Yocto Setup TFTP/NFS

From Variscite Wiki

1 Running Yocto rootfs on Variscite board using TFTP & NFS

1.1 Host

Make sure you installed NFS server:

$ sudo apt-get install nfs-kernel-server
$ cd ~/var-fsl-yocto
$ sudo mkdir rootfs
$ cd rootfs
$ sudo tar xvf  ../build_xwayland/tmp/deploy/images/imx8qxp-var-som/fsl-image-gui-imx8qxp-var-som.tar.gz
$ sudo gedit /etc/exports

Add the following line (change <uname> to the name of user):

/home/<uname>/var-fsl-yocto/rootfs    *(rw,sync,no_root_squash,no_all_squash,no_subtree_check) 

exit & save

$ sudo /etc/init.d/nfs-kernel-server restart

Make sure you installed TFTP server:

$ sudo apt-get install xinetd tftpd tftp

Verify the following:

$ ls /usr/sbin/in.tftpd
$ sudo gedit /etc/xinetd.d/tftp
service tftp
	protocol = udp
	port = 69
	socket_type = dgram
	wait = yes
	user = nobody
	server = /usr/sbin/in.tftpd
	server_args = /tftpboot
	disable = no

and run:

$ sudo mkdir /tftpboot
$ sudo chmod -R 777 /tftpboot
$ sudo /etc/init.d/xinetd restart
$ cd ~/var-fsl-yocto//

$ sudo cp -a /home/<uname>/var-fsl-yocto/rootfs/boot/*.dtb /tftpboot
$ sudo cp /home/<uname>/var-fsl-yocto/rootfs/boot/Image.gz /tftpboot
Default kernel configuration should be modified to compile Ethernet driver into kernel image instead compiling it as a loadable module.

Follow our kernel compilation guide Build kernel from source code
Run "make menuconfig", go to "Device Drivers → Network device support → Ethernet driver support → Freescale devices → FEC ethernet controller" and press y.

Compile the kernel and copy arch/arm64/boot/Image.gz to /tftpboot

1.2 Target

Make sure you have a serial connection to the target.

Reset and hold the space bar. This will bring you to U-Boot command line.

=> setenv serverip
=> setenv nfsroot /home/<uname>/var-fsl-yocto/rootfs (change <uname> to the name of user)
=> setenv bootcmd run netboot
=> saveenv 

You are all set. Connect Ethernet cable, power cycle the VAR-SOM-MX8X and it should boot over NFS.