src/mesa/drivers/dos/vga.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  4.1
   4  *
   5  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /*
  26  * DOS/DJGPP device driver for Mesa
  27  *
  28  *  Author: Daniel Borca
  29  *  Email : dborca@users.sourceforge.net
  30  *  Web   : http://www.geocities.com/dborca
  31  */
  32
  33
  34 #include <pc.h>
  35 #include <stdlib.h>
  36
  37 #include "video.h"
  38 #include "vga.h"
  39
  40
  41 static vl_mode modes[] = {
  42    {
  43     /* .xres    = */ 320,
  44     /* .yres    = */ 200,
  45     /* .bpp     = */ 8,
  46     /* .mode    = */ 0x13 | 0x4000,
  47     /* .scanlen = */ 320,
  48     /* .sel     = */ -1,
  49     /* .gran    = */ 320*200
  50    },
  51    {
  52     /* .xres    = */ -1,
  53     /* .yres    = */ -1,
  54     /* .bpp     = */ -1,
  55     /* .mode    = */ 0xffff,
  56     /* .scanlen = */ -1,
  57     /* .sel     = */ -1,
  58     /* .gran    = */ -1
  59    }
  60 };
  61
  62 static word16 vga_ver;
  63 static int linear_selector;
  64 static int oldmode = -1;
  65
  66 #define vga_color_precision 6
  67
  68
  69 /* Desc: Attempts to detect VGA, check video modes and create selectors.
  70  *
  71  * In  : -
  72  * Out : mode array
  73  *
  74  * Note: -
  75  */
  76 static vl_mode *
  77 vga_init (void)
  78 {
  79    int rv = 0;
  80
  81    if (vga_ver) {
  82       return modes;
  83    }
  84
  85    __asm("\n\
  86                 movw    $0x1a00, %%ax   \n\
  87                 int     $0x10           \n\
  88                 cmpb    $0x1a, %%al     \n\
  89                 jne     0f              \n\
  90                 cmpb    $0x07, %%bl     \n\
  91                 jb      0f              \n\
  92                 andl    $0xff, %%ebx    \n\
  93                 movl    %%ebx, %0       \n\
  94    0:":"=g"(rv)::"%eax", "%ebx");
  95    if (rv == 0) {
  96       return NULL;
  97    }
  98
  99    if (_create_selector(&linear_selector, 0xa0000, 0x10000)) {
 100       return NULL;
 101    }
 102
 103    modes[0].sel = linear_selector;
 104
 105    vga_ver = rv;
 106    return modes;
 107 }
 108
 109
 110 /* Desc: Frees all resources allocated by VGA init code.
 111  *
 112  * In  : -
 113  * Out : -
 114  *
 115  * Note: -
 116  */
 117 static void
 118 vga_fini (void)
 119 {
 120    if (vga_ver) {
 121       _remove_selector(&linear_selector);
 122    }
 123 }
 124
 125
 126 /* Desc: Attempts to choose a suitable blitter.
 127  *
 128  * In  : ptr to mode structure, software framebuffer bits
 129  * Out : blitter funciton, or NULL
 130  *
 131  * Note: -
 132  */
 133 static BLTFUNC
 134 _choose_blitter (vl_mode *p, int fbbits)
 135 {
 136     BLTFUNC blitter;
 137
 138     switch (fbbits) {
 139         case 8:
 140             blitter = _can_mmx() ? vesa_l_dump_virtual_mmx : vesa_l_dump_virtual;
 141             break;
 142         case 16:
 143             blitter = vesa_l_dump_16_to_8;
 144             break;
 145         case 24:
 146             blitter = vesa_l_dump_24_to_8;
 147             break;
 148         case 32:
 149             blitter = vesa_l_dump_32_to_8;
 150             break;
 151         default:
 152             return NULL;
 153     }
 154
 155     return blitter;
 156
 157     (void)p;
 158 }
 159
 160
 161 /* Desc: Attempts to enter specified video mode.
 162  *
 163  * In  : ptr to mode structure, refresh rate
 164  * Out : 0 if success
 165  *
 166  * Note: -
 167  */
 168 static int
 169 vga_entermode (vl_mode *p, int refresh, int fbbits)
 170 {
 171     if (!(p->mode & 0x4000)) {
 172         return -1;
 173     }
 174
 175     VGA.blit = _choose_blitter(p, fbbits);
 176     if (VGA.blit == NULL) {
 177         return !0;
 178     }
 179
 180     if (oldmode == -1) {
 181         __asm("\n\
 182                 movb    $0x0f, %%ah     \n\
 183                 int     $0x10           \n\
 184                 andl    $0xff, %%eax    \n\
 185                 movl    %%eax, %0       \n\
 186         ":"=g"(oldmode)::"%eax", "%ebx");
 187     }
 188
 189     __asm("int $0x10"::"a"(p->mode&0xff));
 190
 191     return 0;
 192
 193     (void)refresh; /* silence compiler warning */
 194 }
 195
 196
 197 /* Desc: Restores to the mode prior to first call to vga_entermode.
 198  *
 199  * In  : -
 200  * Out : -
 201  *
 202  * Note: -
 203  */
 204 static void
 205 vga_restore (void)
 206 {
 207    if (oldmode != -1) {
 208       __asm("int $0x10"::"a"(oldmode));
 209       oldmode = -1;
 210    }
 211 }
 212
 213
 214 /* Desc: set one palette entry
 215  *
 216  * In  : color index, R, G, B
 217  * Out : -
 218  *
 219  * Note: uses integer values
 220  */
 221 static void
 222 vga_setCI_i (int index, int red, int green, int blue)
 223 {
 224 #if 0
 225    __asm("\n\
 226                 movw    $0x1010, %%ax   \n\
 227                 movb    %1, %%dh        \n\
 228                 movb    %2, %%ch        \n\
 229                 int     $0x10           \n\
 230    "::"b"(index), "m"(red), "m"(green), "c"(blue):"%eax", "%edx");
 231 #else
 232    outportb(0x03C8, index);
 233    outportb(0x03C9, red);
 234    outportb(0x03C9, green);
 235    outportb(0x03C9, blue);
 236 #endif
 237 }
 238
 239
 240 /* Desc: set one palette entry
 241  *
 242  * In  : color index, R, G, B
 243  * Out : -
 244  *
 245  * Note: uses normalized values
 246  */
 247 static void
 248 vga_setCI_f (int index, float red, float green, float blue)
 249 {
 250     float max = (1 << vga_color_precision) - 1;
 251
 252     vga_setCI_i(index, (int)(red * max), (int)(green * max), (int)(blue * max));
 253 }
 254
 255
 256 /* Desc: state retrieval
 257  *
 258  * In  : parameter name, ptr to storage
 259  * Out : 0 if request successfully processed
 260  *
 261  * Note: -
 262  */
 263 static int
 264 vga_get (int pname, int *params)
 265 {
 266    switch (pname) {
 267       case VL_GET_CI_PREC:
 268          params[0] = vga_color_precision;
 269          break;
 270       default:
 271          return -1;
 272    }
 273    return 0;
 274 }
 275
 276
 277 /*
 278  * the driver
 279  */
 280 vl_driver VGA = {
 281    vga_init,
 282    vga_entermode,
 283    NULL,
 284    vga_setCI_f,
 285    vga_setCI_i,
 286    vga_get,
 287    vga_restore,
 288    vga_fini
 289 };