- NetBSD Manual Pages
OFWBOOT(8) NetBSD/macppc System Manager's Manual OFWBOOT(8)
Powered by man-cgi (2021-06-01).
Maintained for NetBSD
by Kimmo Suominen.
Based on man-cgi by Panagiotis Christias.
ofwboot, ofwboot.elf, ofwboot.xcf -- Open Firmware boot command
Open Firmware is a FORTH-like command interpreter started by the BootROM
after the power-on self test (POST). This command interpreter allows the
user flexibility in choosing how their machine boots an operating system.
NetBSD uses Open Firmware to initialize many of the devices in a system
and uses it to load the primary bootloader, ofwboot.
The information in this man page should only serve as a guideline for
users. Apple has made many revisions to Open Firmware, and the earlier
versions had many problems and inconsistencies. You may find that a boot
command that works on one model will not work on another.
In this man page, only one Open Firmware command will be described, boot,
because it is used to pass arguments to ofwboot. The Open Firmware boot
command takes up to three arguments:
boot [boot-device [boot-file]] [options]
boot-device primary bootloader location
boot-file kernel location
options flags passed to the kernel (see below)
The first argument, boot-device, actually designates the primary boot-
loader location and its name in the form:
A typical example, from a PowerBook (FireWire), is
Note that colon (`:') delimits the device to the left, and comma (`,')
separates the boot loader filename from the first part. For Open
Firmware versions before 3, the primary bootloader is installed in parti-
tion ``zero'', and it is not necessary to specify the bootloader-file-
name. For Open Firmware version 3, you must specify the bootloader-file-
Open Firmware stores aliases to common devices in NVRAM. In the example
above, /pci@f2000000/mac-io@17/ata-4@1f000/@0 is the path on a PowerBook
(FireWire) to the built-in ATA/100 hard drive. Use the devalias command
in Open Firmware to print out a list of common device names on a particu-
lar model. The command above could then be simplified to:
boot-loader-file-name is usually ofwboot.xcf. (See also the FILES sec-
tion for further discussion.)
If omitted, the Open Firmware variable boot-device is used.
It may be necessary to specify the boot-file if Open Firmware does not
know where to find the kernel. The default is to load the file named
netbsd on partition ``a'' from the device used to load the primary boot-
For systems with Open Firmware versions less than 3 which are set up
using sysinst, the boot-file argument is not necessary. Systems with
Open Firmware version 3 may need to specify the boot-file.
The syntax is similar to the boot-device argument:
This is a little different, since a kernel-name may be specified without
listing a boot-file-device and partition-num. Additionally, a boot-file-
device and partition-num may need to be specified, while using the
If no kernel-name is specified, the primary bootloader will try to find
kernels named either netbsd or netbsd.gz on the boot-device or (if speci-
Possible options are:
-a ask for the boot device
-s single-user mode boot
-d debug mode
exit exit to Open Firmware after processing arguments
If set, the following Open Firmware variables will be used to determine
which boot-device and boot-file Open Firmware should use when booting a
system. If the user specifies arguments on the command line, these val-
ues are overridden.
boot-device used as the first argument
boot-file used as the second argument
auto-boot? setting this variable to false will present the user with an
Open Firmware command prompt after power-on reset. A value
of true will automatically boot the system using the vari-
ables boot-device and boot-file. (This is not really
related to the boot command, but is included for complete-
To restore these variables to their default values, use the set-default
Open Firmware command: set-default boot-device
The three files ofwboot, ofwboot.elf, and ofwboot.xcf are the same pro-
gram, in different executable formats.
ofwboot ofwboot is installed via installboot(8) on systems with Open
Firmware versions less than 3. It is not necessary to spec-
ify this file name, as it is stored in a special location on
the disk, partition ``zero''. For example, the following
command might be used to boot from a SCSI device with ID 2:
0 >boot scsi-int/sd@2:0.
ofwboot.xcf ofwboot.xcf is in XCOFF format. This file is used on all
Open Firmware 3 systems, and on Open Firmware systems prior
to 3 when the bootloader is not installed in partition
``zero'', such as from an ISO-9660 format CD-ROM.
ofwboot.elf ofwboot.elf is in elf(5) format and only functions on sys-
tems with Open Firmware version 3. To avoid confusion, all
users should be using ofwboot.xcf, as ofwboot.elf offers no
additional functionality. It is only included for histori-
boot.fs This 1.44 MB disk image contains everything necessary to
boot and install NetBSD. It includes the partition ``zero''
bootloader (ofwboot), an INSTALL kernel (with limited device
drivers), and the sysinst utility in a RAM disk. Since Open
Firmware does not care what media files are loaded from,
only whether they are supported and in the correct format,
this disk image may be placed on media other than floppy
disks, such as hard drives or Zip disks. Use dd(1) on Unix,
or DiskCopy on MacOS 9.1 or later, or suntar on any MacOS
version to copy this image onto the media.
netbsd production kernel, using the GENERIC set of devices which
supports almost all hardware available for this platform.
GENERIC kernel (the same as netbsd), with RAM disk and
bootable CDROM image for all supported systems. Usually
Boot an Open Firmware 3 system, with netbsd installed on partition ``a'':
0 > boot hd:,ofwboot.xcf
Boot into single user mode:
0 > boot hd:,ofwboot.xcf netbsd -s
Boot from bootable CDROM with Open Firmware 3 or higher:
0 > boot cd:,\ofwboot.xcf netbsd.macppc
Boot from bootable CDROM (internal SCSI, id=3) of NetBSD 1.5 release with
Open Firmware versions prior to 3:
0 > boot scsi/sd@3:0,OFWBOOT.XCF NETBSD.MACPPC
Boot from floppy disk:
0 > boot fd:0
Boot from network, with bootps, bootptab(5), tftpd(8), and nfsd(8) server
0 > boot enet:0
Boot from network, but use internal root partition of second drive:
0 > boot enet:0 ultra1:0
Boot MacOS, looking for the first available bootable disk:
0 > boot hd:,\\:tbxi
Boot MacOS X residing on partition 10:
0 > boot hd:10,\\:tbxi
DEFAULT CATCH!, code=FF00300 at %SRR0: FF80AD38 %SRR1: 00001070
Could be ``device not found'' or I/O errors on the device. The numbers
are just for example.
Can't LOAD from this device
Open Firmware found the device, but it is not supported by load.
0 > boot yy:0/netbsd
RESETing to change Configuration!
yy:0 doesn't exist, so Open Firmware ignores the string and uses the
default parameters to boot MacOS; the MacOS boot routine then clears some
of the Open Firmware variables.
0 > boot ata/ata-disk@0:9 specified partition is not bootable
As it says.
0 > boot ata/ata-disk@0:0
>> NetBSD/macppc OpenFirmware Boot, Revision 1.3
>> (root@nazuha, Fri Jun 8 22:21:55 JST 2001)
no active package3337696/
and hangs: See the real-base part in the FAQ.
NetBSD/macppc Frequently Asked Questions:
Diskless NetBSD HOW-TO:
IEEE Std 1275-1994 (``Open Firmware'')
ofwboot can only boot from devices recognized by Open Firmware.
Early PowerMacintosh systems (particularly the 7500) seem to have prob-
lems with netbooting. Adding an arp entry at the tftp server with
arp -s booting-host-name its-ethernet-address
may resolve this problem (see arp(8)).
0 > boot CLAIM failed
Once boot failed, successive boots may not be possible. You need to type
reset-all or power-cycle to initialize Open Firmware.
NetBSD 10.99 August 18, 2001 NetBSD 10.99