This guide is probably obsolete, use this instead. Just drag your otp.bin to your browser window and it will compile it for you, I'm leaving the original guide below for those who likes to DIY.

Original post:
Hopefully this guide should silence the whiners

Before we begin I have to say this is my very first guide that I made from my experience and information from other Temp members, and English isn't my primary language so I might make mistakes. If you find any just tell me and I'll try my best to correct them. (The screenshot in the spoiler was taken in OS X with wineskin because I'm lazy, this guide is for Windows only)

So you just dumped your OTP and wondering how do you compile A9LH for your 3DS? Here's a guide to instruct you how to compile and install the payload on your device. This guide assumes you know the basics of 3DS homebrew and Windows command prompt,and just stay away from this if you don't - menuhax is good enough for most people IMO. (I am serious)

DISCLAIMER: Any modifications to your 3DS are done at your own risk. I am not responsible for any bricks that may occur during this process (use your common sense and read the guide carefully)

0. Requirements:

• arm9loaderhax source (https://github.com/capito27/arm9loaderhax), it includes all the file dumps you'll need, except your own OTP
• miniPasta (https://github.com/d0k3/MiniPasta/releases , N3DS only)
• OTP.bin (DO NOT use dumps that are not from your console or the one included with the A9LH source, you WILL brick your 3DS, guaranteed.)
• Python 2.7.11 x86-64 (https://www.python.org/downloads/windows)
• PyCrypto (http://www.voidspace.org.uk/python/pycrypto-2.6.1/pycrypto-2.6.1.win-amd64-py2.7.exe)
• Make(http://gnuwin32.sourceforge.net/packages/make.htm)
• devkitARM (https://sourceforge.net/projects/devkitpro/files/Automated Installer/ , part of devkitPro)
• Your brain

1. Preparation

1. If you have an existing install of Python 3.x/32-bit 2.7.x, remove it first
2. Install Python 2.7 x86-64, make sure you install "add python.exe to patch" sub feature during installation (it's not set by default)
   
   Spoiler

   
3. Install PyCrypto
4. Install devkitPro 1.6.0, you will be be presented with tons of packages but the only ones we're interested are under devkitARM, simply uncheck everything else.
   
   Spoiler

   
5. Install Make, you should download the file with md5:8ae51379d1f3eef8360df4e674f17d6d

2. Compile A9LH

1. Extract the A9LH source to any directory
2. Copy your OTP.bin to the data_input folder and overwrite the one that's included with the zip file
3. Open a CMD window (Shift+right click on the explorer window or cd into it manually)at the root directory of the source files, type "make" (without quotes) and enter.
4. Wait for a minute or so, a data_output folder will appear and there should be no errors
5. Copy the arm9loaderhax.3dsx file from the newly created folder to /3ds/ on your SD card (the installer is built specifically for the 3DS you dumped its OTP from, if you want to install A9LH on more than one 3DS you will to recompile the payload with their respective OTP.bin files)

3.1 Installing A9LH

1. Ensure you have a dump of your SysNAND before you continue
2. Enter hblauncher using an entry point of your choice
3. Run arm9loaderhax.3dsx (see below if you're stuck on "exploiting arm9")
4. The payload will be installed to your NAND and your 3DS will then be rebooted to black screens afterwards. Don't panic, turn off your 3DS

3.2 "exploiting arm9" workaround (required for n3DS, not sure about o3DS)

1. Download and copy the miniPasta 3dsx to your SD card
2. Run miniPasta, the screen will turn black for a few seconds and you will be kicked back to home menu afterwards
3. Re-enter hblauncher and try running the A9LH installer again

4. Testing the payload + conclusion
There's a test binary (forgot who made it) that will power off your 3DS upon pressing any buttons except ZL, ZR or home. Simply copy it to the root of your SD card, wait for a couple seconds and press a button. If your 3DS powers off, then A9LH is successfully installed and woking correctly (congrats). If your 3DS powers off the moment you turn it on, check if the file is named "arm9loaderhax.bin" and placed in the root directory, if it power led stay on and won't respond to button pressed then your 3DS is probably bricked
If you want a cold boot (permanent) CFW (the reason to get A9LH in the first place), check out @Aurora Wright's ReiNand fork. She already documented it very well so I'm not going through it in this thread

FAQ
Q: I'm getting "python: command not found"
A: Make sure you select "add python.exe to path" during installation, alternatively you can set the PATH variable manually by entering this in cmd (Thanks @Kever)

set PATH=C:\Python27;%PATH%

Q: How to uninstall A9LH?[/SIZE][/SIZE]
A: Restore a sysNAND backup made before running arm9loaderhax.3dsx

 

[thatbooisaspy]

.

 

[mikey420]

python package from the site. BTW I uploaded my OTP.bin to my initial post if someone wants to do so for me.

 

[thatbooisaspy]

.

 

[VaiCorinthians]

keep getting errors trying to install pycrypto
it keeps telling me that python 2.7 (Which I just installed) isn't installed....

anyone want to compile for me? PM me ill send you a link to my OTP.bin file.

