3 ms·

I didn't expect to watch that entire video, but it was so interesting. Part of me is jealous of how much knowledge and skill the author has.

nxobject 2y ago
Especially what it takes to reprogram and re-pair NANDs and Macs together. It's absurd that NANDs not only encode board SN, but MAC ID as well.
- oneplane 2y ago
  It is pretty interesting how this has evolved over the decades. Most hardware has some sort of one-way identity that can be stored in a ROM or sometimes just on the mainboard (like adding/removing some zero-ohm resistors). But because the information has gotten so much more involved over time we now have specific areas on almost all hardware that store device-specific calibration data but also code for network cards to be able to function at all (pretty much all Intel PCs have a GbE firmware embedded in the BIOS or UEFI ROM for example). There used to be separate chips for everything as well, but that became too error-prone and limiting, so instead of having 10 ROMs of varying kinds we ended up with 3 in most cases (embedded boot ROM, device ROM and storage ROM), which then got slimmed down even more to the point where there is a SiP or SoC ROM and either NAND or DFU has to do everything else. Depending on the vendor, some have been adding some 'extra' ROMs (usually Flash EEPROMs) for embedded controllers because they can't trust or modify the hardware delivered by their partners (AMD/Intel) as much as they like, so they do it externally (HP SureStart for example). But because those controllers themselves also have a boot ROM and an embedded config ROM you now end up adding 3 ROMs back into the completed product. We even had a short period where the Intel ME in the chipset had one as well, so you ended up with at least 5 boot ROMs (CPU, CH, GbE, USB, EC) and 2 separate combined ROMs (one of which was the combined traditional BIOS ROM, the other purely the EC), just to start up a random desktop PC.
  - 1oooqooq 2y ago
    it's almost like the purple shipping binary blobs dislike being inconvenienced by other people's binary blobs while they ship their binary blobs. shocking.
- rootsudo 2y ago
  What was most interesting is that WI-FI is binded to the Mac Serial Number, meaning that the mac address even though it is able to be manipulated in OSX, gives out so much information about who you are and allows very easy: Mac Address (the wifi serial hw serial number) > Mac Serial address > who you are. It's interesting.
  - sitzkrieg 2y ago
    nation states love this one weird trick
  - Hamuko 2y ago
    Doesn't the operating system use a randomised MAC address when connecting to Wi-Fi though?
    - 1oooqooq 2y ago
      for the AP, yes. apple don't want google nest knowing who you are. but the real mac is used in lots more places. even for "random" uuid generation.

nxobject 2y ago

Especially what it takes to reprogram and re-pair NANDs and Macs together. It's absurd that NANDs not only encode board SN, but MAC ID as well.

oneplane 2y ago
It is pretty interesting how this has evolved over the decades. Most hardware has some sort of one-way identity that can be stored in a ROM or sometimes just on the mainboard (like adding/removing some zero-ohm resistors). But because the information has gotten so much more involved over time we now have specific areas on almost all hardware that store device-specific calibration data but also code for network cards to be able to function at all (pretty much all Intel PCs have a GbE firmware embedded in the BIOS or UEFI ROM for example). There used to be separate chips for everything as well, but that became too error-prone and limiting, so instead of having 10 ROMs of varying kinds we ended up with 3 in most cases (embedded boot ROM, device ROM and storage ROM), which then got slimmed down even more to the point where there is a SiP or SoC ROM and either NAND or DFU has to do everything else. Depending on the vendor, some have been adding some 'extra' ROMs (usually Flash EEPROMs) for embedded controllers because they can't trust or modify the hardware delivered by their partners (AMD/Intel) as much as they like, so they do it externally (HP SureStart for example). But because those controllers themselves also have a boot ROM and an embedded config ROM you now end up adding 3 ROMs back into the completed product. We even had a short period where the Intel ME in the chipset had one as well, so you ended up with at least 5 boot ROMs (CPU, CH, GbE, USB, EC) and 2 separate combined ROMs (one of which was the combined traditional BIOS ROM, the other purely the EC), just to start up a random desktop PC.
- 1oooqooq 2y ago
  it's almost like the purple shipping binary blobs dislike being inconvenienced by other people's binary blobs while they ship their binary blobs. shocking.
rootsudo 2y ago
What was most interesting is that WI-FI is binded to the Mac Serial Number, meaning that the mac address even though it is able to be manipulated in OSX, gives out so much information about who you are and allows very easy: Mac Address (the wifi serial hw serial number) > Mac Serial address > who you are. It's interesting.
- sitzkrieg 2y ago
  nation states love this one weird trick
- Hamuko 2y ago
  Doesn't the operating system use a randomised MAC address when connecting to Wi-Fi though?
  - 1oooqooq 2y ago
    for the AP, yes. apple don't want google nest knowing who you are. but the real mac is used in lots more places. even for "random" uuid generation.