Broadcom

Timeline: May - Dec 2020

I worked on a variety of interesting tasks during my co-op term at Broadcom. The areas I mainly got to improve myself in are as follows:

• Computer Networking

  • Virtual networking, virtual routers
  • Linux networking tools
  • Performance testing using DPDK - it’s a cool tool, check it out! (tldr: it uses a user-space NIC driver instead of a kernel-space driver, making it very efficient at packet processing)

• Linux

  • Recompiling the Linux kernel
    • via the make build tool
    • via building as a Debian package
    • cross-compiling to run on a different platform (ARM64) than it was built (x86)
  • Exploring ways to install Ubuntu & CentOS on the eMMC disk of Broadcom’s Stingray SoC products
    • via ISO images, rootfs tarball
    • fixing bugs in an existing script, adding error handling
  • Building Yocto images
    • lots of terminology around recipes!:)
    • also repeating the Yocto build process inside a Docker container

• Storage

  • Designed and implemented a script for partition resizing of the eMMC disk on Stingray SoC
    • Implemented for efficient usage of the eMMC partitions
      • Goal: To open up more space for an empty data partition without having to reformat the existing partitions
    • The script can free up to %65 of the eMMC disk for the data partition
    • Worked on the procedure from start to end
    • Added various CLI options to customize the partition resizing procedure
      • Resizing if not all of the default partitions are available
      • Shrinking specified partitions
      • Shrinking a partition to a user-defined size (instead of the minimum possible size of the partition, which is the default behavior of the script)
    • Implemented detailed error handling

• Bootloaders

  • Designed and implemented a methodology to add the GRUB bootloader to Stingray SoC, integrated GRUB-related changes with the existing boot procedure
    • In addition to the existing UEFI shell, added support for the GRUB bootloader as a UEFI application
    • Explored various methods for integrating GRUB with the Yocto filesystem in the best way possible
    • Added a modular pipeline to perform and maintain GRUB-related changes to an existing script responsible for updating the Yocto filesystem/kernel images
      • Created GRUB menu & submenu entries in an easy-to-navigate way for all ext4 filesystems installed on the eMMC, with kernel and DTB choices, mimicking the behavior of GRUB on common Linux systems such as Ubuntu
      • Created a default GRUB entry based on which filesystem/kernel/DTB was updated in the script, to make it easy to boot without navigating the GRUB menu
      • Made use of GRUB environment variables to store boot parameters, thus created a viable alternative to using UEFI variables
      • Prepared detailed docs to inform the team about the new procedure