I think you need install python 2.7 x86-64 https://www.python.org/ftp/python/2.7.11/python-2.7.11.amd64.msi

 

[mikey420]

Ive install that a few times over now.....

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

got pycrypto thanks to that comand thanks so much

 

[TechyTurtle]

what 3ds software you have to be to use this hax

 

[VaiCorinthians]

what 3ds software you have to be to use this hax

to get otp file: https://gbatemp.net/threads/otp-guide.415140/page-91#post-6107611
to compile arm9loaderhax.3dsx https://gbatemp.net/threads/how-to-compile-and-install-arm9loaderhax.415776/

 

[Disharmony16]

I did yes

I uploaded my OTP.bin file to my previous post

It keeps saying it cant find python in the registry when I try to install pycrypto

i don't know if someone help you but i compile it for you https://mega.nz/#!5dRyFTID!BU8GKeiIf-ol5csKTjpbpIAcbPrzKQWM1nXc5APx-SU

 

[mikey420]

thanks but I actually got it working after I sorted out the pycrypto issues.

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

BTW is it possible to uninstall this hack once its installed?

 

[evandixon]

BTW is it possible to uninstall this hack once its installed?

Yes, just restore a nand backup from before it was installed. If the install fails, you'll need a hard mod though.

 

[mikey420]

sounds good thank you. I've installed the hack without issue and it works great. thank you all for your help.

 

[AkGBA]

just a question for install ... not deleting NAND.bin will copy this file to sysnnd while install ... Will changing this file to emunand, copy a working emunand to sysnand? Will this work?

This. Got my OTP, but waiting a bit before compiling/installing. I'd like to swap sys & emu nands afterwards.

Could this means I can install a9lh, directly inject a 10.6 emunand backup in sysnand (with a9lh still installed), and then inject a 9.2 sysnand backup in emunand via emunandTool on computer ?

Two birds, one stone ?

 

[dkabot]

This. Got my OTP, but waiting a bit before compiling/installing. I'd like to swap sys & emu nands afterwards.

Could this means I can install a9lh, directly inject a 10.6 emunand backup in sysnand (with a9lh still installed), and then inject a 9.2 sysnand backup in emunand via emunandTool on computer ?

Two birds, one stone ?

You'd have to perform a partition backup of your EmuNAND and inject them all (except FIRM0/1) to SysNAND rather than writing the backup verbatim.
Injecting 9.2 backup to EmuNAND should work fine, though.

Ninja edit: I don't read.
Assuming FIRM0/1 from the EmuNAND's nand.bin are actually valid, maybe.
I would not test that without a hardmod, though.

 

[AkGBA]

Do somebody knows more about the NAND.bin injection at a9lh installation ? Is it installed with firm0/firm 1, or without ?

What would be its use if it installed the nand backup WITH firm0/firm1, and therefore deleting a9lh just after installing it. It would just be plain stupid.

 

[dkabot]

Do somebody knows more about the NAND.bin injection at a9lh installation ? Is it installed with firm0/firm 1, or without ?

What would be its use if it installed the nand backup WITH firm0/firm1, and therefore deleting a9lh just after installing it. It would just be plain stupid.

If you look at the code, it installs the backup, then installs A9LH.
I still hold it's best not to try without a hardmod, however.

 

[max_505]

Successfully got the A9LH exploit to work and tested it with the test binary, which it passed, but I have a question: I used to use Reinand and CTRbootmanager before I switched to this one, which folders do I have to delete to get AuReinand working? Both Reinand and AuReinand use "rei" folders, both also have "Reinand.dat" and the ".3dsx/.smdh" files. Should I also delete boot.3dsx and the config files?

tl;dr I got AL9H to work (tested it out with the test binary), but I can't boot to AuReinand probably because of some of the Reinand and CTRbootmanager files left over. Which files are safe to delete?

 

[VaiCorinthians]

Successfully got the A9LH exploit to work and tested it with the test binary, which it passed, but I have a question: I used to use Reinand and CTRbootmanager before I switched to this one, which folders do I have to delete to get AuReinand working? Both Reinand and AuReinand use "rei" folders, both also have "Reinand.dat" and the ".3dsx/.smdh" files. Should I also delete boot.3dsx and the config files?

tl;dr I got AL9H to work (tested it out with the test binary), but I can't boot to AuReinand probably because of some of the Reinand and CTRbootmanager files left over. Which files are safe to delete?

AuReinand use rei folder too
No need Reinand.dat only firmware.bin inside rei folder and arm9loaderhax.bin on root sd card

 

[AkGBA]

If you look at the code, it installs the backup, then installs A9LH.
I still hold it's best not to try without a hardmod, however.

Interesting.

I don't have a hardmod, so I will not test it. But if it's true, if it's really working just like that, it simplifies a lot the swap procedure.

 

[dkabot]

Interesting.

I don't have a hardmod, so I will not test it. But if it's true, if it's really working just like that, it simplifies a lot the swap procedure.

https://github.com/delebile/arm9loa...payload_installer/installer/source/main.c#L43
Look at all the "printf" lines.

 

[AkGBA]

Thanx, but I'm no coder. Almost had a panic attack just looking at the code