BOOT_SPARC(8)       OpenBSD System Manager's Manual (SPARC)      BOOT_SPARC(8)

NAME
     boot_sparc - sparc system bootstrapping procedures

DESCRIPTION
   System starts
     When powered on, after a panic, or if the system is rebooted via
     reboot(8) or shutdown(8), the PROM will proceed to its initialization,
     and will boot an operating system if autoboot is enabled.

   Boot process description
     System boot blocks are installed near the start of the boot disk using
     the procedure described in installboot(8).  The boot program attempts to
     load the kernel from the selected boot device, which must currently be an
     ``sd'', ``xd'' or ``xy'' disk, or an SCSI CD-ROM (``cd'') or tape drive
     (``st'').

     The SPARC boot ROM comes in two flavours: an ``old-style'' ROM is used in
     sun4 machines, while a ``new-style'' ROM can be found on sun4c and sun4m
     models.  The ``new-style'' SPARC boot ROM is a full-featured Forth system
     with emacs key bindings.  It can be put in ``old-style'' user-interface
     compatibility mode (in which case it shows a simple ``>'' prompt), but
     this is essentially useless.  However, by default the ROM runs in old-
     mode; to enter new-mode type ``n''.  The ROM then shows a Forth-style
     ``ok'' prompt.  It is recommended to have the ROM always start in its na-
     tive ``new-style'' mode.  Utter the following incantation in new-mode to
     force the ROM to always start in new-mode:

          ok setenv sunmon-compat? false

   Old-style PROM operation
     By default, the old ROM will poll for boot devices, unless the eeprom
     settings are set to specify a particular boot device.  The OpenBSD boot-
     loader will then look for a kernel named bsd by default, unless a differ-
     ent filename has been specified in the boot command.

     Refer to the ``PROM User's Manual'' for more information.

   OpenBoot PROM version 1 operation
     Older OpenBOOT PROM, as well as hybrid (dual-mode) versions operating in
     compatibility mode (with the variable version2? set to false) will look
     for a bootloader and kernel filename as specified by the boot-from vari-
     able.  To change the default so that OpenBSD will be loaded, type the
     following:

          ok setenv boot-from sd(0,0,0)bsd

     Replace ``sd(0,0,0)'' with the appropriate boot device if necessary.

     Autoboot is enabled by setting the auto-boot? variable to ``true'', and
     is the factory default.

   OpenBoot PROM version 2 operation
     Version 2 OpenBOOT PROM will look for a bootloader on the device speci-
     fied by the boot-device variable.  The OpenBSD bootloader will then look
     for a kernel named bsd by default, unless the boot-file variable is set,
     or a different filename has been specified in the boot command.  To reset
     this variable to its default, empty, value, type the following:

          ok set-default boot-file

     Autoboot is enabled by setting the auto-boot? variable to ``true'', and
     is the factory default.

   Boot process options
     The following options are recognized:

           -a    Prompt for the root filesystem and swap devices after the de-
                 vices have been configured.
           -c    Enter the ``User Kernel Configuration'' mode upon startup
                 (see boot_config(8)).
           -d    Enter the debugger , ddb(4), as soon as the kernel console
                 has been initialized.
           -s    Boot the system single-user.  The system will be booted mul-
                 ti-user unless this option is specified.

   Abnormal system termination
     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 con-
     figured 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.

   Accessing the PROM during runtime
     If the sysctl(8) variable ddb.console is enabled, at any time you can
     break back to the ROM by pressing the ``L1'' (also known as the ``stop
     key'') and ``a'' keys at the same time (if the console is a serial port
     the same is achieved by sending a ``break''), and entering machine prom
     at the prompt.  If you do this accidentally you can continue whatever was
     in progress by typing go on an OpenBOOT PROM, or c on an old-style PROM
     to return to ddb, and then cont to return to the system.

FILES
     /bsd              default system kernel
     /bsd.rd           standalone installation kernel, suitable for disaster
                       recovery
     /usr/mdec/bootxx  primary bootstrap for ``ffs'' file system
     /usr/mdec/boot    secondary bootstrap (usually also installed as /boot)

SEE ALSO
     ddb(4), boot_config(8), halt(8), init(8), installboot(8), reboot(8),
     savecore(8), shutdown(8)

OpenBSD 4.7                     January 3, 2010                              2
