LibNXT and FwFlash v0.2 David Anderson ==================== What? ===== LibNXT is setting out to be a full NXT control library for a host computer to talk a Lego Mindstorms NXT intelligent brick. This includes: - Handling USB communication and locating the NXT in the USB tree, - Interaction with the Amtel AT91SAM boot assistant; especially: - Flashing of a firmware image to the NXT Currently planned features: - Interaction with the official firmware (called NxtOS here) - Language bindings to various higher-level languages (C++, Perl, Python, Java, Lua, ...) (If you have ideas of other stuff, please send it in!) LibNXT is targetted at the platforms that the official Lego Minstorms NXT software overlooks. Specifically, it will work on any POSIX-compliant operating system where libusb 0.1 (http://libusb.sf.net/) is supported. The design of LibNXT is layered, meaning you can plug into it at any level of complexity or abstraction you desire, from the lowest level USB bulk bit-pushing interface, to an API exposing the SAM-BA commandset, right up to just calling nxt_firmware_flash() and having everything taken care of! FwFlash is the first utility program that uses LibNXT. As its name hints, its purpose is to take a NXT firmware image file and flash it to a connected NXT device. Who? ==== Uh, that would be me. David Anderson, linux/open source developer and enthusiast, and an MDP participant :-). When? ===== Started the day after receiving the NXT kit, I started by working out the firmware flashing procedure from the specs and a USB dump of the windows software at work. Since then, after obtaining a proof-of-concept application, I've been implementing this library to abstract the horrors of low-level USB chatter into a nice, clean library. - Release 0.2 (17/03/2006) : firmware flashing is now done entirely with open source code. The flash driver routine has been replaced with open source code implementing the flashing procedure. - Release 0.1.1 (10/03/2006) : add big-endian host arch support, and make the firmware image reading process a little less linux-centric (use of the posix open/read/close API instead of mmap). - Release 0.1 (10/03/2006) : featuring the FwFlash utility and a LibNXT with just enough API in it to get FwFlash working :-) How? ==== To compile all of this you'll need a copy of libusb 0.1 on your system, as well as the scons project manager. - Libusb 0.1: http://libusb.sf.net/ - Scons: http://www.scons.org/ When you have all that, just run 'scons' in the libnxt directory, and compilation should follow. Once you're done, you can try fwflash out by resetting your NXT (see your user manual for details on this) and running: ./fwflash nxtos.bin nxtos.bin is the official Lego Mindstorms NXT firmware RC0, bundled in this package for convenience. You can take the one on your current installation of the Mindstorms software, they are the same file. If all goes well, fwflash should inform you that it has found the NXT on your USB device bus, and that flashing has started. After a few seconds, it should announce successful flashing, and say that it has booted the new firmware, which should be answered by the greeting sound of NxtOS as the brick starts up :-). If it doesn't, well it's either a problem with your USB device permissions (if fwflash can't find the NXT), or it's a bug (if the brick doesn't reboot properly, or if some weird error is reported by fwflash and it bombs out. The release tarball comes with a 'flash.bin'. This file is the compiled version of the open onboard flash driver. If you want to rebuild this file yourself, you'll need an ARM cross-compiling toolchain, such as the one provided by the excellent Scratchbox project (http://www.scratchbox.org/). Once you have it set up one way or another, cd to the flash_write directory and type 'make' to produce the flash driver binary.