What is mrc.bin and system agent binary?

[Iru Cai]

Hi,

I've bought a Chromebook Pixel 2013 and want to reflash the
firmware. I saw in the config that I need a system agent binary.  I
looked into 3rdparty/blobs/nb/intel/sb/ and found three binary files,
and the default one in nb/intel/sb/kconfig is systemagent-r6.bin.  And
I read the google/link wiki and saw another word called mrc.bin.  Are
they the same thing? And can I use the coreboot native MRC code for
google/link?

Regards,
Iru