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

 

[Metalomeus]

Thanx a lot ^^

 

[TheReturningVoid]

Thanx a lot ^^

Sent you a PM with it.

 

[ronildo66]

To date, Which CFW are compatible with arm9loaderhax?

I have a O3DS XL

 

[metaljay]

Could someone compile this for me please?
http://www.megafileupload.com/6bcl/metaljayOTP.bin

I keep getting stuck and I'm at my ends

 

[Stack3r]

So im on my euro n3ds and i run my compiled .3dsx, it starts off at exploiting arm9 and then the screen flashes and then it says install NAND backup with some random codes at the bottom, ive tried to run it atleast 3 times

 

[turbotronic]

someone able to compile it for me? stuck on not having access to my own computer atm.

http://www.megafileupload.com/6cce/OTP.bin

<3

thx in advance

 

[muimu]

someone able to compile it for me? stuck on not having access to my own computer atm.

http://www.megafileupload.com/6cce/OTP.bin

<3

thx in advance

https://mega.nz/#!Tt9kiC6R!m3WRKZ6NN63_PJoLKorxvZtu2CWZVPUieblWwn66JcY

 

[turbotronic]

thx mate

 

[ootnes2]

So im on my euro n3ds and i run my compiled .3dsx, it starts off at exploiting arm9 and then the screen flashes and then it says install NAND backup with some random codes at the bottom, ive tried to run it atleast 3 times

Do you have a nand.bin file in the root of your sd card? If so it will first restore that to your nand and then install arm9loaderhax

 

[N64]

Do you have a nand.bin file in the root of your sd card? If so it will first restore that to your nand and then install arm9loaderhax

is it okay to interrupt it? i got this too on an american n3ds

edit: I'm just gonna let it run, if it fails to install i'll remove nand.bin
edit 2: installed fine. i hope OP updates first post to mention the nand stuff.

 

[ootnes2]

is it okay to interrupt it? i got this too on an american n3ds

edit: I'm just gonna let it run, if it fails to install i'll remove nand.bin
edit 2: installed fine. i hope OP updates first post to mention the nand stuff.

It would be nice if people mentioned it. You'd think that the default wouldn't be do a restore without the user doing something first

 

[TheReturningVoid]

woah my internernet is acting up big time :/

Could someone compile this for me please?
http://www.megafileupload.com/6bcl/metaljayOTP.bin

I keep getting stuck and I'm at my ends

Sent you a pm.

 

[TheReturningVoid]

>snip doublepost<

 

[WiiUBricker]

I feel like I missed something big. Can someone summon the pros and cons for arm9loaderhax vs emuNand?

 

[TR_mahmutpek]

Can we use arm9loaderhax for emunand coldboot or whatelse? Thanks.

 

[TheReturningVoid]

I feel like I missed something big. Can someone summon the pros and cons for arm9loaderhax vs emuNand?

arm9loaderhax and emuNAND are two different things. EmuNAND is a copy of the 3ds operating system on your SD Card, and arm9loaderhax is an almost coldboot entrypoint with arm9 access.

Can we use arm9loaderhax for emunand coldboot or whatelse? Thanks.

Yes, however the only CFW I know of that works at the moment is AuReiNand.

 

[ootnes2]

I feel like I missed something big. Can someone summon the pros and cons for arm9loaderhax vs emuNand?

(I'm assuming you mean pros and cons of arm9loaderhax vs emuNand and menuhax using other hacks)

Pros
Faster emunand boot (10 sec vs 25 sec for n3ds)
100% cold boot rate
Ability to have a CFW sysnand
Ability to prevent future bricks (for example, using function in AuReiNand that blocks writes to Firm1/Firm2 where arm9loaderhax lives, ability to boot directly to decrypt9)

Cons
Could brick your 3ds during install (likely biggest con)
Need sd card in 3ds to even boot sysnand (likely second biggest con)
Takes a couple hours to install

 

[WiiUBricker]

(I'm assuming you mean pros and cons of arm9loaderhax vs emuNand and menuhax using other hacks)

Pros
Faster emunand boot (10 sec vs 25 sec for n3ds)
100% cold boot rate
Ability to have a CFW sysnand
Ability to prevent future bricks (for example, using function in AuReiNand that blocks writes to Firm1/Firm2 where arm9loaderhax lives, ability to boot directly to decrypt9)

Cons
Could brick your 3ds during install (likely biggest con)
Need sd card in 3ds to even boot sysnand (likely second biggest con)
Takes a couple hours to install

Assuming I have installed arm9loaderhax. Can it be patched with a new system update? On emuNand this won't be a problem but since arm9loaderhax is running on sysNand..

 

[Just Passing By]

Assuming I have installed arm9loaderhax. Can it be patched with a new system update? On emuNand this won't be a problem but since arm9loaderhax is running on sysNand..

If you're using AuReiNand then no it's unpatchable. Basically everything about AuReiNand is unpatchable afaik.

 

[ootnes2]

Assuming I have installed arm9loaderhax. Can it be patched with a new system update? On emuNand this won't be a problem but since arm9loaderhax is running on sysNand..

Arm9loaderhax itself will likely not need to be updated if a new system version is released (but it can be updated if need be), but it also isn't usually the case that the hax that you use is updated. If you mean, can SysNand and EmuNand be updated if you use Arm9loaderhax:

* Updating Emunand from the settings app shouldn't be a problem (unless Nintendo comes out with some new security system, but even then it likely won't be)

* Updating Sysnand from the settings app also shouldn't be a problem (BUT SEE NEXT SENTENCE) on the latest AuReiNAND since that has a function that blocks the 3ds from writing to the part of the NAND where arm9loaderhax is stored. That said, its something you do at your own risk. There are other safer complicated ways of achieving the same result (namely making an up to date emunand, dumping parts of it and restoring those parts to sysnand).

 

[WiiUBricker]

I guess I will stick with classic emunand for now. If it ain't broke, don't fix it™.