INSTALLBOOT(8) | System Manager's Manual | INSTALLBOOT(8)

# NAME

`installboot` — install disk bootstrap software

# SYNOPSIS

`installboot` | [`-fnv`] [`-B` s2bno] [`-b` s1bno] [`-m` machine] [`-o` options] [`-t` fstype] [`-u` U-Boot-paths] filesystem primary [secondary]

`installboot` | `-c` [`-fnv`] [`-m` machine] [`-o` options] [`-t` fstype] filesystem

`installboot` | `-e` [`-fnv`] [`-m` machine] [`-o` options] bootstrap

# DESCRIPTION

The `installboot` utility installs and removes NetBSD disk bootstrap software into a file system. `installboot` can install primary into filesystem, or disable an existing bootstrap in filesystem.

## Traditional NetBSD boot

Generally, NetBSD disk bootstrap software consists of two parts: a “primary” bootstrap program usually written into the disklabel area of the file system by `installboot`, and a “secondary” bootstrap program that usually resides as an ordinary file in the file system.

When booting, the primary bootstrap program is loaded and invoked by the machine's PROM or BIOS. After receiving control of the system it loads and runs the secondary bootstrap program, which in turn loads and runs the kernel. The secondary bootstrap may allow control over various boot parameters passed to the kernel.

Perform the following steps to make a file system bootable:

1. Copy the secondary bootstrap (usually /usr/mdec/boot.⟨MACHINE⟩ or /usr/mdec/boot) to the root directory of the target file system.
2. Use `installboot` to install the primary bootstrap program (usually /usr/mdec/bootxx_⟨FSTYPE⟩) into filesystem.

   The following platforms do not require this step if the primary bootstrap already exists and the secondary bootstrap file is just being updated: alpha, amd64, amiga, i386, pmax, sparc64, and vax.

   The following platform does not require the first step since a single bootstrap file is used. The single bootstrap is installed like the primary bootstrap on other platforms: next68k.

On some architectures the options of an existing installed bootstrap, or those of a bootstrap file can be changed. Installing a new primary bootstrap will reset those options to default values.

## Embedded board types

Some platforms, typically embedded system platforms, are umbrella platforms that support many different individual board types, each with their own boot loader binary and installation procedure requirements. On these platforms, it may be necessary to provide specific board type information to `installboot`. Information about known boards and their requirements is loaded from a database at run-time. Sometimes these platforms also require the use of 3rd-party boot loader software, such as U‐Boot. To support these platforms, `installboot` scans known locations for these 3rd-party boot loader packages for database overlays that contain additional board-specific boot loader installation information in a file called installboot.plist.

The following platforms have this requirement and utilize this database overlay feature: evbarm.

## UEFI boot

On platforms that boot with UEFI, there is a single boot loader in the EFI system partition at EFI/boot/boot⟨ARCH⟩.efi where ARCH is the UEFI name for the architecture, such as `ia32` (NetBSD/i386), `x64` (NetBSD/amd64), or `aa64` (NetBSD/aarch64).

`installboot` is not needed for UEFI boot. However, it may be used on a platform that supports UEFI boot to make a hybrid image that can be booted either with UEFI boot or with, e.g., BIOS or U‐Boot. Hybrid images may also require a special GPT for BIOS boot; see gpt(8).

## Options

The options and arguments recognized by `installboot` are as follows:

`-B` s2bno
  When hard-coding the blocks of secondary into primary, start from block s2bno instead of trying to determine the block numbers occupied by secondary by examining filesystem. If this option is supplied, secondary should refer to an actual secondary bootstrap (rather than the file name of the one present in filesystem) so that its size can be determined.
`-b` s1bno
  Install primary at block number s1bno instead of the default location for the machine and file system type. [alpha, i386/amd64 (bootxx_fat16 only), pmax, vax]
`-c`
  Clear (remove) any existing bootstrap instead of installing one.
`-e`
  Edit the options of an existing bootstrap. This can be used to change the options in bootxx_⟨FSTYPE⟩ files, raw disk partitions, and the pxeboot_ia32.bin file. With `-v` and without `-o`, show the current options. [amd64, i386]
`-f`
  Forces `installboot` to ignore some errors.
`-m` machine
  Use machine as the target machine type. The default machine is determined from uname(3) and then `MACHINE` environment variable. The following machines are currently supported:
  `alpha`, `amd64`, `amiga`, `evbarm`, `ews4800mips`, `hp300`, `hppa`, `i386`, `landisk`, `macppc`, `news68k`, `newsmips`, `next68k`, `pmax`, `sparc`, `sparc64`, `sun2`, `sun3`, `vax`, `x68k`
`-n`
  Do not write to filesystem.
`-o` options
  Machine specific `installboot` options, comma separated.

