Raspberry Pi Investigation Flash Instructions - magic-lantern-studio/mle-documentation GitHub Wiki

This page provides information on how to flash the Raspberry Pi images built using the instructions found on the Raspberry Pi Investigation Build Instructions wiki page. These instructions assume you are updating the SD card from the Ubuntu 20.04 LTS 64-bit Host Development Platform.

Copying the binaries to an SD card (or eMMC)

Copying the binaries to an SD card (or eMMC)

After the build completes, the bootloader, kernel and rootfs image files can be found in /deploy/images/$MACHINE with MACHINE is coming from your local.conf.

The meta-rpi/scripts directory has some helper scripts to format and copy the files to a microSD card.

See this post for an additional first step required for the RPi Compute eMMC.

mk2parts.sh Script

This script will partition an SD card with the minimal 2 partitions required for the RPI.

Insert the microSD into your workstation and note where it shows up.

lsblk is convenient for finding the microSD card.

For example

$ lsblk
NAME    MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda       8:0    0 931.5G  0 disk
|-sda1    8:1    0  93.1G  0 part /
|-sda2    8:2    0  93.1G  0 part /home
|-sda3    8:3    0  29.8G  0 part [SWAP]
|-sda4    8:4    0     1K  0 part
|-sda5    8:5    0   100G  0 part /oe5
|-sda6    8:6    0   100G  0 part /oe6
|-sda7    8:7    0   100G  0 part /oe7
|-sda8    8:8    0   100G  0 part /oe8
|-sda9    8:9    0   100G  0 part /oe9
`-sda10   8:10   0 215.5G  0 part /oe10
sdb       8:16   1   7.4G  0 disk
|-sdb1    8:17   1    64M  0 part
`-sdb2    8:18   1   7.3G  0 part

So we will use sdb for the card on this machine.

It doesn’t matter if some partitions from the SD card are mounted. The mk2parts.sh script will unmount them.

WARNING: This script will format any disk on your workstation so make sure you choose the SD card.

cd ~/rpi/meta-rpi/scripts
sudo ./mk2parts.sh sdb

You only have to format the SD card once.

Temporary mount point

You will need to create a mount point on your workstation for the copy scripts to use.

This is the default

sudo mkdir /media/card

You only have to create this directory once.

If you don’t want that location, you will have to edit the following scripts to use the mount point you choose.

copy_boot.sh Script

This script copies the GPU firmware, the Linux kernel, dtbs and overlays, config.txt and cmdline.txt to the boot partition of the SD card.

This copy_boot.sh script needs to know the TMPDIR to find the binaries. It looks for an environment variable called OETMP.

For instance, if I had this in build/conf/local.conf

TMPDIR = "/oe4/rpi/tmp-dunfell"

Then I would export this environment variable before running copy_boot.sh

export OETMP=/oe4/rpi/tmp-dunfell

If you didn’t override the default TMPDIR in local.conf, then set it to the default TMPDIR

export OETMP=~/rpi/build/tmp

The copy_boot.sh script also needs a MACHINE environment variable specifying the type of RPI board.

export MACHINE=raspberrypi3

export MACHINE=raspberrypi0-wifi

Then run the copy_boot.sh script passing the location of SD card

./copy_boot.sh sdb

This script should run very fast.

If you want to customize the config.txt or cmdline.txt files for the system, you can place either of those files in the meta-rpi/scripts directory and the copy_boot.sh script will copy them as well.

Take a look at the script if this is unclear.

copy_rootfs.sh Script

This script copies the root file system to the second partition of the SD card.

The copy_rootfs.sh script needs the same OETMP and MACHINE environment variables.

The script accepts an optional command line argument for the image type, for example console or qt5. The default is console if no argument is provided.

The script also accepts a hostname argument if you want the host name to be something other then the default MACHINE.

Here’s an example of how you would run copy_rootfs.sh

./copy_rootfs.sh sdb console

./copy_rootfs.sh sdb qt5 rpi3

The copy_rootfs.sh script will take longer to run and depends a lot on the quality of your SD card. With a good Class 10 card it should take less then 30 seconds.

The copy scripts will NOT unmount partitions automatically. If an SD card partition is already mounted, the script will complain and abort. This is for safety, mine mostly, since I run these scripts many times a day on different machines and the SD cards show up in different places.

Here’s a realistic example session where I want to copy already built images to a second SD card that I just inserted.

sudo umount /dev/sdb1
sudo umount /dev/sdb2
export OETMP=/oe4/rpi/tmp-dunfell
export MACHINE=raspberrypi2
cd rpi/meta-rpi/scripts
./copy_boot.sh sdb
./copy_rootfs.sh sdb console rpi3

Once past the development stage I usually wrap all of the above in another script for convenience.

Both copy_boot.sh and copy_rootfs.sh are simple scripts, easily customized.