INSTALLBOOT(8)      OpenBSD System Manager's Manual (Amiga)     INSTALLBOOT(8)

NAME
     installboot - install a bootstrap on an FFS filesystem partition

SYNOPSIS
     installboot bootblock device

DESCRIPTION
     installboot copies the bootblock to a bootable partition. The bootstrap
     is written into the bootblock area on the partition, right in front of
     the superblock, and hence limited in size to 8192 bytes.

     The bootstrap resides in the first few blocks on the partition (as
     specified by Commodore-Amiga Inc.) The bootstrap is loaded into memory by
     the ROM from bootable devices: RDB devices, where the partition is marked
     as bootable, or (not on the DraCo) floppy disks in Amiga format
     (880K/1760k).

     In presence of more than one bootable partiton/floppy disk, the partition
     is chosen by the bootpriority (from the RDB), which can be overridden by
     the operator from the boot menu (on Amiga machines, hold down the outer
     mouse buttons during boot; on DraCo machines, press the left mouse button
     when prompted).

     On RDB devices, the whole bootblock is loaded by the ROM. The number of
     boot blocks in the RDB partition entry must be correct.

     On floppy disks, the ROM always loads the first two blocks (1024 bytes),
     and the bootblock allocates memory and loads the whole bootblock on
     startup.

     After receiving control, the bootblock uses the stand-alone filesystem
     code in ``libsa.a'' to load the kernel from the filesystem on the parti-
     tion it was started from.  The code for the boot program can be found in
     /usr/mdec/fdboot (floppy disk code) or /usr/mdec/xxboot (generic RDB disk
     code).

     The arguments are:

     bootblock  The file containing the bootblock (normally /usr/mdec/xxboot
                for RDB devices).

     device     The name of the character special device specifying the parti-
                tion on which the bootstrap is to be installed.

EXAMPLES
     The following command will install the boot program in the bootblock area
     on ``sd0a'':

           installboot /usr/mdec/xxboot /dev/rsd0a

CAVEATS
     If installboot is used on the whole disk partition, the RDB will be over-
     written.

     Some third-party accellerator boards are not auto-configuring. You won't
     be able to use their memory when booting from the bootblock after a cold
     start.

     Some third-party disk controllers don't support bootblock booting.

     Phase 5 68060 boards don't set the SysBase->AttnFlags bit for the 68060
     CPU (a patch program which is called during AmigaOS startup does this).
     Currently, OpenBSD is not able to detect this condition, and will fail.

BUGS
     There is currently no easy way to edit the RDB from within OpenBSD.

     As normal dd is used to install the bootblock, you can only install onto
     your currently used root (or any other mounted) partiton from single-user
     mode, or while otherwise running in insecure mode.

SEE ALSO
     dd(1)

HISTORY
     The installboot command first appeared in NetBSD-current post 1.2

OpenBSD 3.0                    November 29, 1996                             2
