SPI connection Galileo- Arduino

Hi folks...

I have connected Intel Galileo gen1 and Arduino uno in SPI communication as Galileo as a Master device and Arduino as a Slave device .Now, I want to transfer my sensor (IR distance sensor) values with current stamps from slave( Arduino) to Mastar (Galileo)device continueously. In parallel to that I want to get acknowledgement from master to slave. I am using MRAA 0 .9.0. library.
in Galileo and writing in C++ by using putty serial terminal.

Any help would be appreciated.

How often do you need to transfer data from slave to master?

Does the Galileo support I2C?