Boot9.bin is a critical component of the 3DS's boot process, and its significance extends far beyond its original purpose. The Boot9 exploit has opened up new possibilities for 3DS owners, enabling them to create and run custom software. While there are risks associated with using the exploit, it has also provided a platform for creative and innovative software.
For a fully bricked 3DS (no boot9strap, no CFW), hardware hackers use a soldered NAND reader. Once the raw NAND is dumped to PC, boot9.bin is used to decrypt it, allowing repair of the CTRNAND partition.
The Boot ROM is a piece of read-only memory physically baked into the ARM9 silicon during manufacturing. When you press the power button on your 3DS, the ARM9 processor executes the code inside this Boot ROM before anything else loads—even before the operating system on the internal NAND storage chips boots up. Boot9.bin 3ds
arm9loaderhax (A9LH) was the previous standard CFW loader. boot9strap (B9S) succeeded it in May 2017. B9S is faster, more reliable, and easier to update. All modern guides have migrated to boot9strap, and Luma3DS no longer supports the A9LH format.
When you hack a Nintendo 3DS using Boot9strap, one of the first homebrew tools you install is . GodMode9 is a powerful file browser that has full access to the console's hardware. For a fully bricked 3DS (no boot9strap, no
You can dump this file directly from your console using custom firmware tools: Hold Start while powering on to enter GodMode9 . Press Home for the action menu. Navigate to Scripts > GM9MegaScript > Dump Options . Select Dump Boot9.bin & Boot11.bin . The file will be saved to /gm9/out/ on your SD card. Using fastboot3DS:
While the BootROM is the same on every console, it is not recommended to download it from third‑party sources. Dumping your own copy is trivial with GodMode9 and guarantees you are using a legitimate, unmodified version. Downloaded files could be malicious or incomplete. When you press the power button on your
To prevent developers and hackers from analyzing its secrets, Nintendo implemented a strict write-once hardware lock. The Boot9 code is divided into two halves:
If you used GodMode9 to hack your system, you likely already have this file in your /gm9/out/ folder. Losing this file won't break your DS, but losing it and your system files later could be a permanent disaster.
Because the BootROM is identical across all 3DS and 2DS models, the boot9.bin file itself is essentially the same on every console. It contains various encryption keys and cryptographic routines that are necessary for decrypting system software and game data.
Nintendo uses to verify that firmware images are authentic before they are allowed to run Processor Role