I am starting to get a feel again. I think what we have here is dkernel is installed to enable yaffs2 support. Then the tarball includes a not from flash micro os, thzat is booted to, taking control from the production bootloader, & the yaffs2 are written to allow the flash commands for fastboot. It is a pain because they seem to be using some TI pioneered tech alongside the Qualcomm SoC. The appsboot.mbn in the fwupdate tarball definitely contains some things stripped out of the flash meemory appsboot (emmc_appsboot.mbn). If you look at the duplicate files in fwupdate, it starts to make sense. It appears like they may be using a payload OS to handle updating.