Home page
http://www.lctech-inc.com/cpzx/LCPIxl/2021/1009/532.html

Cherry Pi V3s Version

Assumed that Linux Ubuntu is installed

Example application for GPIO handling

Lcd
Touchscreen

TBD

1. First make sure to following packages are installed in system

   sudo apt-get install gawk wget diffstat unzip texinfo gcc-multilib build-essential chrpath socat libsdl1.2-dev xterm emscripten libmpc-dev libgmp3-dev

   Note: More informations can be found on Yocto reference manual.

2. Download necessary Yocto packaged listed below. Be sure to be in root of home folder.

   mkdir yocto
   cd yocto
   mkdir build
   git clone git://git.yoctoproject.org/poky --depth 1 -b kirkstone
   cd poky
   git clone git://git.openembedded.org/meta-openembedded --depth 1 -b kirkstone
   git clone https://github.com/meta-qt5/meta-qt5.git --depth 1 -b kirkstone
   git clone https://github.com/voloviq/meta-cherrypi-v3s --depth 1 -b kirkstone
   

3. Select directory to build Linux

   Nano version
   source oe-init-build-env ~/yocto/build/cherrypi-v3s
   

4. Modify bblayers.conf(located in ~/yocto/build/cherrypi-v3s/conf)

   BBLAYERS ?= " \
   ${HOME}/yocto/poky/meta \
   ${HOME}/yocto/poky/meta-poky \
   ${HOME}/yocto/poky/meta-openembedded/meta-oe \
   ${HOME}/yocto/poky/meta-openembedded/meta-networking \
   ${HOME}/yocto/poky/meta-openembedded/meta-python \
   ${HOME}/yocto/poky/meta-openembedded/meta-multimedia \
   ${HOME}/yocto/poky/meta-qt5 \
   ${HOME}/yocto/poky/meta-cherrypi-v3s \
   "
   

   Note: Please adapt PATH of conf/bblayers.conf if necessary.
   

5. Modify local.conf(located in ~/yocto/build/cherrypi-v3s/conf) file

   • modify line with "MACHINE ??" to add "cherrypi-v3s-sdcard" or for SPI NOR Flash "cherrypi-v3s-spinor"

   • align DL_DIR = "${HOME}/yocto/downloads"
     

   • align SSTATE_DIR = "${HOME}/yocto/sstate-cache"
     

   • align TMPDIR = "${HOME}/yocto/tmp"
     

   • add at the end following records
     
     RM_OLD_IMAGE = "1"
     INHERIT += "rm_work"
     MACHINEOVERRIDES .= ":use-mailine-graphics"
     LICENSE_FLAGS_ACCEPTED = "commercial"
     

   • for spi flash change DISTRO ?= "poky" to DISTRO ?= "cherrypi-v3s-tiny"
     

   Note: Please adapt rest of conf/local.conf parameters if necessary.
   

6. Build objects

   • When using SPI NOR Flash use following image

   • core image minimal
     bitbake core-image-minimal
     

   • console image
     bitbake console-image
     

   • qt5 image
     bitbake qt5-image
     

   • qt5 toolchain sdk
     bitbake meta-toolchain-qt5
     

7. After compilation images appears in

   Nano version
   ~/yocto/tmp/deploy/images/cherrypi-v3s
   

8. Insert SD CARD into dedicated CARD slot and issue following command to write an image

   Note:
   Be 100% sure to provide a valid device name (of=/dev/sde/mmcblk0). Wrong name "/dev/sde/mmcblk0" dameage Your system file !
   
   Nano version
   sudo dd if=~/yocto/tmp/deploy/images/cherrypi-v3s-sdcard/core-image-minimal-cherrypi-v3s-sdcard.sunxi-sdimg of=/dev/mmcblk0 bs=1024
   

9. SPI NOR Flash update tool compilation(if valid sunxi-tools installed go to point 10)
   git clone https://github.com/Icenowy/sunxi-tools.git -b v3s-spi
   sudo apt-get install libz libusb-1.0-0-dev
   make
   sudo make install
   

10. Flash SPI NOR flash
    To enter into bootlader mode it is necessary to erase u-boot section from spi nor flash.
    To do this it is necessary to stop booting U-Boot and enter following commands.
    sf probe 0
    sf erase 0 70000
    sunxi-fel -p spiflash-write 0 ~/yocto/tmp/deploy/images/cherrypi-v3s-spinor/core-image-minimal-cherrypi-v3s-spinor.sunxi-spinor
    To write only u-boot...spl just type
    sudo sunxi-fel -v uboot u-boot-sunxi-with-spl.bin
    

11. How to handle GPIO from userfs - example (used PE3 as GPIO)
    

    1. Take a GPIO for instance PE3
       echo 131 > /sys/class/gpio/export
       
    2. Set as out or in
       echo "out" > /sys/class/gpio/gpio131/direction
       
    3. Set GPIO state if configured as ouput
       echo 1 > /sys/class/gpio/gpio131/value
       echo 0 > /sys/class/gpio/gpio131/value