Since I've seen so many threads about people having trouble using Gateway alongside A9LH, I thought that I'd finally pop my guide cherry to provide the information in a centralized location. This guide assumes that you've already followed Plailect's OTP guide up to at least Part 5, Section III. Until Gateway comes out with their A9LH payload, there are pretty much two ways to boot into Gateway Mode while using Luma3DS+A9LH. They both involve the use of EmuNAND, so the choice really comes down to which would you like to be more convenient: booting into GW Mode (10.7 EmuNAND) or installing GBA/DSiWare (10.7 SysNAND). Make sure that "Use SysNAND FIRM as default" is turned off and "Autoboot SysNAND" is turned on in either setup for it to work properly. 1. If booting straight into GW Mode is of importance, then you will need a 9.2 SysNAND and a 10.7 EmuNAND. On the 9.2 SysNAND, set up MenuHax with Trigger 1 (no-buttons) and CtrBootManager to autoboot GW.3dsx. The drawbacks to this setup are that you're still relying on MenuHax and GBA/DSiWare have to be double installed to work with EmuNAND. However, I find this build to be far more user-friendly for everyday use. Want to boot into GW Mode? Insert GW card and press the power button. Want to play GBA/DSiWare? Hold L while turning on the console. 2. If ease of installing GBA/DSiWare is more important, then you will need a 10.7 SysNAND and 9.2 EmuNAND. On the 9.2 EmuNAND you can either use MenuHax+CtrBootManager as above or the GW Launcher cia file. If using MenuHax+CtrBootManager, you should use Trigger 1 (L) for your MenuHax trigger and set the CtrBootManager recovery to any button other than L. Regardless of method chosen to launch GW.3dsx, you have to access the Gateway Menu by holding L at launch or not having the GW card inserted. Then, you have to hold B to bring up the Gateway SysNAND option and press X to confirm. The tradeoff here is having to install GBA/DSiWare once in exchange for steps added to launching GW Mode each time you power on the system. With this setup, you'll have to hold L while booting to get into GW Mode. To boot into Luma3DS to play GBA/DSiWare, just turn on the 3DS. Regardless of which method you choose, I recommend installing Quick Reboot to make switching between GW and Luma3DS easier. It saves you from having to turn the 3DS off and on whenever you're switching.