  Supported options are (with the machines for they are valid in brackets):

  `alphasum`
    [alpha] Recalculate and restore the Alpha checksum. This is the default for NetBSD/alpha.
  `append`
    [alpha, pmax, vax] Append primary to the end of filesystem, which must be a regular file in this case.
  `board`[`=`type]
    [evbarm] Specify the board type used to determine the correct boot loader image and installation procedure. If omitted, `installboot` will attempt to guess the board type based on system information if run natively.
  `bootconf`
    [amd64, i386] (Don't) read a boot.cfg file.
  `command``=`commandline
    [amiga] Modify the default boot command line.
  `console``=`name
    [amd64, i386] Set the console device. name must be one of: `pc`, `com0`, `com1`, `com2`, `com3`, `com0kbd`, `com1kbd`, `com2kbd`, `com3kbd`, or `auto`.
  `dtb``=`dtbfile
    [evbarm] Attempt to determine the board type from information in the device tree blob file at dtbfile. If both `board` and `dtb` options are specified, `board` takes precedence.
  `ioaddr``=`ioaddr
    [amd64, i386] Set the IO address to be used for the console serial port. Defaults to the IO address used by the system BIOS for the specified port.
  `keymap``=`keymap
    [amd64, i386] Set a boot time keyboard translation map. Each character in keymap will be replaced by the one following it. For example, an argument of `zyz` would swap the lowercase letters ⟨y⟩ and ⟨z⟩.
  `media``=`type
    [evbarm] Some boards require a different boot loader binary and/or installation procedure depending on what type of media will be used to boot the system. For such boards, this option is required, and omitting it will display a usage message that lists the valid media types for the board. For boards that do not require special media handling, this option is not allowed. Common values: `sdmmc`, `emmc`, `usb`.
  `modules`
    [amd64, i386] (Don't) load kernel modules.
  `password``=`password
    [amd64, i386] Set the password which must be entered before the boot menu can be accessed.
  `resetvideo`
    [amd64, i386] Reset the video before booting.
  `speed``=`baud
    [amd64, i386] Set the baud rate for the serial console. If a value of zero is specified, then the current baud rate (set by the BIOS) will be used.
  `sunsum`
    [alpha, pmax, vax] Recalculate and restore the Sun and NetBSD/sparc compatible checksum. Note: The existing NetBSD/sparc disklabel should use no more than 4 partitions.
  `timeout``=`seconds
    [amd64, i386] Set the timeout before the automatic boot begins to the given number of seconds.
`-t` fstype
  Use fstype as the type of filesystem. The default operation is to attempt to auto-detect this setting. The following file system types are currently supported:
  `ffs`
    BSD Fast File System.
  `raid`
    Mirrored RAIDframe File System.
  `cd9660`
    ISO 9660 File System.
  `raw`
    “Raw” image. Note: if a platform needs to hard-code the block offset of the secondary bootstrap, it cannot be searched for on this file system type, and must be provided with `-B` s2bno.
`-u` U-Boot-paths
  U-Boot-paths is a colon-separated list of search paths to scan for U‐Boot packages with `installboot` installation overlays. If multiple overlays are found, overlays from paths closer to the front of the list take precedence. If not specified, environment variable `INSTALLBOOT_UBOOT_PATHS` is used if defined; otherwise, the default path is /usr/pkg/share/u-boot. This option is only used on platforms that support using U‐Boot.
`-v`
  Verbose operation.
filesystem
  The path name of the device or file system image that `installboot` is to operate on. It is not necessary for filesystem to be a currently mounted file system.
primary
  The path name of the “primary” boot block to install. The path name must refer to a file in a file system that is currently mounted.
secondary
  The path name of the “secondary” boot block, relative to the root of the file system in the device or image specified by the filesystem argument. Note that this may refer to a file in a file system that is not mounted. Most systems require secondary to be in the “root” directory of the file system, so the leading ‘`/`’ is not necessary on secondary.

