Hardware What's the whole eFuses thing?

[tunip3]

There are way more efuses than there will be updates for the console's lifetime. However, if more (or less probably too) efuses are burnt than the system is expecting, it won't boot.

If their is less than it will burn up to the number needed, fuses arent just burnt during updates

 

[xXDungeon_CrawlerXx]

If we want to use different Firmware Versions (OFW Version =/= CFW Version), we either need to disable the efuses-check or change the bit/byte for the number of efuses in the Firmware itself.
For now, both methods aren't available but as far as I know, there will be a efuse-check-bypass in Atmosphere

 

[INobody]

I think the idea here was to create a firmware 1.0.0 with an overwritten (needed burned fuses) file. So it would boot the most exploitable firmware with any number of burned fuses.

But this is basically the same problem we got with downgrading. If we are able to sign this new firmware, which it needs to be to boot properly, we could sign anything and won’t need a lower firmware. For frankenfirmwares/partial downgrades: I don’t know the file structure and checks from the firmwares, but I think the ASLR (Memory Randomization) kills every exploit which would be useful for that