### Clone and build the Blinky example project

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/getting-started.md

Clone the Nerves examples repository and build the 'Blinky' project, a basic hardware example. Set the MIX_TARGET environment variable before building.

```bash
git clone https://github.com/nerves-project/nerves_examples
export MIX_TARGET=rpi0_2
cd nerves_examples/blinky
mix do deps.get, firmware, firmware.burn
```

--------------------------------

### erlinit Configuration Example

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Configure erlinit, the PID 1 process that starts the BEAM VM. This example sets the console TTY, hostname, uses nbtty for the console, and mounts the application data partition.

```shell
# erlinit.config for my_board
-v

# Console TTY
--ctty ttyS0

# Hostname
--hostname nerves

# Use nbtty for the console
--pre-run-exec /usr/bin/nbtty

# Mount the application data partition
--mount /dev/mmcblk0p3:/data:f2fs::
```

--------------------------------

### Main fwup.conf Example for Nerves

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

This configuration defines firmware metadata, file resources, and tasks for complete firmware installation and upgrades. It includes partition setup and resource writing for both boot and rootfs partitions.

```conf
require-fwup-version="1.0.0"

# Include partition layout
include("fwup_include/fwup-common.conf")

# Firmware metadata
meta-product = "My Board Nerves Image"
meta-description = "Nerves firmware for My Board"
meta-version = ${NERVES_FW_VERSION}
meta-platform = "my_board"
meta-architecture = "aarch64"
meta-author = "Your Name"

# File resources - these are files that get packed into the .fw bundle
file-resource bootpart.vfat {
    host-path = "${NERVES_SYSTEM}/images/bootpart.vfat"
}
file-resource rootfs.img {
    host-path = "${NERVES_SYSTEM}/images/rootfs.squashfs"
}

# Task: complete - write everything to a blank SD card
task complete {
    on-init {
        mbr_write(mbr-a)
        fat_mkfs(${BOOT_A_PART_OFFSET}, ${BOOT_A_PART_COUNT})
        fat_mkfs(${BOOT_B_PART_OFFSET}, ${BOOT_B_PART_COUNT})
    }

    on-resource bootpart.vfat {
        raw_write(${BOOT_A_PART_OFFSET})
    }

    on-resource rootfs.img {
        raw_write(${ROOTFS_A_PART_OFFSET})
    }

    on-finish {
        # Initialize the application data partition
        raw_memset(${APP_PART_OFFSET}, 256, 0xff)
    }
}

# Task: upgrade - update the inactive slot
task upgrade.a {
    # Upgrade B -> A
    require-partition1-offset = ${BOOT_B_PART_OFFSET}

    on-resource bootpart.vfat {
        raw_write(${BOOT_A_PART_OFFSET})
    }

    on-resource rootfs.img {
        raw_write(${ROOTFS_A_PART_OFFSET})
    }

    on-finish {
        mbr_write(mbr-a)
    }
}

task upgrade.b {
    # Upgrade A -> B
    require-partition1-offset = ${BOOT_A_PART_OFFSET}

    on-resource bootpart.vfat {
        raw_write(${BOOT_B_PART_OFFSET})
    }

    on-resource rootfs.img {
        raw_write(${ROOTFS_B_PART_OFFSET})
    }

    on-finish {
        mbr_write(mbr-b)
    }
}

```

--------------------------------

### Custom Buildroot Package Config.in Example

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Example of a root `Config.in` file for a Nerves system, including a custom package menu.

```plain
menu "Custom Packages"

source "$NERVES_DEFCONFIG_DIR/packages/libfoo/Config.in"

endmenu
```

--------------------------------

### Erlinit Mount Command Example

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/advanced-configuration.md

Example of an erlinit.config command to mount the configdata and logdata partitions.

```bash
# Mount the configdata and logdata partitions
-m /dev/mmcblk0p3:/root:ext4::;/dev/mmcblk0p4:/mnt/log:ext4::
```