  Only certain combinations of platform (`-m` machine) and file system type (`-t` fstype) require that the name of the secondary bootstrap is supplied as secondary, so that information such as the disk block numbers occupied by the secondary bootstrap can be stored in the primary bootstrap. These are:

  Platform | File systems
  macppc | ffs, raw
  news68k | ffs, raw
  newsmips | ffs, raw
  sparc | ffs, raid, raw
  sun2 | ffs, raw
  sun3 | ffs, raw

# ENVIRONMENT

`INSTALLBOOT_UBOOT_PATHS`
  A colon-separated list of search paths to scan for U‐Boot packages with `installboot` installation overlays. If multiple overlays are found, overlays from paths closer to the front of the list take precedence. If not specified, the default path is /usr/pkg/share/u-boot. This environment variable is only used on platforms that support using U‐Boot.
`MACHINE`
  Default value for machine, overriding the result from uname(3).

# FILES

Most NetBSD ports will contain variations of the following files:

/usr/mdec/bootxx_⟨FSTYPE⟩
  Primary bootstrap for file system type FSTYPE. Installed into the bootstrap area of the file system by `installboot`.
/usr/mdec/bootxx_fat16
  Primary bootstrap for MS-DOS FAT16 file systems. This differs from bootxx_msdos in that it doesn't require the filesystem to have been initialised with any “reserved sectors”. It also uses the information in the “Boot Parameter Block” to get the media and filesystem properties. The “hidden sectors” field of the BPB must be the offset of the partition in the disk. This can be set using the `-b` s1bno option.
/usr/mdec/bootxx_ffsv1
  Primary bootstrap for FFSv1 file systems (the “traditional” file system prior to NetBSD 6.0). Use dumpfs(8) to confirm the file system format is FFSv1.
/usr/mdec/bootxx_ffsv2
  Primary bootstrap for FFSv2 file systems (the default file system for some platforms as of NetBSD 6.0). Use dumpfs(8) to confirm the file system format is FFSv2.
/usr/mdec/bootxx_lfsv1
  Primary bootstrap for LFSv1 file systems.
/usr/mdec/bootxx_lfsv2
  Primary bootstrap for LFSv2 file systems (the default LFS version).
/usr/mdec/bootxx_msdos
  Primary bootstrap for MS-DOS FAT file systems.
/usr/mdec/bootxx_ustarfs
  Primary bootstrap for TARFS boot images. This is used by various install media.
/usr/mdec/boot.⟨MACHINE⟩
  Secondary bootstrap for machine type MACHINE. This should be installed into the file system before `installboot` is run.
/usr/mdec/boot
  Synonym for /usr/mdec/boot.⟨MACHINE⟩
/boot.⟨MACHINE⟩
  Installed copy of secondary bootstrap for machine type MACHINE.
/boot
  Installed copy of secondary bootstrap. Searched for by the primary bootstrap if /boot.⟨MACHINE⟩ is not found.

## NetBSD/evbarm files

The NetBSD/evbarm platform covers a wide variety of board types, many of which use U‐Boot. Running `installboot` with no options will display a list of known boards. Using the verbose option will also display information about which U‐Boot package needs to be installed to support that board, and if the required U‐Boot package is installed, the path at which it is located.

/usr/pkg/share/u-boot
  The default location scanned for U‐Boot packages with installation overlays.
/usr/share/installboot/evbarm/boards.plist
  Base board database, used to provide information about which U‐Boot package is required for a given board.

## NetBSD/evbmips files

The NetBSD/evbmips bootstrap files currently only apply to the SBMIPS kernels for the SiByte/Broadcom BCM1250 and BCM1480 CPUs. There is also U‐Boot support for the Creator CI20.

