Boot9.bin File (1080p)

Technically, boot9 is identical across all retail 3DS consoles (unlike console-unique keys). However, using a friend’s dump is still copyright infringement of Nintendo’s boot ROM. Moreover, some later CFW tools perform checks to ensure the boot9 dump matches the console’s hardware ID; a mismatch can cause a brick.

The emulation and homebrew communities argue that dumping your own boot9.bin from your own legally purchased 3DS console falls under fair use (or its international equivalents). The argument is: boot9.bin file

Setting up 3DS emulators on your PC to play games you've legally dumped. Technically, boot9 is identical across all retail 3DS