--------------------------------

### Custom Buildroot Package External.mk Example

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Example of a root `external.mk` file for a Nerves system, including custom package makefiles.

```make
include $(sort $(wildcard $(NERVES_DEFCONFIG_DIR)/packages/*/*.mk))
```

--------------------------------

### U-Boot Boot Script Example

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

An example U-Boot boot script (`boot.cmd`) for an Allwinner AArch64 board. It defines standard U-Boot environment variables for loading the kernel, device tree, and setting kernel command line arguments.

```shell
# boot.cmd - U-Boot boot script for Nerves


```

--------------------------------

### Install Build Tools for Arch Linux

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Installs necessary packages for building Nerves systems on Arch Linux.

```bash
sudo pacman -Syu git base-devel bc cmake cvs wget curl mercurial python python-aiohttp flake8 python-ijson python-nose2 python-pexpect python-pip python-requests rsync subversion unzip gawk jq squashfs-tools openssl automake autoconf ncurses
```

--------------------------------

### Board ID Configuration Example

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Configure the `boardid` tool to read a unique identifier for the board. This example shows how to attempt reading from U-Boot environment variables and CPU information.

```shell
# Try reading the serial number from different sources
-b uboot_env -u nerves_serial_number
-b cpuinfo -f Serial
```

--------------------------------

### Install Nerves Archives

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Installs the Nerves bootstrap archive and local rebar if they are not already set up.

```bash
mix archive.install hex nerves_bootstrap
mix local.rebar
```

--------------------------------

### View Zig Targets

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/environment-variables.md

Install zig and run this command to view available target configurations.

```shell
zig targets | less

```

--------------------------------

### U-Boot Boot Script Example

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

This U-Boot script loads the kernel and device tree from the active boot partition and then boots the kernel. Ensure the `root=` parameter matches your rootfs partition.

```bash
setenv bootargs console=ttyS0,115200 root=/dev/mmcblk0p2 rootfstype=squashfs rootwait

fatload mmc 0 ${kernel_addr_r} Image
fatload mmc 0 ${fdt_addr_r} sun50i-a64-pine64-plus.dtb

booti ${kernel_addr_r} - ${fdt_addr_r}
```

--------------------------------

### Manually install mise plugins

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Manually installs Erlang and Elixir plugins for mise if automatic installation fails.

```bash
mise plugin install erlang
```

```bash
mise plugin install elixir
```

--------------------------------

### Install nerves_bootstrap archive

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Installs the nerves_bootstrap Mix archive, which is required for bootstrapping the Nerves Mix environment and generating new Nerves projects.

```bash
mix archive.install hex nerves_bootstrap
```

--------------------------------

### Nerves Partition Definition File Example

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

An example configuration file defining partition offsets and sizes for a standard Nerves MBR layout on an SD card. It uses `define` and `define-eval` for dynamic offset calculations.

```conf
# Firmware partition definitions

# Let fwup know the image is for an SD card
define(NERVES_FW_DEVPATH, "/dev/mmcblk0")

# U-Boot environment (small key/value store before the partitions)
define(UBOOT_ENV_OFFSET, 16)
define(UBOOT_ENV_COUNT, 16)

# Boot A partition (FAT32, holds kernel + DTB + boot.scr)
define(BOOT_A_PART_OFFSET, 63)
define(BOOT_A_PART_COUNT, 65536)

# Boot B partition
define-eval(BOOT_B_PART_OFFSET, "${BOOT_A_PART_OFFSET} + ${BOOT_A_PART_COUNT}")
define(BOOT_B_PART_COUNT, 65536)

# Rootfs A partition (squashfs)
define-eval(ROOTFS_A_PART_OFFSET, "${BOOT_B_PART_OFFSET} + ${BOOT_B_PART_COUNT}")
define(ROOTFS_A_PART_COUNT, 524288)

# Rootfs B partition
define-eval(ROOTFS_B_PART_OFFSET, "${ROOTFS_A_PART_OFFSET} + ${ROOTFS_A_PART_COUNT}")
define(ROOTFS_B_PART_COUNT, 524288)

# Application data partition (F2FS, fills the rest)
define-eval(APP_PART_OFFSET, "${ROOTFS_B_PART_OFFSET} + ${ROOTFS_B_PART_COUNT}")
define(APP_PART_COUNT, 0)
define(NERVES_FW_APPLICATION_PART0_DEVPATH, "/dev/mmcblk0p3")
define(NERVES_FW_APPLICATION_PART0_FSTYPE, "f2fs")
define(NERVES_FW_APPLICATION_PART0_TARGET, "/data")
```

