Syslinux - Apr 2010 - Calling getoneblk() from com32

Is there an easy way to call getoneblk() (along with access to the
required disk struct) from
com32? I know I can use the gpllib read_sectors() but since the
device_init already has
the c/h/s/etc it sure would be nice to grab it from there and use getoneblk().

Any hints are greatly appreciated.

Cheers,

don