bsd.rd breakdown
by from OpenBSD Journal on (#73N4C)
Every OpenBSD admin has booted bsd.rd at least once - to install, upgrade, or rescue a broken system. But few people stop to look at what's actually inside that file.
In this article over at the OpenBSD Jumpstart site, they take a look at just that.
The contents and format of the bsd.rd ramdisk kernel is shown, so you can understand and customize it for your own needs.
Enjoy!