--------------------------------

### Install Build Tools for Apt-based Linux

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Installs essential packages for building Nerves systems on Ubuntu and Debian-based distributions.

```bash
sudo apt update && sudo apt install -y git build-essential bc cmake cvs wget curl mercurial python3 python3-aiohttp python3-flake8 python3-ijson python3-nose2 python3-pexpect python3-pip python3-requests rsync subversion unzip gawk jq squashfs-tools libssl-dev automake autoconf libncurses5-dev
```

--------------------------------

### Install Arch Linux Dependencies

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Installs essential build tools and libraries for Nerves on Arch-based systems using yay.

```bash
yay -S base-devel ncurses5-compat-libs git squashfs-tools curl wget bc cpio
```

--------------------------------

### Complete Nerves Defconfig Example for AArch64 Board

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

A comprehensive `nerves_defconfig` example for an AArch64 Allwinner board, demonstrating configurations for architecture, toolchain, system, kernel, U-Boot, packages, root filesystem, and build hooks.

```kconfig
# Architecture
BR2_aarch64=y
BR2_cortex_a53=y

# Toolchain (Nerves external)
BR2_TOOLCHAIN_EXTERNAL=y
BR2_TOOLCHAIN_EXTERNAL_CUSTOM=y
BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y
BR2_TOOLCHAIN_EXTERNAL_URL="https://github.com/nerves-project/toolchains/releases/download/v13.2.0/nerves_toolchain_aarch64_nerves_linux_gnu-linux_x86_64-13.2.0-B21A7B8.tar.xz"
BR2_TOOLCHAIN_EXTERNAL_CUSTOM_PREFIX="aarch64-nerves-linux-gnu"
BR2_TOOLCHAIN_EXTERNAL_GCC_13=y
BR2_TOOLCHAIN_EXTERNAL_HEADERS_5_4=y
BR2_TOOLCHAIN_EXTERNAL_CUSTOM_GLIBC=y
BR2_TOOLCHAIN_EXTERNAL_CXX=y
BR2_TOOLCHAIN_EXTERNAL_FORTRAN=y
BR2_TOOLCHAIN_EXTERNAL_OPENMP=y

# System
BR2_INIT_NONE=y
BR2_ROOTFS_SKELETON_CUSTOM=y
BR2_ROOTFS_SKELETON_CUSTOM_PATH="${BR2_EXTERNAL_NERVES_PATH}/board/nerves-common/skeleton"
BR2_NERVES_SYSTEM_NAME="nerves_system_my_board"

# Kernel
BR2_LINUX_KERNEL=y
BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="${NERVES_DEFCONFIG_DIR}/linux-6.6.defconfig"
BR2_LINUX_KERNEL_DTS_SUPPORT=y
BR2_LINUX_KERNEL_INTREE_DTS_NAME="allwinner/sun50i-a64-pine64-plus"

# U-Boot
BR2_TARGET_UBOOT=y
BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
BR2_TARGET_UBOOT_CUSTOM_VERSION=y
BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2024.04"
BR2_TARGET_UBOOT_BOARD_DEFCONFIG="pine64_plus"

# Packages
BR2_PACKAGE_NERVES_CONFIG=y
BR2_PACKAGE_BUSYBOX_CONFIG="${BR2_EXTERNAL_NERVES_PATH}/board/nerves-common/busybox.config"
BR2_PACKAGE_NBTTY=y
BR2_PACKAGE_CA_CERTIFICATES=y

# Root filesystem
BR2_TARGET_ROOTFS_SQUASHFS=y
BR2_TARGET_ROOTFS_SQUASHFS_LZ4=y

# Build hooks
BR2_ROOTFS_OVERLAY="${BR2_EXTERNAL_NERVES_PATH}/board/nerves-common/rootfs_overlay ${NERVES_DEFCONFIG_DIR}/rootfs_overlay"
BR2_ROOTFS_POST_BUILD_SCRIPT="${BR2_EXTERNAL_NERVES_PATH}/board/nerves-common/post-build.sh ${NERVES_DEFCONFIG_DIR}/post-build.sh"
BR2_ROOTFS_POST_SCRIPT_ARGS="${NERVES_DEFCONFIG_DIR}"
```

