mega_ext_passthru * mega_prepare_extpassthru (adapter_t * adapter, scb_t * scb, Scsi_Cmnd * cmd, int channel, int target);
adapter - pointer to our soft state scb - our scsi control block cmd - scsi command from the mid-layer channel - actual channel on the controller target - actual id on the controller.
prepare a command for the scsi physical devices. This rountine prepares commands for devices which can take extended CDBs (>10 bytes)