Short answer: uLaunchELF (often written uLE or wLaunchELF in FreeDVDBoot) is a file manager that boots from the FreeDVDBoot disc. Its FileBrowser lists devices by short names: mass:/ is your USB drive, mc0:/ is the memory card in Slot 1, mc1:/ is Slot 2, and cdfs:/ is the disc. Select an .ELF file and press Circle (or the button your uLaunchELF build uses for Execute) to run it.

The device names

• mass:/ — USB storage. Only FAT32 with an MBR partition table is reliably visible; NTFS, exFAT, and GPT drives appear empty or freeze the browser (see mass:/ empty).
• mc0:/ — memory card, Slot 1. The install target for FreeMCBoot and Fortuna.
• mc1:/ — memory card, Slot 2.
• cdfs:/ — the optical disc you booted from.
• hdd0:/ — internal hard drive on a Fat with a network adapter (only if formatted and present).

Everyday tasks

• Run an installer: FileBrowser → mass:/ → find FREE_MCBOOT.ELF or the Fortuna installer → Execute.
• Copy files: highlight a file, use the Copy command (R1 menu in most builds), navigate to the destination device, and Paste. Copying OPL into mc0:/BOOT/ is the standard way to make it a permanent menu item.
• Launch a single homebrew: navigate to its .ELF anywhere (USB or disc) and Execute it. No installation is needed to try something.
• Get unstuck: if FileBrowser freezes on mass:/, the USB drive is the suspect — remove it, reboot, and reformat it FAT32/MBR on a PC.

Buttons and configuration

Button mappings in uLaunchELF are configurable and differ slightly between builds, so check the on-screen help in your build before assuming a key. The two things worth configuring early are the default startup path (so uLaunchELF opens where your tools live) and, if you install FreeMCBoot, the FMCB menu entries that point at OPL and uLaunchELF themselves — that way you never need the disc again for daily use, but you keep it as a recovery tool.

Next steps

• Install FreeMCBoot with FreeDVDBoot
• Fix mass:/ empty (USB)
• Build a custom disc

Verified against: CTurt README (uLaunchELF as initial program; run homebrew over USB mass storage) and standard uLaunchELF device naming, checked 2026-10-24.