Intel DQ77MK board with latest (July 28, 2015) BIOS. Samsung MZVPV128HDGM on PCIe riser card. 4.2 installer on USB drive boots, finds the NVMe disk and happily installs PVE. Reboot, and no bootable devices found. None showing in BIOS. Disabled legacy boot per p.20 of this guide to no effect.