reactos/boot/freeldr/freeldr/arch/i386/pccons.c

   1 /* $Id$
   2  *
   3  *  FreeLoader
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License along
  16  *  with this program; if not, write to the Free Software Foundation, Inc.,
  17  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #include <freeldr.h>
  21
  22 #define TEXTMODE_BUFFER      0xb8000
  23 #define TEXTMODE_BUFFER_SIZE 0x8000
  24
  25 #define TEXT_COLS  80
  26 #define TEXT_LINES 25
  27
  28 VOID
  29 PcConsPutChar(int Ch)
  30 {
  31   REGS Regs;
  32
  33   /* If we are displaying a CR '\n' then do a LF also */
  34   if ('\n' == Ch)
  35     {
  36       /* Display the LF */
  37       PcConsPutChar('\r');
  38     }
  39
  40   /* If we are displaying a TAB '\t' then display 8 spaces ' ' */
  41   if ('\t' == Ch)
  42     {
  43       /* Display the 8 spaces ' ' */
  44       PcConsPutChar(' ');
  45       PcConsPutChar(' ');
  46       PcConsPutChar(' ');
  47       PcConsPutChar(' ');
  48       PcConsPutChar(' ');
  49       PcConsPutChar(' ');
  50       PcConsPutChar(' ');
  51       PcConsPutChar(' ');
  52       return;
  53     }
  54
  55   /* Int 10h AH=0Eh
  56    * VIDEO - TELETYPE OUTPUT
  57    *
  58    * AH = 0Eh
  59    * AL = character to write
  60    * BH = page number
  61    * BL = foreground color (graphics modes only)
  62    */
  63   Regs.b.ah = 0x0E;
  64   Regs.b.al = Ch;
  65   Regs.w.bx = 1;
  66   Int386(0x10, &Regs, &Regs);
  67 }
  68
  69 BOOLEAN
  70 PcConsKbHit(VOID)
  71 {
  72   REGS Regs;
  73
  74   /* Int 16h AH=01h
  75    * KEYBOARD - CHECK FOR KEYSTROKE
  76    *
  77    * AH = 01h
  78    * Return:
  79    * ZF set if no keystroke available
  80    * ZF clear if keystroke available
  81    * AH = BIOS scan code
  82    * AL = ASCII character
  83    */
  84   Regs.b.ah = 0x01;
  85   Int386(0x16, &Regs, &Regs);
  86
  87   return 0 == (Regs.x.eflags & I386FLAG_ZF);
  88 }
  89
  90 int
  91 PcConsGetCh(void)
  92 {
  93   REGS Regs;
  94   static BOOLEAN ExtendedKey = FALSE;
  95   static char ExtendedScanCode = 0;
  96
  97   /* If the last time we were called an
  98    * extended key was pressed then return
  99    * that keys scan code. */
 100   if (ExtendedKey)
 101     {
 102       ExtendedKey = FALSE;
 103       return ExtendedScanCode;
 104     }
 105
 106   /* Int 16h AH=00h
 107    * KEYBOARD - GET KEYSTROKE
 108    *
 109    * AH = 00h
 110    * Return:
 111    * AH = BIOS scan code
 112    * AL = ASCII character
 113    */
 114   Regs.b.ah = 0x00;
 115   Int386(0x16, &Regs, &Regs);
 116
 117   /* Check for an extended keystroke */
 118   if (0 == Regs.b.al)
 119     {
 120       ExtendedKey = TRUE;
 121       ExtendedScanCode = Regs.b.ah;
 122     }
 123
 124   /* Return keystroke */
 125   return Regs.b.al;
 126 }
 127
 128 /* EOF */