OpenEmbedded/Yocto BSP layer for Altera DE1-SoC

• BSP layer based on:
  • meta-altera
  • meta-intelfpga

Environment proposal

• Creating directory tree

  mkdir -p ~/Projects/Yocto/shared/downloads
  mkdir -p ~/Projects/Yocto/shared/sstate-cache
  mkdir -p ~/Projects/Yocto/Builds/DE1SoC
  
  cd ~/Projects/Yocto/Builds/DE1SoC && \
      git clone --branch kirkstone git://git.yoctoproject.org/poky.git
  
  cd ~/Projects/Yocto/Builds/DE1SoC/poky && \
      git clone https://github.com/anderson-pereira/meta-de1-soc.git

• Directories Overview

  tree ~/Projects/Yocto/
  ├── shared
  │   ├── downloads
  │   └── sstate-cache
  └── Builds
  └── DE1SoC
      ├── build
      └── poky
          ├── meta-de1-soc
          ├── meta-poky
          └── ...

Configurations and first build

• Starting build environment

  docker run -it --rm \
      --volume ~/Projects/Yocto/shared/downloads:/yocto/downloads \
      --volume ~/Projects/Yocto/shared/sstate-cache:/yocto/sstate-cache \
      --volume ~/Projects/Yocto/Builds/DE1SoC:/yocto/DE1SoC \
      --name=yocto-build-container \
      --workdir=/yocto/DE1SoC \
      --user=$UID \
      andersonazevedo/yocto-build-env \
      bash

• Inside docker container, start with Yocto build environment:

   cd /yocto/DE1SoC
   source poky/oe-init-build-env build

  After that, ~/Projects/Yocto/Builds/DE1SoC/build directory will be created in your host containing all configuration and temporary files for this build (config/local.conf, config/bblayers.conf):

• Add some base configurations in config/local.conf:

   MACHINE = "de1-soc"
   IMAGE_INSTALL:append = " readbridgesfpga writebridgefpga writeconfigfpga "
   DL_DIR = "/yocto/downloads"
   SSTATE_DIR = "/yocto/sstate-cache"

• Add meta-de1-soc layer in config/bblayers.conf:

   BBLAYERS ?= " \
   /yocto/DE1SoC/poky/meta \
   /yocto/DE1SoC/poky/meta-poky \
   /yocto/DE1SoC/poky/meta-yocto-bsp \
   /yocto/DE1SoC/poky/meta-de1-soc \
   "

• Run the first build (and go grab a coffee):

   bitbake core-image-full-cmdline

  The generated SDCard image can be found in Projects/Yocto/Builds/DE1SoC/build/tmp/deploy/images/de1-soc/core-image-full-cmdline-de1-soc.wic.

Development skills

TFTP Boot

TFTP Boot is most used in cases of kernel and device-tree development, preventing to repetitives copies of files to SDCards.

Host configuration

• Install TFTP requirements in host

   sudo apt-get update && sudo apt-get install xinetd tftpd tftp
   sudo mkdir /tftpboot/
   sudo chmod -R 777 /tftpboot/
   sudo chown -R nobody /tftpboot/

• Edit /etc/xinetd.d/tftp file:

   service tftp
   {
   	protocol = udp
   	port = 69
   	socket_type = dgram
   	wait = yes
   	user = nobody
   	server = /usr/sbin/in.tftpd
   	server_args = /tftpboot
   	disable = no
   }

• Restarting the service

   sudo service xinetd restart

  Now, you can copy zImage and socfpga_cyclone5_socdk.dtb files from build/tmp/deploy/images/de1-soc/ directory to /tftpboot and use its with U-Boot. In your case, socfpga_cyclone5_socdk.dtb needs to be renamed to socfpga.dtb in /tftpboot directory.

U-Boot side

• Let's first define some environment variables:

   setenv ipaddr <DE1SoC IP Addr to beused>
   setenv ethaddr 62:c9:03:2d:e8:aa #DE1-SoC MAC
   setenv gatewayip <your gateway IP>
   setenv serverip <your host IP>
   setenv tftpload 'tftp ${loadaddr} ${bootimage};tftp ${fdtaddr} ${fdtimage}'
   saveenv

• To load zImage and socfpga_cyclone5_socdk.dtb files stored in /tftpboot directory on host, run:

   run tftpload
   run mmcboot

  Now, the kernel and device-tree will be loaded and started. The rootfs used will be as defined in mmcroot environment variable, default value is /dev/mmcblk0p3.

Network File System (NFS)

Host configuration

• Install NFS requirements in host

   sudo apt-get install nfs-kernel-server rpcbind
   sudo mkdir /nfs

• Edit /etc/exports file:

   /nfs *(rw,nohide,insecure,no_subtree_check,async,no_root_squash)

• Edit /etc/default/nfs-kernel-server file:

   #RPCNFSDCOUNT=8
   RPCNFSDCOUNT="--no-nfs-version 4"

• Restarting the service

   sudo service nfs-kernel-server restart
   sudo exportfs -a

  Now, you can mount rootfs images on /nfs directory, like core-image-full-cmdline-de1-soc.ext3 generated by Yocto build in build/tmp/deploy/images/de1-soc/ directory.

   sudo mount core-image-full-cmdline-de1-soc.ext3 /nfs

U-Boot side

• Let's first define some environment variables:

   setenv tftpboot 'setenv bootargs console=ttyS0,115200 root=/dev/nfs ip=dhcp nfsroot=${serverip}:/nfs/,v3,tcp; run tftpload; bootz ${loadaddr} - ${fdtaddr}'
   saveenv

• With this environment variable above, tftpload will be used to load zImage and socfpga.dtb files from TFTP. ǸFS will be used by kernel when boots up. To start, just run:

   run tftpboot

  Now, you can interact with rootfs running on DE1-SoC by editing /nfs directory in your host. All the system is running via network at this point, only U-Boot is used from SDCard.