A Linux distribution for the Internet of Things.

This repository is intended for use by Cortex-OS developers, to build your own version of the OS and enhance functionality.

See contributing below for details on how to be a part of this project.

Building

The distribution is designed to be built on a Raspberry Pi device or compatible. This repository hosts the most minimal bootable Debian-based distribution possible, which will then expand and install itself using Debian's unattended net installer.

The following packages are required on a host machine to build this distribution:

• pv - pv shows the progress of data through a pipeline by giving information such as time elapsed, percentage completed (with progress bar), current throughput rate, total data transferred, and ETA.
• git - Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.
• curl - curl is a tool to transfer data from or to a server, using one of the supported protocols (DICT, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3, POP3S, RTMP, RTSP, SCP, SFTP, SMTP, SMTPS, TELNET and TFTP). The command is designed to work without user inter‐ action.
• bzip2 - bzip2 compresses files using the Burrows-Wheeler block sorting text compression algorithm, and Huffman coding. Compression is generally considerably better than that achieved by more conventional LZ77/LZ78-based compressors, and approaches the performance of the PPM family of statistical compressors.
• zip - zip is a compression and file packaging utility for Unix, VMS, MSDOS, OS/2, Windows 9x/NT/XP, Minix, Atari, Macintosh, Amiga, and An RISC OS. It is analogous to a combination of the Unix commands tar(1) and compress(1) and is compatible with PKZIP (Phil Katz's ZIP for MSDOS systems).
• xz-utils - xz is a general-purpose data compression tool with command line syntax similar to gzip(1) and bzip2(1). The native file format is the .xz format, but the legacy .lzma format used by LZMA Utils and raw com‐ pressed streams with no container format headers are also supported.
• gnupg - GnuPG is a set of programs for public key encryption and digital signa‐ tures. The program most users will want to use is the OpenPGP command line tool, named gpg. gpgv is a stripped down version of gpg with no encryption functionality, used only to verify signatures against a trusted keyring. There is also a tool called gpgsplit to split OpenPGP messages or keyrings into their component packets. This is mainly use‐ ful for seeing how OpenPGP messages are put together.
• kpartx This tool, derived from util-linux' partx, reads partition tables on specified device and create device maps over partitions segments detected. It is called from hotplug upon device maps creation and dele‐ tion.
• dosfstools fsck.fat verifies the consistency of MS-DOS filesystems and optionally tries to repair them.
• binutils - The GNU Binary Utilities, or binutils, are a set of programming tools for creating and managing binary programs, object files, libraries, profile data, and assembly source code originally written by progra- mmers at Cygnus Solutions.
• bc - bc is a language that supports arbitrary precision numbers with inter‐ active execution of statements. There are some similarities in the syntax to the C programming language. A standard math library is available by command line option. If requested, the math library is defined before processing any files. bc starts by processing code from all the files listed on the command line in the order listed. After all files have been processed, bc reads from the standard input. All code is executed as it is read. (If a file contains a command to halt the processor, bc will never read from the standard input.)

The base netinst scripts are tightly based on debian-pi/raspbian-ua-netinst.

Flashing to removal storage

The whole installation is intended to be automated and unattended. Writing to removable storage like an SD card or USB flash drive will completely format the storage device, losing anything that was present on the device, so proceed with caution.

Once cloning this repository to your host computer and installing the required packages as described above, run the following as root:

./install.sh /path/to/device

In turn, the install script performs the following individual actions:

1. ./clean.sh - removes any downloaded content from previous installations.
2. ./download.sh - downloads the source packages for building the base image.
3. ./build.sh - builds the initial RAM file system (initramfs).
4. ./image.sh - builds the initramfs archive into a raw and compressed disk image.
5. ./flash.sh /path/to/device - flashes the provided device with the disk image.

At this point, the removable storage device can be booted from the end hardware, which must have an internet connection. The OS will boot into the minimal image, then download and expand itself to the Cortex-OS using the numerical scripts within /script.

Editing the filesystem

Within filesystem/ are all the scripts required to automate the build of the Cortex-OS filesystem. Notable files include:

• /etc/udhcpc/default.script run to configure the very small DHCP server for configuring the Raspberry Pi at boot.
• /etc/init.d/rcS is the script that is run at boot time. It executes the scripts in /etc/init.d/rcS.d/ in alphabetical order.

Video to demonstrate build process: https://www.youtube.com/watch?v=hUAfh9p7IZE

Developing devices

Once the OS is built, devices can be developed and hooked up to Neuron. Read the wiki for more information.

Contributing

Would you like to add new functionality to Cortex-OS? You can introduce device capability by adding a new device directory within /src. Scripts within that directory need to implement the Device interface. They are executed when networking is connected or disconnected, allowing devices to continue to operate while there is no Internet availability.

Read the wiki for more information and a guide to write your own device.