Created attachment 247521 [details] Screenshot of earlyprintk=efi Kernel won't boot in kernel 4.9, it worked fine with 4.8. I suspect it was pulled in with this patch: https://patchwork.kernel.org/patch/9360085/ as it introduced efi_memmap_insert.
Created attachment 247531 [details] Kernel config Kernel config used
I've bisected the issue to commit 8e80632fb23f021ce5a6957f2edcdae4645a7030 Seems to be a duplicate of 191121, closing *** This bug has been marked as a duplicate of bug 191121 ***