git.sur5r.net Git - cc65/blob - libsrc/telemon30/_read.s

   1 ;
   2 ; jede jede@oric.org 2017-01-22
   3 ;
   4
   5
   6                 .FEATURE                c_comments,labels_without_colons,pc_assignment, loose_char_term
   7         .export         _read
   8         .import         popax
   9
  10         .include        "zeropage.inc"
  11         .include        "telemon30.inc"
  12 ;               int read (int fd, void* buf, unsigned count);
  13
  14 .proc   _read
  15
  16         sta                     ptr1 ; count
  17         stx                     ptr1+1 ; count
  18         jsr                     popax ; get buf
  19
  20         sta                             PTR_READ_DEST
  21         stx                     PTR_READ_DEST+1
  22         sta                             ptr2 ; in order to calculate nb of bytes read
  23         stx                     ptr2+1 ;
  24
  25         ;jsr popax ; fp pointer don't care in this version
  26
  27         lda                     ptr1 ;
  28         ldy                             ptr1+1 ;
  29         BRK_TELEMON     XFREAD ; calls telemon30 routine
  30         ;  compute nb of bytes read
  31         lda                     PTR_READ_DEST+1
  32         sec
  33         sbc                     ptr2+1
  34         tax
  35         lda                     PTR_READ_DEST
  36         sec
  37         sbc                             ptr2
  38
  39
  40
  41         ; Here A and X contains number of bytes read
  42
  43         rts
  44
  45 .endproc
  46
  47