![IP Address: 192.168.1.1
Netmask: 255.255.255.0
Gateway: 192.168.1.1
BOARD SETUP
1. Insertthe newly written Micro SD into the SD slotof the Raspberry Pi 3;
2. (Optional) connect the Micro HDMI cableto the Raspberry Pi 3 connector;
3. Connect a Micro USB cableto the PC and to the Micro USB connector of the Raspberry Pi 3;
4. Also connect the board with your hostdevice via an ethernet cable.
Once the Micro USB cableis connected, the board is powered up. In caseyou connected the Micro HDMI cable,you
will seea splash screen on the monitor, and a progression bar indicatingthe bootstrap is running.
Once the bootstrap is completed, a new device will beconnected to the PC: /dev/ttyUSB0. The deviceis the virtual
serial portthrough which you can access the Raspberry Pi 3, by issuingthefollowingcommand:
sudo minicom
In caseall previous steps have been completed successfully,you will see the followingmessages appearing on the
terminal:
Welcome to minicom2.7
OPTIONS: I18n
Compiled on Jan 1 2014, 17:13:19.
Port /dev/ttyUSB0, 10:22:24
Press CTRL-A Z for help on special keys
[ 0.000000] Booting Linux on physical CPU0x0
[ 0.000000] Initializingcgroup subsyscpuset
[ 0.000000] Initializingcgroup subsyscpu
[ 0.000000] Initializingcgroup subsyscpuacct
......
Poky (Yocto ProjectReference Distro) 2.1.2 raspberrypi3 ttyS0
raspberrypi3 login:
You can now login as “root” (no password required).
Note:
To open the Minicommenu, press simultaneously ctrl +A and then Z (either l owercaseor uppercase).
Optional: Raspberry Pi 3 Ethernet interface is configured to acquirethe IP address via DHCP. In case you intend to
connect the board with your PC directly, you need to configure the Ethernet connection properly. It is advisableto
create a new Ethernet connection on the Raspberry Pi 3 by editing the file /etc/network/interfaces and to
modify the configuration of the network device eth0 as follows:
# Wired or wireless interfaces
auto eth0](https://image.slidesharecdn.com/labmanual-211111035307/85/Lab-manual-6-320.jpg)
Lab manual
- 1. INTRODUCTION TO THE BOARD AND WORKSPACE SETUP GOAL The goal of this Lab is to introduceyou to the Raspberry Pi 3 board and to provideinstructions abouthowto set up the workspaceused for the followinglabs. PRE-REQUISITES To followthis Lab,you will need: 1. Raspberry Pi 3 board full; 2. Micro USB cable; 3. 8 GB Micro SD card; 4. USB-to-Serial debug module for Raspberry Pi 3 or USB to TTL adapter; 5. Ethernet cable; 6. A PC with Ubuntu Desktop 14.04 LTS, or a virtual machinehostingUbuntu Desktop 14.04 LTS with at least 100 GB of free space; 7. A Micro SD card reader attached to the PC/virtual machine; 8. (Optional) Micro HDMI cable. THE RASPBERRY PI 3 The Raspberry Pi 3 is the successor to the Raspberry Pi 2. It builds upon the Pi 2 by upgrading the Arm cores to Cortex-A53 and addingan onboard single-band 2.4GHz-only wireless chipset. The Raspberry Pi 3 measures the same 85.60mm x 53.98mm x 17mm, with a little overlap for the SD card and connectors that project over the edges. The SoC is a Broadcom BCM2837. This contains a quad-core Cortex-A53 runningat 1.2GHz and a Videocore 4 GPU. Front View WORKPLACE SETUP The setup is divided in two parts:PC setup and board setup.
