Changeset 55 in xtideuniversalbios for trunk/Assembly_Library/Src/Display

Timestamp:

Nov 16, 2010, 4:52:12 PM (14 years ago)

Author:

Tomi Tilli

google:author:

aitotat

Message:

Changes to Assembly Library:

• Character output to buffer now checks buffer length properly.

File:

• trunk/Assembly_Library/Src/Display/DisplayCharOut.asm (modified) (3 diffs)

trunk/Assembly_Library/Src/Display/DisplayCharOut.asm

@@ -2 +2 @@
 ; Project name  :   Assembly Library
 ; Created date  :   26.6.2010
-; Last update   :   8.10.2010
+; Last update   :   24.10.2010
 ; Author        :   Tomi Tilli
 ; Description   :   Functions for outputting characters to video memory.
@@ -117 +117 @@
 ;       DS:     BDA segment (zero)
 ;       ES:DI:  Ptr to destination string buffer
-;       DISPLAY_CONTEXT.wCharOutParam:  Offset to end of buffer (one past last)
+;       DISPLAY_CONTEXT.wCharOutParam:  Characters left in buffer
 ;   Returns:
 ;       ES:DI:  Updated for next character
@@ -125 +125 @@
 ALIGN JUMP_ALIGN
 DisplayCharOut_WriteCharacterToBuffer:
-    cmp     di, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam]
-    jae     SHORT .BufferFull
+    cmp     WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], BYTE 0
+    je      SHORT .BufferFull
     stosb
+    dec     WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam]
 .BufferFull:
     ret