I installed Yosemite in a separate partition on my Macintosh HD. For the first time I tried to boot into Mavericks today. After holding the option key all I saw was the attached screen: No option to boot into mavericks. After creating the Yosemite partition I just downloaded and installed into the new partition. While in Yosemite I see Macintosh HD and I can get files from it. Did I screw up the boot record? Can I get it back?