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Yocto Flash From Net

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VAR-SOM-MX6 - Flash Yocto images from network


1 Flashing a complete Yocto system from Network using TFTP & NFS

NOTES:
  1. Please make sure your host system is ready to use TFTP/NFS. Use our Wiki if required: Yocto Setup TFTP/NFS
  2. This is a concept Wiki. Please adopt it to your system and your requirements.
  3. Android can be flashed in the same way.

1.1 Build minimal file system

$ gedit ../sources/poky/meta/recipes-core/images/core-image-minimal-mtdutils.bb

Set the image to include: IMAGE_INSTALL += "mtd-utils imx-kobs mtd-utils-ubifs"
Build the system:

$ bitbake core-image-minimal-mtdutils

Create a root file system and copy files

$ mkdir ~/flash_rootfs
$ sudo tar xvf tmp/deploy/images/var-som-mx6/core-image-minimal-mtdutils-var-som-mx6.tar.bz2 -C ~/flash_rootfs
$ sudo cp tmp/deploy/images/var-som-mx6/uImage /tftpboot
$ sudo cp tmp/deploy/images/var-som-mx6/uImage-imx*.dtb /tftpboot/
$ sudo rename 's/uImage-imx/imx/' /tftpboot/uImage-*.dtb

Insert the recovery SD card into your host PC and copy the following files from it (assuming it is mounted at /media):

$ sudo cp -a /media/rootfs/opt/images ~/flash_rootfs/opt/
$ sudo cp /media/rootfs/usr/bin/*.sh ~/flash_rootfs/usr/bin

Boot the board, stop the autoboot to get to the U-Boot command line, and set the following environment variables:

=> setenv serverip <your host ip address>
=> setenv nfsroot /home/<your username>/flash_rootfs

If you want to set the fdt file yourself, instead of using the default auto detection:
=> setenv fdt_file <relevant device tree>
=> setenv bootcmd 'run netboot'
=> saveenv
=> boot

On the target flash your system:

$ install_yocto.sh

A complete system is flashed into the SOMs internal storage (NAND flash/eMMC). Once the file system is built you can use it again and again to flash your VAR-SOM-MX6. You can update the images to use your images or custom install_yocto.sh to your requirements.