cam interface support

Hi,
Few questions:

  1. where I can get documentation about CAM interface support in QNX.
  2. <sys/cpt.h> says
    cam_data_ptr /*physical address of buffer or offset from start of
    struct to scatter gather list */

Does it mean that I can allocate my own buffer ( with mmap) and this buffer
will be used to perform DMA ?

  1. source code of ported cdrecord

regards,
Oleg