The uTasker project includes KBOOT support (USB-HID and UART). as well as the legacy HID loader HIDloader.exe from AN4764, which can be optionally combined with SD card, USB-MSD and Ethernet web server loaders (depending on the available processor's interfaces)
It builds for just about any KE, KL or K part and includes out-of-the-box projects for IAR, Keil, Rowley Crossworks, Atollic, CooCox, CodeWarrior 10.x, KDS and stand-alone GCC.
The uTasker implementation achieves about 8x faster USB loading than the present KBOOT SW and smaller memory footprints.
Thanks Mark. We went to the Kinetis Freedom Day training a week ago and thought the functionality of plugging the board in with USB and being able to drag and drop a new application on it looked interesting. I have been developing all of our bootloaders that operate using RS232 or RS485 on a wide range of uC for about 15 years. Code size is a consideration. For example, my serial bootloader on a 32 bit MCore is less than 20K and includes some hardware abstraction calls that the application can access once it is loaded. I was actually looking at using the Freescale code and adapting it to have some of the additional functionality of our existing products. If I can find some free time, I may evaluate your uTasker some time over the next few months.
A USB-MSD loader occupies less that 10k of code space and is probably more practical in many cases than the KBOOT-HID mode (needs special PC SW and is fairly slow).
With 18k it is possible to have an Ethernet web server based boot loader which is probably the fastest and often most practical method.
The uTasker serial loader (including the various optional methods) also includes an OS in its size which makes it very modular and easy to maintain. FSL_Kinetis_Bootloader_1_0_2 is built up with call tables and is rather difficult to follow so I wouldn't like to extend and have to maintain functionality. It took 2 days to add KBOOT USB-HID and UART modes to the uTasker serial loader, test on various KE, KL and K devices using several IDEs (noting that the operation is completely simulated in the uTasker Kinetis simulator so no HW target debugging was necessary) but it seems the FSL_Kinetis_Bootloader_1_0_2 method needs to have different projects developed for different devices and there are several months between releases with little new functionality (the PC SW side is still quite Beta in operation and newer embedded code seems to have lost some device support on the way - possibly due to the high maintenance overhead for multiple devices).
There are CAN, I2C and SPI interface modes that look to be planned for the future but I don't really know whether they will be used much since this then needs a HW module connected to the PC for it to be able to work and I would think that anyone developing, for example, a CAN based node would probably rather add network based updates as a part of the standard application than use the KBOOT mode; at least I have never heard anyone asking about the progress of these planned modes - but I continue monitoring to keep up to date.