--------------------------------

### extlinux.conf Example for Distroboot

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

This configuration file is used by U-Boot's distroboot mechanism. It specifies the kernel image and kernel command line arguments. Place this file in the `extlinux/` directory on the boot partition.

```bash
DEFAULT nerves
TIMEOUT 0

LABEL nerves
    LINUX /bzImage
    APPEND root=/dev/sda2 rootfstype=squashfs rootwait console=ttyS0,115200
```

--------------------------------

### Get Project Dependencies

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/getting-started.md

Navigate to your Nerves project directory and fetch all necessary dependencies for the specified target.

```bash
cd hello_nerves
MIX_TARGET=rpi0_2 mix deps.get
```

--------------------------------

### Install Nerves Dependencies on MacOS

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Installs essential tools like fwup, squashfs, coreutils, xz, and pkg-config using Homebrew.

```bash
brew update
brew install fwup squashfs coreutils xz pkg-config
```

--------------------------------

### Install Avahi Utilities on Linux

Source: https://github.com/nerves-project/nerves/blob/main/guides/core/connecting-to-a-nerves-target.md

Installs the necessary Avahi utilities for improved mDNS discovery on Debian/Ubuntu and Fedora/RHEL systems.

```bash
# On Ubuntu/Debian
sudo apt-get install avahi-utils
# On Fedora/RHEL
sudo dnf install avahi-tools
```

--------------------------------

### Install Nerves Dependencies on Fedora

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Installs development tools, git, squashfs-tools, and development libraries required for Nerves on Fedora systems.

```bash
sudo dnf install @development-tools automake autoconf git squashfs-tools pkgconf-pkg-config curl libmnl-devel openssl-devel ncurses-devel help2man libconfuse-devel libarchive-devel
```

--------------------------------

### Configure Erlinit Console Output

Source: https://github.com/nerves-project/nerves/blob/main/guides/core/iex-with-nerves.md

Example configuration for `erlinit.config` to specify where the IEx prompt should be sent. Only one console output option can be enabled at a time.

```text
 Specify where erlinit should send the IEx prompt. Only one may be enabled at
# a time.
-c ttyAMA0     # UART pins on the GPIO connector
```

--------------------------------

### Install Build Tools for RPM-based Linux

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Installs required packages for building Nerves systems on Red Hat, Fedora, and similar RPM-based distributions.

```bash
sudo dnf install -y git @development-tools @c-development kernel-devel cvs wget curl mercurial python3 python3-aiohttp python3-flake8 python3-ijson python3-nose2 python3-pexpect python3-pip python3-requests rsync  unzip gawk jq squashfs-tools openssl-devel ncurses-devel
```

--------------------------------

### Update application.ex to use Mix.target()

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/updating-projects.md

Replace `Mix.Project.config()[:target]` with `Mix.target()` in `application.ex` when determining runtime configurations or starting processes.

```elixir
@target Mix.Project.config()[:target]
```

```elixir
@target Mix.target()
```

--------------------------------

### Install Nerves Dependencies on Ubuntu/Debian

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Installs build tools, git, squashfs-tools, and development libraries required for Nerves on Ubuntu and Debian-based systems.

```bash
sudo apt install build-essential automake autoconf git squashfs-tools pkg-config curl libmnl-dev libnl-genl-3-dev libssl-dev libncurses5-dev help2man libconfuse-dev libarchive-dev file unzip libgnutls28-dev
```

