w[0]);
 236   } else {
 237     rm.eax.w[0] = 0x1130;               /* Get Font Information */
 238     rm.ebx.w[0] = 0x0600;               /* Get 8x16 ROM font */
 239     __intcall(0x10, &rm, &rm);
 240     rom_font = MK_PTR(rm.es, rm.ebp.w[0]);
 241     __vesacon_font_height = 16;
 242   }
 243   unpack_font((uint8_t *)__vesacon_graphics_font, rom_font,
 244               __vesacon_font_height);
 245   __vesacon_text_rows = (VIDEO_Y_SIZE-2*VIDEO_BORDER)/__vesacon_font_height;
 246   __vesacon_init_cursor(__vesacon_font_height);
 247
 248   /* Now set video mode */
 249   rm.eax.w[0] = 0x4F02;         /* Set SVGA video mode */
 250   if (mi->mode_attr & 0x0080)
 251     mode |= 0x4000;             /* Request linear framebuffer if supported */
 252   rm.ebx.w[0] = mode;
 253   __intcall(0x10, &rm, &rm);
 254   if ( rm.eax.w[0] != 0x004F )
 255     return 9;                   /* Failed to set mode */
 256
 257   __vesacon_init_copy_to_screen();
 258
 259   /* Tell syslinux we changed video mode */
 260   rm.eax.w[0] = 0x0017;         /* Report video mode change */
 261   /* In theory this should be:
 262
 263      rm.ebx.w[0] = (mi->mode_attr & 4) ? 0x0007 : 0x000f;
 264
 265      However, that would assume all systems that claim to handle text
 266      output in VESA modes actually do that... */
 267   rm.ebx.w[0] = 0x000f;
 268   rm.ecx.w[0] = VIDEO_X_SIZE;
 269   rm.edx.w[0] = VIDEO_Y_SIZE;
 270   __intcall(0x22, &rm, NULL);
 271
 272   __vesacon_pixel_format = bestpxf;
 273
 274   return 0;
 275 }
 276
 277
 278 static int init_text_display(void)
 279 {
 280   size_t nchars;
 281   struct vesa_char *ptr;
 282   struct vesa_char def_char = {
 283     .ch = ' ',
 284     .attr = 0,
 285   };
 286
 287   nchars = (TEXT_PIXEL_ROWS/__vesacon_font_height+2)*
 288     (TEXT_PIXEL_COLS/FONT_WIDTH+2);
 289
 290   __vesacon_text_display = ptr = malloc(nchars*sizeof(struct vesa_char));
 291
 292   if (!ptr)
 293     return -1;
 294
 295
 296   vesacon_fill(ptr, def_char, nchars);
 297
 298   return 0;
 299 }
 300
 301 int __vesacon_init(void)
 302 {
 303   int rv;
 304
 305   /* We need the FPU for graphics, at least libpng et al will need it... */
 306   if (x86_init_fpu())
 307     return 10;
 308
 309   rv = vesacon_set_mode();
 310   if (rv)
 311     return rv;
 312
 313   init_text_display();
 314
 315   debug("Mode set, now drawing at %#p\r\n", __vesa_info.mi.lfb_ptr);
 316
 317   __vesacon_init_background();
 318
 319   debug("Ready!\r\n");
 320   return 0;
 321 }