How to set up CFW and emuMMC for a Switch with a modchip installed

This page is for setting up CFW for a Switch console with a modchip installed. And creating an emuMMC with Nintendo connections blocked.
Afterwards you will have a good setup to keep using sysMMC as before, for eShop and playing online. While the separate emuMMC can be used when needing to install homebrew games, forwarders and game backups you've dumped.

Notes

≣ No SD reader: Alternative to taking the micro SD card out of the Switch (click to expand)

As soon as you have Hekate working, you can use Hekate's USB Tools to make the Switch function like a micro SD card reader. And easily connect the Switch to your PC or phone to transfer files.
This is a safer alternative to taking the micro SD card out and putting it back. (The card reader is known to break with little use.)
See How to browse SD card contents via USB for instructions and more options.

≣ Disable cloud saves and automated backups (click to expand)

If you don't have NSO or never enabled cloud saves, it's disabled.
How to:
- Open (System Settings) ➔ Data Management ➔ Save Data Cloud ➔ Settings and disable Automatically Back Up Save Data and Automatically Download Save Data
This can be turned back on again on sysMMC after creating emuMMC.

Partition or file emuMMC: You can read here about the benefits of both, so that you may later decide on which emuMMC type to pick.
- If unsure, choose partition; it is the better option.
Never exFAT with Switch: Once you have completed setting up your device, ensure that you never format your SD card to exFAT. exFAT users are much more likely to experience SD card corruption than FAT32 users. This is a Switch, HOS-specific issue.
Mac/Linux users: If using a Mac, remember to always use Hekate's "Fix Archive Bit" tool after copying files to your micro SD card. Mac often does a minor bit change to files/folders, causing issues for the Switchm and those files/folders will not show.
- From Hekate's main menu press:
  Tools ➔ Arch bit • RCM • Touch • Pkg1/2 ➔ Fix Archive Bit

Step 0 - Getting ready

Checklist

Switch console with modchip installed
a PC (and preferably a USB-C cable)
64 GB Micro SD card (128 GB for OLED), or larger. And card reader.
30 GB free space on micro SD card (60 GB for OLED)
Cloud saves disabled
CFW files

CFW files you need

Everything you need to download. (On GitHub scroll down and find the file under Assets)

Hekate - Download hekate_ctcaer_*.*.*_Nyx_*.*.*.zip from the latest release.
Atmosphère - Download atmosphere-*.*.*-master-*********+hbl-*.*.*+hbmenu-*.*.*.zip from the latest release
SigPatches - Download patch-*.*.*-**.*.zip (alternative download)
- Updated for Atmosphère 1.11.2 (5388824be) & OFW 22.5.x
- All previous versions' patches are included

≣ SX core chip users only: Flash Spacecraft-NX or Get SX Gear: (click to expand)

If you get a BOOT.DAT ? screen when you turn on the Switch, this is you.
- Alternative a) Flash the chip with Spacecraft-NX (guide here).
- Alternative b) Download SX Gear and extract to micro SD card.

Step 1 - SD backup

Backup of all files from your micro SD to a PC (if it was used for the same Switch)
- You can use the Switch to browse the SD card contents via USB (recommended)
When backup is complete, delete all files on your micro SD card

Step 2 - CFW files to micro SD

Extract the following to the root of your micro SD card:
- hekate_ctcaer_*.*.*_Nyx_*.*.*.zip
- atmosphere-*.*.*-xxxxxx-*********+hbl-*.*.*+hbmenu-*.*.*.zip
- patch-x.x.x-xx.x.zip
Rename hekate_ctcaer_x.x.x.bin to payload.bin.

Step 3 - Hekate launch options

This configuration gives you 2 launch options:
- CFW emuMMC - Atmosphere - for emuMMC that loads patches and blanks prodinfo.
- Stock - for sysMMC without Atmosphère.
If you want to use Atmosphère on both sysMMC and emuMMC, you'll need an additional launch option for that.
It also sets a Hekate setting to make Hekate the reboot payload. Meaning you'll restart to Hekate when you use Restart from the power menu. (Hold the power button for 3 seconds, then choose Power Options and select Restart)

Create a file named hekate_ipl.ini inside of your /bootloader/ folder.

Copy (you can use the clipboard button top right 📋) and paste this within the file:

[config]
autoboot=0
autoboot_list=0
bootwait=3
backlight=100
autohosoff=0
autonogc=1
updater2p=1
bootprotect=0

[CFW emuMMC - Atmosphere]
pkg3=atmosphere/package3
emummcforce=1
cal0blank=1
kip1patch=nosigchk
icon=bootloader/res/icon_payload.bmp

[Stock]
pkg3=atmosphere/package3
stock=1
emummc_force_disable=1
icon=bootloader/res/icon_switch.bmp

Step 4 - Blocking Nintendo | Avoiding a console ban

≣ Notes about serial blanking and blocking connections: (click to expand)

📝 Both blanking the console's identifying serial information and blocking connections will be used
Atmosphère can blank serial info. This is enough to avoid a ban, but using only this will cause a crash from version 1.7.0 of Atmosphère. We set this setting with both the cal0blank=1 line in the launch option and also by having this exosphere.ini with the line blank_prodinfo_emummc=1.
- Having both is redundant but not harmful and makes user error less likely.
Atmosphère can block specified connections via its built in DNS.mitm feature using a hosts file.
- This is the emummc.txt we'll add in this step.
Using the setup in this guide, Nintendo will only be blocked while using emuMMC.

