Hi Luminary Fans!!
I am very proud to inform you that today I completed a boot loader (the uTasker Bare-Minimum-Bootloader) for the LM3S6965. It allows complete firmware upgrades via Ethernet (using FTP or HTTP post) and occupies from 2 x 1k FLASH sectors, taking up about 1.7k of actual space (about 1.9k when encrypted upload is enabled).
I tested on the Luminary LM3S6965 Ethernet evaluation board with a 156k file system configured, where the last 94k of it is reserved for accepting the new firmware. This corresponds to a typical configuration, allowing medium code size, 62k of dedicated web pages, a parameter system to comfortably work on the chip and remote upgrades to be made via the Internet without any need for external support (eg. using SPI FLASH).
The development took place purely using the uTasker simulator until I was reasonably sure that the operation was correct. There were a couple of hitches when moving to the target HW caused by the method needed to jump from the boot loader to the application code, plus an endian issue which was not encountered in the simulator.
Otherwise the development went fairly smoothly, aided by the fact that I am still fresh from the same exercise for the LPC project. I again set up the bootloader project using Rowley to fit together with the Rowley uTasker build seeing as this is proving to be the most popular development environment for this chip too.
To avoid surprises with programming times during the boot phase I went straight to 50MHz operation and the programming time for 50k of code was measured at about 3s (comparing with about 1.5s with the 72MHz LPC). This still enables fast firmware uploads where the complete upload time from pressing the browser upload button to establishing communication with the new code is still well below the 10s mark (around 7s).
Since the development version now includes the boot loader and SPI FLASH support for both ATMEL and ST devices I do believe a new service pack would be very worth while - a little new documentation is required but this could be ready quite shortly!!
Regards
Mark
