Added check for disk in drive on chdir().

git-svn-id: svn://svn.cc65.org/cc65/trunk@5859 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/cbm/devicedir.s

@@ -5,9 +5,7 @@
 ;
 
         .export         _getdevicedir
-        .import         opencmdchannel, closecmdchannel
-        .import         writefndiskcmd, readdiskerror
-        .import         isdisk, fnunit, fncmd, devicestr
+        .import         diskinit, devicestr, fnunit
         .import         popa, popax
         .importzp       ptr2, ptr3
 
@@ -29,63 +27,30 @@
         sta     ptr2
         stx     ptr2+1
 
-; Save device
+; Check device readiness
 
         jsr     popa
-        sta     fnunit
-
-; Check for disk device
-
-        tax
-        jsr     isdisk
-        bcs     erange
-
-; Open channel
-
-        jsr     opencmdchannel
-        bne     oserr
-
-; Write command
-
-        lda     #'i'            ; Init command
-        sta     fncmd
-        jsr     writefndiskcmd
-        bne     close
-
-; Read error
-
-        ldx     fnunit
-        jsr     readdiskerror
-
-; Close channel
-
-close:  pha
-        ldx     fnunit
-        jsr     closecmdchannel
-        pla
-        bne     oserr
+        jsr     diskinit
+        beq     size
+        jsr     __mappederrno
+        bne     fail            ; Branch always
 
 ; Check for sufficient buf size
 
-        lda     ptr3+1
+size:   lda     ptr3+1
         bne     okay            ; Buf >= 256
         lda     ptr3
         cmp     #3
         bcs     okay            ; Buf >= 3
-
-erange: lda     #<ERANGE
+        lda     #<ERANGE
         jsr     __directerrno
-        bne     fail            ; Branch always
-
-oserr:  jsr     __mappederrno
-
 fail:   lda     #0              ; Return NULL
         tax
         rts
 
 ; Copy device string representation into buf
 
-okay:   lda     fnunit
+okay:   lda     fnunit          ; Set by diskinit
         jsr     devicestr       ; Returns 0 in A
         sta     __oserror       ; Clear _oserror