boot(8) - NetBSD Manual Pages

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BOOT(8)               NetBSD/sun2 System Manager's Manual              BOOT(8)


NAME

     boot -- system bootstrapping procedures


SYNOPSIS

     b [dev [(cntrl, unit, part)]] [file] [-adqsv]


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.

   Selecting the device and kernel to boot
     Normally, the b command alone is sufficient to boot the system, as the
     PROM chooses a default boot device dev if none is specified.  The PROM
     chooses the first device present on the system from the following ordered
     list:

           sd   SCSI disk
           ie   Intel Ethernet
           ec   3Com Ethernet

     Unless specified, the controller number cntrl, unit number unit, and par-
     tition number part default to zero, which is almost always correct.

     The controller number can be specified if there is more than one of the
     given device in the system.  For example, use ``ie(1,,)'' to boot off of
     the second Intel Ethernet in the system.

     The unit number specifies one of the many devices attached to a con-
     troller.  The exact meaning and values vary depending on the device name.
     For example, ``sd(,18,)'' boots the disk at target 6 on the first SCSI
     controller, 18 being the target number 6, multiplied by 4, and given in
     hexadecimal.

     The partition number specifies one of the many partitions on a device.
     The exact meaning and values vary depending on the device name.  For
     example, ``sd(,18,1)'' boots the second partition on the disk at target 6
     on the first SCSI controller.

     The PROM only loads a first-stage boot program, currently either
     /usr/mdec/bootxx (for a disk boot), or /usr/mdec/bootyy (for a network
     boot).  This first-stage boot program then loads the second-stage boot
     program from the same device, currently either /usr/mdec/ufsboot (for a
     disk boot), or /usr/mdec/netboot (for a network boot).

     The second-stage boot program will then attempt to load the kernel named
     file (or vmunix if none is specified).  The second-stage disk boot pro-
     gram /usr/mdec/ufsboot loads the kernel from the same device that it was
     loaded from, while the second-stage network boot program
     /usr/mdec/netboot will load the kernel from the NFS root as determined by
     the procedure described in diskless(8).

   Boot program options
     -a   Prompt for the root file system device, the system crash dump
          device, and the path to init(8).

     -d   Bring the system up in debug mode.  Here it waits for a kernel
          debugger connect; see ddb(4).

     -q   Boot the system in quiet mode.

     -s   Bring the system up in single-user mode.

     -v   Boot the system in verbose mode.

     Other flags are currently ignored.

     At any time you can break back to the ROM by pressing the `L1' and `a'
     keys at the same time (if the console is a serial port the same is
     achieved by sending a `break').  If you do this accidentally you can con-
     tinue whatever was in progress by typing `c' followed by the return key.


FILES

     /netbsd                  system code
     /usr/mdec/bootxx         first-level boot block for disks
     /usr/mdec/bootyy         first-level boot block for NFS (diskless) boot
     /usr/mdec/netboot        boot program for NFS (diskless) boot
     /usr/mdec/ufsboot        second-level boot program for UFS disks
     /usr/sbin/installboot    program to install bootxx on a disk


SEE ALSO

     disklabel(8), fsck(8), halt(8), init(8), rc(8), shutdown(8), syslogd(8)

NetBSD 5.1.2                    April 29, 2003                    NetBSD 5.1.2