Documentation update (mainly introduction)

[novaboot.git] / README.md

# NAME

novaboot - A tool for booting various operating systems on various hardware or in qemu

# SYNOPSIS

__novaboot__ --help

__novaboot__ \[option\]... \[--\] script...

__./script__ \[option\]...

# DESCRIPTION

This program makes booting of an operating system (e.g. NOVA or Linux)
as simple as running a local program. It facilitates booting on local
or remote hosts or in emulators such as qemu. Novaboot operation is
controlled by command line options and by a so called novaboot script,
which can be thought as a generalization of bootloader configuration
files. Based on this input, novaboot setups everything for the target
host to boot the desired configuration, i.e. it generates the
bootloader configuration file in the proper format, deploy the
binaries and other needed files to required locations, perhaps on a
remote boot server and reset the target host. Finally, target host's
serial output is redirected to standard output if that is possible.

Typical way of using novaboot is to make the novaboot script
executable and set its first line to _\#!/usr/bin/env novaboot_. Then,
booting a particular OS configuration becomes the same as executing a
local program - the novaboot script.

For example, with `novaboot` you can:

1. Run an OS in Qemu. This is the default action when no other action is
specified by command line switches. Thus running `novaboot ./script`
(or `./script` as described above) will run Qemu and make it boot the
configuration specified in the `script`.
2. Create a bootloader configuration file (currently supported
bootloaders are GRUB, GRUB2, Pulsar and U-Boot) and copy it with all
other files needed for booting to a remote boot server.

        ./script --server=192.168.1.1:/tftp --iprelay=192.168.1.2

    This command copies files to the TFTP server and uses
    TCP/IP-controlled relay to reset the target host and receive its
    serial output.

3. Run DHCP and TFTP server on developer's machine to PXE-boot the target
host from it. E.g.

        ./script --dhcp-tftp

    When a PXE-bootable machine is connected via Ethernet to developer's
    machine, it will boot the configuration described in _script_.

4. Create bootable ISO images. E.g.

        novaboot --iso -- script1 script2

    The created ISO image will have GRUB bootloader installed on it and
    the boot menu will allow selecting between _script1_ and _script2_
    configurations.

Note that the options needed for a specific target can be stored in a
["CONFIGURATION FILE"](#configuration-file). Then it is sufficient to use only the __\-t__
option to specify the name of the target.

# PHASES AND OPTIONS

Novaboot performs its work in several phases. Each phase can be
influenced by several options, certain phases can be skipped. The list
of phases (in the execution order) and the corresponding options
follow.

## Configuration reading phase

After starting, novaboot reads configuration files. By default, it
searches for files named `.novaboot` starting from the directory of
the novaboot script (or working directory, see bellow) and continuing
upwards up to the root directory. The configuration files are read in
order from the root directory downwards with latter files overriding
settings from the former ones.

In certain cases, the location of the novaboot script cannot be
determined in this early phase. This happens either when the script is
read from the standard input or when novaboot is invoked explicitly
and options precede the script name, as in the example ["4."](#4) above.
In this case the current working directory is used as a starting point
for configuration file search.

- \-c, --config=_filename_

    Use the specified configuration file instead of the default one(s).

## Command line processing phase

- \--dump-config

    Dump the current configuration to stdout end exits. Useful as an
    initial template for a configuration file.

- \-h, --help

    Print short (__\-h__) or long (__\--help__) help.

- \-t, --target=_target_

    This option serves as a user configurable shortcut for other novaboot
    options. The effect of this option is the same as the options stored
    in the `%targets` configuration variable under key _target_. See
    also ["CONFIGURATION FILE"](#configuration-file).

## Script preprocessing phase

This phases allows to modify the parsed novaboot script before it is
used in the later phases.

- \-a, --append=_parameters_

    Append a string to the first `load` line in the novaboot script. This
    can be used to append parameters to the kernel's or root task's
    command line. Can appear multiple times.

- \-b, --bender

    Use `bender` chainloader. Bender scans the PCI bus for PCI serial
    ports and stores the information about them in the BIOS data area for
    use by the kernel.

- \--chainloader=_chainloader_

    Chainloader that is loaded before the kernel and other files specified
    in the novaboot script. E.g. 'bin/boot/bender promisc'.

- \--dump

    Print the modules to boot and their parameters after this phase
    finishes. Then exit. This is useful for seeing the effect of other
    options in this section.

- \-k, --kernel=`file`

    Replace the first word on the first `load` line in the novaboot
    script with `file`.

- \--scriptmod=_perl expression_

    When novaboot script is read, _perl expression_ is executed for every
    line (in $\_ variable). For example, `novaboot
    --scriptmod=s/sigma0/omega6/g` replaces every occurrence of _sigma0_
    in the script with _omega6_.