- 2. PC SETUP The following operations mustbe done once, to set up the Linux distribution you areusingto be ready for building embedded Linux on the Raspberry Pi 3. Install thefollowingpackages: sudo apt-get install gawk wget git diffstat unzip texinfo gcc-multilib build-essential sudo apt-get install chrpath socat libsdl1.2-dev xterm ncurses-dev lzop sudo apt-get install minicom u-boot-tools curl You will need to install the latestversion of python. Type python -–version to check, or usethe following command to download it. sudo apt-get install python Install therepo utility: mkdir ~/bin curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > ~/bin/repo chmod a+x ~/bin/repo export PATH=$PATH:~/bin If you areusingGit for the firsttime in your system, you have to set your username and email address as follows: git config --global user.name "username" git config --global user.email “email@example.com” Download the source code of embedded Linux for Raspberry Pi 3: mkdir -p ~/raspberryPi3/sources cd ~/raspberryPi3/sources git clone -b krogoth git://git.yoctoproject.org/poky git clone -b krogoth git://git.openembedded.org/meta-openembedded git clone -b krogoth git://git.yoctoproject.org/meta-raspberrypi NOTE: Be patient, this operation may take several minutes as several megabytes of sourcecode have to be downloaded. It is now time to define a specific network configuration for our lab experiments. For this purpose, let us create the followingdirectory: mkdir ~/raspberryPi3/sources/poky/meta/recipes-core/init-ifupdown/init-ifupdown- 1.0/raspberrypi3
- 3. In this directory, placea filenamed “interfaces” with the followingcontent: # /etc/network/interfaces -- configuration file for ifup(8), ifdown(8) # The loopback interface auto lo iface lo inet loopback # Wireless interfaces iface wlan0 inet dhcp wireless_mode managed wireless_essid any wpa-driver wext wpa-conf /etc/wpa_supplicant.conf iface atml0 inet dhcp # Wired or wireless interfaces auto eth0 iface eth0 inet static address 192.168.1.2 netmask 255.255.255.0 gateway 192.168.1.1 network 192.168.1.0 # Ethernet/RNDIS gadget (g_ether) # ... or on host side, usbnet and random hwaddr iface usb0 inet static address 192.168.7.2 netmask 255.255.255.0 network 192.168.7.0 gateway 192.168.7.1 # Bluetooth networking iface bnep0 inet dhcp Among the other activities,with this file,we set the IP address for the Ethernet device to 192.168.1.2. Configure the environment to build the sourcejustdownloaded for the Raspberry Pi 3 and accept the license agreement: cd ~/raspberryPi3/ source sources/poky/oe-init-build-env rpi-build Using your preferred editor program, edit the file“rpi-build/conf/local.conf”, remove the existing content, and type/paste in the followingcontent, to includethe needed information to build embedded Linux for the Raspberry Pi 3: MACHINE ?= "raspberrypi3" PREFERRED_VERSION_linux-raspberrypi = "4.%" DISTRO_FEATURES_remove = "x11 wayland" DISTRO_FEATURES_append = " systemd" VIRTUAL-RUNTIME_init_manager = "systemd" ENABLE_UART = "1"
- 4. Usingyour favoriteeditor program, edit the file “rpi-build/conf/bblayers.conf”, remove the existing content, and type/paste in the followingcontent, to includethe needed information to build embedded Linux for the Raspberry Pi 3 (ensure it is formatted exactly as shown, spaces and missingindents can causeparseerrors): LCONF_VERSION = "6" BBPATH = "${TOPDIR}" BSPDIR := "${@os.path.abspath(os.path.dirname(d.getVar('FILE', True)) + '/../..')}" BBFILES ?= "" BBLAYERS ?= " ${BSPDIR}/sources/poky/meta ${BSPDIR}/sources/poky/meta-yocto ${BSPDIR}/sources/poky/meta-yocto-bsp ${BSPDIR}/sources/meta-openembedded/meta-oe ${BSPDIR}/sources/meta-openembedded/meta-multimedia ${BSPDIR}/sources/meta-raspberrypi " Once this operation is completed, the environment is ready for buildingembedded Linux for the Raspberry Pi 3. Ensure you are still in thebuild environment “rpi-build”.The Linux for the Raspberry Pi 3 can now be builtby issuingthefollowingcommand: bitbake rpi-basic-image NOTE: Be patient, this operation may take up to two hours,depending on the PC you areusing,as several megabytes of sourcecodehave to be compiled.If you are compilingtheimageon a virtual machine,this may takeseveral hours. Once the build is completed, an SD card image for booting up the Raspberry Pi 3 can be found in the following path: raspberryPi3/rpi-build/tmp-glibc/deploy/images/raspberrypi3/rpi-basic-image- raspberrypi3.rpi-sdimg The image can be copied to a Micro SD usingsome Linux functionality (assumingtheMicro SD is availableto the PC as /dev/sdN). Alternatively,and more easily,a flash programcould beused. First,run the sudo fdisk -l command to determine which device to flash to (plugin and unplugthe SD card to determine which device itis). For this example, the SD card is under the name “sdc” (this may be different in your environment). Next, ensure that the device is unmounted. This can be done usingthe command: sudo umount /dev/sdc* Once this is done, the followingcommand can be used to copy the image across to the SD card (substituteany folder names and device names to ensure they arerelevant to your specific environment). sudo dd bs=1M if=/home/user/raspberryPi3/rpi-build/tmp- glibc/deploy/images/raspberrypi3/rpi-basic-image-raspberrypi3.rpi-sdimg of=/dev/sdc
