Newer HP machines (#Elitebook laptops, #Elitedesk desktops) seem to be woefully incompatible with #OpenBSD. During boot, both the regular kernel and the ramdisk kernel hang at "entry point at 0x1001000". After tinkering for literal hours (BIOS options, different boot mediums, different versions, etc) I managed to get it working. The problem is with the memory space. It can be fixed relatively simple with a custom kernel that uses a different address space. Here is the patch:

'fyi: get HP EliteBook 830 G7/G8 booting' - MARC