3DS custom theme FAQ

There seems to be a lot unclear about this subject, so I thought it could be useful to make a FAQ about it.
If you have any questions ask them here, if you have an answer for a question you've seen a lot also post it (with the question) and I will add it to the list!

Q: How do I install a theme?
A: Download https://github.com/yellows8/3ds_homemenu_extdatatool/releases
Copy the body_LZ.bin (and bg.btstm) from the theme into /3ds/3ds_homemenu_extdatatool or to the root if you're using gateway.
Use the tool to enable cache (If you had a DLC theme selected it's already on but it doesn't hurt to check!) and then copy SD theme cache to extdata.
You can now go to the menu and the theme should appear

Q: Do I need a DLC theme for this?
A: No, but having one does have benefits! If you have a DLC theme selected and then install a custom theme it will stay after a reboot without it you'll have to enable the cache and re-install the theme every time. If you're using a gateway it should't matter as soon as gateway allows for unsigned cia's!

Q: What files should be included with a theme?
A: Most themes will come as body_LZ.bin and if it has background music with a bg.bcstm file (but they can have a ThemeManager.bin file though not common nor needed)
Cache dumps (most likely for pirated themes) will have 3 files:
- BodyCache.bin
- ThemeManager.bin
- bg.bcstm
Cache dumps of mulitible themes at once (9.3+) will have these files:
- BodyCache_rd.bin
- ThemeManger.bin
- bg.bcstm
Gateway themes will be in .cia format (but won't work unless signed!)

Q: Does this overwrite my theme?
A: No, you can choose another theme and then the original one and it will turn back to normal. This is because the tool (by Yellows8) only overwrites the cache witch is replaced when another theme is chosen!

Q: Can you pirate themes with this tool?
A: Yes. (Anyone's cache dump of a DLC theme will work (They are not version specific but BodyCache_RD.bin only works on 9.3+ all others work with any 9.x+ firmware))

Q: Are themes region locked?
A: No.

Q: How long will it keep my own custom theme?
A: If you have a DLC theme (and have it selected) before injecting cache it will stay until you either replace it or load another theme, if you don't it will stay until you close your 3DS, open a game/app or reboot your 3DS (basically useless).

Q: Can I make my own themes?
A: Yes, if you want to know how here is a simple guide by ChrisCerne:

If anyone of you is having trouble making your own theme, here's how.

1. Download the tool here (https://gbatemp.net/threads/release-theme-customization-tools.374206/)
2. Create a new BLANK BMP image with the dimensions 512 x 256 pixels for the top screen.
3. At the coordinates (0, 0) of that new image, insert the picture you want with the dimensions of 400 x 240. This will be the top screen.
4. Create a new BLANK BMP image with the dimensions 1024 x 256 pixels for the bottom screen.
5. Starting at coordinates (0, 0) of that new image, insert the three different images you want to transition on the bottom screen.
6. These three images should be each 320 x 240 pixels, and at coordinates (0, 0), (320, 0), and (640, 0) respectively.
7. Remember that these images will not fill up all of the white-space within the container BMP images. This is supposed to happen.
8. In the 3DS Theme Editor that you downloaded in step one, import the default theme by pressing File>Open and navigating to data/body_BZ.bin.
9. For slide 0, press File>Import and select the BMP Image you need for the top screen.
10. For slide 1, press File>Import and select the BMP Image you need for the bottom screen.
11. Once you're done importing, press simulator to do a test-run of your theme thus far.
12. If you're happy with your results, press File>Save to save your body_BZ.bin file.

Q: How do I add sound to my theme?
A: First make a .wav file with a piece of music (The file must have a size of 0x337000 or 3.371.008 bytes you can fill up extra space with 0 bytes using a HEX editor)
Use Every File Explorer (https://gbatemp.net/threads/release-every-file-explorer.373615/) to convert it to .bcstm (File -> New from File -> Nintendo 3DS Plugin -> CTR Stream -> open .wav -> save icon -> save as bgm.bcstm)

Q: Why do some themes have a white box at the top left?
A: This is most likely a small bug in the theme maker! You'll probably have to live with it for now.