--------------------------------

### Define Custom Partition Sizes in fwup.conf

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/advanced-configuration.md

Use 'define' and 'define-eval' in fwup.conf to specify the offsets and sizes for new partitions. This example defines partitions for configuration and log data.

```bash
# fwup.conf

# (Sizes are in 512 byte blocks)
define(UBOOT_ENV_OFFSET, 16)
define(UBOOT_ENV_COUNT, 16)  # 8 KB

define(BOOT_A_PART_OFFSET, 63)
define(BOOT_A_PART_COUNT, 38630)
define-eval(BOOT_B_PART_OFFSET, "${BOOT_A_PART_OFFSET} + ${BOOT_A_PART_COUNT}")
define(BOOT_B_PART_COUNT, ${BOOT_A_PART_COUNT})

# Let the rootfs have room to grow up to 128 MiB and align it to the nearest 1
# MB boundary
define(ROOTFS_A_PART_OFFSET, 77324)
define(ROOTFS_A_PART_COUNT, 289044)
define-eval(ROOTFS_B_PART_OFFSET, "${ROOTFS_A_PART_OFFSET} + ${ROOTFS_A_PART_COUNT}")
define(ROOTFS_B_PART_COUNT, ${ROOTFS_A_PART_COUNT})

# Configuration partition
define-eval(CONFIG_PART_OFFSET, "${ROOTFS_B_PART_OFFSET} + ${ROOTFS_B_PART_COUNT}")
define(CONFIG_PART_COUNT, 1048576)

# Log partition
define-eval(LOG_PART_OFFSET, "${CONFIG_PART_OFFSET} + ${CONFIG_PART_COUNT}")
define(CONFIG_PART_COUNT, 1048576)

# ...

```

--------------------------------

### Enter Nerves System Shell

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/customizing-systems.md

Starts the Nerves system shell for customizing the system. This provides a Buildroot environment for configuration.

```bash
$ mix nerves.system.shell
Mix environment
 MIX_TARGET:   custom_rpi3
 MIX_ENV:      dev

==> nerves
Compiling 25 files (.ex)
Generated nerves app

 Preparing Nerves Shell

Creating build directory...
Cleaning up...
Nerves  /nerves/build >
```

--------------------------------

### Nerves Bootstrap Call Tree - mix firmware

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/internals.md

This outlines the sequence of tasks executed when running `mix firmware`, including precompilation and environment setup.

```Elixir
alias
  nerves.precompile
    NERVES_PRECOMPILE = 1
    Mix.Tasks.Nerves.Env
      Mix.Tasks.Deps.Loadpaths.run ["--no-compile"]
      Mix.Tasks.Deps.Compile.run ["nerves", "--include-children"]
      Nerves.Env.start()
        load_packages()
            Mix.Project.deps_paths
              Package.config_path
              Package.load_config
                build_runner()
              validate_packages()
    Mix.Tasks.Deps.Compile Nerves.Env.system.app
    Mix.Tasks.Compile.run(--no-deps-check) Only if parent == system_app
    NERVES_PRECOMPILE = 0
    Mix.Tasks.Nerves.Loadpaths.run()
      Mix.task.run(nerves.env) Nerves.Env
        Nerves.Env.start() ?? See above
      Nerves.Env.bootstrap()
        system_path()
          Nerves.Env.system()
            Nerves.Artifact.dir()
              System.get_env(env_var(pkg)) NERVES_SYSTEM
        toolchain_path()
          Nerves.Env.toolchain()
            Nerves.Artifact.dir()
              System.get_env(env_var(pkg)) NERVES_TOOLCHAIN
        platform.bootstrap(pkg) Nerves.Env.system.platform ||Nerves.Env.system.config[:build_platform]
          nerves_env.exs Nerves.System.BR
```

--------------------------------

### Get Dependencies and Compile Project

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Standard Mix commands to fetch project dependencies and compile the Elixir code. The initial compilation may take a significant amount of time.

```bash
mix deps.get
mix compile
```

