Hi
I have to admit that I have completely forgotten this extract from the boot loader document. It was a part of the original idea but only the Ethernet boot loader was actually implemented. There will also be a USB boot loader shortly (for the devices with USB).
Concentrating on UART loading, there are 2 main strategies. The first is to load the new code to free FLASH (or external FLASH / EEPROM), reboot and let the "Bare-minimum-boot-loader" do its standard job. This is supported for internal and external SPI FLASH but not EEPROM. It means that the download support has to be added to the application.
The second strategy - the one that actually makes most sense for UART loading is to add the loader directly to the boot loader code. This certainly makes the code a few kBytes larger but it can then load directly to the SW code location. The serial loader can be activated if no valid code is found and also if a certain input is in a defined state.
The fact is that both of the 2 methods above have been used in some projects together with UART (S-REC download) but these are not presently integrated in the uTasker project/boot loader.
Therefore I am sorry to disappoint at the moment. If you need some example code to do this please contact me by email/personal message.
Regards
Mark