No CVR or FDR on 787: Instead, Two EAFRs (Enhanced Airborne Flight Recorder) [pdf]
geaerospace.com
geaerospace.com
But, the 787 uses Enhanced Airborne Flight Recorders (EAFRs), which combine both cockpit voice and flight data functions. The functions are combined into a single unit. There are two units per aircraft: one located forward, one aft, providing redundancy. Each unit includes a Recorder Independent Power Supply (RIPS), which is relevant given early speculation about a possible electrical fault.
https://www.militaryaerospace.com/power/article/16718134/ge-...
From a 2012 incident, you can check out what kind of data the EAFRs pull in:
https://data.ntsb.gov/Docket/Document/docBLOB?ID=40431665&Fi...
For more on the data storage within the EAFR: https://skybrary.aero/sites/default/files/bookshelf/2955.pdf