USB DFU bootloader for Bondtech INDX board

This is a DFU-capable USB bootloader for the Bondtech INDX toolboard.

It supports directly updating and booting a firmware image, as well as chainloading to a second stage bootloader. This is used to support RepRapFirmware CAN programming as well as DFU-based programming.

This directory contains only the USB bootloader itself. To build the amalgation bootloader, the correct Duet3 bootloader must be supplied as part of the build.

Usage

To download a firmware to the board, use dfu-util or other suitable DFU programming utility, e.g.:

dfu-util -D firmware.dfu

The firmware must prepared to be compatible with RepRapFirmware. In particular:

• The firmware must be built to run at offset 0x10000, where the bootloader will place it.
• At offset 0x1C of the firmware binary must be a pointer to the end of the firmware in memory. I.e. the pointer should be to 0x10000 + the length of the firmware binary.
• Finally, a CRC32 of the entire preceeding firmware must be appended to the end of the firmware binary.

Building

To build the bootloader, you'll need at least:

• uv and Python ≥3.9
• an arm-none-eabi-gcc toolchain including newlib or other embedded-suitable libc
• git

The bootloader can be compiled in either standalone or chainloading mode.

To compile in standalone mode, simply run:

$ make clean
$ make all

The resulting binary will be at build/indxboot.elf and build/indxboot.bin.

To compile in chainloading mode, run:

$ make clean
$ make BOOT2=<path_to_chained_bootloader> amalgamation 

The chainloaded bootloader must be in RepRapFirmware compatible format (see Usage section). This will produce a bootloader at build/amalgamation.bin.

Programming device

To program the board, OpenOCD can be used. If using a standard CMSIS-DAP programming, the following can be used:

openocd -f interface/cmsis-dap.cfg -f target/atsame5x.cfg -c "program build/amalgamation.bin verify reset exit 0x0"

Acknowledgements

This bootloader is based on the 1kB SAMDx1-USB-DFU-Bootloader.