BOOT(8)

NAME
boot - system bootstrapping procedures

SYNOPSIS
boot [-adqsv] [ -- <boot string>]

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 Sun boot firmware, either old-style or new-style (Open Boot Prom), performs a Power On Self Test (POST), and then will boot an operating system according to configuration in Open Firmware environment variables.

  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 gdb(1).

-C  Boot kernel in compat mode. Starting with revision 1.14 (introduced on 2003/03/01), the sparc boot program loads the NetBSD kernel at its linked virtual address. This feature requires a kernel built after 2003/02/21 (corresponding to kernel version 1.6Q). To load older kernels, the -C option must be used, which loads the kernel at physical address 0x4000. The size of a kernel loaded in this way is limited to approximately 3MB.

-q  Boot the system in quiet mode.

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

-v  Boot the system in verbose mode.

Any extra flags or arguments, or the <boot string> after the -- separator are passed to the boot PROM. Other flags are currently ignored.

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 on sun4c models, 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 native “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

The ROM will normally load the kernel from “sd(0,0,0)vmunix”. To change the default so that NetBSD will be loaded from somewhere else, type the following

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

On newer SPARC machines, there are various aliases to access common devices. A typical list of usable boot devices (extracted from the output of the Open Boot PROM command devalias) is:

    floppy         /obio/SUNW,fdtwo
    net-aui        /iommu/sbus/ledma@f,400010:aui/le@f,c00000
    net-tpe        /iommu/sbus/ledma@f,400010:tpe/le@f,c00000
    net            /iommu/sbus/ledma@f,400010/le@f,c00000
    disk           /iommu/sbus/espdma@f,400000/esp@f,800000/sd@3,0
    cdrom          /iommu/sbus/espdma@f,400000/esp@f,800000/sd@6,0:d
    tape           /iommu/sbus/espdma@f,400000/esp@f,800000/st@4,0
    tape1          /iommu/sbus/espdma@f,400000/esp@f,800000/st@5,0
    tape0          /iommu/sbus/espdma@f,400000/esp@f,800000/st@4,0
    disk3          /iommu/sbus/espdma@f,400000/esp@f,800000/sd@3,0
    disk2          /iommu/sbus/espdma@f,400000/esp@f,800000/sd@2,0
    disk1          /iommu/sbus/espdma@f,400000/esp@f,800000/sd@1,0
    disk0          /iommu/sbus/espdma@f,400000/esp@f,800000/sd@0,0

For new-style machines, if a device specification includes a partition letter (for example cdrom in above list), that partition is used by default, otherwise the first (a) partition is used. If booting from the net device, there is no partition involved.

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 continue whatever was in progress by typing ‘go’.

OPEN BOOT PROM ENVIRONMENT VARIABLES
This section only applies to new-style machines.

All Open Boot PROM environment variables can be printed with the printenv command and changed with the setenv command. The boot process relevant variables and their suggested value for booting NetBSD are:

    auto-boot?            true
    boot-file
    boot-device           disk
    diag-switch?          false

Of course you may select any other boot device, if you do not want to boot from the device aliased to disk, see the discussion on devices above.

OPEN BOOT PROM ABBREVIATED COMMAND SUMMARY
This section only applies to new-style machines.

The following Open Boot PROM commands are related to the boot process:

    boot               boot the system from the default device
    boot device filename arguments
                       boot the specified device, filename and arguments
    probe-ide          list devices on the primary IDE controller
    probe-ide-all      list devices on all known IDE controllers
    probe-scsi         list devices on the primary SCSI controller
    probe-scsi-all     list devices on all known SCSI controllers
    reset              reset the system

For disk and tape devices, the boot device is specified as ‘/path/device@target,lun:partition’.

PROM MONITOR ABBREVIATED COMMAND SUMMARY
This section only applies to old-style machines.

The following PROM monitor commands are related to the boot process:

    b       boot the system from the default device
    b device filename arguments
            boot the specified device, filename and arguments
    b?      list boot device types
    k2      reset the system

For SCSI disk and tape devices, the boot device is specified as ‘device(controller,unit,partition)’, where ‘unit’ is the hexidecimal value of the SCSI id of the target multiplied by eight plus the lun, and ‘partition’ is the partition number, starting from 0.

FILES
/netbsd
    system code
/boot
    system bootstrap

SEE ALSO
crash(8), disklabel(8), fsck(8), halt(8), init(8), installboot(8), rc(8), shutdown(8), sparc64/boot(8), syslogd(8)

BUGS
On sun4 machines, the NetBSD sparc boot loader can only boot from RAID partitions that start at the beginning of the disk.

On sun4 and early PROM version sun4c machines, the PROM can only boot from the first 1Gb of the disk.

On later PROM version sun4c and early PROM version sun4m machines, the PROM can only boot from the first 2Gb of the disk.

On later PROM version sun4m machines, the PROM can only boot from the first 4Gb of the disk.