36C3 - Uncover, Understand, Own - Regaining Control Over Your AMD CPU
Why Hacker News recommends it
Cited in discussions of open firmware and trust as a thorough reverse engineering of the PSP.
What it is
A 36C3 talk on the AMD Platform Security Processor, an undocumented ARM core inside AMD CPUs that runs before the main processor. The speakers present their reverse engineering of its internals.
Recommended by 1 HN commenters across 1 different months, 2019 to 2021.
What Hacker News said
Strong rec TobTobXX · 2021-09 · on “Ministry of Freedom – GNU+Linux laptops with Libreboot preinstalled”
There's this great talk from a CCC about reverse engeneering the PSP: Uncover, Understand, Own - Regaining Control Over Your AMD CPU [this video] At 47:10, they mention that they haven't found anything evil. Ofc, this isn't hard proof, but if I trust anyone's answer, then it's theirs. (Btw, watch the whole talk, it's nothing short of incredible.)
Recommends TobTobXX · 2021-09 · on “The Framework is the most exciting laptop I've used”
There's this great talk from a CCC about reverse engeneering the PSP: Uncover, Understand, Own - Regaining Control Over Your AMD CPU [this video] At 47:10, they mention that they haven't found anything evil. Ofc, this isn't hard proof, but if I trust anyone's answer, then it's theirs. I think the likelihood of it being malicious is nonzero, but small enough that I'd condemn active backdoors into the realm of conspiracy theories. There's always the possibility of it being exploited by others, but c'mon: Basically ANY other exploit would be way easier to distribute and activate than one in the PSP.
Cites peter_d_sherman · 2019-12 · on “Uncover, Understand, Own – Regaining Control over Your AMD CPU [video]”
Excerpt: "The AMD Platform Security Processor (PSP) is a dedicated ARM CPU inside your AMD processor and runs undocumented, proprietary firmware provided by AMD. It is a processor inside your processor that you don't control. It is essential for system startup. In fact, in runs before the main processor is even started and is responsible for bootstrapping all other components. This talk presents our efforts investigating the PSP internals and functionality and how you can better understand it. Our talk is divided into three parts: The first part covers the firmware structure of the PSP and how we analyzed this proprietary firmware. We will demonstrate how to extract and replace individual fi
Cites didericis · 2021-03 · on “I want a computer that I own”
If you’re referring to Intel ME and the AMD PSP, people who have analyzed the PSP seem to think it’s safe: [this video]
Cites garaetjjte · 2021-09 · on “Libreboot: Freedom-Respecting Boot Firmware”
That's switch for TPM features only. You cannot disable PSP as it is responsible for x86 initialization. [this video]