Introduced getdevicedir() - with implementation for the CBMs.

git-svn-id: svn://svn.cc65.org/cc65/trunk@5840 b7a2c559-68d2-44c3-8de9-860c34a00d81
2012-10-07 19:18:56 +00:00
parent 3470f230ae
commit 987c3066a3
5 changed files with 143 additions and 20 deletions
--- a/libsrc/cbm/devicedir.s
+++ b/libsrc/cbm/devicedir.s
@@ -0,0 +1,97 @@
+;
+; Oliver Schmidt, 2012-09-10
+;
+; char* __fastcall__ getdevicedir (unsigned char device, char* buf, size_t size);
+;
+
+        .export         _getdevicedir
+
+        .import         opencmdchannel, closecmdchannel
+        .import         writefndiskcmd, readdiskerror
+        .import         isdisk, fnunit, fncmd, devicestr
+        .import         popa, popax
+        .importzp       ptr2, ptr3
+
+        .include        "errno.inc"
+
+;------------------------------------------------------------------------------
+; _getdevicedir
+
+.proc   _getdevicedir
+
+; Save size
+
+        sta     ptr3
+        stx     ptr3+1
+
+; Save buf
+
+        jsr     popax
+        sta     ptr2
+        stx     ptr2+1
+
+; Save device
+
+        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
+
+; Check for sufficient buf size
+
+        lda     ptr3+1
+        bne     okay            ; Buf >= 256
+        lda     ptr3
+        cmp     #3
+        bcs     okay            ; Buf >= 3
+
+erange: lda     #<ERANGE
+        bne     errno           ; Branch always
+
+oserr:  jsr     __osmaperrno
+
+errno:  jsr     __seterrno      ; Returns 0 in A
+        tax                     ; Return NULL
+        rts
+
+; Copy device string representation into buf
+
+okay:   lda     fnunit
+        jsr     devicestr
+
+; Success, return buf
+
+        lda     ptr2
+        ldx     ptr2+1
+        rts
+
+.endproc