U007D/yocto-pi4.md

## yocto-pi4.md

      
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              yocto-pi4.md
            
          
    Raspberry Pi minimal image

This guide intends to summarize the essencial steps performed to build a Raspberry Pi minmal image using Yocto.
Download software dependencies

To build the image we are going to use the Poky and the layers meta-openembedded , meta-raspberrypi .
The list of all meta-raspberrypi dependencies are contained in the Readme.md the provided MACHINE's are  listed on the layer-contentens.md

Use Git to clone Poky repo using the apropriate version branch.

$ git clone -b sumo git://git.yoctoproject.org/poky.git


Enter into the Poky folder

$ cd poky


Use Git to clone the meta-rasperrypi layer repo using the apropriate version branch.

$ git clone -b sumo git://git.yoctoproject.org/meta-raspberrypi


Use Git to clone the meta-openembedded layer repo using the apropriate version branch.

$ git clone -b sumo git://git.openembedded.org/meta-openembedded

Build Your Image


Initialize the build env

$ source oe-init-build-env


Modify your local.conf file

Set your machine to MACHINE = "raspberrypi4-64" according to your Raspberry Pi model.
(Optional) Set the package manager to deb PACKAGE_CLASSES ?= "package_deb"
(Optional--[u007d] didn't seem to help for me) Set the SSTate Mirrors to save time in the builds.

SSTATE_MIRRORS = "\
    file://.* http://sstate.yoctoproject.org/dev/PATH;downloadfilename=PATH \n \
    file://.* http://sstate.yoctoproject.org/2.4/PATH;downloadfilename=PATH \n \
    file://.* http://sstate.yoctoproject.org/2.5/PATH;downloadfilename=PATH \n \"


Modify the bbplayers.conf file and add all the listed dependencies listed on the Readme.md.

BBLAYERS ?= " \
    /workdir/poky/meta \
    /workdir/poky/meta-poky \
    /workdir/poky/meta-yocto-bsp \
    /workdir/poky/meta-openembedded/meta-oe \
    /workdir/poky/meta-openembedded/meta-multimedia \
    /workdir/poky/meta-openembedded/meta-networking \
    /workdir/poky/meta-openembedded/meta-python \  
    /workdir/poky/meta-raspberrypi \
    "


Build the image  minimal $ bitbake -k core-image-minimal.

Other available images are listed here.


Transfer the image to the sd card

Check what is your sd card device. Example uses dummy device /dev/XYZ. Be carefull this operation is not reversible.
To check what is your sd card device use $ sudo lsblk -io KNAME,TYPE,SIZE,MODEL --nodep 
Copy the image out of the Docker container


In Finder, Connect to Server (Cmd-K)
Connect to 127.0.0.2
Log in as Guest
Navigate to desired content


## Create `.img` file

cd ~/Development/3rd_party/qemu/0xmirasio/qemu-patch-raspberry4/build

./qemu-img convert -f raw -O qcow2 core-image-minimal-raspberrypi4-64.ext3 core-image-minimal-raspberrypi4-64.img
./qemu-img resize ~/Development/core-image-minimal-raspberrypi4-64.img 256M # or some other power-of-two
$ sudo dd if=build/tmp/deploy/images/raspberrypi/core-image-minimal-raspberrypi-20180810110222.rootfs.rpi-sdimg of=/dev/XYZ status=progress

Boot the image

Insert the sd card into your Raspberry Pi.

If everything went smoothly you should be able to see a login prompt. Just use root without any password.
Boot the image (qemu)

Try:
# cd ~/Development/3rd_party/qemu/0xmirasio/qemu-patch-raspberry4/build`
./qemu-system-aarch64 -M raspi4b2g -dtb bcm2711-rpi-4-b.dtb -sd core-image-full-cmdline-raspberrypi4-64.rpi-sdimg -kernel kernel8.img -nographic -append "rw earlyprintk loglevel=8 console=ttyAMA0,115200 dwc_otg.lpm_enable=0 root=/dev/mmcblk0p2"