yocto-public/2-usage/machinecreate.md

Create a Machine / Board Support Package

Creation

In the layer directory:

mkdir $LAYER/conf/machine

MACHINE=my-machine
touch $LAYER/conf/machine/$MACHINE.conf

See below for an interactive script to create a machine.

Machine conf. file

Edit $LAYER/conf/machine/$MACHINE.conf to set variables:

Variable	Role	Link
TARGET_ARCH	CPU architecture (arm, i386, x86_64, etc.)	More
PREFERRED_PROVIDER_virtual/kernel	Linux kernel recipe to use (linux-yocto)
MACHINE_FEATURES	See Combined Features
SERIAL_CONSOLES	Serial consoles to enable & their configurations (115200;ttyS0 115200;ttyS1)	More
KERNEL_IMAGETYPE	Type of the kernel image (default: zImage)	More
IMAGE_FSTYPES	Type of the output filesystem image (default: ext3 tar.bz2)	More

Kernel config file

Bitbake builds the kernel .config file using configuration fragments from the kernel recipe.

There are two ways to setup kernel configuration:

• Using .scc files
• Using .cfg files

Both files can be added to SRC_URI in the kernel recipe to be used.

See $POKY/meta/recipes-kernel/linux for recipe examples

.cfg files

.cfg files contains fragments of kernel .config file.

If multiple cfg files are added to the recipe, the values contained in the last included will override other values that were already set.

You can view the resulting kernel .config with the standard kernel menuconfig UI:

bitbake virtual/kernel -c menuconfig

Extracting a config fragment:

• Go to $POKY/build/tmp/work/*/$KERNEL_RECIPE_NAME/*/$KERNEL_RECIPE_NAME-*-build
• Use a diff tool (vimdiff, meld, kdiff3) to list differences between .config and .config.old

At this time, there is no practical tool to create configuration fragments.

.scc files

.scc files are like a wrapper around .cfg files.

They can include multiple .cfg or .scc, define which kernel branch to use, the architecture and other things.

define KMACHINE my-machine
define KTYPE tiny
define KARCH i386

kconf hardware general.cfg
kconf hardware liveboot.cfg

include ktypes/tiny/tiny.scc
branch my-machine

include my-machine.scc

More

Formfactor

HAVE_TOUCHSCREEN=0
HAVE_KEYBOARD=1

# Display rotation, size, colors, ...
DISPLAY_CAN_ROTATE=0
DISPLAY_ORIENTATION=0
#DISPLAY_WIDTH_PIXELS=640
#DISPLAY_HEIGHT_PIXELS=480
#DISPLAY_BPP=16
DISPLAY_DPI=150
DISPLAY_SUBPIXEL_ORDER=vrgb

Interactive script

The script `yocto-bsp create ` creates a layer named `` with a BSP for the architecture `` into.
You can get the list of supported arch with `yocto-bsp list karch`

This is an interactive script to create a BSP contained in a new layer:

yocto-bsp create my-machine i386
# Checking basic git connectivity...
# Done.
#
# Would you like to use the default (3.14) kernel? (y/n) [default: y]
# Do you need a new machine branch for this BSP (the alternative is to re-use an existing branch)? [y/n] [default: y]
# Getting branches from remote repo git://git.yoctoproject.org/linux-yocto-3.14.git...
# Please choose a machine branch to base this BSP on: [default: standard/base]
# 	1) standard/arm-versatile-926ejs
# 	2) standard/base
# 	3) standard/beagleboard
# 	4) standard/beaglebone
# 	5) standard/ck
# 	6) standard/common-pc/base
# 	7) standard/edgerouter
# 	8) standard/fsl-mpc8315e-rdb
# 	9) standard/mti-malta32
# 	10) standard/mti-malta64
# 	11) standard/qemuarm64
# 	12) standard/qemuppc
# 	13) standard/routerstationpro
# 2
# Do you need SMP support? (y/n) [default: y] n
# Which machine tuning would you like to use? [default: tune_core2]
# 	1) i586 tuning optimizations
# 	2) Atom tuning optimizations
# 	3) Core2 tuning optimizations
# 2
# Do you need support for X? (y/n) [default: y] n
# Does your BSP have a touchscreen? (y/n) [default: n] n
# Does your BSP have a keyboard? (y/n) [default: y] y
#
# New i386 BSP created in meta-my-machine

Don't forget to add the layer to BBLAYER if you want to use it

Generated tree

poky/build/meta-my-machine
├── binary
├── conf
│   ├── layer.conf                     => Layer configuration file
│   └── machine
│       └── my-machine.conf                => Machine configuration file
├── COPYING.MIT
├── README
├── README.sources
├── recipes-bsp
│   └── formfactor
│       ├── formfactor
│       │   └── my-machine
│       │       └── machconfig         => Input device support
│       └── formfactor_0.0.bbappend
├── recipes-graphics                   => Empty, can be deleted
│   └── xorg-xserver
│       └── xserver-xf86-config
│           └── my-machine
└── recipes-kernel
		└── linux
				├── files
				│   ├── my-machine.cfg     => Kernel configuration file
				│   ├── my-machine-preempt-rt.scc
				│   ├── my-machine.scc
				│   ├── my-machine-standard.scc
				│   ├── my-machine-tiny.scc
				│   ├── my-machine-user-config.cfg
				│   ├── my-machine-user-features.scc
				│   └── my-machine-user-patches.scc
				└── linux-yocto_3.14.bbappend      => Kernel recipe