Yocto BSP Tools Documentation

Note: This documentation is the same as the documentation submitted to the Yocto BSP Developer's Guide. It's here temporarily as a convenience until that document has been officially published.

Using the Yocto BSP Tools

The Yocto Project includes a couple of tools that enable you to create a BSP from scratch (yocto- bsp) and do basic configuration and maintenance of the kernel (yocto-kernel) without ever looking at a Yocto metadata file.

The following sections describe each of those tools in detail, but there are some features common to both that will be useful to describe before delving into the details of either.

First, a word about how the tools are structured. Designed to have a 'git-like' command interface, each tool is structured as a set of sub-commands under a 'top-level' command. The top-level command (yocto-bsp or yocto-kernel) itself does nothing but invoke or provide help on the sub-commands it supports.

Secondly, since the tools themselves live in the scripts/ subdirectory, in order to use them, you need to 'source' the environment just as you would when invoking a build:

$ source oe-init-build-env [build_dir]

With that in mind, the most immediately useful function to describe is the built-in help system common to both tools.

The built-in help system makes it easy to drill down at any time and remind oneself of the syntax required for any specific command.

Simply entering the name of the command, or the command along with 'help' will display a list of the available sub-commands. For example:

trz@elmorro:/usr/local/dev/Yocto/build$ yocto-bsp

Usage: 

 Create a customized Yocto BSP layer.

 usage: yocto-bsp [--version] [--help] COMMAND [ARGS]

 The most commonly used 'yocto-bsp' commands are:
    create            Create a new Yocto BSP
    list              List available values for options and BSP properties

 See 'yocto-bsp help COMMAND' for more information on a specific command.
 

Options:
  --version    show program's version number and exit
  -h, --help   show this help message and exit
  -D, --debug  output debug information

Similarly, entering just the name of a sub-command will show the detailed usage for that sub- command:

trz@elmorro:/usr/local/dev/Yocto/build$ yocto-bsp create

Usage: 

 Create a new Yocto BSP

 usage: yocto-bsp create <bsp-name> <karch> [-o <DIRNAME> | --outdir <DIRNAME>]
            [-i <JSON PROPERTY FILE> | --infile <JSON PROPERTY_FILE>]

 This command creates a Yocto BSP based on the specified parameters.
 The new BSP will be a new Yocto BSP layer contained by default within
 the top-level directory specified as 'meta-bsp-name'.  The -o option
 can be used to place the BSP layer in a directory with a different
 name and location.

 The value of the 'karch' parameter determines the set of files that
 will be generated for the BSP, along with the specific set of
 'properties' that will be used to fill out the BSP-specific portions
 of the BSP.  The possible values for the 'karch' paramter can be
 listed via 'yocto-bsp list karch'. 


Options:
  -h, --help            show this help message and exit
  -o OUTDIR, --outdir=OUTDIR
                        name of BSP dir to create
  -i PROPERTIES_FILE, --infile=PROPERTIES_FILE
                        name of file containing the values for BSP properties
                        as a JSON file
  -c, --codedump        dump the generated code to bspgen.out

With the knowledge that there are two commands, yocto-bsp and yocto-kernel, and a built-in help system available for each, it should be relatively straightforward to discover the commands necessary to create a BSP and do basic kernel maintainence of that BSP using the tools. The following sections are provided, however, in order to serve as a concrete starting point and to expand on a few points that may not be immediately obvious or that could use further explanation.