Hacking How to downgrade Nintendo Switch firmware 6.2.0?

[Silver324]

So could anyone PLEASE clarify DISTINCTLY, which means not those half-hearted answers like "yea, sort of" or "You'll have to boot with RCM mode" or even "Not in 6.2.0 yet."
that it IS possible ATM to downgrade from 6.2.0 to 6.1.0 (WITHOUT THE NEED OF RCM LATER TO BOOT + PROPERLY WORKING SLEEP MODE ONCE IM ON 6.1.0 AGAIN) if I
- used ChoiDujourNX to upgrade from 6.1.0 to 6.2.0 without blowing the fuses of 6.1.0 before,
- have a complete NAND backup of 6.1.0,
- am able to use hekate only in bootloader since hb and CFW wont work (ergo no ChoiDujourNX on 6.2.0 yet) to restore 6.1.0
???

For several hours now, I read through the whole internet trying to find a WHOLE answer to this, but merely finding any answers from "impossible" over "depends on blabla" to "yea it should be BUT" SO I HAVE NO CLUE WHAT TO BELIEVE ANYMORE.

So now I stated my intention under the above named conditions. IS IT POSSIBLE??
Pls redeem me, thank u..

 

[ccfman2004]

So could anyone PLEASE clarify DISTINCTLY, which means not those half-hearted answers like "yea, sort of" or "You'll have to boot with RCM mode" or even "Not in 6.2.0 yet."
that it IS possible ATM to downgrade from 6.2.0 to 6.1.0 (WITHOUT THE NEED OF RCM TO BOOT + PROPERLY WORKING SLEEP MODE ONCE IM ON 6.1.0 AGAIN) if I
- used ChoiDujourNX to upgrade from 6.1.0 to 6.2.0 without blowing the fuses of 6.1.0 before,
- have a complete NAND backup of 6.1.0,
- am able to use hekate only in bootloader since hb and CFW wont work (ergo no ChoiDujourNX on 6.2.0 yet) to restore 6.1.0
???

For several hours now, I read through the whole internet trying to find a WHOLE answer to this, but merely finding any answers from "impossible" over "depends on blabla" to "yea it should be BUT" SO I HAVE NO CLUE WHAT TO BELIEVE ANYMORE.

So now I stated my intention under the above named conditions. IS IT POSSIBLE??
Pls redeem me, thank u..

If you ever booted OFW 6.2 it will automatically burn fuses. As long as your fuse count is 7 you can restore your 6.1.0 backup and it should run without needing to boot through RCM. If your fuse count is 8 than no. Use Hekate to check your fuse count by dumping them. It will be displayed on the screen how many fuses are burnt.

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

I have a similar question, if it's okay I hijack for a moment;

I have a backup from pre-6.0 before I hacked it to mess around with homebrew briefly. Let's Go updated me to 6.2 today, I didn't realize it was not just a title update. So here's my question;

Am I currently locked of RCM booting to something like Hekate and NAND dumping my current 6.2, downgrading to that pre-6.0 backup, then when I'm done messing around with homebrew restoring that 6.2 NAND?

Nintendo can't magically patch the Tegra exploit as the section that contains the bug is read-only and cannot be modified by a software update. If you restore the pre-6.0 backup, anything that was installed to Nand after the pre-6.0 backup will have to be reinstalled. Also you must always use a CFW to boot as the pre-6.0 software will not run in OFW mode. Then you can always restore the 6.2 backup and loose CFW for now.

Make sure your Boot1/2 files match the system software to down grade to or you'll run into errors. There is a way to recreate them but I'll let someone else fill that part in as I don't it yet.

 

[Silver324]

If you ever booted OFW 6.2 it will automatically burn fuses. As long as your fuse count is 7 you can restore your 6.1.0 backup and it should run without needing to boot through RCM. If your fuse count is 8 than no. Use Hekate to check your fuse count by dumping them. It will be displayed on the screen how many fuses are burnt.