    When this option is present, it overrides _$script\_modifier_ variable
    from the configuration file, which has the same effect. If this option
    is given multiple times all expressions are evaluated in the command
    line order.

## File generation phase

In this phase, files needed for booting are generated in a so called
_build directory_ (see ["--build-dir"](#build-dir)). In most cases configuration
for a bootloader is generated automatically by novaboot. It is also
possible to generate other files using _heredoc_ or _"<"_ syntax in
novaboot scripts. Finally, binaries can be generated in this phases by
running `scons` or `make`.

- \--build-dir=_directory_

    Overrides the default build directory location.

    The default build directory location is determined as follows: If the
    configuration file defines the `$builddir` variable, its value is
    used. Otherwise, it is the directory that contains the first processed
    novaboot script.

    See also ["BUILDDIR"](#builddir) variable.

- \-g, --grub\[=_filename_\]

    Generates grub bootloader menu file. If the _filename_ is not
    specified, `menu.lst` is used. The _filename_ is relative to the
    build directory (see __\--build-dir__).

- \--grub-preamble=_prefix_

    Specifies the _preable_ that is at the beginning of the generated
    GRUB or GRUB2 config files. This is useful for specifying GRUB's
    timeout.

- \--grub-prefix=_prefix_

    Specifies _prefix_ that is put in front of every file name in GRUB's
    `menu.lst`. The default value is the absolute path to the build directory.

    If the _prefix_ contains string $NAME, it will be replaced with the
    name of the novaboot script (see also __\--name__).

- \--grub2\[=_filename_\]

    Generate GRUB2 menuentry in _filename_. If _filename_ is not
    specified `grub.cfg` is used. The content of the menuentry can be
    customized with __\--grub-preable__, __\--grub2-prolog__ or
    __\--grub\_prefix__ options.

    In order to use the the generated menuentry on your development
    machine that uses GRUB2, append the following snippet to
    `/etc/grub.d/40_custom` file and regenerate your grub configuration,
    i.e. run update-grub on Debian/Ubuntu.

        if [ -f /path/to/nul/build/grub.cfg ]; then
          source /path/to/nul/build/grub.cfg
        fi

- \--grub2-prolog=_prolog_

    Specifies text _preable_ that is put at the beginning of the entry
    GRUB2 entry.

- \-m, --make\[=make command\]

    Runs `make` to build files that are not generated by novaboot itself.

- \--name=_string_

    Use the name _string_ instead of the name of the novaboot script.
    This name is used for things like a title of grub menu or for the
    server directory where the boot files are copied to.

- \--no-file-gen

    Do not generate files on the fly (i.e. "<" syntax) except for the
    files generated via "<<WORD" syntax.

- \-p, --pulsar\[=mac\]

    Generates pulsar bootloader configuration file named `config-_mac_`
    The _mac_ string is typically a MAC address and defaults to
    _novaboot_.

- \--scons\[=scons command\]

    Runs `scons` to build files that are not generated by novaboot
    itself.

- \--strip-rom

    Strip _rom://_ prefix from command lines and generated config files.
    The _rom://_ prefix is used by NUL. For NRE, it has to be stripped.

- \--gen-only

    Exit novaboot after file generation phase.

## Target connection check

If supported by the target, the connection to it is made and it is
checked whether the target is not occupied by another novaboot
user/instance.

- \--iprelay=_addr\[:port\]_

    Use TCP/IP relay and serial port to access the target's serial port
    and powercycle it. The IP address of the relay is given by _addr_
    parameter. If _port_ is not specified, it default to 23.

    Note: This option is supposed to work with HWG-ER02a IP relays.

- \-s, --serial\[=device\]

    Target's serial line is connected to host's serial line (device). The
    default value for device is `/dev/ttyUSB0`.

    The value of this option is exported in NB\_NOVABOOT environment
    variable to all subprocesses run by `novaboot`.

- \--stty=_settings_

    Specifies settings passed to `stty` invoked on the serial line
    specified with __\--serial__ option. If this option is not given,
    `stty` is called with `raw -crtscts -onlcr 115200` settings.

- \--remote-cmd=_cmd_

    Command that mediates connection to the target's serial line. For
    example `ssh server 'cu -l /dev/ttyS0'`.

- \--remote-expect=_string_

    Wait for reception of _string_ after establishing the the remote
    connection before continuing.

## File deployment phase

In some setups, it is necessary to copy the files needed for booting
to a particular location, e.g. to a TFTP boot server or to the
`/boot` partition.

