src/lib/doslib/hw/vesa/vesa240.c

   1
   2 /* TODO: Make the 320x200x256-color override hack optional (and off by default).
   3  *
   4  *       On an S3 Virge PCI card I own, substituting a VESA BIOS mode for mode
   5  *       13h causes additional compatability problems because things like
   6  *       horizontal pel and other standard VGA tricks don't work at all.
   7  *       Considering you just finished the Standard VGA version of this hack,
   8  *       the mode 13h hack is no longer necessary and it should be disabled by
   9  *       default though available as an option. */
  10
  11 #include <stdio.h>
  12 #include <conio.h> /* this is where Open Watcom hides the outp() etc. functions */
  13 #include <stddef.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <unistd.h>
  17 #include <assert.h>
  18 #include <fcntl.h>
  19 #include <math.h>
  20 #include <dos.h>
  21
  22 #include <hw/dos/dos.h>
  23 #include <hw/vesa/vesa.h>
  24
  25 struct mode_remap {
  26         uint16_t        source_mode;
  27         uint16_t        target_mode;
  28 };
  29
  30 #define MAX_REMAP       256
  31
  32 void                    (__interrupt __far *old_int10)();
  33 struct mode_remap       remap[MAX_REMAP];
  34 int                     remap_count=0;
  35 union REGS              remap_rr;
  36
  37 void __interrupt __far new_int10(union INTPACK ip) {
  38         if (ip.h.ah == 0x00) {
  39                 unsigned int i,j;
  40
  41                 for (i=0;i < remap_count;i++) {
  42                         if (remap[i].source_mode == (ip.h.al&0x7F)) {
  43                                 j = remap[i].target_mode | ((ip.h.al&0x80)?0x8000:0x0000);
  44                                 __asm {
  45                                         push    ds
  46                                         mov     ax,seg old_int10
  47                                         mov     ds,ax
  48                                         mov     ax,0x4F02
  49                                         mov     bx,j
  50                                         pushf
  51                                         callf   dword ptr [old_int10]
  52                                         pop     ds
  53                                 }
  54
  55                                 return;
  56                         }
  57                 }
  58         }
  59         else if (ip.w.ax == 0x4F02) {
  60                 unsigned int i;
  61
  62                 for (i=0;i < remap_count;i++) {
  63                         if (remap[i].source_mode == (ip.w.bx&0x3FFF)) {
  64                                 ip.w.bx = remap[i].target_mode | (ip.w.bx & 0xC000);
  65                                 break;
  66                         }
  67                 }
  68         }
  69
  70         _chain_intr(old_int10);
  71 }
  72
  73 static void help() {
  74         printf("VESA240 /INSTALL\n");
  75         printf("\n");
  76         printf("Intercept VESA BIOS calls to force video modes with at least 480 scan lines,\n");
  77         printf("which may improve video quality with scan converters or enable capture/viewing\n");
  78         printf("where devices would normally ignore 400-line output.\n");
  79         printf("(C) 2014 Jonathan Campbell\n");
  80 }
  81
  82 void end_of_resident();
  83
  84 void install_320x200x256_remap() {
  85         struct vbe_mode_info nmi;
  86         uint16_t nmode,tnmode;
  87         int nentry;
  88
  89         nmode=0;
  90         for (nentry=0;nentry < 1024;nentry++) {
  91                 tnmode = vbe_read_mode_entry(vbe_info->video_mode_ptr,nentry);
  92                 if (tnmode == 0xFFFF) break;
  93                 memset(&nmi,0,sizeof(nmi));
  94                 if (!vbe_read_mode_info(tnmode,&nmi)) continue;
  95                 if (!(nmi.mode_attributes & VESA_MODE_ATTR_HW_SUPPORTED)) continue;
  96                 if (!(nmi.mode_attributes & VESA_MODE_ATTR_GRAPHICS_MODE)) continue;
  97                 if (nmi.x_resolution != 320) continue;
  98                 if (nmi.y_resolution != 240) continue;
  99                 if (nmi.number_of_planes != 1) continue;
 100                 if (nmi.bits_per_pixel != 8) continue;
 101                 if (!(nmi.memory_model == 5/*non-chain 4 256-color*/ || nmi.memory_model == 4/*packed*/ || nmi.memory_model == 3/*4-plane*/)) continue;
 102                 nmode = tnmode;
 103                 break;
 104         }
 105
 106         if (nmode != 0) {
 107                 printf("  Remapping mode 0x13 to 0x%03x (%ux%ux%u)\n",nmode,
 108                                 nmi.x_resolution,nmi.y_resolution,nmi.bits_per_pixel);
 109
 110                 if (remap_count < MAX_REMAP) {
 111                         remap[remap_count].source_mode = 0x13;
 112                         remap[remap_count].target_mode = nmode&0x3FFF;
 113                         remap_count++;
 114                 }
 115         }
 116         else {
 117                 printf("  No mapping available for mode 0x13\n");
 118         }
 119 }
 120
 121 int main(int argc,char **argv) {
 122         char *a,*command=NULL;
 123         unsigned int entry;
 124         uint16_t mode;
 125         int i;
 126
 127 #if TARGET_MSDOS != 16
 128 # error you are not supposed to compile this for protected mode!
