I have added eMMC support to the StarterWare SD Card example. It is a large amount of work as the differences between the MMC protocol and SD protocol are quite large. I used the u-boot driver, linux sd/mmc drivers and the protocol docs for reference.
Unfortunately, I cannot share the code. Belongs to the client. Probably not the response you wanted. You can probably handle your specific eMMC device by stepping through the setup sequence and porting code for each message as you go.