- \-d, --dhcp-tftp

    Turns your workstation into a DHCP and TFTP server so that the OS can
    be booted via PXE BIOS (or similar mechanism) on the test machine
    directly connected by a plain Ethernet cable to your workstation.

    The DHCP and TFTP servers require root privileges and `novaboot`
    uses `sudo` command to obtain those. You can put the following to
    _/etc/sudoers_ to allow running the necessary commands without
    asking for password.

        Cmnd_Alias NOVABOOT = /bin/ip a add 10.23.23.1/24 dev eth0, /bin/ip l set dev eth0 up, /usr/sbin/dhcpd -d -cf dhcpd.conf -lf dhcpd.leases -pf dhcpd.pid, /usr/sbin/in.tftpd --foreground --secure -v -v -v --pidfile tftpd.pid *, /usr/bin/touch dhcpd.leases, /usr/bin/pkill --pidfile=dhcpd.pid, /usr/bin/pkill --pidfile=tftpd.pid
        your_login ALL=NOPASSWD: NOVABOOT

- \--iso\[=filename\]

    Generates the ISO image that boots NOVA system via GRUB. If no filename
    is given, the image is stored under _NAME_.iso, where _NAME_ is the name
    of the novaboot script (see also __\--name__).

- \--server\[=\[\[user@\]server:\]path\]

    Copy all files needed for booting to another location (implies __\-g__
    unless __\--grub2__ is given). The files will be copied (by __rsync__
    tool) to the directory _path_. If the _path_ contains string $NAME,
    it will be replaced with the name of the novaboot script (see also
    __\--name__).

- \--concat

    If __\--server__ is used and its value ends with $NAME, then after
    copying the files, a new bootloader configuration file (e.g. menu.lst)
    is created at _path-wo-name_, i.e. the path specified by __\--server__
    with $NAME part removed. The content of the file is created by
    concatenating all files of the same name from all subdirectories of
    _path-wo-name_ found on the "server".

- \--rsync-flags=_flags_

    Specifies which _flags_ are appended to `rsync` command line when
    copying files as a result of _\--server_ option.

## Target power-on and reset phase

- \--on, --off

    Switch on/off the target machine. Currently works only with
    __\--iprelay__.

- \-Q, --qemu\[=_qemu-binary_\]

    Boot the configuration in qemu. Optionally, the name of qemu binary
    can be specified as a parameter.

- \--qemu-append=_flags_

    Append _flags_ to the default qemu flags (QEMU\_FLAGS variable or
    `-cpu coreduo -smp 2`).

- \-q, --qemu-flags=_flags_

    Replace the default qemu flags (QEMU\_FLAGS variable or `-cpu coreduo
    -smp 2`) with _flags_ specified here.

- \--reset-cmd=_cmd_

    Command that resets the target.

## Interaction with the bootloader on the target

- \--uboot

    Interact with uBoot bootloader to boot the thing described in the
    novaboot script. Implementation of this option is currently tied to a
    particular board that we use. It may be subject to changes in the
    future!

- \--uboot-init

    Command(s) to send the U-Boot bootloader before loading the images and
    booting them.

## Target interaction phase

In this phase, target's serial output is redirected to stdout and if
stdin is a TTY, it is redirected to the target's serial input allowing
interactive work with the target.

- \--exiton=_string_

    When _string_ is sent by the target, novaboot exits. This option can
    be specified multiple times.

    If _string_ is `-re`, then the next __\--exiton__'s _string_ is
    treated as regular expression. For example:

        --exiton -re --exiton 'error:.*failed'

- \-i, --interactive

    Setup things for interactive use of target. Your terminal will be
    switched to raw mode. In raw mode, your system does not process input
    in any way (no echoing of entered characters, no interpretation
    special characters). This, among others, means that Ctrl-C is passed
    to the target and does no longer interrupt novaboot. Use "~~."
    sequence to exit novaboot.

- \--expect=_string_

    When _string_ is received from the target, send the string specified
    with the subsequent __\--send\*__ option to the target.

- \--expect-re=_regex_

    When target's output matches regular expression _regex_, send the
    string specified with the subsequent __\--send\*__ option to the target.

- \--expect-raw=_perl-code_

    Provides direct control over Perl's Expect module.

- \--send=_string_

    Send _string_ to the target after the previously specified
    __\--expect\*__ was matched in the target's output. The _string_ may
    contain escape sequences such as "\\n".

    Note that _string_ is actually interpreted by Perl, so it can contain
    much more that escape sequences. This behavior may change in the
    future.

    Example: `--expect='login: ' --send='root\n'`

- \--sendcont=_string_

    Similar to __\--send__ but continue expecting more input.

    Example: `--expect='Continue?' --sendcont='yes\n'`

# NOVABOOT SCRIPT SYNTAX

The syntax tries to mimic POSIX shell syntax. The syntax is defined
with the following rules.

