Hacking How to access your Switch's eMMC or microSD card as an USB disk on your PC

[Zumoly]

Get my memloader payload from https://switchtools.sshnuke.net
Extract the contents of the "sample" folder in the zip to the root of your microsd, before inserting it into the Switch
Run the memloader.bin payload using your preferred launcher (fusee-launcher, TegraRcmSmash, NXLoader, whatever)
On the screen, choose ums_emmc.ini to have the eMMC appear as a USB disk, or ums_sd.ini to have the microSD appear as a USB disk on your PC (with volume buttons), then press the Power button to launch selection

WARNING: RUNNING U-BOOT UMS MODE ON eMMC MIGHT MAKE YOUR SWITCH NOT BOOT ANYMORE (works for me but if they're being truthful, happened to a user), MAKE SURE TO HAVE A RAWNAND BACKUP AND A WAY TO RESTORE IT IF YOU ARE TO DO THIS

The screen should clear (but the backlight should still be on) and you should hear a device plugged in notification, and the disk drive should appear (in windows, eMMC does not get a drive letter because there's nothing to mount)
This is going to be quite slow (3-6MB/s) as it doesn't run the switch memory at its high frequency (because this requires a non-redistributable proprietary blob), and also u-boot does not use UHS-I modes of the microSD (keeps the IO at 3.3v only), however it's still quite useful for adding/replacing some files on your microSD, or exploring the eMMC partitions via HacDiskMount (the USB disk device is openable as a Physical Drive inside of it)

(On Windows, if after launching the ums ini, in device manager you see a device with a yellow exclamation mark, right click and uninstall it, then click the Scan for Hardware changes button to get it to appear properly)

Memloader source code available at https://github.com/rajkosto/memloader

No, I have not been living under a rock for the past month.
BUT... I can't believed I missed THIS!?
I've been removing and inserting my "precious" SD card more times than I wanted just to test new homebrew versions. I guess that's over now.
Thank you very much for this. You indeed are an SD saver!

Edit1:
Windows does not have the necessary drivers to see the SD card.
Any help in the matter is appreciated.

Edit2:
Figured out the driver issue by running the files in tools folder which by the way only support 64 bits windows.
Ah well time to have a second Win7 system then.

 

[rajkosto]

(On Windows, if after launching the ums ini, in device manager you see a device with a yellow exclamation mark, right click and uninstall it, then click the Scan for Hardware changes button to get it to appear properly)

No "necessary drivers" are required. Just keep uninstalling (with the checkbox for delete driver selected, if applicable) until it shows up properly

 

[Zumoly]

No "necessary drivers" are required. Just keep uninstalling (with the checkbox for delete driver selected, if applicable) until it shows up properly

Man! You are the Man!
It works after unplugging and re-plugging it.

 

[phunky1]

When I boot memloader.bin it gives no options to select and goes into screen saying. "Attempting to communicate with USB host....." I only have the sample folder on my sd card?

 

[rajkosto]

When I boot memloader.bin it gives no options to select and goes into screen saying. "Attempting to communicate with USB host....." I only have the sample folder on my sd card?

you extract the CONTENTS of the sample folder to the root of your microsd.

 

[phunky1]

you extract the CONTENTS of the sample folder to the root of your microsd.

Oh nice.....doh. Thanks!

 

[shchmue]

I'm able to load the payload and select from the ini options but when I do, the screen goes blank as it should, I hear a "device disconnected" sound on my computer, the Switch disappears from Device Manager altogether, no new disks, nothing in Disk Management either. Tried two cables (the one that comes with the Switch Pro Controller and an Anker, both able to load payloads fine) and two different PCs.

The ums_*.ini files are in the root of the SD card alongside the uboot folder. It's formatted FAT32 and works fine for homebrew and saving screenshots. There are other files on the card, is that a problem?

 

[rajkosto]

Read section about warning icons in device manager and how it can appear as something else (like bootloader device whatever) if youve installed other drivers.

 

[shchmue]

Read section about warning icons in device manager and how it can appear as something else (like bootloader device whatever) if youve installed other drivers.

no warnings anywhere, and when i view -> devices by connection, there's nothing showing showing as connected to that same USB controller anymore

 

[PRAGMA]

Can we modify Card ID and Extended Card ID values with this?

 

[SliverSrufer]

no warnings anywhere, and when i view -> devices by connection, there's nothing showing showing as connected to that same USB controller anymore

This happens to me as well. I just kept rebooting into rcm and reloading the payload and eventually windows will pick up on the drive.

I have a question, is there a way to port this to an app in the HBmenu and up the USB transfer speed? This is a great app btw.

 

[shchmue]

This happens to me as well. I just kept rebooting into rcm and reloading the payload and eventually windows will pick up on the drive.

I have a question, is there a way to port this to an app in the HBmenu and up the USB transfer speed? This is a great app btw.

I'm glad I finally found someone with the same problem, I'm shocked no one has posted about this especially in the firmware change thread where you have to do this 3-4 times in a row... What on earth is wrong with our setups, this is gonna take forever.

 

[SliverSrufer]

I'm glad I finally found someone with the same problem, I'm shocked no one has posted about this especially in the firmware change thread where you have to do this 3-4 times in a row... What on earth is wrong with our setups, this is gonna take forever.

Not sure its not always like that, sometimes it works first try. Something I noticed is if you just reboot into rcm mode via autorcm it doesn't work. I have to power off the switch for about 10 seconds before booting rcm.

 

[shchmue]

Not sure its not always like that, sometimes it works first try. Something I noticed is if you just reboot into rcm mode via autorcm it doesn't work. I have to power off the switch for about 10 seconds before booting rcm.

hmm I did use AutoRCM but only after it didn't work a lot of times in a row and I obviously did the long power off every time it failed to mount. anyway I got the firmware switched so it's okay now I suppose.

 

[Saver175]

I need help my sd card reader not working and not recognize any cards can I copy and paste files through usb USB type c

 

[guily6669]

Some kind of file manager with fast FTP support would be pretty awesome, are you ever planing to do something like that?

I need help my sd card reader not working and not recognize any cards can I copy and paste files through usb USB type c

Try formatting to Fat32.

 

[Saver175]

Some kind of file manager with fast FTP support would be pretty awesome, are you ever planing to do something like that?

Try formatting to Fat32.

I will try and tell you first of all thank you very much

 

[xiaohei]

I have tried several times to get this to work. When I boot - the disk appears then dissapears after about 3 seconds. I unplug and replug and it will not show up again (did this several times). I tried uninstalling the driver over and over again and no luck. I also tried different usb ports. I also tried restarting the whole proccess over and over again and the drive appears in my computer then immediately dissapears. I am running out of ideas. Can someone please help me.

 

[TamarindoJuice]

WARNING: RUNNING U-BOOT UMS MODE ON eMMC MIGHT MAKE YOUR SWITCH NOT BOOT ANYMORE (works for me but if they're being truthful, happened to a user), MAKE SURE TO HAVE A RAWNAND BACKUP AND A WAY TO RESTORE IT IF YOU ARE TO DO THIS

The same applies to SD card access?
Is it secure to mount it using the TegraRCMGui built-in payload?

 

[rajkosto]

never use TegraRCMGui.

 

[TamarindoJuice]

never use TegraRCMGui.

Really? It can gimme some trouble?