Update md.asm

Sstack use optimization

Source/HBIOS/md.asm

@@ -319,7 +319,7 @@ MD_RDSECF:				; CALLED FROM MD_RW
 					; WHICH WAS SETUP BY MD_IOSETUPF
 ;
 	LD	IX,MD_F4KBUF		; SET DESTINATION ADDRESS
-	LD	BC,MD_FREAD_R		; PUT ROUTINE TO CALL
+	LD	HL,MD_FREAD_R		; PUT ROUTINE TO CALL
 	CALL	MD_FNCALL		; EXECUTE: READ 4K SECTOR
 ;
 MD_SECM:
@@ -426,11 +426,11 @@ MD_WRSECF:				; CALLED FROM MD_RW
 	CALL	MD_CALBAS		; SETUP BANK AND SECTOR
 ;
 	LD	IX,MD_F4KBUF		; SET DESTINATION ADDRESS
-	LD	BC,MD_FREAD_R		; PUT ROUTINE TO CALL
+	LD	HL,MD_FREAD_R		; PUT ROUTINE TO CALL
 	CALL	MD_FNCALL		; EXECUTE: READ 4K SECTOR
 ;
 MD_SECM1:				; DESIRED SECTOR IS IN BUFFER
-	LD	BC,MD_FERAS_R		; PUT ROUTINE TO CALL
+	LD	HL,MD_FERAS_R		; PUT ROUTINE TO CALL
 	CALL	MD_FNCALL		; EXECUTE: ERASE 4K SECTOR
 	OR	A
 	RET	NZ			; RETURN IF ERROR
@@ -452,25 +452,25 @@ MD_SECM1:				; DESIRED SECTOR IS IN BUFFER
 	LDIR				; THE DISK BUFFER TO 4K SECTOR
 ;
 	LD	IX,MD_F4KBUF		; SET SOURCE ADDRESS
-	LD	BC,MD_FWRIT_R		; PUT ROUTINE TO CALL
+	LD	HL,MD_FWRIT_R		; PUT ROUTINE TO CALL
 	CALL	MD_FNCALL		; EXECUTE: WRITE 4K SECTOR
 ;
 	XOR	A			; PRESUME SUCCESS STATUS
 ;
 #IF (MD_FVAR==1)
 	LD	IX,MD_F4KBUF		; SET SOURCE ADDRESS
-	LD	BC,MD_FVERI_R		; PUT ROUTINE TO CALL
+	LD	HL,MD_FVERI_R		; PUT ROUTINE TO CALL
 	CALL	MD_FNCALL		; EXECUTE: VERIFY 4K SECTOR
 ;
 	OR	A
 	RET	Z			; RETURN IF SUCCESSFUL
 ;
 	LD	IX,MD_F4KBUF		; SET SOURCE ADDRESS		; RETRY
-	LD	BC,MD_FWRIT_R		; PUT ROUTINE TO CALL		; WRITE
+	LD	HL,MD_FWRIT_R		; PUT ROUTINE TO CALL		; WRITE
 	CALL	MD_FNCALL		; EXECUTE: WRITE 4K SECTOR	; ONCE
 ;
 	LD	IX,MD_F4KBUF		; SET SOURCE ADDRESS		; VERIFY
-	LD	BC,MD_FVERI_R		; PUT ROUTINE TO CALL		; AGAIN
+	LD	HL,MD_FVERI_R		; PUT ROUTINE TO CALL		; AGAIN
 	CALL	MD_FNCALL		; EXECUTE: VERIFY 4K SECTOR
 ;
 	OR	A			; SET FINAL STATUS AFTER RETRY
@@ -716,11 +716,11 @@ MD_PROBE:
 	LD	A,'='			; NUMBER
 	CALL	COUT
 #ENDIF
+	PUSH	HL
 	CALL	MD_CALBAS		; SETUP BANK AND SECTOR
-	LD	BC,MD_FIDENT_R		; PUT ROUTINE TO CALL
+	LD	HL,MD_FIDENT_R		; PUT ROUTINE TO CALL
 	CALL	MD_FNCALL		; EXECUTE: IDENTIFY FLASH CHIP
 
-	PUSH	HL
 	LD	HL,MD_TGTDEV		; IF WE MATCH WITH
 	XOR	A			; A NON 39SF040
 	SBC	HL,BC			; CHIP SET THE
@@ -836,12 +836,7 @@ FF_NXT2:
 ;  RETURN WITH ID CODE.
 ;======================================================================
 ;
-MD_FNCALL:	
-	PUSH	HL			; USING HBX_BUF FOR CODE AREA
-	PUSH	DE
-
-	PUSH	BC			; GET ROUTINE TO CALL
-	POP	HL
+MD_FNCALL:				; USING HBX_BUF FOR CODE AREA
 ;
 	LD	DE,HBX_BUF		; EXECUTE / START ADDRESS
 	LD	BC,MD_CSIZE		; CODE SIZE. MAXIMUM 64 BYTES
@@ -881,8 +876,6 @@ MD_FNCALL:
 #ENDIF
 ;
 	LD	A,C			; RETURN WITH STATUS IN A
-	POP	DE
-	POP	HL
 	RET				; RETURN TO MD_READF, MD_WRITEF
 ;
 MD_SAVSTK	.DW	0