Interesting boot-loader article! I have to give a glance to the U-boot universal boot loader you mention. It seems very good for big operating systems. And I suppose instead of using a computer with something like Hyper-Terminal software a microcontroller can due the part of the host computer through the UART or RS-232 serial port. Boot-loaders get even more complex when they have to handle the software upgrade process. They might boot-up the system in a different mode like the industry standard DFU (Device Firmware Upgrade) mode and after that, switch the device to the normal user mode. This can be done with only one value in a memory register and the system goes and reads such address and boot accordingly.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.