Changeset 258 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Device/Serial/SerialCommand.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/Device/Serial/SerialCommand.asm (modified) (5 diffs)

trunk/XTIDE_Universal_BIOS/Src/Device/Serial/SerialCommand.asm

@@ -56 +56 @@
 ;   Returns:
 ;       AH:     INT 13h Error Code
+;       CX:     Number of successfully transferred sectors (for transfer commands)
 ;       CF:     Cleared if success, Set if error
 ;   Corrupts registers:
@@ -309 +310 @@
         dec     al              ; decrement sector count
         push    ax              ; save
-        jz      SerialCommand_OutputWithParameters_ReturnCodeInALCF    ; CF=0 from "cmp ax,bp" returning Zero above
+        jz      SerialCommand_OutputWithParameters_ReturnCodeInAL
 
         cli                     ; interrupts back off for ACK byte to host
@@ -409 +410 @@
 
 .clearBufferComplete:
-        stc
-        mov     al,1
-
-ALIGN JUMP_ALIGN
-SerialCommand_OutputWithParameters_ReturnCodeInALCF:
+        mov     al, 3           ;  error return code and CF (low order bit)
+
+ALIGN JUMP_ALIGN
+SerialCommand_OutputWithParameters_ReturnCodeInAL:
 %if 0
         sti                     ;  all paths here will already have interrupts turned back on
 %endif
-        mov     ah,al
-
-        pop     bp              ;  recover ax (command and count) from stack, throw away
+        mov     ah, al          ;  for success, AL will already be zero
+
+        pop     bx              ;  recover "ax" (command and count) from stack
 
         pop     bp
         pop     di
         pop     si
+
+        mov     ch, 0
+        mov     cl,[bp+IDEPACK.bSectorCount]
+        sub     cl, bl          ; subtract off the number of sectors that remained
+        
+        shr     ah, 1           ; shift down return code and CF
 
         ret
@@ -632 +638 @@
         call    FindDPT_ToDSDIforSerialDevice
         pop     si
+%ifdef MODULE_SERIAL_FLOPPY
+        jc      .founddpt
+;
+; If not found above with FindDPT_ToDSDIforSerialDevice, DI will point to the DPT after the last hard disk DPT
+;
+        cmp     byte [RAMVARS.xlateVars+XLATEVARS.bFlopCntAndFirst], 0
+        jz      .notfounddpt
+.founddpt:
+%else
         jnc     .notfounddpt
+%endif
         mov     ax, [di+DPT_SERIAL.wSerialPortAndBaud]
 .notfounddpt:
@@ -678 +694 @@
 ; which is read by FinalizeDPT and DetectDrives
 ;
-        mov     [es:si+ATA6.wVendor],dx
+        mov     [es:si+ATA6.wSerialPortAndBaud],dx
 
 .notFound: