Yocto

https://www.yoctoproject.org

Yocto offical web

System envn.

• Git 1.8.3.1 or greater

• tar 1.27 or greater

• Python 3.4.0 or greater.

sudo apt-get install gawk wget git-core diffstat unzip texinfo gcc-multilib      build-essential chrpath socat cpio python python3 python3-pip python3-pexpect      xz-utils debianutils iputils-ping python3-git python3-jinja2 libegl1-mesa libsdl1.2-dev      xterm

The first demo.

download poky-sumo-19.0.3.tar.bz2 from web and extract it.
The default machine is x86.

The first thing is to init the env. by run below script

source oe-init-build-env

command to build: bitbake core-image-minimal
command to run qemu: runqemu qemux86

  

image name
description core-image-minimal A small image just capable of allowing a device to boot. core-image-base A console-only image that fully supports the target device hardware. core-image-sato Image with sato, a mobile environment and visual style for mobile devices.  The image supports X11 with a Sato theme, Pimlico applications and contains terminal, editor and file manager. fsl-image-test Builds contents core-image-base plus Freescale test applications and multimedia components. fsl-image-gui Builds contents of core-image-sato with Freescale test applications and multimedia with hardware accelerated X11

 

The built images are located in

cd tmp/deploy/images 

#Using a existing layer

1. Clone a layer from git 

git clone -b sumo git://git.yoctoproject.org/meta-freescale 

2. add the layer to yocto (it must be in build folder)

bitbake-layers add-layer ../meta-freescale

#List local layers
bitbake-layers show-layer

#to build the firmware for imx6ullevk
edit build/conf/local.conf , change the machine as MACHINE ??= "imx6ullevk"
bitbake core-image-minimal

bitbake -c clean core-image-minimal

#to build the application developement environment
bitbake -c do_populate_sdk_ext core-image-minimal

#create a new layer  

on the build folder

bitbake-layers create-layer meta-stfir-ul

bitbake-layers add-layer ../meta-stfir-ul
bitbake-layers show-layers

#to find the layer which cotains linux kernel
bitbake-layers show-recipes | grep linux -A 10 | grep meta-freescale -B 5

#check the layer
yocto-check-layer meta-ul

#know which linux version and name is used
bitbake -e virtual/kernel | grep "^PV"
bitbake -e virtual/kernel | grep "^PN"

PN is the package name
PV is the package version

bitbake -e u-boot | grep "^PN"

-e means environment

Where is from virtual/kernel?

PREFERRED_PROVIDER

Determines which recipe should be given preference when multiple recipes provide the same item. You should always suffix the variable with the name of the provided item, and you should set it to the PN of the recipe to which you want to give precedence. Some examples:

     PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto"
     PREFERRED_PROVIDER_virtual/xserver = "xserver-xf86"
     PREFERRED_PROVIDER_virtual/libgl ?= "mesa"                    

#the bblayers.conf must in meta-ul for searching the dependence metas.

 

#Customize kernel setting
bitbake -c menuconfig virtual/kernel
or
bitbake linux-imx -c menuconfig

bitbake -c savedefconfig virtual/kernel
the defconfig file will be saved in build/tmp/work/fpa1000-poky-linux-gnueabi/linux-imx/4.9.88-r0/build/
you can copy the file to the layer for finally customizing linux when compilation.

#to list all commands in virutal/kernel
bitbake -c listtasks virtual/kernel
bitbake -c listtasks virtual/bootloader

#to clear the state to initial in case the menuconfig is wrong
bitbake -c cleansstate virtual/kernel

#to show all the bbappends
bitbake-layers show-appends

#update the kernel configuration fragment

recommend to update the kernel configuration fragment.
in your layer, example recipes-kernel\linux\
file: PN_PV.bbappend (linux-imx_4.9.88.bbappend)
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}-${PV}:"

COMPATIBLE_MACHINE = "(fpa1000)"

SRC_URI += "file://can_config"

a folder name : linux-imx-4.9.88 has file can_config, which is to disable the CAN device
CONFIG_CAN is not set
CONFIG_CAN_FLEXCAN is not set
CONFIG_CAN_M_CAN is not set

how to generate a configuration fragment
bitbake linux-imx -c menuconfig
change what you want, save it when exit, run below command will generate the config.frame which is the changes
bitbake linux-imx -c diffconfig
compile the kernel
bitbake linux-imx -c compile -f
deploy
bitbake linux-imx -c deploy
install and package
bitbake linux-imx

---The summay

To apply kernel config, there are two methods,
1. copy whole file defconfig
bitbake linux-imx -c menuconfig
#bitbake linux-imx -c savedefconfig
copy the generated defconfig to your bbapend folder
cp ./tmp/work/fpa1000-poky-linux-gnueabi/linux-imx/4.9.88-r0/build/.config ../meta-ul/recipes-kernel/linux/linux-imx-4.9.88/defconfig
in the bbapend file
SRC_URI += " \
file://defconfig \
file://git/arch/arm/boot/dts/fpa1000.dts \
"
2. using config frame,
it is better to use patch file, but now I use the whole file
The config framement must be *.cfg.
copy the *.cfg to the destination folder (linux-imx-4.9.88/poky), and change *.bbappend

SRC_URI += "file://disable_can.cfg"
SRC_URI += "file://git/arch/arm/boot/dts/fpa1000.dts"
SRC_URI += "file://disable_media.cfg"
SRC_URI += "file://disable_ATA.cfg"
SRC_URI += "file://disable_network.cfg"

Note: The search file path is very import. According to the debug information below, it will search the paths ins sequencly.
It will patch the file in case find the file. Special for the same file name. for example, defconfig, it is same name in meta-freescale and meta-ul, it always failure when I put the
file in linux-imx-4.9.88/. it is success when I put the file in linux-imx-4.9.88/poky/
checking the log.do_fetch at temp.
DEBUG: Searching for defconfig in paths:
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/poky
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/poky
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/poky
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/poky
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/fpa1000
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/fpa1000
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/fpa1000
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/fpa1000
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/mx6ull
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/mx6ull
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/mx6ull
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/mx6ull
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/imxepdc
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/imxepdc
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/imxepdc
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/imxepdc
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/imxpxp
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/imxpxp
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/imxpxp
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/imxpxp
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/mx6
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/mx6
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/mx6
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/mx6
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/imx
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/imx
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/imx
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/imx
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/armv7ve
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/armv7ve
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/armv7ve
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/armv7ve
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/arm
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/arm
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/arm
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/arm
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/
DEBUG: Searching for git/arch/arm/boot/dts/fpa1000.dts in paths:
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/poky
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/poky
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/poky
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/poky
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/fpa1000
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/fpa1000
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/fpa1000
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/fpa1000
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/mx6ull
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/mx6ull
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/mx6ull
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/mx6ull
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/imxepdc
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/imxepdc
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/imxepdc
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/imxepdc
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/imxpxp
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/imxpxp
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/imxpxp
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/imxpxp
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/mx6
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/mx6
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/mx6
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/mx6
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/imx
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/imx
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/imx
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/imx
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/armv7ve
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/armv7ve
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/armv7ve
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/armv7ve
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/arm
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/arm
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/arm
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/arm
/home/zjb/yocto/poky-sumo-19.0.3/meta-ul/recipes-kernel/linux/linux-imx-4.9.88/
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx-4.9.88/
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/linux-imx/
/home/zjb/yocto/poky-sumo-19.0.3/meta-freescale/recipes-kernel/linux/files/

 

#customize u-boot
#the command will show the all commands for u-boot
bitbake u-boot-imx -c listtasks
#below command will create a terminate and switch to u-boot git folder, in git folder you can use menuconfig oldconfig related to customize u-boot.
bitbake u-boot-imx -c devshell

you can use build only recipe
e.g. bitbake linux-imx or bitbake u-boot-imx

The build log file can be found at build/tmp/...
using commmand below to find the exactly folder
bitbake -e linux-imx | grep ^T=

to find the source folder
bitbake -e linux-imx | grep ^S=
bitbake -e u-boot-imx | grep ^S=

#device tree

The device tree is loacted in : home/zjb/yocto/poky-sumo-19.0.3/build/tmp/work/fpa1000-poky-linux-gnueabi/linux-imx/4.9.88-r0/git/arch/arm/boot/dts
only compile the dts
bitbake linux-imx -c devshell
make dtbs

#add image to build
CORE_IMAGE_EXTRA_INSTALL += " <packagename>"
or
IMAGE_INSTALL_append = " lighttpd wget"

#how to use local mirror to build
in your layer.conf file

build with network, normally the all tar files are achieved in downloads folder:
bitbake core-image-minimal

copy:
copy build/downloads/* to /home/zjb/SourceMirror/

change to "No network" in layer.conf

SOURCE_MIRROR_URL ?= "file:///home/zjb/SourceMirror/"
INHERIT += "own-mirrors"
BB_NO_NETWORK = "1"

#override the files because the internet is not avaliable

example lighthttpd, the original bb file URI as below
SRC_URI = "http://download.lighttpd.net/lighttpd/releases-1.4.x/lighttpd-${PV}.tar.xz \
file://index.html.lighttpd \
file://lighttpd.conf \
file://lighttpd \
file://lighttpd.service \
file://0001-Use-pkg-config-for-pcre-dependency-instead-of-config.patch \
"

as we don‘t have interrnet access, recreate bbappend in your meta layer
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}-${PV}:"

COMPATIBLE_MACHINE = "(fpa1000)"

SRC_URI = "file://lighttpd-1.4.48.tar.gz \
file://index.html.lighttpd \
file://lighttpd.conf \
file://lighttpd \
file://lighttpd.service \
file://0001-Use-pkg-config-for-pcre-dependency-instead-of-config.patch \
"
you can see, we only replace the main URL as local file address.
add copy the download lighttpd-1.4.48.tar.gz in your /lighttpd-1.4.48/ folder

#how to know which packages are installed
the manifest are located in tmp/delploy/images/<imagename>/<imagename.manifest

#customize busybox
bitbake -c menuconfig busybox, quit and save what your changes
bitbake -c diffconfig, system will generate the config fragment.

