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mion Porting Guide

This guide covers required steps for creating a new Yocto Project Board Support package (BSP) for mion; It is possible that further steps may need to be taken to support your board, such as platform specific variables.

NOTE: This process and the files outlined below are subject to change as the format of meta-mion-bsp is codified

Table of Contents

Resources

Environment Variables

Directories and Files

Kernel Configuration

Platform Recipes

Resources

Below are links that you may find helpful. The Yocto Project BSP guide in particular is recommended prerequisite reading, and a helpful reference source. Github repository links for Open Network Linux (ONL) and the Open Network Install Environment (ONIE) may be useful references, especially for platform recipes.

Environment Variables

The platform-specific variables below are required for file names and config settings in the BSP, where the strings are the Original Equipment Manufacturer (OEM) names as defined by ONL*.

* NOTE: Whereas ONL strings have words generally delineated with an underscore("_"), for the BSP layer you write, words are separated using a dash ("-") Examples of this can be seen throughout this guide

  • ONL_VENDOR (ONIE_VENDOR): Vendor name, e.g. accton, stordis.
  • ONL_MACHINE (ONIE_MACHINE): Machine name, e.g. as4610-30, bf2556c-1t.
  • ONL_ARCH (ONIE_ARCH): Machine arch, e.g. x86-64 (x86_64), armel, armhf.

Creating the BSP Package directories and files

First, you should check to see if meta-mion-bsp/meta-mion-<ONL_VENDOR>/ already exists. If it doesn't, then you'll need to create the directory. For example, if you want to port an accton switch, and the folder doesn't exist,

mkdir `meta-mion-bsp/meta-mion-accton/`

You can also copy an existing one recursively, and precede with editing the existing files:

cd meta-mion-bsp
cp -r meta-mion-stordis/  meta-mion-accton/
cd meta-mion-accton/

Next, create platform config directory: meta-mion-bsp/meta-mion-<ONL_VENDOR>/conf/, and populate it with the files and directories based on the existing BSPs:

  • conf/layer.conf -- This is similar to existing layer.conf files used for other BSPs. As the name suggests, this file provides information about your bsp layer.

  • conf/machine/<ONL_VENDER>-<ONL_MACHINE>.conf -- This is a typical Yocto Project machine config. See the Yocto Project BSP Guide section, Hardware Configuration Options for more information. A good working example is the one for the APS Networks (formerly STORDIS) BF2556X-1T platform: stordis-bf2556x-1t.conf

  • conf/platform-profiles/platform-<ONL_VENDOR>.inc -- base this on the other platform profiles. This contains various platform variables. Example: platform-accton.inc

Create directory meta-mion-<ONL_VENDOR>/conf/onie-profiles/<ONL_VENDOR>-<ONL_MACHINE>/ and populate onlpv{1,2}/{machine,platform}.conf:

.
├── onlpv1
│   ├── machine.conf
│   └── platform.conf
├── onlpv2
│   ├── machine.conf
│   └── platform.conf
  • machine.conf -- contains a single line:PLATFORM="<ONIE_ARCH>-<ONIE_VENDOR>_<ONIE_MACHINE>". Note that ONIE_VENDOR and ONIE_MACHINE is separated by an underscore.
  • platform.conf: contains platform specific ONIE installer variables and functions usually found in the ONIE repo.

Create meta-mion-<ONL_VENDOR>/recipes-platform/ (if it doesn't exist) and populate the following as needed:

  • Directory onlpv1/<ONL_VENDOR>-<ONL_MACHINE>/ and Directory/file onlpv1/onplv1_%.bbappend -- This contains the ONLP specific patches.

Kernel Configuration

To Modify the kernel config and add defconfig files, Create the directory path:

  • meta-mion-bsp/meta-mion-<ONL_VENDOR>/recipes-kernel/linux/<MACHINE>/

Now add a kernel defconfig in the above directory -- it might be possible to generate this file using ONL or base it on a similar system already in meta-mion-bsp.

  • Add any required config fragments (*.cfg)

Now Modify meta-mion-bsp/meta-mion-<ONL_VENDOR>/recipes-kernel/linux/linux-yocto_<VER>.bbappend and add the following defined variables:

  • KMACHINE_<MACHINE>
  • KBRANCH_<MACHINE>
  • SRC_URI_append_<MACHINE>
  • SRCREV_machine_<MACHINE>
  • KERNEL_EXTRA_FEATURES_<MACHINE>
  • Add <MACHINE> to COMPATIBLE_MACHINE

See linux-yocto_5.4.bbappend for an example with the accton-asgvolt64.

Platform recipes

Like the Linux kernel recipe above, some machine specific variables may need to be set, or require overrides due to the nature of platform implementations within ONL. Examples include EXTRA_OEMAKE_append to set the needed ARCH, and do_install (either to overwrite it or append/prepend).

Also, you will likely need to patch the Makefile within the platform’s onlp/builds directory to set FILTER from src to <ONIE_VENDOR>_<ONIE_ARCH>_<ONIE_MACHINE>.

This part of the port is very vendor and platform specific and tends to require the most effort.