bryanyjs/meta-altera-1

Minimal version of the Altera BSP layer for OpenEmbedded/Yocto Project - with step by step guide

This is a forked Version of kraj/meta-altera, the official OpenEmbedded/Yocto BSP layer for Altera SoCFPGA platforms.

With this layer the board support package (BSP) for ARM based Intel (ALTERA) SoC-FPGAs is added to the Yocto Project.

Usually the Yocto project can generate all required components (rootfs, device tree, bootloaders,...) to boot up a final embedded Linux. But this is not compatible with Intel's Boot flow. This Boot flow uses the Intel Embedded Design Suite (EDS) to build the device tree and all necessary bootloaders.

For that reason, I forked this BSP-layer and I removed all nonrequired parts. This includes the board specific u-boot- and device tree-generation and the support for only the .tar.gz-file type for the rootFs.

I used this layer to build rsYocto, an open source embedded Linux System for Intel SoC-FPGAs, by me own.

Supported Device families

Device Family	Architecture	Machine Name
Intel (ALTERA) Cylone V	ARMv7A	MACHINE ="cyclone5"
Intel (ALTERA) Arria V	ARMv7A	MACHINE ="arria5"
Intel (ALTERA) Arria 10	ARMv7A	MACHINE ="arria10"
Intel (ALTERA) Stratix 10	ARMv8A	MACHINE ="stratix10"
Intel (ALTERA) Agilex	ARMv8A	MACHINE ="agilex"

Linux Kernel Types

Linux Version Name	Version Type	Supported Linux Kernel Versions
"linux-altera"	Regular Linux Version	5.0, 5.1, 5.2, 5.3, 5.4
"linux-altera-ltsi"	Long term stable Linux Version (LTSI)	4.14.130
"linux-altera-ltsi-rt"	Long term stable Linux Version (LTSI) with real time support	4.14.126

The Linux Kernel source code is available on this official Intel (ALTERA) repository.

Getting started with the Yocto Project and usage of this BSP-layer

The following step by step guide shows how to use this layer to build a Yocto-based Linux System for an Intel SoC-FPGAs:

1. Step: Install the latest Version of the Yocto project

   • As a Building machine I prefer regular Ubuntu-Linux running as a VmWare ESXi VM
   • Required components for the Yocto Project with Ubuntu Linux:

      sudo apt-get install gawk wget git diffstat unzip texinfo gcc-multilib build-essential chrpath socat xterm libsdl2-image-2.0-0 u-boot-tools python-minimal python3 python3-pip python3-pexpect python3-git python3-jinja2 libncurses-dev

   • Install the Yocto Project it self with:

      git clone git://git.yoctoproject.org/poky

2. Step: Download this BSP-layer

   cd poky/
   git clone https://github.com/robseb/meta-altera.git

3. Step: Run the bitbake initialization script

   source oe-init-build-env

   • Do not run this command or any other Yocto commands as root!
   • Do not use the command: “sudo ./ oe-init-build-env”. With this line Bitbake crashes later during the build process without any traceable error message
   • The repeatment of this bitbkake command do not interact the choosen configuration
   • The script should create the folder: "/build"

4. Step: Add this BSP-layer to your Yocto project solution

   • Open the "bblayers.conf"-file (poky/build/conf) with a text editor, for example with MS Visual Studio Code:

      code conf/bblayers.conf

   • At following line to this file to include the BSP-layer:

      /home/vm/poky/meta-altera \

     • Note: Replace the user name "vm" with your user name
   • Now should the "bblayers.conf"-file look like this:

      # POKY_BBLAYERS_CONF_VERSION is increased each time build/conf/bblayers.conf
      # changes incompatibly
      POKY_BBLAYERS_CONF_VERSION = "2"
     
      BBPATH = "${TOPDIR}"
      BBFILES ?= ""
      BBLAYERS ?= " \
        /home/vm/poky/meta \
        /home/vm/poky/meta-poky \
        /home/vm/poky/meta-yocto-bsp\
        /home/vm/poky/meta-altera \
      "

5. Step: Configure the machine type and Linux Version

   • Open the "local.conf"-file (poky/build/conf) with a text editor, for example with MS Visual Studio Code:

      code conf/local.conf

   • Select your Intel SoC-FPGA family by adding the value "MACHINE this configuration file
     • For the different devices use string of the table above
     • For example, for an Intel Cyclone V SoC-FPGA add following to this file:

        MACHINE ="cyclone5"

     • Be sure that default "qwmux86" is removed

        # MACHINE ??= "qemux86"

   • Select the Linux Kernel type
     • If you want to use the regular ALTERA socfpga-Linux Kernel add the line above to the "local.conf"-file:

        PREFERRED_PROVIDER_virtual/kernel = "linux-altera"

     • If you want the long term stable (LTSI) ALTERA socfpga-Linux Kernel use this line:

        PREFERRED_PROVIDER_virtual/kernel = "linux-altera-ltsi"

   • Select the Linux Kernel Version
     • With following code line,it is possible to select the prefered Linux Kernel Version (here with Version 5.3)

        PREFERRED_VERSION_linux-altera = "5.3%"
       

     • All supported Linux Kernel versions are listed above
   • Choosing Toolchain Versions
     • The following lines select the GCC and SDK Version:

        GCCVERSION = "linaro-5.2"
        SDKGCCVERSION = "linaro-5.2"
       

     *Add this two lines to the "local.conf"-file independent of your machine choose
   • Select the used CPU Version
     • For an Dual Core Intel (ALTERA) Cyclone V, Arria 5 or Arria 10 add the following line to the "local.conf"-file:

      DEFAULTTUNE = "cortexa9hf-neon"
     

     • This selects the ARMv7 Cortex-A9 dual core CPU with the NEON-Engine and a vector floating-point unit
   • Save and close this file

6. Step: Check if your settings are vailed and executable

   • The following shell-command lists all for this build used layers (executed inside poky/build/):

      bitbake-layers show-layers
     

     • If an error occured certainly something with the "local.conf- or "bblayers.conf"-file went wrong
   • This command gives the used Linux Kernel Version

      bitbake --show-versions | grep linux  
     

7. Step: Optimal: Change the Linux Kernel configuration

   • To configure the Linux property for a specific device family it is necessary to change the Linux Kernel configuration
   • But for a first Yocto project build is the Linux Kernel configured well enough
   • Read and change the BSP-layer with "defcongig"
     • One part is configured by a "defconfig-file"
     • With that it is possible to enable or disabled every component, like for example ETHERNET, CAN, EXT2, HPS-Bridges and PCI
     • The following bitbake shell-command stores the "defconfig-file locally (executed inside poky/build/)

      bitbake -c savedefconfig virtual/kernel 

     • This command prints the directory of the saved file at the end
   • Read and change the Linux Kernel with menueconfig
     • Use this command to start the "menueconfiguration"-tool:

      bitbake -c menuconfig -f virtual/kernel

     • A window like this should appear:

     • Here it is possible to change any kernel settings, ARM-Platform specific settings or enable or disable some peripheral components

   • To execute any BSP-layer change use following command:

      bitbake -f -c compile virtual/kernel && bitbake -f -c deploy virtual/kernel

8. Step: Build the complete Yocto-project

   • With this command the full yocto project build process starts (executed inside poky/build/):

   bitbake core-image-minimal

   • This process can taken some time
   • For an Intel Arria 10 SoC-FPGA following start print should appear:
   • This signaled that bitbake was able to decode the previously shown configuration

9. Step: Locate the final Kernel- and rootFs-File

   • After a successful build the final compressed Linux Kernel file and the rootfs tar.gz- archive is stored here:
     • for an Intel Cyclone V:

      poky/build/tmp/delopy/images/cyclone5/

     • for an Intel Arria 10:

      poky/build/tmp/delopy/images/arria10/

   • The rootFs-file is called: core-image-minimal-cyclone5-<Date Code>.rootfs.tar.gz
   • The Linux Kernel file is called: zImage-<*...+>.bin
   • Be sure that the files are not a Shortcut!
   • In the case of an Intel Cyclone V, these two files are located here:

At this point a Linux for an Intel SoC-FPGA is generated. Unfortunately to boot this up also an device tree, a primary- and secondary bootloader and for Intel Arria and Stratix two FPGA configuration files must be required.

Continuation

How to desgin the requiered bootloaders and the DeviceTree with Intel EDS ?

Inside my "Mapping HPS Peripherals, like I²C or CAN, over the FPGA fabric to FPGA I/O and using embedded Linux to control them"-guide I show that in details (see here).

For accessing the FPGA-Manager or to execute shell scripts at boot up you can use my meta-rstools-layer. I also wrote a python script to pre-install Python pip (PyPI)- Packages within a final Yocto Project Linux Image automatically (see here).

Credits & Contribution

Big thanks to Khem Raj for his maintaince work!

Author

• Robin Sebastian

This guide is my own non official solution, as a part of this academic project: rsYocto Today I'm a Master Student of electronic engineering with the major embedded systems. I ‘m looking for an interesting job offer to share and deepen my shown skills starting summer 2020.