eMMC user partition empty - only have emuNand

[karatefeet]

I have a modded switch and was trying to do a system update in stock. It would result in a 2002-3540 unable to access system memory error.
In trying to update the picofly firmware, I seem to have corrupted the eMMC as now the user partition is empty. Booting to stock results in a purple screen.
Unfortunately, I don't have a nand backup but do have a working emuNand. Booting the emuNand works fine.

Is there a way to restore the stock user partition using the emuNand or am I better off doing the level 1 unbricking guide? I have the prod keys and prodinfo from atmosphere's auto backup.

Thanks for reading

 

[jkyoho]

emunand prodinfo should be same as sysnand unless you did blank before.

FYI what modchip did you use?

 

[karatefeet]

Thanks @jkyoho for the reply. It's a rp2040 core chip from Aliexpress.
It's a customer v2 and I was just trying to update the firmware in stock.
I did not blank the prodinfo.

Issue is now it purple screens when booting to OFW which I believe is due to the user partition being empty.
Booting emuNand is working no issues.

Probably the best way to recover is to do the level 2 switch bricking procedures?

 

[thesjaakspoiler]

I vaguely recall it was possible to build a NAND from an emunand/emummc.

 

[impeeza]

I vaguely recall it was possible to build a NAND from an emunand/emummc.

there are two tutorials here on gbatemp about recreate a NAND from a donor one. use the search bar at top of page.

BUT if you know what are you doing you should have a NAND backup at the moment of install the chip and before making any change. use the backup to restore the NAND.