Q: Why do many themes have folders with a mario bullet on them?
A: This is the default folder for the custom theme tool, this means that many theme makers didn't change it.

Q: Can themes have custom icons for games?
A: Most likely yes, but none have at the moment (and it's unsure when the tool will support this (and if we can even do this!))
For documentation on the cached icons that could be edited: http://3dbrew.org/wiki/Home_Menu#Cache.dat_.26_CacheD.dat

Q: Does this mean NINJHAX has kernel?
A: No, however it is able to read and write both NAND and SD extdata which is still cool (and might be useful)

 

[nolimits59]

Little question guys, i applied my custom theme to emunand(Noisecontrollers 2009 theme with venom piano melody on the background, i give it to ya all if there is some hardstyle fans over here... ^^).
And now a want to downgrade my console and update my emunand, does my theme will still be there if i update ?

 

[MarioBrosThe]

ustom folders are the images 2,3,4 and 5 in the template.
for example: you can open a theme with the 3DS Theme Editor -> go to body_LZ.bin -> navigate to image 2 and click on "File" -> "Export".
then you got my folder design. You can paint your own on it.

k thanks!

 

[MarioBrosThe]

Little question guys, i applied my custom theme to emunand(Noisecontrollers 2009 theme with venom piano melody on the background, i give it to ya all if there is some hardstyle fans over here... ^^).
And now a want to downgrade my console and update my emunand, does my theme will still be there if i update ?

I'm an EDM fan m8

 

[weatMod]

what about the sound that plays when you select an item from the home menu? how do you change that? and if you overwrite to existing theme with this what happens?it uses the sound from that theme? or the default no theme sound?
can someone give specifics how to change this, file size requirement etc
and also how do i pad the btscm file in a hex editor to make it the correct size? i don't math and i dont hex so can someone please explain for idiots? someone should at least put a brief explanation for people who have no clue how to use hex editor and do this

also the link to the tool is only in 3dsx where do i find the compiled .cia, and what is this .sdmh file for?

EDIT:actually i have a previously downloaded .cia version of the tool but i dont think it is the latest 1.1 version
you should put links for the .cia versions on 1.1 tool in OP OP

 

[MarioBrosThe]

Any one here like Monstercat? I do, and I made a Monstercat theme!

Download with custom music inside (song: Aero Chord - Surface): https://www.dropbox.com/s/2ffth63wd9xdd5f/Monstercat Theme by Damon.zip?dl=0

 

[starly396]

Can animated themes / panoramas on the top screen be created?

 

[Chrisser_75]

I'm an EDM fan m8

Hardstyle, Rawstyle, Hardcore and so on-Fan

 

[weatMod]

delete

 

[nolimits59]

Cool that there is some hard dance fans ! But i still need my answer if someone have it ! ^^ if i update my custom themed 9.2 emuNAND to 9.4, did it will keep my theme ?

 

[weatMod]

ok can someone please clarify what i am supposed to do with the audio?
i am getting all fucked up here because i am looking at 2 different tutorials a they both say totally different thing
1st one here
https://gbatemp.net/threads/tutorial-how-to-make-a-custom-3ds-theme.377533/

he says this

6. File -> Save As untitled.bstrm
7. Rename untitled.bstrm to BgmCache.bin and place on SD card

ok 1st of all what is bStrm? does he mean bCstrm? or bRstm? or is this a 3rd file type?

second, he says to "rename untitiled.bstrm to BGMcache.bin"

but in this thread it say to just...
" save as bgm.bcstm)" it doesn't say to rename it to bgmcache.bin

so i am using GW so what do i put on the SD card? do i rename the .bcstrm file to bgm.bcstm or do i rename it to BgmCache.bin ?

also i assume i don't have to bother with the hex editor and file padding since i just used an .mp3 file then converted it to brstm with the brstm converter then converted that to a bcstm file ?

also the guy who posted the link to the brstm converter said to use a wav file and convert it to brstm , but the converter kept crashing with the wav but it worked with the mp3