--------------------------------

### Nerves Init System and Skeleton Configuration

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Configure Nerves to use no init system and a custom root filesystem skeleton provided by `nerves_system_br`. This setup is essential for Nerves's unique approach where `erlinit` acts as PID 1.

```kconfig
BR2_INIT_NONE=y
BR2_ROOTFS_SKELETON_CUSTOM=y
BR2_ROOTFS_SKELETON_CUSTOM_PATH="${BR2_EXTERNAL_NERVES_PATH}/board/nerves-common/skeleton"
```

--------------------------------

### Get Network Interface Information with VintageNet

Source: https://github.com/nerves-project/nerves/blob/main/guides/core/iex-with-nerves.md

Use VintageNet.info to display all network interfaces, their types, states, and configurations. This is useful for understanding the current network setup.

```elixir
iex> VintageNet.info
All interfaces:       ["eth0", "lo", "wlan0", "wwan0"]
Available interfaces: ["wlan0", "wwan0"]

Interface eth0
  Type: VintageNetEthernet
  Present: true
  State: :configured (1 days, 14:59:09)
  Connection: :disconnected (1 days, 14:59:09)
  Configuration:
    %{type: VintageNetEthernet, ipv4: %{method: :dhcp}}

Interface wlan0
  Type: VintageNetWiFi
  Present: true
  State: :configured (1 days, 14:59:05)
  Connection: :internet (5:02:35)
  Addresses: 192.168.99.81/24, fe80::9a48:27ff:fedd:a10e/64
  Configuration:
    %{ 
      type: VintageNetWiFi, 
      ipv4: %{method: :dhcp},
      vintage_net_wifi: ...
    }

Interface wwan0
  Type: VintageNetQMI
  Power: On (watchdog timeout in 59969 ms)
  Present: true
  State: :configured (14:44:50)
  Connection: :internet (14:43:51)
  Addresses: 100.101.32.76/29, fe80::8eb:885f:3fce:d37d/64
  Configuration:
    %{ ... 
    }

```

--------------------------------

### Copy Starter Configuration

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Copies the starter configuration file to create a new configuration for building Nerves systems.

```bash
cp config/starter-config.exs config/config.exs
```

--------------------------------

### Download and Buildroot System

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Clone the Buildroot repository and configure it for your specific board. This is a prerequisite for creating a Nerves system.

```bash
git clone https://gitlab.com/buildroot.org/buildroot/
cd buildroot

# If using a built-in defconfig
make <your_board>_defconfig
make
```

--------------------------------

### Install Erlang and Elixir with asdf

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Adds Erlang and Elixir plugins to asdf and installs specific versions compatible with Nerves.

```bash
asdf plugin add erlang
```

```bash
asdf plugin add elixir
```

```bash
asdf install erlang 28.1.1
```

```bash
asdf install elixir 1.19.1-otp-28
```

```bash
asdf set -u erlang 28.1.1
```

```bash
asdf set -u elixir 1.19.1-otp-28
```

--------------------------------

### Set MIX_TARGET and Build Firmware

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/customizing-systems.md

Set the MIX_TARGET environment variable to your custom system name and run `mix deps.get` and `mix firmware` to build your custom firmware. The first build may take 15-30 minutes.

```bash
cd ~/projects/your_project
export MIX_TARGET=custom_rpi3
mix deps.get
mix firmware
```

--------------------------------

### Build Nerves Project with Custom System

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Build your Nerves project using 'mix deps.get' and 'mix firmware'. The environment variables ensure your custom-built system is used.

```bash
mix deps.get
mix firmware
```

--------------------------------

### Install Latest Nerves Bootstrap Archive

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/updating-projects.md

Use this command to install the latest Nerves Bootstrap archive, which is required for Nerves v0.9.0 and later.

```bash
mix local.nerves
```

```bash
mix archive.install hex nerves_bootstrap
```

--------------------------------

### Linux Boot Sequence Flowchart

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Visualizes the step-by-step process of a Linux system booting up, from power on to running the initial process (PID 1).

```text
Power on 

 Bootloader 

 Kernel 

 mounts rootfs 

 runs PID 1
```