/usr/mdec/sbmips/boot
  NetBSD/evbmips secondary bootstrap for FFSv1, FFSv2, LFSv1, and LFSv2.
/usr/mdec/sbmips/bootxx_cd9660
  SBMIPS primary bootstrap for ISO 9660 file system.
/usr/mdec/sbmips/bootxx_ffs
  SBMIPS primary bootstrap for FFSv1 and FFSv2 file system.
/usr/mdec/sbmips/bootxx_lfs
  SBMIPS primary bootstrap for LFSv1 and LFSv2 file system.
/usr/mdec/sbmips/netboot
  SBMIPS primary bootstrap for network root.
/usr/share/installboot/evbmips/boards.plist
  Base board database, used to provide information about which U‐Boot package is required for a given board.

## NetBSD/hppa files

/usr/mdec/xxboot
  NetBSD/hppa primary bootstrap for FFSv1, FFSv2, LFSv1, and LFSv2.
/usr/mdec/cdboot
  NetBSD/hppa primary bootstrap for ISO 9660 file system.
/usr/mdec/sdboot
  Synonym for /usr/mdec/xxboot

## NetBSD/macppc files

/usr/mdec/bootxx
  NetBSD/macppc primary bootstrap.
/usr/mdec/ofwboot
  NetBSD/macppc secondary bootstrap.
/ofwboot
  Installed copy of NetBSD/macppc secondary bootstrap.

## NetBSD/next68k files

/usr/mdec/boot
  NetBSD/next68k bootstrap.

## NetBSD/sparc64 files

/usr/mdec/bootblk
  NetBSD/sparc64 primary bootstrap.
/usr/mdec/ofwboot
  NetBSD/sparc64 secondary bootstrap.
/ofwboot
  Installed copy of NetBSD/sparc64 secondary bootstrap.

# EXAMPLES

## Common

Verbosely install the Berkeley Fast File System primary bootstrap on to disk ‘`sd0`’:

`installboot -v /dev/rsd0c /usr/mdec/bootxx_ffs`

Note: the “whole disk” partition (‘`c`’ on some ports, ‘`d`’ on others) is used here, since the ‘`a`’ partition probably is already opened (mounted as /), so `installboot` would not be able to access it.

Remove the primary bootstrap from disk ‘`sd1`’:

`installboot -c /dev/rsd1c`

## NetBSD/amiga

Modify the command line to change the default from ‘`netbsd -ASn2`’ to ‘`netbsd -S`’:

    installboot -m amiga -o command="netbsd -S" /dev/rsd0a \
        /usr/mdec/bootxx_ffsv1

## NetBSD/evbarm

Install the U‐Boot boot loader for a Pinebook into an image that will be written to an SDMMC card:

`installboot -m evbarm -o board=pine64,pinebook arm64.img`

Install/update the U‐Boot boot loader for the current running system on the eMMC device ‘`ld0`’ and display verbose information about the procedure:

`installboot -v /dev/rld0c`

Install a specific U‐Boot package for a BeagleBone Black into an image that will be written to an SDMMC card:

    installboot -m evbarm -o board=ti,am335x-bone-black armv7.img \
        /path/to/experimental/u-boot/package

## NetBSD/ews4800mips

Install the System V Boot File System primary bootstrap on to disk ‘`sd0`’, with the secondary bootstrap /boot already present in the SysVBFS partition on the disk:

`installboot /dev/rsd0p /usr/mdec/bootxx_bfs`

Note: On NetBSD/ews4800mips the ‘`p`’ partition is the “whole disk” (i.e., raw) partition.

## NetBSD/i386 and NetBSD/amd64

Install new boot blocks on an existing FFSv2 mounted root file system on ‘`wd0`’, setting the timeout to five seconds, after installing an MBR bootcode and copying a new secondary bootstrap:

`fdisk -c /usr/mdec/mbr /dev/rwd0d`

Note: See fdisk(8) and x86/mbr(8) for more details.

`cp /usr/mdec/boot /boot`
`installboot -v -o timeout=5 /dev/rwd0a /usr/mdec/bootxx_ffsv2`

Note: Pre NetBSD 6.0 systems used FFSv1 file systems on these platforms; double check with dumpfs(8) to be sure to use the correct secondary bootstrap.