 

#only build a specific bb file.

bitbake -b xx.bb to only build a specific bb file.

#using self customized device tree.
copy a device tree from original to the folder, e.g. fpa1000.dts
meta-ul/recipes-kernel/linux/linux-imx-4.9.88/git/arch/arm/boot/dts/

and then in the machine conf, e.g. fpa1000.conf, change the device config.
#KERNEL_DEVICETREE = "imx6ull-14x14-evk.dtb imx6ull-14x14-evk-btwifi.dtb"
KERNEL_DEVICETREE = "fpa1000.dtb"

 

#The image in sd-card of one board does not work, use below method to burn the image from nxp offical web
1. connect the micro sd card to linux
2. fdisk -l to find out which device name, it is /dev/sdc in my system or lsblk
3. bunzip2 -dk -f fsl-image-validation-imx-x11-imx6ull14x14evk.sdcard.bz2
4. sudo dd if=fsl-image-validation-imx-x11-imx6ull14x14evk.sdcard of=/dev/sdc bs=1M conv=fsync

#using below command to find out which output format
bitbake core-image-minimal -e | grep ^IMAGE_FSTYPES

#using wic.gz image
gunzip core-image-minimal-fpa1000-20190621060255.rootfs.wiz.gz
sudo dd if=core-image-minimal-fpa1000-20190621060255.rootfs.wiz of=/dev/sdb bs=1M iflag=fullblock oflag=direct conv=fsync

using self-build image, need to change the fdt_file in uboot to fpa1000.dtb

#how to change the u-boot using self-device
1. fpa1000.conf
UBOOT_CONFIG ??= "sd"
#UBOOT_CONFIG[sd] = "mx6ull_14x14_evk_config,sdcard"
#UBOOT_CONFIG[mfgtool] = "mx6ull_14x14_evk_config"
UBOOT_CONFIG[sd] = "fpa1000_config,sdcard"
UBOOT_CONFIG[mfgtool] = "fpa1000_config"

2. in ul/recipes-bsp/u-boot
1). u-boot-imx_2017.03.bbappend
SRC_URI += "file://git/configs/fpa1000_defconfig"
SRC_URI += "file://git/arch/arm/dts/fpa1000.dts"
SRC_URI += "file://git/arch/arm/dts/Makefile"

2). fpa1000_defconfig is copy from u-boot/git/configs/mx6ul_14x14_evk_defconfig with change
3). fpa1000.dts is copy from u-boot/git/arch/arm/imx6ul-14x14-evk.dts without change
4). Makefile is copy from u-boot/git/arch/arm/makefile with change

 

#u-boot source code
the u-boot source code is not in work/tmp folder, using bitbake u-boot-imx -c unpack

#u-boot enviroment string is defined in mx6ullevk.h
/home/zjb/yocto/poky-sumo-19.0.3/build/tmp/work/fpa1000-poky-linux-gnueabi/u-boot-imx/2017.03-r0/git/include/configs

#find command
find . -name ‘defconfig‘

#grep a text in files
grep -rnw . -e ‘findfdt‘

#how to use patch
The folder structure of generating patch is very important, because the patch command want to know where to apply.
for example, we want to apply the patch for file ./include/configs/mx6ullevk.h
1. generate the patch
setup two folders with same structure as file
./include/configs/mx6ullevk.h (or used the origin source code)
./modify/configs/mx6ullevk.h
diff -Nupr --no-dereference ./include/ ./modify/ >mx6ullevk.h.patch

2. in bbapend file.
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}-${PV}:"
SRC_URI += "file://mx6ullevk.h.patch"

and put the generate mx6ullevk.h.patch to the folder ${PN}-${PV}

#how to change default fdt_file in u-boot enviornment
The variable is stored in the u-boot source code /include/configs/mx6ullevk.h
using patch to change it.

#enable cgi for lighttpd
1. in lighttpd.conf
server.modules = (
# "mod_rewrite",
# "mod_redirect",
"mod_alias",
"mod_access",
# "mod_cml",
# "mod_trigger_b4_dl",
# "mod_auth",
# "mod_status",
# "mod_setenv",
# "mod_fastcgi",
# "mod_proxy",
# "mod_simple_vhost",
# "mod_evhost",
# "mod_userdir",
"mod_cgi",
"mod_compress",
# "mod_ssi",
# "mod_usertrack",
# "mod_expire",
# "mod_secdownload",
# "mod_rrdtool",
# "mod_webdav",
"mod_accesslog" )

cgi.assign = (
".cgi" => ""
)

alias.url += ("/cgi-bin" => "/www/pages/cgi-bin")

##
# which extensions should not be handle via static-file transfer
#
# .php, .pl, .fcgi are most often handled by mod_fastcgi or mod_cgi
static-file.exclude-extensions = ( ".php", ".pl", ".fcgi", ".cgi" )

2. in lighttpd_%.bbapend
RDEPENDS_${PN} += "lighttpd-module-cgi \
lighttpd-module-alias \
lighttpd-module-compress"

#to view which module is compile
build/deploy/

in board
cat /proc/config.gz |gunzip

#where to find the log informationtmp/work/yourlinuxfolder/version/temp