Taking to its developer portal, Sony has posted a download for the complete open-sourced software for its newest giant device the Xperia Z Ultra. Even though it hasn't been broadly released yet — currently slated for a September 12th launch — Sony is releasing a full archive of the software (version 14.1.B.0.461) for the C6802 HSPA+ model for download. Sony has a pretty good track record when it comes to open-sourcing its device software, and we're glad they're doing it again here.
Enterprising developers and tinkerers alike that are trying to get a head start on development for the device can grab a download of the full archive at the source link below. The download clocks in at a hefty 228MB for the whole deal, and will give you access to all the bits you'll want to have your hands on.