I completed this trek last month. Online, I could not find any GPX or any other GPS supported files related to this trek. Here is the link to the GPX file logged by my GPS during our trek.
Day 1: Gangotri to Chirbasa
Day 2: Chirbasa to Bhojwassa
Day 3: Bhojwassa to Tapovan
Day 4: Tapovan to Nandanvan
Day 5: Nandanvan to Vasuki Tal
Day 6: Vasuki Tal to Khara Pattar
Day 7: Khara Pattar to Shweta Glacier
Day 8: Shweta Glaciet to Kalindi Base
Day 9: Kalindi base to Raj Parav
Day 10: Raj Parav to Ghastoli
Day 11: Ghastoli to Badrinath
All the photographs were geotagged and here is a link to some of them.