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

Thanks for the quick answer.
No I've never been on 6.2.
My fuse count is 7.
I'd like to use this method to go online on 6.2 but isn't that a bit risky? Since the amount of burnt fuses will be incorrect (if Big N could check that somehow) and autorcm has to be installed (?) as far as I read through ChoiDujourNX and I always avoided that feature..
Furthermore, is it even clear what kind of telemetry takes place on 6.2 if I actually would give that a try? I don't trust this whole update somehow and the least thing I'd want is suck a ban bc of some recklessness..

 

[ZachyCatGames]

Thanks for the quick answer.
No I've never been on 6.2.
My fuse count is 7.
I'd like to use this method to go online on 6.2 but isn't that a bit risky? Since the amount of burnt fuses will be incorrect (if Big N could check that somehow) and autorcm has to be installed (?) as far as I read through ChoiDujourNX and I always avoided that feature..
Furthermore, is it even clear what kind of telemetry takes place on 6.2 if I actually would give that a try? I don't trust this whole update somehow and the least thing I'd want is suck a ban bc of some recklessness..

Don't update to 6.2.0 at all, even with ChoiDujourNX

 

[larrypretty]

To All, I have found a guide, https://guide.sdsetup.com/#/manual620downgrade.

 

[Aniblaze]

Thanks for the quick answer.
No I've never been on 6.2.
My fuse count is 7.
I'd like to use this method to go online on 6.2 but isn't that a bit risky? Since the amount of burnt fuses will be incorrect (if Big N could check that somehow) and autorcm has to be installed (?) as far as I read through ChoiDujourNX and I always avoided that feature..
Furthermore, is it even clear what kind of telemetry takes place on 6.2 if I actually would give that a try? I don't trust this whole update somehow and the least thing I'd want is suck a ban bc of some recklessness..

Fuses are a bit that can only be switched from 0 to 1 once within the Switch hardware. It isn't something that can be changed again. CFW prevents these fuses from being changed or checked when the Switch is turned on. So as long as you never boot into OFW, the bit won't be switched. Unfortunately, CFW doesn't work on 6.2, so you can't prevent 6.2 from changing a fuse.

The fuse check in OFW is done in two instances:

#1 On cold boot. The firmware boots up on a system that was turned off, and checks the fuse count.
#2 On warm boot. The system wakes up from sleep mode, and checks the fuse count.

The first check is what is disabled by CFW. So if you downgrade your system to 6.1 from 6.2, and use CFW to boot up 6.1, it will work. However! The second check, for a reason I can't explain, can't be disabled, and will always happen. Meaning that if you put that downgraded 6.1 CFW into sleep mode, and attempt to wake it up, it will shut down the system, since there's a fuse mismatch.

 

[Silver324]

...so you can't prevent 6.2 from changing a fuse....

I see.
Then how is this meant to be accessible:
"Downgrade is possible, but only if you had backed up your NAND, and was managing your e-fuse, then you could restore from a lower firmware backup to downgrade."
from httpsREPLACEwwwDOTmod3dscardDOTcom/blog/are-we-safe-to-update-nintendo-switch-firmware-to-the-newest-v6-2-0/
(substitute "REPLACE" with "://" and "DOT" with "." since my newbie-status DOESNT ALLOW ME TO HYPERLINK, WTF -_-)

So does this mean there is a way atm to boot into OFW on 6.2 without burning the 8th fuse by "managing" them?
What does that sentence mean if not?

 

[tnnuy]

if you update officially it will be burned! if you do with another program it will not burn

 

[Deleted User]

So could anyone PLEASE clarify DISTINCTLY, which means not those half-hearted answers like "yea, sort of" or "You'll have to boot with RCM mode" or even "Not in 6.2.0 yet."
that it IS possible ATM to downgrade from 6.2.0 to 6.1.0 (WITHOUT THE NEED OF RCM LATER TO BOOT + PROPERLY WORKING SLEEP MODE ONCE IM ON 6.1.0 AGAIN) if I
- used ChoiDujourNX to upgrade from 6.1.0 to 6.2.0 without blowing the fuses of 6.1.0 before,
- have a complete NAND backup of 6.1.0,
- am able to use hekate only in bootloader since hb and CFW wont work (ergo no ChoiDujourNX on 6.2.0 yet) to restore 6.1.0
???

