[ros-diffs] [cfinck] 40176: - If we determine that the keyboard buffer is full, only call INT 16h, 0 once without checking again whether the buffer is free afterwards Fixes bug #4264 - Get rid of another procedure for getting a character, can be replaced with two instructions in the only place where this procedure was called See issue #4264 for more details.

Author: cfinck
Date: Mon Mar 23 02:36:48 2009
New Revision: 40176
URL: http://svn.reactos.org/svn/reactos?rev=40176&view=rev
Log:
- If we determine that the keyboard buffer is full, only call INT 16h,0 once without
checking again whether the buffer is free afterwards
  Fixes bug #4264
- Get rid of another procedure for getting a character, can be replaced with two
instructions in the only place where this procedure was called
See issue #4264 for more details.
Modified:
    trunk/reactos/boot/freeldr/bootsect/isoboot.asm
Modified: trunk/reactos/boot/freeldr/bootsect/isoboot.asm
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/bootsect/isob…
==============================================================================
--- trunk/reactos/boot/freeldr/bootsect/isoboot.asm [iso-8859-1] (original)
+++ trunk/reactos/boot/freeldr/bootsect/isoboot.asm [iso-8859-1] Mon Mar 23 02:36:48 2009
@@ -898,41 +898,23 @@
        sti
        mov     si, err_bootfailed
        call    writestr
-       call    getchar
+       xor     ax, ax          ; Wait for keypress
+       int     16h
        cli
        mov     word [BIOS_magic], 0    ; Cold reboot
        jmp     0F000h:0FFF0h           ; Reset vector address
-getchar:
-.again:
-       mov     ah, 1           ; Poll keyboard
-       int     16h
-       jz      .again
-.kbd:
-       xor     ax, ax          ; Get keyboard input
-       int     16h
-.func_key:
-       ret
-
 ;
 ; pollchar_and_empty: check if we have an input character pending (ZF = 0) and empty the
input buffer afterwards
 ;
 pollchar_and_empty:
        pushad
-       mov ah, 1               ; Poll keyboard
+       mov ah, 1               ; Did the user press a key?
        int 16h
-       jz      .end
-.empty_buffer:
-       mov ah, 0               ; Read from keyboard
+       jz      .end            ; No, then we're done
+       mov ah, 0               ; Otherwise empty the buffer by reading it
        int 16h
-
-       mov ah, 1               ; Poll keyboard again
-       int 16h
-       jz      .buffer_emptied
-       jmp .empty_buffer
-.buffer_emptied:
-       and ax, ax      ; ZF = 0
 .end:
        popad
        ret