Some guides may also recommend a dsi_sd_card.bin file for complete SD card emulation.
The Nintendo DSi architecture utilizes two main central processing units (CPUs) derived from ARM architecture: the ARM9 and the ARM7. The file is the 64KB binary dump of the internal Boot ROM embedded inside the DSi's ARM7 processor. Technical Specifications File Size: Exactly 64 KB (65,536 bytes). dsi bios7.bin
The Ultimate Guide to dsi bios7.bin: Understanding and Configuring Nintendo DSi Emulation Some guides may also recommend a dsi_sd_card