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00001 /* $Id: pccons.c 53440 2011-08-25 09:44:21Z tkreuzer $
00002  *
00003  *  FreeLoader
00004  *
00005  *  This program is free software; you can redistribute it and/or modify
00006  *  it under the terms of the GNU General Public License as published by
00007  *  the Free Software Foundation; either version 2 of the License, or
00008  *  (at your option) any later version.
00009  *
00010  *  This program is distributed in the hope that it will be useful,
00011  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00012  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013  *  GNU General Public License for more details.
00014  *
00015  *  You should have received a copy of the GNU General Public License along
00016  *  with this program; if not, write to the Free Software Foundation, Inc.,
00017  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
00018  */
00019 
00020 #include <freeldr.h>
00021 
00022 #define TEXTMODE_BUFFER      0xb8000
00023 #define TEXTMODE_BUFFER_SIZE 0x8000
00024 
00025 #define TEXT_COLS  80
00026 #define TEXT_LINES 25
00027 
00028 VOID
00029 PcConsPutChar(int Ch)
00030 {
00031   REGS Regs;
00032 
00033   /* If we are displaying a CR '\n' then do a LF also */
00034   if ('\n' == Ch)
00035     {
00036       /* Display the LF */
00037       PcConsPutChar('\r');
00038     }
00039 
00040   /* If we are displaying a TAB '\t' then display 8 spaces ' ' */
00041   if ('\t' == Ch)
00042     {
00043       /* Display the 8 spaces ' ' */
00044       PcConsPutChar(' ');
00045       PcConsPutChar(' ');
00046       PcConsPutChar(' ');
00047       PcConsPutChar(' ');
00048       PcConsPutChar(' ');
00049       PcConsPutChar(' ');
00050       PcConsPutChar(' ');
00051       PcConsPutChar(' ');
00052       return;
00053     }
00054 
00055   /* Int 10h AH=0Eh
00056    * VIDEO - TELETYPE OUTPUT
00057    *
00058    * AH = 0Eh
00059    * AL = character to write
00060    * BH = page number
00061    * BL = foreground color (graphics modes only)
00062    */
00063   Regs.b.ah = 0x0E;
00064   Regs.b.al = Ch;
00065   Regs.w.bx = 1;
00066   Int386(0x10, &Regs, &Regs);
00067 }
00068 
00069 BOOLEAN
00070 PcConsKbHit(VOID)
00071 {
00072   REGS Regs;
00073 
00074   /* Int 16h AH=01h
00075    * KEYBOARD - CHECK FOR KEYSTROKE
00076    *
00077    * AH = 01h
00078    * Return:
00079    * ZF set if no keystroke available
00080    * ZF clear if keystroke available
00081    * AH = BIOS scan code
00082    * AL = ASCII character
00083    */
00084   Regs.b.ah = 0x01;
00085   Int386(0x16, &Regs, &Regs);
00086 
00087   return 0 == (Regs.x.eflags & EFLAGS_ZF);
00088 }
00089 
00090 int
00091 PcConsGetCh(void)
00092 {
00093   REGS Regs;
00094   static BOOLEAN ExtendedKey = FALSE;
00095   static char ExtendedScanCode = 0;
00096 
00097   /* If the last time we were called an
00098    * extended key was pressed then return
00099    * that keys scan code. */
00100   if (ExtendedKey)
00101     {
00102       ExtendedKey = FALSE;
00103       return ExtendedScanCode;
00104     }
00105 
00106   /* Int 16h AH=00h
00107    * KEYBOARD - GET KEYSTROKE
00108    *
00109    * AH = 00h
00110    * Return:
00111    * AH = BIOS scan code
00112    * AL = ASCII character
00113    */
00114   Regs.b.ah = 0x00;
00115   Int386(0x16, &Regs, &Regs);
00116 
00117   /* Check for an extended keystroke */
00118   if (0 == Regs.b.al)
00119     {
00120       ExtendedKey = TRUE;
00121       ExtendedScanCode = Regs.b.ah;
00122     }
00123 
00124   /* Return keystroke */
00125   return Regs.b.al;
00126 }
00127 
00128 /* EOF */
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