--------------------------------

### Install fwup on Windows with Chocolatey

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Installs the Windows version of fwup using Chocolatey. This is required for burning firmware to SD cards when using WSL2.

```powershell
choco install fwup /y
```

--------------------------------

### Configure Git Repository for Custom System

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Set up a Git repository for your custom Nerves system, including renaming the default remote and pushing to a new origin.

```bash
cd custom_rpi3
git remote rename origin upstream
git remote add origin git@github.com:YourGitHubUserName/custom_rpi3.git
git checkout -b main
git push origin main
```

--------------------------------

### Build Nerves Systems

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Initiate the build process for all systems defined in your configuration file. This task generates Buildroot `.config` files and compiles the systems.

```bash
mix ns.build
```

--------------------------------

### Force nerves_bootstrap installation for older Elixir versions

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/updating-projects.md

If you cannot update Elixir to 1.9+ but need to create new projects, use this command to install a compatible version of nerves_bootstrap.

```bash
mix archive.install hex nerves_bootstrap "~> 1.5.0"
```

--------------------------------

### Configure Buildroot

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Use 'make menuconfig' to modify the Buildroot configuration for your Nerves system.

```bash
make menuconfig
```

--------------------------------

### Add and Install fwup via asdf on Ubuntu/Debian

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Adds the fwup plugin to asdf and installs the latest version. Nerves uses fwup for firmware image creation.

```bash
asdf plugin add fwup https://github.com/fwup-home/asdf-fwup.git
asdf install fwup latest
asdf set -u fwup latest
```

--------------------------------

### Copy fwup.conf and cmdline.txt for Overlays

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/advanced-configuration.md

These bash commands demonstrate how to locate and copy the `fwup.conf` and `cmdline.txt` files from a Nerves system dependency to your project's `config` directory. This is the first step in customizing boot partition files.

```bash
# Locate the fwup.conf files available in your deps directory
find deps -name fwup.conf
# Copy the one that matches your target to the config directory.
cp deps/nerves_system_rpi0/fwup.conf config/
# Also copy cmdline.txt as you'll need it below.
```

```bash
cp deps/nerves_system_rpi0/cmdline.txt config/
```

--------------------------------

### Build External Tree and Configure

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Use this command to build with an external tree from a manufacturer. It configures the build system for a specific board.

```bash
make BR2_EXTERNAL=../my-external my_board_defconfig
make
```

--------------------------------

### Build and Burn Nerves Firmware

Source: https://github.com/nerves-project/nerves/blob/main/README.md

Set the target environment, fetch dependencies, compile firmware, and burn it to an SD card. The `mix firmware.burn` command may require sudo privileges.

```bash
export MIX_TARGET=rpi3
mix deps.get      # Fetch the dependencies
mix firmware      # Cross-compile dependencies and create a .fw file
mix firmware.burn # Burn firmware to an inserted SD card
```

--------------------------------

### Display Toolshed Help

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/getting-started.md

Access the help documentation for the `Toolshed` package within the IEx prompt. This command is useful for exploring available runtime commands.

```elixir
iex> h Toolshed
```

--------------------------------

### Firmware Build Success Message

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/getting-started.md

This message indicates that the firmware compilation was successful and provides options for installation.

```plain
Firmware built successfully! 🎉

Now you may install it to a MicroSD card using `mix burn` or upload it
to a device with `mix upload` or `mix firmware.gen.script`+`./upload.sh`.
```

--------------------------------

### Preload Build Dependencies

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Download all required files for a Nerves system in advance within its output directory. This can speed up subsequent builds, especially when working offline or on slow networks.

```bash
cd o/<system name>
make source
```

--------------------------------

### Verify nerves_bootstrap version for Elixir 1.9+

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/updating-projects.md

Check that nerves_bootstrap version 1.6.0 or later is installed before proceeding with Elixir 1.9+ updates.

```bash
$ mix archive
```

--------------------------------

### Uninstall Erlang and Elixir on MacOS

Source: https://github.com/nerves-project/nerves/blob/main/guides/introduction/installation.md

Removes existing Erlang and Elixir installations managed by Homebrew to prevent conflicts with asdf or mise.

```bash
brew uninstall elixir
brew uninstall erlang
```

