12 ms·

AMD Details OpenSIL for Advancing Open-Source System Firmware

122 points by YakBizzarro 4y ago

bradfa 4y ago
I was wondering how Oxide would be able to follow through on their claims to be open sourcing even the firmware for their AMD systems. This makes it a little more clear.
- wmf 4y ago
  Oxide phbl https://github.com/oxidecomputer/phbl https://github.com/oxidecomputer/phbl doesn't use OpenSIL. I assume it's written from scratch based on documentation and maybe looking at AGESA. Why can't other server/firmware vendors do the same? Because they're just not willing to.
  - dfox 4y ago
    On AMD's amd64 platforms there is not much for the firmware to do in terms of the platform bring up as everything that is inside the CPU MCM gets initialized to some sane state (by a PSP-like additional management core, but AFAIK it is distinct hardware from PSP) before the actual CPU cores come out of reset. Most of what BIOS/UEFI firmware do on these platforms is about providing the right PC-like abstractions to the running OS. If you control the OS and do not have to support backward compatibility you can shift lot of that logic into the OS itself and you end up with the firmware being essentially an ELF loader, which is not a bad description of what PHBL actually does. On the Intels side of things the FSP is somewhat complex piece of software that does various low-level poking at the hardware in order to make running sane code possible. There probably is a historical reason for that in that AMD started with K8 Opterons which are ccNUMA with packet switched interconnect from the inception and relegating initial power on configuration of that to the amd64-side firmware is not exactly an practical design (at least without breaking various assumptions inherent in the "PC" platform). Contrast that to Intel who got something like 15 years worth of products that used variations of the same Pentium Pro FSB (which as an shared bus removes some of the complexity involved in the platform initialization).
mmphosis 4y ago
Does any of this do away with things like AMD Platform Security Processor? https://en.wikipedia.org/wiki/AMD_Platform_Security_Processor https://en.wikipedia.org/wiki/AMD_Platform_Security_Processo...
- deleted 4y ago
  [deleted]
- oneplane 4y ago
  Probably not, both because the PSP can be part of the SIL bringup which you statically link anyway, and because plenty of business customers want a Secure Enclave and the legal world is having a hard time getting paperwork to suggest it's both secure and open at the same time.
- kmeisthax 4y ago
  No, and you can't remove the PSP without rearchitecturing the processor. However, they could release a PSP firmware that just loads the x86 cores with your chosen BIOS and then halts. Businesses that want their systems to have management backdoors[0] can use the PSP firmware that implements that functionality, while users that care about Free boot chains can use the minimized firmware. [0] Is it a backdoor if the owner put it there deliberately to be able to detect regular OS-level viruses?
  - gray_charger 4y ago
    PSP is a trusted execution environment not a remote management platform. There is no reason anyone should want to remove this from a privacy perspective. In fact, privacy and security software may be hindered without something like PSP or SGX.
    - the8472 4y ago
      Perhaps if you could replace the trust root with your own. But as they are now it's the manufacturer that's in control.
deleted 4y ago
[deleted]
oneplane 4y ago
This is great. It's hopefully slightly better on the technical side than the FSP that we usually get, while also being less of a NDA-encumbered mess that you currently get with any of the big hardware and silicon vendors.

122 points by YakBizzarro 4y ago

I was wondering how Oxide would be able to follow through on their claims to be open sourcing even the firmware for their AMD systems. This makes it a little more clear.

wmf 4y ago
Oxide phbl https://github.com/oxidecomputer/phbl https://github.com/oxidecomputer/phbl doesn't use OpenSIL. I assume it's written from scratch based on documentation and maybe looking at AGESA. Why can't other server/firmware vendors do the same? Because they're just not willing to.
- dfox 4y ago
  On AMD's amd64 platforms there is not much for the firmware to do in terms of the platform bring up as everything that is inside the CPU MCM gets initialized to some sane state (by a PSP-like additional management core, but AFAIK it is distinct hardware from PSP) before the actual CPU cores come out of reset. Most of what BIOS/UEFI firmware do on these platforms is about providing the right PC-like abstractions to the running OS. If you control the OS and do not have to support backward compatibility you can shift lot of that logic into the OS itself and you end up with the firmware being essentially an ELF loader, which is not a bad description of what PHBL actually does. On the Intels side of things the FSP is somewhat complex piece of software that does various low-level poking at the hardware in order to make running sane code possible. There probably is a historical reason for that in that AMD started with K8 Opterons which are ccNUMA with packet switched interconnect from the inception and relegating initial power on configuration of that to the amd64-side firmware is not exactly an practical design (at least without breaking various assumptions inherent in the "PC" platform). Contrast that to Intel who got something like 15 years worth of products that used variations of the same Pentium Pro FSB (which as an shared bus removes some of the complexity involved in the platform initialization).

mmphosis 4y ago

Does any of this do away with things like AMD Platform Security Processor? https://en.wikipedia.org/wiki/AMD_Platform_Security_Processor https://en.wikipedia.org/wiki/AMD_Platform_Security_Processo...

deleted 4y ago
[deleted]
oneplane 4y ago
Probably not, both because the PSP can be part of the SIL bringup which you statically link anyway, and because plenty of business customers want a Secure Enclave and the legal world is having a hard time getting paperwork to suggest it's both secure and open at the same time.
kmeisthax 4y ago
No, and you can't remove the PSP without rearchitecturing the processor. However, they could release a PSP firmware that just loads the x86 cores with your chosen BIOS and then halts. Businesses that want their systems to have management backdoors[0] can use the PSP firmware that implements that functionality, while users that care about Free boot chains can use the minimized firmware. [0] Is it a backdoor if the owner put it there deliberately to be able to detect regular OS-level viruses?
- gray_charger 4y ago
  PSP is a trusted execution environment not a remote management platform. There is no reason anyone should want to remove this from a privacy perspective. In fact, privacy and security software may be hindered without something like PSP or SGX.
  - the8472 4y ago
    Perhaps if you could replace the trust root with your own. But as they are now it's the manufacturer that's in control.

deleted 4y ago

[deleted]

oneplane 4y ago

This is great. It's hopefully slightly better on the technical side than the FSP that we usually get, while also being less of a NDA-encumbered mess that you currently get with any of the big hardware and silicon vendors.