Description of problem: After installing Fedora 23 on a Lenovo Carbon X1 gen4 with an NVMe disk, the system fails to boot in either UEFI or BIOS mode (system reinstalled in both modes.) In UEFI mode, "Fedora" shows in the boot menu, but selecting it just returns to the boot menu.
In neither mode does even the boot loader UI show. On the other hand, booting from external media works in both UEFI and BIOS modes.
I was able to find a workaround: if I zero out the entire hard disk including the partition table, EFI system partition and the factory reset partition, then Fedora will install and boot correctly in UEFI mode, but not in BIOS mode. It boots correctly in BIOS mode from other media, but this is obviously sufficient for my needs. This machine also needs intel_pstate=disable to boot with the install kernel due to a BIOS bug; I understand a fix for that is going into the 4.6 upstream. I'm not sure if there is a suitable place to document this.
This message is a reminder that Fedora 23 is nearing its end of life. Approximately 4 (four) weeks from now Fedora will stop maintaining and issuing updates for Fedora 23. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '23'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 23 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete.
Fedora 23 changed to end-of-life (EOL) status on 2016-12-20. Fedora 23 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.