 129 #endif
 130
 131         for (i=1;i < argc;) {
 132                 a = argv[i++];
 133                 if (*a == '/' || *a == '-') {
 134                         do { a++; } while (*a == '/' || *a == '-');
 135
 136                         if (!strcasecmp(a,"i") || !strcasecmp(a,"install")) {
 137                                 command = a;
 138                         }
 139                         else {
 140                                 fprintf(stderr,"Unknown switch %s\n",a);
 141                                 command = NULL;
 142                                 break;
 143                         }
 144                 }
 145                 else {
 146                         fprintf(stderr,"Unknown switch %s\n",a);
 147                         command = NULL;
 148                         break;
 149                 }
 150         }
 151
 152         if (command == NULL) {
 153                 help();
 154                 return 1;
 155         }
 156         if (!vbe_probe() || vbe_info == NULL) {
 157                 printf("VESA BIOS not found\n");
 158                 return 1;
 159         }
 160         if (vbe_info->video_mode_ptr == 0UL) {
 161                 printf("VBE bios does not provide a mode list\n");
 162                 return 1;
 163         }
 164
 165         /* also find a mapping from mode 0x13 (320x200x256) to VESA BIOS */
 166         install_320x200x256_remap();
 167
 168         for (entry=0;entry < 1024;entry++) {
 169                 struct vbe_mode_info mi={0},nmi;
 170                 uint16_t nmode,tnmode;
 171                 int nentry;
 172
 173                 mode = vbe_read_mode_entry(vbe_info->video_mode_ptr,entry);
 174                 if (mode == 0xFFFF) break;
 175                 if (!vbe_read_mode_info(mode,&mi)) continue;
 176                 if (!(mi.mode_attributes & VESA_MODE_ATTR_HW_SUPPORTED)) continue;
 177                 if (!(mi.mode_attributes & VESA_MODE_ATTR_GRAPHICS_MODE)) continue;
 178
 179                 if (mi.y_resolution < 240 || (mi.y_resolution > 240 && mi.y_resolution < 480)) {
 180                         printf("Mode 0x%03x (%ux%ux%u) has less than 480 lines\n",mode,
 181                                 mi.x_resolution,mi.y_resolution,mi.bits_per_pixel);
 182
 183                         /* look for a target mode to remap to */
 184                         nmode=0;
 185                         for (nentry=0;nentry < 1024;nentry++) {
 186                                 tnmode = vbe_read_mode_entry(vbe_info->video_mode_ptr,nentry);
 187                                 if (tnmode == 0xFFFF) break;
 188                                 memset(&nmi,0,sizeof(nmi));
 189                                 if (!vbe_read_mode_info(tnmode,&nmi)) continue;
 190                                 if (!(nmi.mode_attributes & VESA_MODE_ATTR_HW_SUPPORTED)) continue;
 191                                 if (!(nmi.mode_attributes & VESA_MODE_ATTR_GRAPHICS_MODE)) continue;
 192                                 if (nmi.x_resolution != mi.x_resolution) continue;
 193                                 if (nmi.number_of_planes != mi.number_of_planes) continue;
 194                                 if (nmi.bits_per_pixel != mi.bits_per_pixel) continue;
 195                                 if (nmi.number_of_banks != mi.number_of_banks) continue;
 196                                 if (nmi.memory_model != mi.memory_model) continue;
 197
 198                                 if (mi.y_resolution < 240 && nmi.y_resolution == 240) {
 199                                         /* found one: should remap 320x200 -> 320x240 */
 200                                         nmode = tnmode;
 201                                         break;
 202                                 }
 203                                 else if (mi.y_resolution >= 240 && nmi.y_resolution == 480) {
 204                                         /* found one: should remap 320/640x350/400 to 320/640x480 */
 205                                         nmode = tnmode;
 206                                         break;
 207                                 }
 208                         }
 209
 210                         if (nmode != 0) {
 211                                 printf("  Remap to 0x%03x (%ux%ux%u)\n",nmode,
 212                                         nmi.x_resolution,nmi.y_resolution,nmi.bits_per_pixel);
 213                         }
 214                         else {
 215                                 printf("  Remap to nothing\n");
 216                         }
 217
 218                         if (remap_count >= MAX_REMAP) break;
 219                         remap[remap_count].source_mode = mode&0x3FFF;
 220                         remap[remap_count].target_mode = nmode&0x3FFF;
 221                         remap_count++;
 222                 }
 223         }
 224
 225         if (remap_count == 0) {
 226                 printf("Nothing to remap\n");
 227                 return 0;
 228         }
 229
 230         _cli();
 231         old_int10 = _dos_getvect(0x10);
 232         _dos_setvect(0x10,new_int10);
 233         _sti();
 234         printf("INT 10h hooked\n"); fflush(stdout);
 235         _dos_keep(0,(34000+sizeof(remap))>>4); /* FIXME! */
 236         return 0;
 237 }
 238
 239 void end_of_resident() {
 240 }
 241