Hacking Switch boot procedure is now documented in switchbrew, and it has downgrade protection with fuses.

[TerraPhantm]

what happens once all the fuses are burnt? or is there such a large number of fuses that its not the case? wondering if that kind of protection would fail if they ran out of fuses to burn.

If they burned all the efuses, then it would be possible to downgrade to whatever version was the one that burnt the last one (unless there's some other form of downgrade protection also in there). But there's likely a large enough number of those efuses for that not to happen. It's also possible that they'll only burn efuses for major software versions (1.0 -> 2.0 -> 3.0, etc).

 

[Noctosphere]

If they burned all the efuses, then it would be possible to downgrade to whatever version was the one that burnt the last one (unless there's some other form of downgrade protection also in there). But there's likely a large enough number of those efuses for that not to happen. It's also possible that they'll only burn efuses for major software versions (1.0 -> 2.0 -> 3.0, etc).

I think the last option you and i mentionned is the correct one
They surely burn a fuse only for major update such as 3.0 4.0 5.0 etc

--------------------- MERGED ---------------------------

They will probably burn a fuse when they fix a major entrypoint

 

[aut0mat3d]

They will probably burn a fuse when they fix a major entrypoint

As on 3.01

 

[dAVID_]

As long as the OTP Dump isn't below the newest Version....is everything fine ^^

It stands for One Time Programmable.

 

[Noctosphere]

Do you guys will make a page on something like switch.guide where we will see to which firmware we can downgrade if the fact that they dont burn a fuse every single update is verified?
For exemple, telling us which was the latest update to burn a fuse compared to the fw version your switch is currently on

 

[GerbilSoft]

Do you guys will make a page on something like switch.guide where we will see to which firmware we can downgrade if the fact that they dont burn a fuse every single update is verified?
For exemple, telling us which was the latest update to burn a fuse compared to the fw version your switch is currently on

eFuse counts are listed here: http://switchbrew.org/index.php?title=Fuses#Anti-downgrade

 

[TimX24968B]

They will probably burn a fuse when they fix a major entrypoint

wonder if a buttload of major entrypoints could be made then. we would constantly need to be making them though, but only one per version.

 

[Noctosphere]

eFuse counts are listed here: http://switchbrew.org/index.php?title=Fuses#Anti-downgrade

Do you know how many fuses there are totally in a switch?

 

[DeadlyFoez]

Do you know how many fuses there are totally in a switch?

From what I gather on the wiki page is 256.

 

[Noctosphere]

From what I gather on the wiki page is 256.

And are they all used for downgrade protection?