So you want to submit a patch for Armbian, but you are not sure how to do this. Well, I just did my first patch and I'm going to tell you how. What I've done is improved the workflow with GitHub CLI, so you can do everything from a command prompt without having to use the web UI (except deleting forked repo).

• Create an Ubuntu 20.04 VM with VirtualBox or other hypervisor.
• Install Github CLI
  • sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key C99B11DEB97541F0
  • sudo apt-add-repository https://cli.github.com/packages
  • sudo apt update
  • sudo apt -y install gh git
• Configure git
  • git config --global user.email "your@email.com"
  • git config --global user.name "Your Name"
• Generate gpg key
  • gpg --generate-key
• Generate Github login token
• Login to Github (you only have to do the steps above once)
  • gh auth login --with-token <<< 'your_token'
• Fork armbian/build, clone and add remote
• gh repo fork armbian/build --clone=true --remote=true
• Create branch
  • cd build
  • git checkout -b your_branch_name
    • Change branch name for your patch
• Compile Armbian (this use case is to change something in the device tree and test the built image)
  • ./compile.sh CREATE_PATCHES="yes"
    • Full OS image for flashing
    • Do not change kernel configuration
    • Chose a board
    • Chose a kernel
    • Chose a release package base
    • Chose image type
    • Chose image type
    • Configuring apt-cacher-ng
• Wait for prompt to make u-boot changes (press Enter after making changes in specified directory)
  • [ o.k. ] * [l][c] enable-distro-bootcmd.patch
  • [ warn ] Make your changes in this directory: [ /home/yourhome/build/cache/sources/u-boot-odroidxu/odroidxu4-v2017.05 ]
  • [ warn ] Press <Enter> after you are done [ waiting ]
• Open another terminal or Files window
• In this case I want to add gpio-line-names to the Odroid UX4 device tree when prompted to do so
  • sudo nano build/cache/sources/linux-odroidxu4/odroid-5.4.y/arch/arm/boot/dts/exynos5420-pinctrl.dtsi
• Wait for prompt to make kernel changes (press Enter after making changes in specified directory)
  • [ warn ] Make your changes in this directory: [ /home/yourhome/build/cache/sources/linux-odroidxu4/odroid-5.4.y ]
  • [ warn ] Press <Enter> after you are done [ waiting ]
• Test changes you made on your board
  • Mine was located in /home/yourhome/build/output/images/Armbian_21.02.0-trunk_Odroidxu4_focal_current_5.4.83.img
• Rename patch to something meaningful and move to proper location
  • mv output/patch/kernel-odroidxu4-current.patch patch/kernel/odroidxu4-current/add-gpio-line-names.patch
• Add patch
  • git add patch/kernel/odroidxu4-current/add-gpio-line-names.patch
• Commit patch
  • git commit -S -m "XU4 add gpio-line-names"
• Create pull request (select armbian/build as base repo and push branch to your fork)
  • gh pr create --title "XU4 add gpio-line-names" --body "Aded gpio-line-names, connector and physical pin number"

  ? Which should be the base repository (used for e.g. querying issues) for this directory? armbian/build
  ? Where should we push the 'add-gpio-line-names' branch? yourgithub/build
  
  Creating pull request for yourgithub:add-gpio-line-names into master in armbian/build
  
  Username for 'https://github.com': your@email.com
  Password for 'https://your@email.com@github.com': 
  remote: 
  remote: 
  To https://github.com/yourgithub/build.git
   * [new branch]        HEAD -> add-gpio-line-names
  Branch 'add-gpio-line-names' set up to track remote branch 'add-gpio-line-names' from 'origin'.
  https://github.com/armbian/build/pull/prnum