Changeset 258 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH0h_HReset.asm

Timestamp:

Feb 22, 2012, 7:01:53 PM (13 years ago)

Author:

gregli@…

google:author:

gregli@hotmail.com

Message:

Added floppy drive emulation over the serial connection (MODULE_SERIAL_FLOPPY). Along the way, various optimizations were made to stay within the 8K ROM size target. Also, serial code now returns the number of sectors transferred.

File:

• trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH0h_HReset.asm (modified) (7 diffs)

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH0h_HReset.asm

@@ -22 +22 @@
     eMOVZX  bx, dl                      ; Copy requested drive to BL, zero BH to assume no errors
     call    ResetFloppyDrivesWithInt40h
-    test    bl, bl
-    jns     SHORT .SkipHardDiskReset
     call    ResetForeignHardDisks
     call    AH0h_ResetHardDisksHandledByOurBIOS
@@ -64 +62 @@
     xor     ah, ah                      ; Disk Controller Reset
     call    Int13h_CallPreviousInt13hHandler
-    jmp     SHORT BackupErrorCodeFromTheRequestedDriveToBH
-
+;;; fall-through to BackupErrorCodeFromTheRequestedDriveToBH
+
+
+;--------------------------------------------------------------------
+; BackupErrorCodeFromTheRequestedDriveToBH
+;   Parameters:
+;       AH:     Error code from the last resetted drive
+;       DL:     Drive last resetted
+;       BL:     Requested drive (DL when entering AH=00h)
+;   Returns:
+;       BH:     Backuped error code
+;   Corrupts registers:
+;       Nothing
+;--------------------------------------------------------------------
+ALIGN JUMP_ALIGN
+BackupErrorCodeFromTheRequestedDriveToBH:
+    cmp     dl, bl              ; Requested drive?
+    eCMOVE  bh, ah
+    ret
+        
 
 ;--------------------------------------------------------------------
@@ -82 +98 @@
     mov     dl, bl
     call    RamVars_IsDriveHandledByThisBIOS
-    jnc     SHORT .Return               ; Return what was in BL unmodified
+    jc      SHORT .Return               ; Return what was in BL unmodified
     mov     dl, 80h
 .Return:
@@ -101 +117 @@
 ALIGN JUMP_ALIGN
 AH0h_ResetHardDisksHandledByOurBIOS:
-    mov     dh, [RAMVARS.bDrvCnt]       ; Load drive count to DH
+    mov     dx, [RAMVARS.wDrvCntAndFirst]   ; DL = drive number, DH = drive count
     test    dh, dh
     jz      SHORT .AllDrivesReset       ; Return if no drives
-    mov     dl, [RAMVARS.bFirstDrv]     ; Load number of our first drive
     add     dh, dl                      ; DH = one past last drive to reset
 ALIGN JUMP_ALIGN
@@ -114 +129 @@
     jb      SHORT .DriveResetLoop       ;  If not, reset next drive
 .AllDrivesReset:
-    ret
-
+%ifdef MODULE_SERIAL_FLOPPY
+;
+; "Reset" emulatd serial floppy drives, if any.  There is nothing to actually do for this reset,
+; but record the proper error return code if one of these floppy drives is the drive requested.
+;
+    call    RamVars_UnpackFlopCntAndFirstToAL
+
+    cbw                                                 ; Clears AH (there are flop drives) or ffh (there are not)
+                                                        ; Either AH has success code (flop drives are present)
+                                                        ; or it doesn't matter because we won't match drive ffh
+
+    cwd                                                 ; clears DX (there are flop drives) or ffffh (there are not)
+
+    adc     dl, al                                      ; second drive (CF set) if present
+                                                        ; If no drive is present, this will result in ffh which 
+                                                        ; won't match a drive
+    call    BackupErrorCodeFromTheRequestedDriveToBH
+    mov     dl, al                                      ; We may end up doing the first drive twice (if there is
+    jmp     BackupErrorCodeFromTheRequestedDriveToBH    ; only one drive), but doing it again is not harmful.
+%else
+    ret
+%endif
+        
 ;--------------------------------------------------------------------
 ; .BackupErrorCodeFromMasterOrSlaveToBH
@@ -144 +180 @@
     ret
 
+        
 ;--------------------------------------------------------------------
 ; GetBasePortToCX
@@ -167 +204 @@
 
 
-;--------------------------------------------------------------------
-; BackupErrorCodeFromTheRequestedDriveToBH
-;   Parameters:
-;       AH:     Error code from the last resetted drive
-;       DL:     Drive last resetted
-;       BL:     Requested drive (DL when entering AH=00h)
-;   Returns:
-;       BH:     Backuped error code
-;   Corrupts registers:
-;       Nothing
-;--------------------------------------------------------------------
-ALIGN JUMP_ALIGN
-BackupErrorCodeFromTheRequestedDriveToBH:
-    cmp     dl, bl              ; Requested drive?
-    eCMOVE  bh, ah
-    ret