For several hours now, I read through the whole internet trying to find a WHOLE answer to this, but merely finding any answers from "impossible" over "depends on blabla" to "yea it should be BUT" SO I HAVE NO CLUE WHAT TO BELIEVE ANYMORE.

So now I stated my intention under the above named conditions. IS IT POSSIBLE??
Pls redeem me, thank u..

Depends. If you started with rcm mode. and upgraded to 6.2 through unofficial means (which you didn't) then you don't need rcm after downgrading (fuse wouldn't be burned) but since you did update through official means, then a efuse was burned, thefore you have to use rcm mode. As you would have too many fuses burned for that firmware.

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

To break it down for you.
IF you did update through choidujour. and have rcm.
1. sleep mode wouldn't work on 6.2 (as long as you have 7 fuses burned. (6.2 requires 8) .
2. sleep mode will work on versions 1.0-6.1. (hekate patches sleep mode.)
3. You can only boot firmware's properly without hekate if the amount of fuses burned match the requirement. AKA, if you have 7 fuses burned, you can return to 6.1 or 6.0 just fine with functioning sleep mode and without hekate.
If you did burn a fuse (aka didn't update with choidurjour) then your fucked.
All versions below 6.2 with your switch can never return to 6.1 or lower without the help of rcm mode or hekate.
Does this makes sense? It depends on what you have done. As there are anti-downgrade measures in place.

 

[nachuz]

Of course he doesnt. He probably (like the rest of people who will come crying here) updated and now trying to find a ''secret hack'' to downgrade because he foolishly updated despite people literally screaming out every single update NOT TO FREAKING UPDATE before you know whats going on.

most of them are SX kids who believed that an "all firmwares" advertisement would work forever when ads doesn't works like that

 

[Silver324]

Depends. If you started with rcm mode. and upgraded to 6.2 through unofficial means (which you didn't) then you don't need rcm after downgrading (fuse wouldn't be burned) but since you did update through official means, then a efuse was burned, thefore you have to use rcm mode. As you would have too many fuses burned for that firmware.

I'm still on 6.1.
My fuse-burn is 7.
The scenario I stated was a theoretical one if I would downgrade once I would be on 6.2.

if you update officially it will be burned! if you do with another program it will not burn

Right, and that's why I wanted to use ChoiDujourNX - to get on 6.2 without further fuse-burning.
So STILL the same simple question remains:
Is a bootloader like hekate able to boot into OFW on 6.2 (and would this prevent fuse burning) at this time of unavailability of CFW for 6.2 OR is it even impossible to just set up that bootload on 6.2?

So in other words, I thought I could proceed as follows:
1. Load Firmware 6.2 via ChoiDujourNX in order to keep fuses.
2. Start hekate bootloader into that 6.2 Original Firmware in order to keep fuses.
3. If I would have finished using 6.2 OFW, I'd restore my 6.1 backup using hekate to launch OFW or CFW with still 7 burnt fuses again.

So if anyone would FINALLY tell me that WITH NAMED METHOD it isn't possible to launch into OFW with hekate and thus being unable to keep the fuses, I would have clarification.
Since in the FAQ section of the link posted by @larrypretty, there is the statement by the writer "If you ever launched your Switch into Horizon without Hekate/fusee/ReiNX/SXOS on firmware 6.2.0, you will have 8 fuses burnt" SO I'm just wondering if the fuses won't be burnt if you launch WITH Hekate/fusee/ReiNX/SXOS on 6.2 since that sentence possibly could indicate that this wanted opposite indeed IS possible.

Thanks for sticking with me.

 

[Ronhero]

I am going to try this over the weekend, a friend just said they got a low SN used on 6.2.

