Changeset 259 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs

Timestamp:

Feb 23, 2012, 7:14:06 AM (13 years ago)

Author:

gregli@…

google:author:

gregli@hotmail.com

Message:

For function int13/0h, restored the code to only reset the floppy drives if a floppy drive was passed in for reset. Other minor optimizations. Better create new floppy support in Serial Server.

File:

• trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/FindDPT.asm (modified) (5 diffs)

trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/FindDPT.asm

@@ -23 +23 @@
     add     al, [RAMVARS.xlateVars+XLATEVARS.bFlopCreateCnt]
 %endif
-    xchg    ax, dx      
-    ; Fall to FindDPT_ForDriveNumber
-
+    xchg    ax, dx
+    ; fall-through to FindDPT_ForDriveNumber
 
 ;--------------------------------------------------------------------
@@ -66 +65 @@
     xchg    di, ax                      ; Restore AX and put result in DI
     pop     dx
-    ret
+        
+    ret
+
+;--------------------------------------------------------------------
+; Consolidator for checking the result from RamVars_IsDriveHandledByThisBIOS
+; and then if it is our drive, getting the DPT with FindDPT_ForDriveNumber
+;
+; RamVars_IsDriveHandledByThisBIOS_And_FindDPT_ForDriveNumber
+;   Parameters:
+;       DL:     Drive number
+;       DS:     RAMVARS segment
+;   Returns:
+;       DS:DI:  Ptr to DPT, if it is our drive
+;       CF:     Set if not our drive, clear if it is our drive
+;   Corrupts registers:
+;       Nothing
+;--------------------------------------------------------------------
+ALIGN JUMP_ALIGN
+RamVars_IsDriveHandledByThisBIOS_And_FindDPT_ForDriveNumber:
+    call    RamVars_IsDriveHandledByThisBIOS
+    jnc     FindDPT_ForDriveNumber
+    ret
+
 
 ;--------------------------------------------------------------------
@@ -212 +233 @@
     push    cx
 
-    mov     cl, [RAMVARS.bDrvCnt]       
-    mov     ch, 0
-        
     mov     di, RAMVARS_size            ; Point DS:DI to first DPT
         
-    jcxz    .NotFound                   ; Return if no drives
+    mov     cl, [RAMVARS.bDrvCnt]
+    xor     ch, ch                      ; Clears CF  
+        
+    jcxz    .AllDptsIterated            ; Return if no drives, CF will be clear from xor above
         
 ALIGN JUMP_ALIGN
@@ -223 +244 @@
     call    si                          ; Is wanted DPT?
     jc      SHORT .AllDptsIterated      ;  If so, return
-    add     di, BYTE LARGEST_DPT_SIZE   ; Point to next DPT
+    add     di, BYTE LARGEST_DPT_SIZE   ; Point to next DPT, clears CF
     loop    .LoopWhileDPTsLeft
-        
-.NotFound:      
-    clc                                 ; Clear CF since DPT not found
+    
+    ; fall-through: DPT was not found, CF is already clear from ADD di inside the loop
         
 ALIGN JUMP_ALIGN
@@ -233 +253 @@
     pop     cx
     ret
+