BOOT(8) (macppc)

BOOT(8) | System Manager's Manual (macppc) | BOOT(8)

# NAME

`boot` — Macppc system bootstrapping procedures

# DESCRIPTION

## 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 macppc/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. https://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. https://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 macppc/ofwboot(8).
`boot-file`
  Kernel location. Value depends on a variety of factors. See macppc/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 macppc/ofwboot(8) and https://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 macppc/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 macppc/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.

# FILES

/boot
  NetBSD secondary bootstrap program (Open Firmware 1.x and 2.x)
/netbsd
  default NetBSD system kernel
/usr/mdec/bootxx
  NetBSD primary bootstrap program (Open Firmware 1.x and 2.x) a.k.a. “partition zero” bootloader
/usr/mdec/ofwboot
  NetBSD secondary bootstrap program (Open Firmware 1.x and 2.x)
/usr/mdec/ofwboot.xcf
  primary bootstrap for netboot and “cd9660” (ISO 9660), “MS-DOS”, “HFS”, and “HFS+” file systems.

# SEE ALSO

ddb(4), intro(4), diskless(8), halt(8), init(8), installboot(8), macppc/ofwboot(8), rc(8), reboot(8), savecore(8), shutdown(8)

https://www.NetBSD.org/ports/macppc/faq.html
https://www.NetBSD.org/docs/network/netboot/

# STANDARDS

IEEE Std 1275-1994 (“Open Firmware”) http://playground.sun.com/1275/home.html

# BUGS

The device names used by NetBSD/macppc and Open Firmware often have no relation to each other.

Apple Computer's Open Firmware implementation is easily confused. It is best to reboot your computer after a failed boot attempt, `halt`, or `shutdown -h`. Use the Open Firmware `reset-all` command.

Apple Computer's Open Firmware implementation is notoriously bad. Thorough instructions for installing and booting NetBSD are in the install notes (INSTALL.html) included with every release of NetBSD.

February 17, 2017 | NetBSD 11.0