Buy sxox license
Use tx to make a nand backup
Use this guide to dg to 6.1

https://gbatemp.net/threads/how-to-...nofficially-without-burning-any-fuses.507461/

Boot into RCM TX and setup enunand
Restore the nand backup and activate Auto RCM
Reboot, inject and profit

 

[delete12345]

Nintendo can't magically patch the Tegra exploit as the section that contains the bug is read-only and cannot be modified by a software update.

Hmmm, what if 6.2.0 firmware is actually a completely-rewritten firmware, intentionally avoiding the hardware exploit?

I'm just reading this thread here:

https://www.resetera.com/threads/ni...-and-stopped-the-hacking-scene-for-now.82581/

It says the quote here:

To any one playing along, the changes in 6.2 are genuinely fascinating in how Nintendo rebuilt their boot process to build a completely new, secure boot:

Nintendo has figured out how to defeat a hardware flaw with a software update.

The Big N did a real good job here, real damn good. We'll see if it can remain undefeated for a while but so long as TSEC remains secure, the only way to hack 6.2+ Switches will be through userland even with the older hardware-shot model. Meaning that we've entered a possible line in the sand for the Switch hacking scene that ends at 6.1.0.

 

[tnnuy]

if you are in 6.1, do not upgrade .. you will lose cfw and if you use sx os in 6.1 you will lose the sleeping mod



Edit: wait a few days until things get resolved 6.2 ... everything indicates that it was crack 6.2

 

[ccfman2004]

Hmmm, what if 6.2.0 firmware is actually a completely-rewritten firmware, intentionally avoiding the hardware exploit?

I'm just reading this thread here:

https://www.resetera.com/threads/ni...-and-stopped-the-hacking-scene-for-now.82581/

It says the quote here:

But as long as you don't update you can still use CFW. They still can't fully patch the Tegra bug and stop hekate.

 

[Darkprime23]

I want to know how Nintendo is burning these fuses through this software update. I don't really understand the technical details but how is that even possible? To cause some sort of electrical discharge through software?

 

[ccfman2004]

I want to know how Nintendo is burning these fuses through this software update. I don't really understand the technical details but how is that even possible? To cause some sort of electrical discharge through software?

The efuses are designed to be burned through software using special code that tells the CPU to burn it. I suppose some jack wagon could design a brick code to burn a bunch of efuses to stop you from booting OFW.

Edit: it's probably done the same way you blow a regular fuse. By shoving more current than the fuse is rated for causing it to fail to protect the stuff behind it.

 

[Zaybokk]

guys need help downgrading to 6.1.0 from 6.2.0, but having problems and stuck on this point.. any help would be appreciated.. using :
https://guide.sdsetup.com/#/manual620downgrade
on :
Step 4: Converting Firmware Files
where it says this: In the command prompt, type "ChoiDujour.exe --keyset=keys.txt fw" without quotes
problems with : ChoiDujour.exe
dont work for me trying this, in the pic(s) below...

also second problem is below as with this:
https://gbatemp.net/threads/how-to-get-switch-keys-for-hactool-xci-decrypting.506978/
#4 - Dumping Keys

1. python keys.py SBK_Here_From_Biskeydump TSEC_Here_From_Biskeydump
2. It should say: "Now you can do hactool --keyset=keys.txt to use them!", if it does, and there's no warning messages, you're good to go!
3. but here's also it gives me problems trying this...

 

[sharkdog360]

Is there any possibility to downgrade the V6.2.0 to v6.1.0 or lower ones and how? I just made this mistake, stupied......

Same thing happened to me. I was playing Mario Odyssey and accidentally clicked update. Just wait for new exploit, they have already cracked the new firmware.

 

[Zaybokk]

Same thing happened to me. I was playing Mario Odyssey and accidentally clicked update. Just wait for new exploit, they have already cracked the new firmware.

same thing to me as well, except I was playing Pokemon Let's go... guess no one is gonna help us trying to downgrade, im stuck, I asked nearly everyone, but one seems to have solid answer for where im stuck at, just gives me errors on them both to downgrade, I honestly don't care about losing sleep mode as I really didn't use it that much anyways tbh..