Changeset 155 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Device/Timer.asm

Timestamp:

May 1, 2011, 6:44:29 PM (14 years ago)

Author:

Tomi Tilli

google:author:

aitotat

Message:

Changes to XTIDE Universal BIOS:

• AH=4h again uses VERIFY command (copy-pasting had changed it to WRITE).
• Timeout should now work on all overflow situations.
• Cleaned code a bit.

File:

• trunk/XTIDE_Universal_BIOS/Src/Device/Timer.asm (copied) (copied from trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/Common/HTimer.asm ) (9 diffs)

trunk/XTIDE_Universal_BIOS/Src/Device/Timer.asm

@@ -6 +6 @@
 
 ;--------------------------------------------------------------------
-; HTimer_InitializeTimeoutWithTicksInCX
+; Timer_InitializeTimeoutWithTicksInCL
 ;   Parameters:
-;       CX:     Timeout value in system timer ticks
+;       CL:     Timeout value in system timer ticks
 ;       DS:     Segment to RAMVARS
 ;   Returns:
@@ -16 +16 @@
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
-HTimer_InitializeTimeoutWithTicksInCX:
-    mov     [RAMVARS.wTimeoutCounter], cx   ; Store timeout ticks
+Timer_InitializeTimeoutWithTicksInCL:
+    mov     [RAMVARS.bTimeoutTicksLeft], cl     ; Ticks until timeout
     call    ReadTimeFromBdaToCX
-    add     [RAMVARS.wTimeoutCounter], cx   ; End time for timeout
+    mov     [RAMVARS.bLastTimeoutUpdate], cl    ; Start time
     ret
 
 
 ;--------------------------------------------------------------------
-; HTimer_SetCFifTimeout
+; Timer_SetCFifTimeout
 ;   Parameters:
 ;       DS:     Segment to RAMVARS
@@ -34 +34 @@
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
-HTimer_SetCFifTimeout:
+Timer_SetCFifTimeout:
     call    ReadTimeFromBdaToCX
-    cmp     [RAMVARS.wTimeoutCounter], cx
+    cmp     cl, [RAMVARS.bLastTimeoutUpdate]
+    je      SHORT .StillPollingTheSameTick
+    mov     [RAMVARS.bLastTimeoutUpdate], cl
+    sub     BYTE [RAMVARS.bTimeoutTicksLeft], 1 ; DEC does not update CF
+.StillPollingTheSameTick:
     ret
 
@@ -44 +48 @@
 ; RTC resolution is 977 microsecs.
 ;
-; HTimer_DelayMicrosecondsFromAX
+; Timer_DelayMicrosecondsFromAX
 ;   Parameters:
 ;       AX:     Number of microsecs to wait
@@ -52 +56 @@
 ;       AX
 ;--------------------------------------------------------------------
-HTimer_DelayMicrosecondsFromAX:
+Timer_DelayMicrosecondsFromAX:
 %ifndef USE_AT
     mov     ax, 2
@@ -69 +73 @@
     pop     dx
     mov     ax, 1                               ; Prepare to wait 1 timer tick
-    jc      SHORT HTimer_DelayTimerTicksFromAX  ; Event Wait was unsupported or busy
+    jc      SHORT Timer_DelayTimerTicksFromAX   ; Event Wait was unsupported or busy
     ret
 %endif
@@ -78 +82 @@
 ; will occur at 54.9 ms intervals.
 ;
-; HTimer_DelayTimerTicksFromAX
+; Timer_DelayTimerTicksFromAX
 ;   Parameters:
 ;       AX:     Number of timer ticks to wait
@@ -86 +90 @@
 ;       AX
 ;--------------------------------------------------------------------
-HTimer_DelayTimerTicksFromAX:
+Timer_DelayTimerTicksFromAX:
     sti                             ; Make sure that interrupts are enabled
     call    ReadTimeFromBdaToCX
@@ -93 +97 @@
     call    ReadTimeFromBdaToCX
     cmp     cx, ax
-    jb      SHORT .WaitLoop         ; Loop until end time is reached
+    jne     SHORT .WaitLoop         ; Loop until end time is reached
     ret