some questions about l4bd.c in l4linux

Hi Adam， I am studying how to support emmc storage in L4Re. I have read the file l4linux/drivers/block/l4bd.c. I have some questions 1、 In “l4linux/drivers/block/l4bd.c”, I can’t find the function implementation of “l4fdxc_request_write” and some with prefix l4fdxc in l4linx or l4， is there some demos? 2、 If it is implemented by ourselves, where is more reasonable to place “l4fdxc_request_write” , in l4 or l4linux ? 3、 If in l4, Which implementation is more reasonable , lib or server? Thank you very much