An IPV6, TFTP bootloader for networked microcontrollers

This project implements an IPV6 (UDP only) stack and Trivial FTP (tftp) server for use as a bootloader in embedded systems.

It currently supports platforms using a Microchip PIC33 CPU with SPI attached ENC28J60 network controller chip.

The booloader:

• Detects and counts the holding of the reset button, beeping once per second (piezo attached to PWM output)
• Initialises a Microchip PIC33 microcontroller and SPI attached ENC28J60 ethernet controller
• Gets the MAC address from an I2C attached mc24aa00 EEPROM
• Responds to IPV6 neighbour solicitation messages (using the link-local EUI64 calculated from the MAC address)
• Responds to IPV6 ping requests
• Accepts tftp write requests for a single binary file (the "user" code)
• Writes the contents of the sent file to the program EEPROM of the microcontroller (without overwriting the bootloader code)

Normal operation sequence:

• Bootloader executes on reset
• Detects if reset button is held
• While button is held, beep once per second and count number of beeps
• Once reset button released:
  • if hold count < 10
    • Detect if "user" code has not been uploaded/programmed and emit 3 quick beeps to indicate this, then halt.
    • Otherwise, jump to "user" code, making the button hold count available to the "user" code main() function
  • Otherwise, go into tftp server mode, ready to recieve uploaded "user" code if the hold count is equal to 10

Building

This project is docker enabled - so it can create a suitable build environment into a docker container.

Prerequisites

You will need at least GNU make.

If you want to use docker for a build environment, you will need to install docker.io, and be a member of the docker group so that you can run docker commands. Ensure the docker service is running.

Otherwise, install the Microchip XC16 compiler.

Building the docker build environment (one time)

make docker will build the microchip/xc16 container

Building the project

make will build the project.

If you have made the docker image, the build will execute in the docker container. Otherwise, the build runs in the local environment.

Other make targets

• clean - cleans the project build
• prog - program the built .hex file to the CPU using the pk2cmd tool (local only)
• bin - converts the built .hex file to binary using srec_cat (docker enabled)

Unit tests

Test exist under the /test directory.

Prerequisites

The unit tests use the NovaProva testing framework.

Coverage data requires lcov package.

Make targets

From /test

• test ( default ) - builds and runs the unit tests
• coverage - runs the unit tests, collects coverage data and generates html output to /test/coverage/index.html