AMD UEFI Inside: What is really behind AGESA, the PSP and Combo PI?

AMD UEFI Inside: What is really behind AGESA, the PSP (Platform Security Processor) and especially Combo PI?
Igor Wallossek

Since there are always questions and some things are often confused, we will give you some insights into AMD-UEFI, what is colloquially called “the BIOS” (although it is no longer correct). I have also broken down the following extremely to remain as simple and understandable as possible. Nevertheless, what happens when the PC starts up is the classic hen-and-egg problem that you simply have to talk about. Software starts hardware, whereas hardware without software does not actually work and software without hardware does nothing. Now what?[…]

In BOTH English and German:

https://www.igorslab.de/en/inside-amd-bios-what-is-really-hidden-behind-agesa-the-psp-platform-security-processor-and-the-numbers-of-combo-pi/

https://www.igorslab.de/inside-amd-bios-was-verbirgt-sich-wirklich-hinter-agesa-dem-psp-platform-security-processor-und-den-zahlen-von-combo-pi/