Replace Your Exploit-Ridden Firmware with Linux - Ronald Minnich, Google

What people said

anonym29 · 2023-04 · Strong recommendation

Intel CSME (formerly ME) and AMT ST (formerly PSP) have many properties that are / would be desireable for someone who is/was building a backdoor (DMA, TCP/IP stack that can use onboard ethernet without the host OS being aware, closed source, unremovable, etc). Keep in mind that even if there has not been a backdoor deliberately added, there absolutely have been serious exploits in ME and PSP, and even for those who are not worried about the government, these security coprocessors still pose grave risk to data privacy and security, potentially handing "ring -3" access to non-government hackers. While I personally share your belief that these are probable backdoors, it is important to remind skeptics that they pose a grave security and privacy threat even outside the context of a government backdoor conspiracy. There's a great talk on the risks posed by the capabilities of these security coprocessors by an extremely well-versed individual at Google who was (leading? involved at a high level?) working on Google's efforts to neutralize these dangerous subsystems at Embedded Linux Con in 2017: [VIDEO]

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SEJeff · 2017-11 · Strong recommendation

Absolutely fantastic video from a google engineer (and the original author of LinuxBios / Coreboot) on how they replaced the UEFI firmware with Linux to get Dell servers to boot in 20 seconds: [VIDEO]

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ignoramous · 2023-03 · Recommendation

The gist is (which doesn't hold universally true), when the CPU is powered up, it initializes its internal RAM, loads in a pre-boot ROM, executes it. pre-boot ROM's job is to initialize whatever it has to, to bring in the initial bootloader which initializes RAM, finds a suitable bootloader program and loads it in. This program, also called second-stage bootloader , is an Operating System in its own right. It can understand filesystems, explore attached hardware, speak multiple network protocols, initialize devices as needed. The second-stage bootloader (there may also be a third-stage ) usually then boots into a Kernel. The Linux Kernel invokes the init process and things proceed into the userspace from there. At each of those stages, the bootloader images, the kernel image, the device trees, and the disk / filesystem are verified ("measured") for integrity eventually anchored on a "hardware root-of-trust". If you're a visual learner: How TI Beagleboard boots (33m): [LINK] / [LINK] How ARM Cortex M boots (9m): [LINK] / [LINK] Bootloader 101 (embedded devices; 38m): [LINK] / [LINK] Measured Boot (39m): [LINK] / [LINK] Coreboot (38m): [VIDEO] / [VIDEO] U-Boot (1h 25m): [LINK] UEFI for U-Boot (38m): [LINK] / [LINK] Device Trees (43m): [LINK] / [LINK] ARM Trust Zone (46m): [LINK]

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