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

Timestamp:

Feb 22, 2012, 7:01:53 PM (12 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.asm (modified) (5 diffs)

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h.asm

@@ -29 +29 @@
     mov     [RAMVARS.xlateVars+XLATEVARS.bXlatedDrv], dl
     call    RamVars_IsFunctionHandledByThisBIOS
-    jnc     SHORT Int13h_DirectCallToAnotherBios
+    jc      SHORT Int13h_DirectCallToAnotherBios
+
     call    FindDPT_ForDriveNumber      ; DS:DI now points to DPT
 
@@ -139 +140 @@
 ALIGN JUMP_ALIGN
 Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH:
+%ifdef MODULE_SERIAL_FLOPPY
+    mov     al, [bp+IDEPACK.intpack+INTPACK.dl]
+Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH_ALHasDriveNumber:   
+    call    Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH_ALHasDriveNumber
+%else
     call    Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH
+%endif
 Int13h_ReturnFromHandlerWithoutStoringErrorCode:
     or      WORD [bp+IDEPACK.intpack+INTPACK.flags], FLG_FLAGS_IF   ; Return with interrupts enabled
@@ -154 +161 @@
 ;   Returns:
 ;       Depends on function
+;       NOTE: ES:DI needs to be returned from the previous interrupt 
+;             handler, for floppy DPT in function 08h
 ;   Corrupts registers:
-;       BX, DI, ES
+;       None
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
 Int13h_CallPreviousInt13hHandler:
-    push    di
     call    ExchangeCurrentInt13hHandlerWithOldInt13hHandler
     int     BIOS_DISK_INTERRUPT_13h
-    call    ExchangeCurrentInt13hHandlerWithOldInt13hHandler
-    pop     di
-    ret
-
+;;;  fall-through to ExchangeCurrentInt13hHandlerWithOldInt13hHandler
 
 ;--------------------------------------------------------------------
@@ -174 +179 @@
 ;       Nothing
 ;   Corrupts registers:
-;       DI
+;       Nothing
+;       Note: Flags are preserved
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
 ExchangeCurrentInt13hHandlerWithOldInt13hHandler:
     push    es
-    LOAD_BDA_SEGMENT_TO es, di
-    mov     di, [RAMVARS.fpOldI13h]
+    push    si
+    LOAD_BDA_SEGMENT_PRESERVE_FLAGS_TO  es, si
+    mov     si, [RAMVARS.fpOldI13h]
     cli
-    xchg    di, [es:BIOS_DISK_INTERRUPT_13h*4]
-    mov     [RAMVARS.fpOldI13h], di
-    mov     di, [RAMVARS.fpOldI13h+2]
-    xchg    di, [es:BIOS_DISK_INTERRUPT_13h*4+2]
+    xchg    si, [es:BIOS_DISK_INTERRUPT_13h*4]
+    mov     [RAMVARS.fpOldI13h], si
+    mov     si, [RAMVARS.fpOldI13h+2]
+    xchg    si, [es:BIOS_DISK_INTERRUPT_13h*4+2]
     sti
-    mov     [RAMVARS.fpOldI13h+2], di
+    mov     [RAMVARS.fpOldI13h+2], si
+    pop     si
     pop     es
     ret
@@ -204 +212 @@
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
+%ifdef MODULE_SERIAL_FLOPPY
+Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH_ALHasDriveNumber:
+    ; Store error code to BDA
+    mov     bx, BDA.bHDLastSt
+    test    al, al
+    js      .HardDisk
+    mov     bl, BDA.bFDRetST & 0xff
+.HardDisk:
+    LOAD_BDA_SEGMENT_TO ds, di
+    mov     [bx], ah        
+%else
 Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH:
     ; Store error code to BDA
-    LOAD_BDA_SEGMENT_TO ds, di
+    LOAD_BDA_SEGMENT_TO ds, di      
     mov     [BDA.bHDLastSt], ah
+%endif
 
     ; Store error code to INTPACK