boot —
hppa system bootstrapping procedures
When powered on, after a panic, or if the system is rebooted via
  reboot(8) or
  shutdown(8), the hppa
  firmware (“PDC”) will proceed to its initialization, and will
  boot an operating system if autoboot is enabled.
System boot blocks are provided as a “LIF” (Logical Interchange
  Format) archive, either on a disk device, or via the network, using the
  bootp or rboot protocols, depending on the
  PDC version.
If autoboot is enabled, the PDC will attempt to boot from the specified
  “boot path” value. If no “boot path” has been
  specified, the PDC will then scan for bootable devices and boot from the first
  found, after a few seconds allowing the user to interrupt the boot process. If
  autoboot is disabled, the PDC will enter interactive mode, after an optional
  device scan. In all cases, it is possible to enter interactive mode by holding
  the escape key during the selftests, or when prompted to do so to abort the
  current operation, unless the PDC has been configured in “secure
  mode”.
“ISL” stands for “Initial System Loader” and is the
  boot program in NetBSD. On all
  versions of the PDC except for the 712 and 725 models the “boot”
  command (see below) will be followed by the question: “Interact with
  IPL (Y, N, or Cancel)?>” where a positive answer will invoke an
  interactive prompt in the boot program later and
  negative will thus suppress it. A cancellation will abort the boot process.
On the 712 and 725 models firmware an additional
    “isl” argument should be given to the “boot”
    command to invoke the boot interactive prompt. The
    default behaviour is a non-interactive boot process.
This version is used on the following models: 705, 7x0, 715/33/50/75, 725/50/75,
  735, 755. There are two levels of interactive commands in this version. The
  first level is a short menu:
b)   Boot from specified device
s)   Search for bootable device
a)   Enter Boot Administration mode
x)   Exit and continue boot sequence
Select from menu:
 
which provides the following commands:
  - b
- boot from a device found during the scan, either with its short
      “P#” form, or a complete name specification. For example, to
      boot from the SCSI disk with id 6 off the built-in (first) controller, one
      would enter bscsi.6.0.
- s
- rescan for bootable devices.
- a
- enter the second part of interactive mode.
- x
- resume an interrupted boot sequence.
 
The “Boot Administration” mode, recognizable with
    its BOOT_ADMIN> prompt, controls the various boot
    options. The complete list of commands depends on the machine and PDC
    version. The following list only mentions commands impacting the boot
    process.
  - AUTOSELECT
- Displays or changes the autoboot setting. If autoselect is set to
      “on”, the PDC will always attempt to boot the first bootable
      device found in this order:
    
      - Boot device path setting.
- SCSI devices connected to the built-in SCSI controller, the highest ID
          numbers being preferred.
- Network rboot server (see also
          rbootd(8)).
- Other SCSI devices connected to secondary controllers, the highest ID
          numbers being preferred.
 If the primary path setting defines a bootable device, no
      device scan will occur.
- BOOT
- Boots off the specified device. It is similar to the
      bcommand from the short menu above. The
      “primary” and “alternate” path settings may be
      booted withbootpri andbootalt respectively.
- PATH
- Displays or changes the boot and console devices. The boot device is
      defined as the “primary” path, and another setting may be
      stored as the “alternate” path for rescue purposes. For
      example, to define the primary boot path to the SCSI disk with ID 5
      connected to the built-in controller, one would enter
      path primaryscsi.5When invoked without parameters, pathwill list the various path settings.
 
 
Machines equipped with 7100LC, 7200, or 7300LC CPU types are usually blessed
  with a different kind of PDC. There is only one interactive mode, with a
  BOOT_ADMIN> prompt, which provides both boot settings and
  commands. The complete list of commands depends on the machine and PDC
  version. The following list only mentions commands impacting the boot process.
  - auto
    boot
- Displays or changes the autoboot setting. If auto
      bootis set to “on”, the PDC will always attempt to
      boot. The booted device chosen will depend on theauto
      searchsetting.
- auto
    search
- Displays or changes the device scan setting. If auto
      searchis set to “on”, the PDC will attempt to boot
      the first bootable device found in this order:
      - Boot device path setting.
- SCSI devices connected to the built-in SCSI controller, the highest ID
          numbers being preferred.
- Network bootp server (see also
          dhcpd(8)).
- Other SCSI devices connected to secondary controllers, the highest ID
          numbers being preferred.
 Ifauto searchis set to “off” and the
      primary boot path points to a bootable device, no device scan will occur.Note that setting auto searchto
        “on” will force autoboot, regardless of theauto bootvalue.
 
- boot
- Boots off the specified device. The “primary” and
      “alternate” path settings may be booted with
      bootpri andbootalt respectively.
- path
- Displays or changes the boot and console devices. The boot device is
      defined as the “primary” path, and another setting may be
      stored as the “alternate” path for rescue purposes. For
      example, to define the primary boot path to the SCSI disk with ID 5
      connected to the built-in controller, one would enter
      path priscsi.5.When invoked without parameters, pathwill list the various path settings.
 
 
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
  multi-user boot cycle), and after the dump is complete (successful or not) the
  kernel will attempt a reboot.
  - boot.lif
- network bootstrap and kernel combined image
- /netbsd
- default NetBSD system kernel
- /usr/mdec/xxboot
- primary bootstrap for “ffs” file system
- /usr/mdec/boot
- system bootstrap (usually also installed as
    /boot)