dnl $OpenBSD: prep,v 1.16 2005/08/19 12:45:10 jmc Exp $ To be able to boot the OpenBSD/MACHINE installation program, you will need to acquire some limited knowledge of Open Firmware, the low-level process that controls the microprocessor after hardware initialization and diagnostics are performed but before control is handed to the operating system. To access Open Firmware, you should simultaneously hold down the Command, Option, O, and F keys immediately upon booting. You will be presented with information and a ">" prompt that will look something like this (example taken from a Power Macintosh G4): Apple PowerMac3,1 2.4f1 BootROM built on 02/18/00 at 09:44:35 Copyright 1994-2000 Apple Computer, Inc. All Rights Reserved Welcome to Open Firmware To continue booting, type "mac-boot" and press return To shut down, type "shut-down" and press return ok 0 > If you are installing OpenBSD/macppc on an Xserve, you will need to do so in headless mode. This means you must remove the graphics card and use the serial console. To bring up Open Firmware via the serial console, hold down the System Identifier button while pressing the Power button. When the upper LED bank begins lighting up in sequence (similar to KITT from Knight Rider), repeatedly press the System Identifier button until the seventh LED from the right is highlighted on the lower bank. Now hold the System Identifier button for two seconds. For more details, read: http://docs.info.apple.com/article.html?artnum=75489 Important Open Firmware command examples: boot cd:,ofwboot /OSREV/MACHINE/bsd.rd (boot from an appropriately prepared OpenBSD CD-ROM in the CD/DVD drive) boot enet:,ofwboot /bsd.rd (netboot from a pre-configured bootp/tftp/nfs server containing the "ofwboot" and "bsd.rd" files at the root directory of the tftp server) boot ide1:,ofwboot /bsd (After installation, boot /bsd from the slave device on the second ATA bus) mac-boot (boot into Mac OS) reset-all (reboot the machine) shut-down (halt the machine; shutdown) printenv (print current machine variables) setenv (set a machine variable) devalias (list device aliases; useful for locating other devices in the machine such as hard drives, etc) As seen above, device aliases typically take the form of "ide", "cd", etc. To boot to an alternative device, you may substitute them with entries from this list (example devices taken from a Power Macintosh G4): ultra0 = hd = master device, primary ATA bus (factory-installed drive) ultra1 = slave device, primary ATA bus ide0 = cd = master device, secondary ATA bus (CD/DVD drive) ide1 = slave device, secondary ATA bus (Zip drive, if installed) enet = motherboard Ethernet device Other Open Firmware command examples: setenv auto-boot? false (force the machine to wait at Open Firmware for user input at next reboot; options are true/false) setenv boot-device ide:,ofwboot (force the machine to boot into OpenBSD automatically at next reboot) dev / (change to root level of the device tree) pwd (show current location in the device tree) ls (show items at current location in the device tree) words (show methods of items at current location in the device tree) .properties (show properties of items at current location in the device tree) To reset a Power Macintosh to the factory-configured Open Firmware settings, simultaneously hold down the Command, Option, P, and R keys immediately upon booting. Typically the machine will then attempt to load Mac OS, if available. Autobooting OpenBSD/MACHINE It is possible to automatically boot into OpenBSD (selectably into Mac OS) by setting up the following: setenv auto-boot? true setenv boot-device hd:,ofwboot [to save the results into NVRAM] reset-all These settings assume that the master of the first IDE bus has OpenBSD installed on it, either in MBR format or in shared mode with ofwboot copied into the first HFS(+) partition. It is not necessary to specify '/bsd' on the boot line or in the boot-device variable, since it is the default. To boot in Mac OS with this setup (works on most supported machines), press and hold down the Alt/Option key during reboot, and select which (Mac OS/Mac OS X) partition to boot in the graphical boot selector presented. Note that OpenBSD does not currently show up in this boot selector except for the installation CD-ROM. This works on most machines this has been tested with, but does not work on a Rev C (333MHz) iMac; perhaps this feature was added to the Open Firmware ROM after that machine. Sharing a disk with Mac OS: OpenBSD/MACHINE is capable of booting either from a dedicated disk using an MBR partitioned disk or sharing a disk with Mac OS. If the disk is to be shared between Mac OS and OpenBSD, it is necessary to reformat and install the Mac OS partitions first, using "Drive Setup", leaving space on the disk as an "Unused" partition. If the disk was previously partitioned, it is possible to reuse a partition for OpenBSD, as long as it is not the first partition on the disk. The bootloader is expected to be found in that first (HFS) partition. For dedicated disks, MACHINE port boots off a boot program in an MSDOS filesystem. This is set up by the install program and no special setup is required.