Create a bootable CD-ROM with an ISO 9660 file system for an i386 system with a serial console:

    mkdir cdrom
    cp sys/arch/i386/compile/mykernel/netbsd cdrom/netbsd
    cp /usr/mdec/boot cdrom/boot
    cp /usr/mdec/bootxx_cd9660 bootxx
    installboot -o console=com0,speed=19200 -m i386 -e bootxx
    makefs -t cd9660 -o 'bootimage=i386;bootxx,no-emul-boot' boot.iso \
        cdrom

Create a bootable floppy disk with an FFSv1 file system for a small custom kernel (note: bigger kernels needing multiple disks are handled with the ustarfs file system):

`newfs -s 1440k /dev/rfd0a`

Note: Ignore the warnings that newfs(8) displays; it can not write a disklabel, which is not a problem for a floppy disk.

    mount /dev/fd0a /mnt
    cp /usr/mdec/boot /mnt/boot
    gzip -9 < sys/arch/i386/compile/mykernel/netbsd > /mnt/netbsd.gz
    umount /mnt
    installboot -v /dev/rfd0a /usr/mdec/bootxx_ffsv1

Create a bootable FAT file system on ‘`wd1a`’, which should have the same offset and size as a FAT primary partition in the Master Boot Record (MBR):

`newfs_msdos -r 16 /dev/rwd1a`

Notes: The `-r` `16` is to reserve space for the primary bootstrap. newfs_msdos(8) will display an “MBR type” such as ‘`1`’, ‘`4`’, or ‘`6`’; the MBR partition type of the appropriate primary partition should be changed to this value.

    mount -t msdos /dev/wd1a /mnt
    cp /usr/mdec/boot /mnt/boot
    cp path/to/kernel /mnt/netbsd
    umount /mnt
    installboot -t raw /dev/rwd1a /usr/mdec/bootxx_msdos

Make the existing FAT16 filesystem on ‘`sd0e`’ bootable. This can be used to make USB memory bootable provided it has 512 byte sectors and that the manufacturer correctly initialised the file system.

    mount -t msdos /dev/sd0e /mnt
    cp /usr/mdec/boot /mnt/boot
    cp path/to/kernel /mnt/netbsd
    umount /mnt
    installboot /dev/rsd0e /usr/mdec/bootxx_fat16

It may also be necessary to use fdisk(8) to make the device itself bootable.

Switch the existing installed bootstrap to use a serial console without reinstalling or altering other options such as timeout.

`installboot -e -o console=com0 /dev/rwd0a`

## NetBSD/macppc

Note the `installboot` utility is only required for macppc machines with OpenFirmware version 2 to boot. OpenFirmware 3 cannot load bootblocks specified in the Apple partition map.

Install the Berkeley Fast File System primary bootstrap on to disk ‘`wd0`’:

`installboot /dev/rwd0c /usr/mdec/bootxx /ofwboot`

The secondary NetBSD/macppc bootstrap is located in /usr/mdec/ofwboot.

The primary bootstrap requires the raw ofwboot for the secondary bootstrap, not ofwboot.xcf, which is used for the OpenFirmware to load kernels.

## NetBSD/next68k

Install the bootstrap on to disk ‘`sd0`’:

`installboot /dev/rsd0c /usr/mdec/boot`

## NetBSD/pmax

Install the Berkeley Fast File System primary bootstrap on to disk ‘`sd0`’:

`installboot /dev/rsd0c /usr/mdec/bootxx_ffs`

NetBSD/pmax requires that this file system starts at block 0 of the disk.

Install the ISO 9660 primary bootstrap in the file /tmp/cd-image:

`installboot -m pmax /tmp/cd-image /usr/mdec/bootxx_cd9660`

Make an ISO 9660 filesystem in the file /tmp/cd-image and install the ISO 9660 primary bootstrap in the filesystem, where the source directory for the ISO 9660 filesystem contains a kernel, the primary bootstrap bootxx_cd9660 and the secondary bootstrap boot.pmax:

    mkisofs -o /tmp/cd-image -a -l -v iso-source-dir
    ...
    48 51 iso-source-dir/bootxx_cd9660
    ...
    installboot -b $((48 * 4)) /tmp/cd-image /usr/mdec/bootxx_cd9660

## NetBSD/sparc

Install the Berkeley Fast File System primary bootstrap on to disk ‘`sd0`’, with the secondary bootstrap /boot already present:

`installboot /dev/rsd0c /usr/mdec/bootxx /boot`

## NetBSD/sparc64

Install the primary bootstrap on to disk ‘`sd0`’:

`installboot /dev/rsd0c /usr/mdec/bootblk`

The secondary NetBSD/sparc64 bootstrap is located in /usr/mdec/ofwboot.