- 5. Note that if not done properly, the image being flashed across to the SD card may causeproblems when attempting to turn on the board. If this is the case, itmay be worth retrying the process again and ensuringthatit is done properly,or use a flash programto automate the process. Whilethe SD card is still connected to the development host, use the followinglines to navigateto the etc folder on the SD card (assumingthedevice has now been mounted). cd /media/user/SD_name/etc – Use the ls command to find the name of the SD card in the user folder. Then, use a terminal text editor to open the shadow file. sudo vi shadow Or sudo gedit shadow Check that there are no characters between the firsttwo colons in the firstline.If there is,remove it so that the firstlinelooks likethis: Root::17728:0:99999:7::: Exit the text editor by entering :x or simply closingthe application! MINICOM SETUP Connect the USB-to-Serial debug module for Raspberry Pi 3 or USB to TTL adapter to J8 on the Raspberry Pi 3 board (pins 8 and 10 are UART0_TX and UART0_RX, which are the lines where the serial consoleof BCM2837 is routed). And configurethe communication parameter to 1152008N1 in your preferred serial terminal emulation program (under Linux uses the device /dev/ttyUSB0 or /dev/ttyUSB1). Once the programming of the Micro SD is completed, we are ready to configure the communication program that we will useto connect to the board: minicom. Issuethe followingcommand to start minicom in setup mode: sudo minicom -s Then, perform the followingsteps: 1. Select “Serial port setup” in the configuration menu; 2. Press A to modify the Serial Device and to set it to “/dev/ttyUSB0”; 3. Press F to set Hardware Flow Control to “No”; 4. Press enter to return to the previous menu; 5. Select “Save setup as dfl”, to savethe setup as default configuration; 6. Select “Exit” from Minicom. Optional: Raspberry Pi 3 Ethernet interfaceis configured to acquirethe IP address via DHCP.In caseyou intend to connect the board with your PC directly, you need to configure the Ethernet connection properly. It is advisable to create a new Ethernet connection on your PC using the following statically assigned IPv4 configuration:
- 6. IP Address: 192.168.1.1 Netmask: 255.255.255.0 Gateway: 192.168.1.1 BOARD SETUP 1. Insertthe newly written Micro SD into the SD slotof the Raspberry Pi 3; 2. (Optional) connect the Micro HDMI cableto the Raspberry Pi 3 connector; 3. Connect a Micro USB cableto the PC and to the Micro USB connector of the Raspberry Pi 3; 4. Also connect the board with your hostdevice via an ethernet cable. Once the Micro USB cableis connected, the board is powered up. In caseyou connected the Micro HDMI cable,you will seea splash screen on the monitor, and a progression bar indicatingthe bootstrap is running. Once the bootstrap is completed, a new device will beconnected to the PC: /dev/ttyUSB0. The deviceis the virtual serial portthrough which you can access the Raspberry Pi 3, by issuingthefollowingcommand: sudo minicom In caseall previous steps have been completed successfully,you will see the followingmessages appearing on the terminal: Welcome to minicom2.7 OPTIONS: I18n Compiled on Jan 1 2014, 17:13:19. Port /dev/ttyUSB0, 10:22:24 Press CTRL-A Z for help on special keys [ 0.000000] Booting Linux on physical CPU0x0 [ 0.000000] Initializingcgroup subsyscpuset [ 0.000000] Initializingcgroup subsyscpu [ 0.000000] Initializingcgroup subsyscpuacct ...... Poky (Yocto ProjectReference Distro) 2.1.2 raspberrypi3 ttyS0 raspberrypi3 login: You can now login as “root” (no password required). Note: To open the Minicommenu, press simultaneously ctrl +A and then Z (either l owercaseor uppercase). Optional: Raspberry Pi 3 Ethernet interface is configured to acquirethe IP address via DHCP. In case you intend to connect the board with your PC directly, you need to configure the Ethernet connection properly. It is advisableto create a new Ethernet connection on the Raspberry Pi 3 by editing the file /etc/network/interfaces and to modify the configuration of the network device eth0 as follows: # Wired or wireless interfaces auto eth0
- 7. iface eth0 inet static address 192.168.1.2 netmask 255.255.255.0 gateway 192.168.1.255 Test to see if the network is configured properly using: ifconfig You should seean address of 19.168.1.2; however, if this is not the case,you can run the commands: ifdown eth0 ifup eth0 After runningthese two commands, itshould be configured properly. If you are usinga Linux virtual machine as the host, for the sole-purpose of communicating between the board and the host,you may need to switch the “Network” settings to a “Bridged Adapter” and selectthe ethernet devicebeing used. Once the PC and the Raspberry Pi 3 are configured, you can test the connection with the followingcommand: ping 192.168.1.1 If the configuration is correct,you will seea message appearingon the terminal similarto the following: root@raspberrypi3:~# ping 192.168.1.1 PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data. 64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=1.54 ms 64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=1.61 ms 64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=1.98 ms 64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=1.73 ms POST-LAB PRACTICE In this session,we have builtan initial version of Linux image with Yocto Project. One of the main benefits of using Yocto Projectis that the Linux image can be flexibly customized to accommodate specific usage;the key to manipulateitis by including differentlayers and recipes. There are two files that determine the above feature, conf/local.conf and conf/bblayers.conf;to have a better understandingof these two files and the customization feature of Yocto Project,we shall carry outadditional practice.