Power fail and crash recovery

Normally, the system will reboot itself at power-up or after crashes. An automatic consistency check of the file systems will be performed as described in fsck(8), and unless this fails, the system will resume multi-user operations.

Cold starts

The boot ROM performs a Power On Self Test (POST) then loads Open Firmware. Depending on the Open Firmware variable ‘auto-boot?' it will either stop at the Open Firmware prompt or attempt to boot an operating system. Depending on the contents of the ‘use-nvramrc?', ‘boot-command', ‘boot-device', and ‘boot-file' Open Firmware variables, it will attempt to boot MacOS, MacOS X, or NetBSD.

To boot NetBSD, Open Firmware loads the bootloader ofwboot(8) from the specified ‘boot-device'. The bootloader then loads the kernel from the ‘boot-file', (if it exists). Otherwise, it tries to load (in the following order): netbsd, netbsd.gz, or netbsd.macppc on the “a” partition of the same device that had the bootloader.

Open Firmware Commands

An essential but incomplete list of Open Firmware commands follows. A more thorough list is contained in the FAQ. http://www.NetBSD.org/ports/macppc/faq.html#ofw-use

boot [boot-device [boot-file]] [options]

Boot an operating system. The default arguments for this command are taken from the Open Firmware environment variables:

boot-device

primary bootloader location

boot-file

kernel location

options

flags passed to the kernel

reset-all

Reset the system, and proceed as specified by the ‘use-nvramrc?' and ‘auto-boot?' variables. If ‘use-nvramrc?' is set to ‘true', then the system will attempt to execute the commands stored in the ‘nvramrc' variable. If ‘auto-boot?' is set to ‘true', the system will attempt to use the values stored in ‘boot-command', ‘boot-device', and ‘boot-file' to boot the system. If ‘auto-boot?' is set to ‘false', the system will halt at the Open Firmware prompt.

shut-down

Power off the system.

setenv variable value

Set an Open Firmware variable, e.g.,

setenv auto-boot? false 
setenv boot-device hd:,\ofwboot.xcf 
setenv boot-file netbsd-GENERIC.gz

set-default variable

Set an Open Firmware variable to its default value.

printenv [variable]

Show Open Firmware variables and values.

eject fd

Eject floppy disk on systems with on-board floppy drives.

mac-boot

Attempt to boot MacOS on an Open Firmware 3 system.

bye

Attempt to boot MacOS on an Open Firmware 1.0.5, 2.0.x, or 2.4 system.

Open Firmware Variables

An essential but incomplete list of Open Firmware variables follows. A more thorough list is contained in the FAQ. http://www.NetBSD.org/ports/macppc/faq.html#ofw-variables

auto-boot?

What Open Firmware will do at system startup or reset:

true

automatically bootstrap an operating system using values from the ‘boot-command', ‘boot-device', and ‘boot-file' variables.

false

stop at the Open Firmware prompt.

use-nvramrc?

If ‘true' runs commands in variable ‘nvramrc'.

real-base

Kernel memory location. Do not modify this value on Open Firmware 3 systems — you may damage your computer. All other Open Firmware versions should use F00000.

load-base

Bootloader memory location. Do not modify this value on Open Firmware 3 systems — you may damage your computer. All other Open Firmware versions should use 600000.

boot-command

The command to use for booting. Typically, the default of ‘boot' is used.

boot-device

Device from which to load primary bootloader. Value depends on a variety of factors. See ofwboot(8).

boot-file

Kernel location. Value depends on a variety of factors. See ofwboot(8).

input-device

What type of console input device (ADB keyboard, USB keyboard, or serial port).

kbd

ADB keyboard on models with ADB, USB keyboard on models with USB, and built-in keyboard on laptops. This is the default on some Open Firmware 2.0.x machines and all Open Firmware 2.4 and 3 machines.

ttya

‘Modem' serial port on machines with serial ports. Properties are 38400 bps, 8 bits, no parity, 1 stop bit, no handshaking. This is the default on all Open Firmware 1.0.5 systems and some Open Firmware 2.0.x systems.

ttyb

‘Printer' serial port on machines with serial ports. Properties are the same as the ‘Modem' port.

scca

Serial port on Xserve models. Properties are 57600 bps, 8 bits, no parity, 1 stop bit, no handshaking.

output-device

What type of console output device (On-board video, AGP video, PCI video, built-in LCD, or serial console). Value depends on a variety of factors. See ofwboot(8) and http://www.NetBSD.org/ports/macppc/faq.html#ofw-input-output-devices

nvramrc

If ‘use-nvramrc?' is set to true, these FORTH commands will be run when the computer is reset

Normal Operation

When Open Firmware loads the primary bootloader, it will print something like the following:

 loading XCOFF 
 tsize=CC50 dsize=14AC bsize=2668 entry=640000 
 SECTIONS: 
 .text    00640000 00640000 0000CC50 000000E0 
 .data    0064D000 0064D000 000014AC 0000CD30 
 .bss     0064E4B0 0064E4B0 00002668 00000000 
 loading .text, done.. 
 loading .data, done.. 
 clearing .bss, done..

When ofwboot(8) is started, it prints something like the following:

 >> NetBSD/macppc OpenFirmware Boot, Revision 1.7 
 >> (autobuild@tgm.daemon.org, Thu Feb  6 17:50:27 UTC 2003)

When ofwboot(8) is loading the kernel, it prints something like the following:

 4395364+254568 [220144+193803]=0x4d477c 
  start=0x100000

When the NetBSD kernel has started it prints a banner similar to the following:

 Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 
     The NetBSD Foundation, Inc.  All rights reserved. 
 Copyright (c) 1982, 1986, 1989, 1991, 1993 
     The Regents of the University of California.  All rights reserved. 
 
 NetBSD 1.6ZC (GENERIC) #0: Tue Sep 30 13:09:10 UTC 2003 
        autobuild@tgm.NetBSD.org:/autobuild/HEAD/macppc/OBJ/autobuild/HEAD/src/sys/arch/macppc/compile/GENERIC

After bootstrap

Once the NetBSD/macppc kernel is booted normally it initializes itself and proceeds to start the system. An automatic consistency check of the file systems takes place, and unless this fails, the system comes up to multi-user operation.

The proper way to shut the system down is with the shutdown(8) command.

If the system crashes, it will enter the kernel debugger, ddb(4), if it is configured in the kernel. If the crash occurred during initialization and the debugger is not present or is exited, the kernel will halt the system.

If the crash occurred during normal operation and the debugger is not present or is exited, the system will attempt a dump to the configured dump device (which will be automatically recovered with savecore(8) during the next bootstrap cycle), and after the dump is complete (successful or not) the kernel will attempt a reboot.