## NetBSD/sun2 and NetBSD/sun3

Install the Berkeley Fast File System primary bootstrap on to disk ‘`sd0`’, with the secondary bootstrap /boot already present:

`installboot /dev/rsd0c /usr/mdec/bootxx /boot`

## NetBSD/vax

Install the Berkeley Fast File System primary bootstrap on to disk ‘`ra0`’:

`installboot /dev/rra0c /usr/mdec/raboot`

The primary bootstrap works with FFSv1 and FFSv2 file systems. The secondary NetBSD/vax bootstrap is located in /usr/mdec/boot.

# DIAGNOSTIC

The `installboot` utility exits 0 on success, and >0 if an error occurs.

# SEE ALSO

uname(3), boot(8), disklabel(8), dumpfs(8), fdisk(8), gpt(8), x86/mbr(8), x86/pxeboot(8)

# HISTORY

This implementation of `installboot` appeared in NetBSD 1.6.

# AUTHORS

The machine independent portion of this implementation of `installboot` was written by Luke Mewburn. The following people contributed to the various machine dependent back-ends: Simon Burge (pmax), Chris Demetriou (alpha), Matthew Fredette (sun2, sun3), Matthew Green (sparc64), Ross Harvey (alpha), Michael Hitch (amiga), Paul Kranenburg (sparc), David Laight (i386), Christian Limpach (next68k), Luke Mewburn (macppc), Matt Thomas (vax), Izumi Tsutsui (news68k, newsmips), and UCHIYAMA Yasushi (ews4800mips).

# BUGS

There are not currently primary bootstraps to support all file systems types which are capable of being the root file system.

If a disk has been converted from FFS to RAID without the contents of the disk erased, then the original FFS installation may be auto-detected instead of the RAID installation. In this case, the `-t` `raid` option must be provided.

## NetBSD/alpha

The NetBSD/alpha primary bootstrap program can only load the secondary bootstrap program from file systems starting at the beginning (block 0) of disks. Similarly, the secondary bootstrap program can only load kernels from file systems starting at the beginning of disks.

The size of primary bootstrap programs is restricted to 7.5KB, even though some file systems (e.g., ISO 9660) are able to accommodate larger ones.

## NetBSD/hp300

The disk must have a boot partition large enough to hold the bootstrap code. Currently the primary bootstrap must be a LIF format file.

## NetBSD/i386 and NetBSD/amd64

The bootstrap must be installed in the NetBSD partition that starts at the beginning of the MBR partition. If that is a valid filesystem and contains the /boot program then it will be used as the root filesystem, otherwise the ‘`a`’ partition will be booted.

The size of primary bootstrap programs is restricted to 8KB, even though some file systems (e.g., ISO 9660) are able to accommodate larger ones.

## NetBSD/macppc

Due to restrictions in `installboot` and the secondary bootstrap implementation, file systems where kernels exist must start at the beginning of disks.

Currently, `installboot` doesn't recognize an existing Apple partition map on the disk and always writes a faked map to make disks bootable.

The NetBSD/macppc bootstrap program can't load kernels from FFSv2 partitions.

## NetBSD/next68k

The size of bootstrap programs is restricted to the free space before the file system at the beginning of the disk minus 8KB.

## NetBSD/pmax

The NetBSD/pmax secondary bootstrap program can only load kernels from file systems starting at the beginning of disks.

The size of primary bootstrap programs is restricted to 7.5KB, even though some file systems (e.g., ISO 9660) are able to accommodate larger ones.

## NetBSD/sun2 and NetBSD/sun3

The NetBSD/sun2 and NetBSD/sun3 secondary bootstrap program can only load kernels from file systems starting at the beginning of disks.

## NetBSD/vax

The NetBSD/vax secondary bootstrap program can only load kernels from file systems starting at the beginning of disks.

The size of primary bootstrap programs is restricted to 7.5KB, even though some file systems (e.g., ISO 9660) are able to accommodate larger ones.

December 29, 2024 | NetBSD 11.0