4.1 Blocking Nintendo connections

Create a file named emummc.txt in /atmosphere/hosts/ (the hosts folder won't exist, so make sure to create it)

And copy and paste this in your emummc.txt file: (You can use the clipboard button top right 📋)

# Block Nintendo Servers
127.0.0.1 *nintendo.*
127.0.0.1 *nintendo-europe.com
127.0.0.1 *nintendoswitch.*
157.230.80.146 *conntest.nintendowifi.net
157.230.80.146 *ctest.cdn.nintendo.net

4.2 Blanking serial info

Create the file exosphere.ini in the root of your SD card

Copy and paste this in your `exosphere.ini` file: (You can use the clipboard button top right 📋 )

[exosphere]
debugmode=1
debugmode_user=0
disable_user_exception_handlers=0
enable_user_pmu_access=0
blank_prodinfo_sysmmc=0
blank_prodinfo_emummc=1
allow_writing_to_cal_sysmmc=0
log_port=0
log_baud_rate=115200
log_inverted=0

Step 5 - Creating emuMMC and finish

Pick which emuMMC type you want to use. emuMMC partition (recommended), or emuMMC file.

Follow either alternative A or B:

≣ Alternative A) Partition-based emuMMC (recommended) and final instructions: (click to expand)

Select the Tools tab, then select Partition SD Card, and finally press Ok.
Move the emuMMC (RAW) slider until it says 29 full (or 58 full for OLED), then press Next Step and finally press Start.
Once the operation is done, press Close and then select the Home tab.
Select emuMMC in the main menu, then select Create emuMMC
Select SD Partition and then select Part 1.
Wait for your emuMMC to get created. Once it's done, select Close and again Close.
Move back any previously deleted files into your SD card:
- Connect the Switch to your PC and enable "USB Mass Storage in Tools" (see guide page) and move back any previously deleted files. Eject the Switch safely and select Close ➔ Close ➔ Home in Hekate to get back to the main menu.
  - IF you instead turn your device off by pressing Power off ➔ Power off and use the card reader you used earlier to move files back into your SD card. You'll have to inject payload again after you've placed your SD card back into your Switch.
Once you're in Hekate, click on launch, and select emuMMC - Atmosphere CFW to launch emuMMC with Atmosphère.
- If you need to go into sysMMC without your CFW, select Reboot and then select OFW.
  - Or select Launch and then select Stock, if you've added that launch option.
- If you want to use Atmosphère with both sysMMC and emuMMC, add an additional launch option to hekate_ipl.ini. See this section.
You did it! You finished CFW and emuMMC setup.

Make a complete sysMMC backup if you haven't already.
Suggestion: After starting emuMMC for the first time, change the system theme to white (or black) so it's different from sysMMC, and you'll have a simple visual to differentiate sysMMC from emuMMC.

≣ Alternative B) File-based emuMMC and final instructions: (click to expand)

Select the Tools tab, then select Partition SD Card, and finally press Ok.
Press Next Step and finally press Start.
Once the operation is done, press Close and then select the Home tab.
Select emuMMC in the main menu, then select Create emuMMC. Select SD File
Wait for your emuMMC to get created. Once it's done, select Close and again Close.
Move back any previously deleted files into your SD card:
- Connect the Switch to your PC and enable "USB Mass Storage in Tools" (see guide page) and move back any previously deleted files. Eject the Switch safely and select Close ➔ Close ➔ Home in Hekate to get back to the main menu.
  - IF you instead turn your device off by pressing Power off ➔ Power off and use the card reader you used earlier to move files back into your SD card. You'll have to inject the payload again after you've placed your SD card back into your Switch.
Once you're in Hekate, click on launch, and select emuMMC - Atmosphere CFW to launch emuMMC with Atmosphère.
- If you need to go into sysMMC without your CFW, select Reboot and then select OFW.
  - Or select Launch and then select Stock, if you've added that launch option.
- If you want to use Atmosphère with both sysMMC and emuMMC, add an additional launch option to hekate_ipl.ini. See this section.
You did it! You finished CFW and emuMMC setup.

Make a complete sysMMC backup if you haven't already.
Suggestion: After starting emuMMC for the first time, change the system theme to white (or black) so it's different from sysMMC, and you'll have a simple visual to differentiate sysMMC from emuMMC.

↵ All CFW setup guides 🦝