BOOT(8)       NetBSD System Manager's Manual (PMAX  Architecture)      BOOT(8)

NNAAMMEE
     bboooott - system bootstrapping procedures

DDEESSCCRRIIPPTTIIOONN
     The NetBSD kernel is started by placing it at the beginning of physical
     memory and transferring to the entry point.  Since the system is not
     reenterable, it is necessary to read it in from disk or tape each time it
     is to be bootstrapped.

     PPoowweerr ffaaiill aanndd ccrraasshh rreeccoovveerryy.. Normally, the system will boot itself at
     power-up or after crashes.  An automatic consistency check of the file
     systems will be performed, and unless this fails, the system will resume
     multi-user operations.

     CCoolldd ssttaarrttss.. At power up, all DECstation ROMs consult the hhaallttaaccttiioonn en-
     vironment variable in EEPROM to determine whether or not to attempt to
     boot automatically.   If this variable is set to hh, the ROM prints a
     prompt on the console and waits for user commands.   If set to bb, the ROM
     attempts to autoboot.

     On the DECstation 2100 and 3100, the path used for automatic booting is
     stored in the bboooottppaatthh environment variable.   The path is made up of a
     device type specifier (e.g., rz, tz, mop or tftp) followed by a triplet
     in the form (x,y,z), followed by a filename to load.

     Within the triplet, x is the controller (always 0), y is the SCSI id of
     the drive to boot from or 0 for net boots, and z is the partition to boot
     from (usually 0 for SCSI devices, always zero for network booting.  For
     network boots, () may be specified instead of (0,0,0).

     The filename is optional for bootp/tftp and mop booting, since in these
     cases the network protocol can be used to determine which file to boot.
     When booting off the tape, no filename should be specified, and when
     booting off of disk, the filename of a kernel must be specified.  Gener-
     ally, the kernel is named nneettbbssdd..

     An example bootpath setting would be:

                          setenv bootpath rz(0,1,0)netbsd

     For automatic boots, the ROM automatically passes a --aa argument to the
     boot loader, requesting that NetBSD attempt to come up to multi-user
     mode.   At the boot ROM prompt, the user may boot NetBSD with either the
     aauuttoo or the bboooott command.   If the aauuttoo command is used, the --aa argument
     is passed to the kernel, requesting a multi-user boot; otherwise the --ss
     argument is passed, requesting that NetBSD boot to single user mode.

     When either the bboooott or the aauuttoo command is issued with no arguments, the
     kernel specified in the bootpath environment variable is booted.   An al-
     ternative kernel may be specified with the --ff flag, followed by the path
     of the kernel to boot, as described above.  For example:

                            boot -f rz(0,4,0)netbsd.new

     On TurboChannel machines (all DECstation 5000 models), the boot path is
     specified in the boot environment variable, along with any arguments to
     be passed to the kernel.   Note that to specify boot arguments (e.g., --aa))
     when setting the bboooott environment variable, the filename and arguments
     must be enclosed in quotes.   For example:

                           setenv boot "3/rz4/netbsd -a"


     The device from which to boot is specified as the TurboChannel slot num-
     ber, a TurboChannel-option-specific device name, and a path to the file
     to load, all seperated by slashes.   You can get a list of the devices
     installed in your TurboChannel slots (as well as any built-in devices
     which appear as TurboChannel slots) by typing the ccnnffgg command at the
     boot prompt.   You can get more detailed information about a specific
     TurboChannel option by typing ccnnffgg followed by the slot number of that
     option.

     For SCSI devices, the option-specific device identifier is either rz# for
     disks or tz# for tapes, where # is the SCSI id of the device.   For net-
     work devices, the option-specific protocol identifier is either mop or
     tftp.  Filename requirements are as for the DECstation 2100 and 3100.

     To start NetBSD from the boot prompt, the bboooott command must be used.
     With no arguments, this simply boots the default kernel with the default
     arguments as set with sseetteennvv bboooott.. If no boot environment variable is set
     or if an alternative kernel is to be booted, the path of that kernel may
     be specified after the boot command as described above, and any arguments
     may be passed similarly.   For example:

                             boot 3/rz4/netbsd.new -a

SSEEEE AALLSSOO
     crash(8m),  fsck(8),  halt(8),  init(8),  newfs(8),  rc(8),  shutdown(8),
      syslogd(8),  reboot(8)

HHIISSTTOORRYY
     The bboooott command is currently under development.

4.4BSD                           July 23, 1991                               2