Created attachment 279123 [details]
screenshot of boot hang, with as many lines as possible
My HP DL585 (1st gen, not G2 or newer) more often than not hangs on bootup during pci detection. Cold boot has higher probabilty of working but it is not reliable either, and warm boot is more often problematic.
This has happened for long time. https://lkml.org/lkml/2018/7/6/858 is my mail about it, and I am now creating a bugzilla entry as suggested by Björn Helgaas.
http://opensolaris-discuss.opensolaris.narkive.com/T0UTXYGZ/solaris-10-06-06-x86-hp-dl585-boot-hang-aftrer-reboot-help is something similar from OpenBSD on the same hardware, and their solution.
Created attachment 279125 [details]
dmesg from good boot of 4.19-rc1+git
Created attachment 279127 [details]
lspci -vvv from good boot
Created attachment 279129 [details]
Better screenshot of hang
Created attachment 279153 [details]