pccons.c File Reference

#include <freeldr.h>

Include dependency graph for pccons.c:

Go to the source code of this file.

Functions
VOID	PcConsPutChar (int Ch)
BOOLEAN	PcConsKbHit (VOID)
int	PcConsGetCh (void)

Function Documentation

PcConsGetCh()

int PcConsGetCh

(

void

)

Definition at line 84 of file pccons.c.

{
  REGS Regs;
  static BOOLEAN ExtendedKey = FALSE;
  static char ExtendedScanCode = 0;
 
  /* If the last time we were called an
   * extended key was pressed then return
   * that keys scan code. */
  if (ExtendedKey)
    {
      ExtendedKey = FALSE;
      return ExtendedScanCode;
    }
 
  /* Int 16h AH=00h
   * KEYBOARD - GET KEYSTROKE
   *
   * AH = 00h
   * Return:
   * AH = BIOS scan code
   * AL = ASCII character
   */
  Regs.b.ah = 0x00;
  Int386(0x16, &Regs, &Regs);
 
  /* Check for an extended keystroke */
  if (0 == Regs.b.al)
    {
      ExtendedKey = TRUE;
      ExtendedScanCode = Regs.b.ah;
    }
 
  /* Return keystroke */
  return Regs.b.al;
}

Referenced by MachInit(), and PcVideoSetDisplayMode().

PcConsKbHit()

BOOLEAN PcConsKbHit

(

VOID

)

Definition at line 63 of file pccons.c.

{
  REGS Regs;
 
  /* Int 16h AH=01h
   * KEYBOARD - CHECK FOR KEYSTROKE
   *
   * AH = 01h
   * Return:
   * ZF set if no keystroke available
   * ZF clear if keystroke available
   * AH = BIOS scan code
   * AL = ASCII character
   */
  Regs.b.ah = 0x01;
  Int386(0x16, &Regs, &Regs);
 
  return 0 == (Regs.x.eflags & EFLAGS_ZF);
}

Referenced by MachInit().

PcConsPutChar()

VOID PcConsPutChar

(

int

Ch

)

Definition at line 22 of file pccons.c.

{
  REGS Regs;
 
  /* If we are displaying a CR '\n' then do a LF also */
  if ('\n' == Ch)
    {
      /* Display the LF */
      PcConsPutChar('\r');
    }
 
  /* If we are displaying a TAB '\t' then display 8 spaces ' ' */
  if ('\t' == Ch)
    {
      /* Display the 8 spaces ' ' */
      PcConsPutChar(' ');
      PcConsPutChar(' ');
      PcConsPutChar(' ');
      PcConsPutChar(' ');
      PcConsPutChar(' ');
      PcConsPutChar(' ');
      PcConsPutChar(' ');
      PcConsPutChar(' ');
      return;
    }
 
  /* Int 10h AH=0Eh
   * VIDEO - TELETYPE OUTPUT
   *
   * AH = 0Eh
   * AL = character to write
   * BH = page number
   * BL = foreground color (graphics modes only)
   */
  Regs.b.ah = 0x0E;
  Regs.b.al = Ch;
  Regs.w.bx = 1;
  Int386(0x10, &Regs, &Regs);
}

Referenced by MachInit(), and PcConsPutChar().