Changeset 258 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH15h_HSize.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/AH15h_HSize.asm (modified) (2 diffs)

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH15h_HSize.asm

@@ -15 +15 @@
 ;   Returns with INTPACK:
 ;       If succesfull:
-;           AH:     3 (Hard disk accessible)
+;           AH:     Hard Disk: 3 (Hard disk accessible)
+;                   Floppy:    1 (Floppy disk, without change detection)
 ;           CX:DX:  Total number of sectors
 ;           CF:     0
@@ -25 +26 @@
 ALIGN JUMP_ALIGN
 AH15h_HandlerForReadDiskDriveSize:
+%ifdef MODULE_SERIAL_FLOPPY
+    mov     cl, 1                                       ; 1 = floppy disk, no change detection
+                
+    test    dl,dl                                       ; DO NOT store the sector count if this is a 
+    jns     .FloppyDrive                                ; floppy disk, some OS's depend on this not 
+                                                        ; happening for floppies in order to boot.
+%endif
+        
     call    AH15h_GetSectorCountToBXDXAX
-    mov     [bp+IDEPACK.intpack+INTPACK.cx], dx ; HIWORD to CX
-    mov     [bp+IDEPACK.intpack+INTPACK.dx], ax ; LOWORD to DX
+    mov     [bp+IDEPACK.intpack+INTPACK.cx], dx         ; HIWORD to CX
+    xchg    [bp+IDEPACK.intpack+INTPACK.dx], ax         ; LOWORD to DX, AL gets drive number
 
-    xor     ah, ah
-    call    Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH    ; Store success to BDA and CF
-    mov     BYTE [bp+IDEPACK.intpack+INTPACK.ah], 3             ; Type code = Hard disk
+    xor     ah, ah      
+%ifdef MODULE_SERIAL_FLOPPY             
+    mov     cl, 3                                       ; 3 = Hard Disk Accessible
+.FloppyDrive:
+        
+    call    Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH_ALHasDriveNumber   ; Store success to BDA and CF       
+    mov     BYTE [bp+IDEPACK.intpack+INTPACK.ah], cl
+%else
+    call    Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH    ; Store success to BDA and CF       
+    mov     BYTE [bp+IDEPACK.intpack+INTPACK.ah], 3
+%endif      
+        
     jmp     Int13h_ReturnFromHandlerWithoutStoringErrorCode