Boot9.bin 3ds | 2K · UHD |
To understand the file, you have to understand the hardware. Every Nintendo 3DS console contains a dedicated security processor known as the ARM9. This processor handles the initial boot process, encryption, and security checks.
Boot9 is the specific hardcoded code located in the ARM9's boot ROM. It is the very first code that runs when you turn on your 3DS. Because it is burned onto the chip during manufacturing, it cannot be changed via a system update. This made it the ultimate target for hackers: if you exploit Boot9, you have permanent, un-patchable control over the device.
Boot9.bin is a 4 KB, console-specific dump of the 3DS’s first bootloader stage. It is essential for installing boot9strap (CFW) and recovering bricks, but must be dumped from your own console. It is not needed after CFW is set up, and should never be shared online.
If you're following the official 3DS hacking guide (3ds.hacks.guide), you will dump Boot9.bin automatically during the boot9strap installation process – but the guide does not require you to keep or manually handle the file afterward.
Unlocking Your 3DS: Why the File is Your Golden Ticket If you’ve spent any time in the 3DS homebrew scene, you’ve likely seen the name
pop up in guides and forums. It sounds technical—and it is—but understanding what it does is the first step toward becoming a power user. Simply put, is a dump of your console's ARM9 BootROM
. This "security processor" is the brain that handles system initialization and vital cryptographic functions during boot-up.
While it’s often just a backup on your SD card, it serves as a master key for your console’s security. Unlike other files that are unique to every handheld, the is actually the same across all 3DS and 2DS devices , making it a universal standard for certain tools. Why Do You Need It?
You won’t need this file for day-to-day gaming, but it is essential for advanced management and emulation tasks: Decrypting Content:
To view or extract files from your NAND backup on a PC, software like requires this file to handle the encryption. High-Speed Game Installation: Tools like Custom Install (along with your unique movable.sed
) to install games directly to your SD card from a PC at much faster speeds than the console itself. Emulation & Database Rebuilds: If you use Citra or need to rebuild your Title Database Boot9.bin 3ds
, this file helps the software understand the system's core encryption. How to Get Your Own Copy
If you have custom firmware installed, you can dump this file in seconds using Launch GodMode9 (usually by holding the button during boot). Navigate to [M:] MEMORY VIRTUAL , and select "Copy to 0:/gm9/out" Power off and find the file on your SD card in the
The boot9.bin file is a dump of your Nintendo 3DS's bootrom, containing essential encryption keys used by the system's security processor during startup. While it serves as a critical backup, it is also a necessary component for various PC-based tools used in 3DS modding and file management. How to Dump boot9.bin
To obtain this file from your own console, you typically use GodMode9, a powerful browser for your 3DS's NAND and SD card.
Launch GodMode9: Hold the Start button while powering on your 3DS. Navigate to Virtual Memory: Go to [M:] MEMORY VIRTUAL. Locate the File: Highlight boot9.bin.
Copy the Dump: Press A on the file and select Copy to 0:/gm9/out.
Retrieve from SD: Turn off your system, insert your SD card into a computer, and find the file in the /gm9/out folder. What is it Used For?
PC Utilities: Tools like custom-install (for fast game installation) or title database rebuilders require boot9.bin to decrypt and process system data on your computer.
Emulation: Some 3DS emulators use this file to accurately simulate the system's startup and cryptographic behavior.
Recovery: It is a vital part of your console's "unique identity" along with movable.sed and otp.bin, often needed for advanced unbricking or system transfers. Important Safety Tips To understand the file, you have to understand the hardware
Keep it Private: Never share your boot9.bin publicly. It contains unique console data and is copyrighted by Nintendo.
Backup Securely: Store a copy of this file in a safe place (like cloud storage or an external drive) in case your SD card fails.
If you'd like to know how to use this file with a specific modding tool or need help with advanced console recovery, just let me know.
To understand boot9.bin, you must first understand BootROM. In any computing device (from a graphing calculator to a PlayStation 5), the BootROM is the very first code that runs when you press the power button. It is burned into the silicon of the main processor during manufacturing. It cannot be changed, deleted, or updated.
The Nintendo 3DS has two critical BootROMs:
Boot9 (often called "BootROM 9") is the security anchor. It verifies cryptographic signatures on every single piece of software that follows—Nintendo’s firmware (NATIVE_FIRM), the home menu, and even game cartridges.
For the first seven years of the 3DS’s life (2011–2018), Boot9 was an impenetrable black box. If you tried to run unsigned code, Boot9 would simply refuse to boot. Hacks existed, but they were software-based (like launching from specific games) and were temporary, requiring re-exploitation every time the console powered off.
Everything changed in 2018.
On May 20, 2017, a hacker named derrek (with contributions from nedwill, plutoo, and others) released boot9strap—an exploit that revealed a catastrophic flaw: the BootROM contained an unsafe hash comparison that allowed arbitrary code execution before the signature check completed.
For the first time, users could dump the BootROM itself. That dumped file became boot9.bin. If you're following the official 3DS hacking guide ( 3ds
Understanding Boot9.bin: The Golden Key of the Nintendo 3DS In the world of Nintendo 3DS homebrew and custom firmware (CFW), boot9.bin is often referred to as the "Holy Grail." It is a 64KB binary file dumped from the console's BootROM—the very first code that executes when you flip the power switch. What is Boot9.bin?
The boot9.bin file contains the primary bootloader code and, most importantly, the hardware cryptographic keys used by the 3DS's ARM9 processor. Because this code is baked into the console's hardware (write-once memory), it cannot be patched or updated by Nintendo.
For years, these keys were the industry's best-kept secret, as they allow the system to verify the digital signatures of every piece of software, from the home menu to the kernel itself. Why is it Important?
Access to boot9.bin changed the landscape of 3DS hacking by enabling Sighax and Boot9Strap. Here is why it matters:
Ultimate Control: With the keys found in boot9.bin, developers can sign their own code to look "official" to the hardware.
Near-Unbrickable Systems: Because Boot9Strap installs itself at the very beginning of the boot process, users can often access recovery tools even if the operating system (the NAND) is completely corrupted.
Decryption: It allows for the decryption of nearly every encrypted file on the 3DS, including games (CIAs), system modules, and save data.
Legal & Technical Boundary: Because the file contains copyrighted Nintendo code and proprietary keys, it cannot be legally shared online. Users must "dump" it from their own consoles using tools like GodMode9. How is it Obtained?
Modern 3DS hacking methods, such as MSET9 or nintrigger, allow users to run unsigned code. Once you have basic homebrew access, you use a file manager like GodMode9 to dump the BootROM. Launch GodMode9. Navigate to [M:] MEMORY VIRTUAL. Select boot9.bin and copy it to your SD card. The Legacy of Boot9
The discovery of the exploits leading to the dumping of boot9.bin effectively "won" the 3DS hacking scene. It moved the community away from unstable software exploits that Nintendo could patch (like those used in the early "Gateway" or "Redcard" era) to a permanent hardware-level solution that remains effective on every version of the 3DS, 2DS, and New 3DS today.