I have a nexus 6 which failed when updating to 6.0.1. I can no longer boot into the Operating System as the /system partition is corrupt. I ran a factory reset - but this didn't fix the problem because factory reset only clears out the /cache and /data partitions.
Since I am able to get into the bootloader and android recovery I was wondering if it is possible to reinstall the OS via ADB. I've searched around it it looks like ADB can only be used for installing updates/programs while fastboot can flash the /system partition with a factory image. I'm unable to use fastboot because the phone is not rooted. So, is there any way to restore the factory image of the OS via ADB on a non-rooted phone?