Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, path names, dummy URLs, user input, and Twitter handles are shown as follows: "To run a task, BitBake will first look for an environment variable called do_ <task name>, which will contain the task code to execute (in Python or a shell)."

A block of code is set as follows:

# LAYER_CONF_VERSION is increased each time build/conf/bblayers.conf
# changes incompatibly
LCONF_VERSION = "6" BBPATH = "${TOPDIR}" BBFILES ?= "" BBLAYERS ?= " \
/home/packt/RASPBERRYPI/poky/meta \
/home/packt/RASPBERRYPI/poky/meta-yocto \
/home/packt/RASPBERRYPI/poky/meta-yocto-bsp \
"BBLAYERS_NON_REMOVABLE ?= " \
/home/packt/RASPBERRYPI/poky/meta \
/home/packt/RASPBERRYPI/poky/meta-yocto \
"

Any command-line input or output is written as follows:

$ modprobe spidev

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Adding a layer is very simple. We just have to click on the Layers button."

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.