Lines starting with "\#" and empty lines are ignored.

Lines that end with "\\" are concatenated with the following line after
removal of the final "\\" and leading whitespace of the following line.

Lines of the form _VARIABLE=..._ (i.e. matching '^\[A-Z\_\]+=' regular
expression) assign values to internal variables. See ["VARIABLES"](#variables)
section.

Lines starting with `load` keyword represent modules to boot. The
word after `load` is a file name (relative to the build directory
(see __\--build-dir__) of the module to load and the remaining words are
passed to it as the command line parameters.

When the `load` line ends with "<<WORD" then the subsequent lines
until the line containing solely WORD are copied literally to the file
named on that line. This is similar to shell's heredoc feature.

When the `load` line ends with "< CMD" then command CMD is executed
with `/bin/sh` and its standard output is stored in the file named on
that line. The SRCDIR variable in CMD's environment is set to the
absolute path of the directory containing the interpreted novaboot
script.

Example:
  \#!/usr/bin/env novaboot
  WVDESC=Example program
  load bin/apps/sigma0.nul S0\_DEFAULT script\_start:1,1 \\
    verbose hostkeyb:0,0x60,1,12,2
  load bin/apps/hello.nul
  load hello.nulconfig <<EOF
  sigma0::mem:16 name::/s0/log name::/s0/timer name::/s0/fs/rom ||
  rom://bin/apps/hello.nul
  EOF

This example will load three modules: `sigma0.nul`, `hello.nul` and
`hello.nulconfig`. sigma0 receives some command line parameters and
`hello.nulconfig` file is generated on the fly from the lines between
`<<EOF` and `EOF`.

## VARIABLES

The following variables are interpreted in the novaboot script:

- BUILDDIR

    Novaboot chdir()s to this directory before file generation phase. The
    directory name specified here is relative to the build directory
    specified by other means (see ["--build-dir"](#build-dir)).

- EXITON

    Assigning this variable has the same effect as specifying ["--exiton"](#exiton)
    option.

- HYPERVISOR\_PARAMS

    Parameters passed to hypervisor. The default value is "serial", unless
    overridden in configuration file.

- KERNEL

    The kernel to use instead of the hypervisor specified in the
    configuration file with the `$hypervisor` variable. The value should
    contain the name of the kernel image as well as its command line
    parameters. If this variable is defined and non-empty, the variable
    HYPERVISOR\_PARAMS is not used.

- QEMU

    Use a specific qemu binary (can be overridden with __\-Q__) and flags
    when booting this script under qemu. If QEMU\_FLAGS variable is also
    specified flags specified in QEMU variable are replaced by those in
    QEMU\_FLAGS.

- QEMU\_FLAGS

    Use specific qemu flags (can be overridden with __\-q__).

- WVDESC

    Description of the wvtest-compliant program.

- WVTEST\_TIMEOUT

    The timeout in seconds for WvTest harness. If no complete line appears
    in the test output within the time specified here, the test fails. It
    is necessary to specify this for long running tests that produce no
    intermediate output.

# CONFIGURATION FILE

Novaboot can read its configuration from one or more files. By
default, novaboot looks for files named `.novaboot` as described in
["Configuration reading phase"](#configuration-reading-phase). Alternatively, its location can be
specified with the __\-c__ switch or with the NOVABOOT\_CONFIG
environment variable. The configuration file has perl syntax and
should set values of certain Perl variables. The current configuration
can be dumped with the __\--dump-config__ switch. Some configuration
variables can be overridden by environment variables (see below) or by
command line switches.

Supported configuration variables include:

- $builddir

    Build directory location relative to the location of the configuration
    file.

- $default\_target

    Default target (see below) to use when no target is explicitly
    specified on command line with the __\--target__ option.

- %targets

    Hash of shortcuts to be used with the __\--target__ option. If the hash
    contains, for instance, the following pair of values

        'mybox' => '--server=boot:/tftproot --serial=/dev/ttyUSB0 --grub',

    then the following two commands are equivalent:

        ./script --server=boot:/tftproot --serial=/dev/ttyUSB0 --grub
        ./script -t mybox

# ENVIRONMENT VARIABLES

Some options can be specified not only via config file or command line
but also through environment variables. Environment variables override
the values from configuration file and command line parameters
override the environment variables.

- NOVABOOT\_CONFIG

    Name of the novaboot configuration file to use instead of the default
    one(s).

- NOVABOOT\_BENDER

    Defining this variable has the same meaning as __\--bender__ option.

# AUTHORS

Michal Sojka <sojka@os.inf.tu-dresden.de>