Turtles all the way down: SoCs and Storage

  computers engineering firmware fpga hardware microprocessors opensource peripherals storage system_on_a_chip trade_offs trust

This brings us along to designs that are rather common even though we don't normally think of them as either common or systems. By this, I refer to SoC's - Systems On A Chip. As the name implies, they are full (or nearly so) computers implemented as single mother-huge silicon chips (relatively speaking). On the die you'll find a CPU or microcontroller, supporting electronics for same, an MMU, and enough interfaces to do whatever you want, be it plug in a USB keyboard and mouse, an Ethernet adapter, or a simple USB-to-serial converter circuit. An excellent example of a SoC is …

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Turtles all the way down: Integrated circuits

  computers engineering fpga hdl integrated_circuits manufacture risk threat_models

The next phase of the trusted open computer project is actually manufacturing usable integrated circuits that you can plug into a circuit board, apply power to, and use to do whatever it is that you do. In other words, processing information.

I hate to be a killjoy, but this is really hard. A vital question that we have to ask at this point is whether or not this is the point at which the project is pwnable by a determined third party. Fabbing integrated circuitry on silicon wafers is, to be gentle, a nontrivial process. Here are a couple of …

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