--------------------------------

### Linux Boot Components Diagram

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Illustrates the three fundamental pieces of any Linux system: the bootloader, the kernel, and the root filesystem, and their interaction during the boot process.

```text
+-------------------+
|    Bootloader     |
+-------------------+    +-------------------+
|                   |    |      Kernel       |
| Initializes HW    |    +-------------------+
| Loads kernel into |    |                   |
| memory, starts it |--->| Manages processes |
|                   |    | Memory mgmt       |
+-------------------+    | Device drivers    |
                         | Filesystems       |
                         +-------------------+
                                |      Rootfs       |
                                +-------------------+
                                |                   |
                                | Programs,         |
                                | libraries,        |
                                | config, your app  |
                                |                   |
                                +-------------------+
```

--------------------------------

### Generate a New Nerves Application

Source: https://github.com/nerves-project/nerves/blob/main/README.md

Use this command to create a new Nerves project. Ensure Elixir and the Nerves toolchain are installed.

```bash
mix nerves.new my_app
```

--------------------------------

### Remove Nerves Systems Source Directory

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Delete the `src` directory to reset the Nerves systems environment. This is useful before reconfiguring or starting over.

```bash
rm -rf src
```

--------------------------------

### Define Device Tree Overlay Resource in fwup.conf

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/advanced-configuration.md

This bash snippet illustrates how to define a file resource for a device tree overlay (`.dtbo`) file within `fwup.conf`. This allows Nerves to include custom hardware configurations, such as for sensors, during the firmware build process.

```bash
# fwup.conf

file-resource overlays/bosch-bmp280.dtbo {
    host-path = "${NERVES_APP}/config/overlays/bosch-bmp280.dtbo"
}
```

--------------------------------

### Verify Custom System Usage

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Run 'mix nerves.info' to confirm that your project is utilizing the custom-built Nerves system, indicated by the output referencing your custom build location.

```bash
mix nerves.info
```

--------------------------------

### Source Environment Script

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/building-systems.md

Source the nerves.env.sh script to set up environment variables for your custom-built system. Remember to do this each time you start a new terminal session.

```bash
. ~/path/to/nerves_systems/o/rpi0/nerves.env.sh
```

--------------------------------

### U-Boot Environment Configuration

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Configure the `fw_printenv`/`fw_setenv` tools to locate the U-Boot environment on disk. Specify the device, offset, and size for the environment storage.

```shell
/dev/mmcblk0 0x100000 0x20000
```

--------------------------------

### Start picocom Communication

Source: https://github.com/nerves-project/nerves/blob/main/guides/core/connecting-to-a-nerves-target.md

Initiate a serial connection to your Nerves target using picocom. Replace `/dev/ttyUSB0` with the actual TTY device name for your cable.

```bash
picocom -b 115200 /dev/ttyUSB0
```

--------------------------------

### Set Target and Build Firmware

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/porting-guide.md

Set the MIX_TARGET environment variable to your custom board and then build the firmware. This command compiles the Nerves system and application into a firmware image.

```bash
export MIX_TARGET=my_board
mix deps.get
mix firmware
```

--------------------------------

### Define Nerves Package Environment Variables

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/environment-variables.md

Example of defining TARGET_* environment variables within the `nerves_package` function in `mix.exs` for a Raspberry Pi Zero system.

```elixir
  defp nerves_package do
    [
      type: :system,
      ...
      env: [
        {"TARGET_ARCH", "arm"},
        {"TARGET_CPU", "arm1176jzf_s"},
        {"TARGET_OS", "linux"},
        {"TARGET_ABI", "gnueabihf"}
      ]
      ...
    ]
  end

```

--------------------------------

### Customize mksquashfs flags in mix config

Source: https://github.com/nerves-project/nerves/blob/main/guides/advanced/experimental-features.md

Example of customizing non-Elixir parts of the firmware, specifically mksquashfs flags, within a project's mix configuration.

```elixir
# Customize non-Elixir parts of the firmware. See

```