Security researchers have asked of Oxide, what are you doing with SMM? SMM is system management mode. This is a concept that exists in x86 CPUs, both Intel and AMD, and it is a mode that the CPU can enter pretty much whenever it wants and do whatever it wants:
What is Oxide doing about System Management Mode (SMM)?
It’s pretty scary. When you enter system management mode, you are executing software that’s been installed by the UEFI BIOS. Why do we need this? Doesn’t this sound like a backdoor into the system? It is a backdoor into the system, a very deliberate one, as it turns out. Why do we do that? The history of this dates all the way back to laptops in the '90s, where computer vendors wanted to put functionality into the system that the operating systems were not yet ready for.
Things like, we’re gonna have a USB mouse, but we actually are gonna run an operating system that doesn’t speak USB yet. So we’re gonna put an entire USB stack in this system management mode. If that sounds terrifying to you, it is. It’s shocking and terrifying. And what is in SMM, when the CPU is there, why it’s there, what it executes, is unknowable to the operating system above it.
Part of the reason we eliminated the BIOS and did our own hypervisor that does that platform initialization is to keep SMM empty. If the CPU were to ever enter a system management mode, our compute sleds would immediately panic and indicate that. Never seen it happen, so we know it’s not doing it of its own accord, but there is no system management mode in the Oxide rack, uniquely in the Oxide rack.
Thanks, and see you next time.