 

[MaNiAlJoWo]

ok can someone please clarify what i am supposed to do with the audio?
i am getting all fucked up here because i am looking at 2 different tutorials a they both say totally different thing
1st one here
https://gbatemp.net/threads/tutorial-how-to-make-a-custom-3ds-theme.377533/

he says this

6. File -> Save As untitled.bstrm
7. Rename untitled.bstrm to BgmCache.bin and place on SD card

ok 1st of all what is bStrm? does he mean bCstrm? or bRstm? or is this a 3rd file type?

second, he says to "rename untitiled.bstrm to BGMcache.bin"

but in this thread it say to just...
" save as bgm.bcstm)" it doesn't say to rename it to bgmcache.bin

so i am using GW so what do i put on the SD card? do i rename the .bcstrm file to bgm.bcstm or do i rename it to BgmCache.bin ?

also i assume i don't have to bother with the hex editor and file padding since i just used an .mp3 file then converted it to brstm with the brstm converter then converted that to a bcstm file ?

also the guy who posted the link to the brstm converter said to use a wav file and convert it to brstm , but the converter kept crashing with the wav but it worked with the mp3

I used this tutorial and it worked great.

http://gbatemp.net/threads/tutorial-how-to-make-bgm-bcstm-files-for-3ds-themes.377927/

 

[dronesplitter]

BgmCache.bin is a correct file when it comes to premium themes that you dump yourself and the 3ds_homemenu_extdatatool will recognize and install them.
But, with the custom themes people are making, the correct file should be bgm.bcstm (.brstm doesn't work afaik - I haven't tried renaming it though).

 

[tyons]

brstm is another format and an user made a tool to convert brstms to bcstms (I linked it twice, maybe in this thread too). there's also a tool that converts wavs to brstms and with which you can make the music loop.

 

[weatMod]

brstm is another format and an user made a tool to convert brstms to bcstms (I linked it twice, maybe in this thread too). there's also a tool that converts wavs to brstms and with which you can make the music loop.

yeah i used it, i used them both , read my post, but the brstm converter did not work with a wav file as input, i used the brstm converter but the brstm converter program crashes every time half way through creating the file when i try it using a wav file for input,

so i found a youtube video tutorial for the brstm conveter tool and the kid in the tutorial video used an mp3 for an input file and not a wav so i tried using an mp3 for input file and it worked it converted the mp3 to the brstm file
then i use the that froggie persons tool you linked and converted the brstm into a bcstm

i used the hakido theme as a base and am making my own theme, and after i dumped the cache to my SD card i had the 3 files on the root,thememanage.bin, bodycache.bin and bgmcache.bin

i replaced the bodycache.bin with my renamed body_LZ.bin

so now do i rename the .bcstm file to bgcache.bin and put that on the SD?

or do i rename it to bgm.bcstm and put it on the sd?

 

[tyons]

name it bgm.bcstm. also, you don't need thememanage.bin.

 

[weatMod]

name it bgm.bcstm. also, you don't need thememanage.bin.

ok i already put it on my SD as Bgmcache.bin and the sound works fine but the top and bottom screens are not changed the top screen is just black and the bottom is the same from the hanufuda theme and not my custom bottom image
so should i try and delete the thememanage.bin from my sd and try it again? leaving the bgmcache.bin and the bodycache.bin there?

 

[dronesplitter]

bgm.bcstm and body_LZ.bin are the only two files you should need to install a custom theme.

 

[tyons]

yes, try.
also try to re-open bodycache.bin (rename it to body_LZ.bin while you're at it) with the theme editor and see if it displays the right images, just in case.

 

[weatMod]

bgm.bcstm and body_LZ.bin are the only two files you should need to install a custom theme.

but why some people saying to rename them then? you people do not make any sense someone else said to rename the body_lZ.bin to bodycache.bin and put that on the SD
i already renamed the sound file to bgmcache.bin at the sound works so now you say i should change it?

 

[dronesplitter]

Not trying to confuse you. I don't know which guide told you to use the other files, I haven't seen a guide like that.