Prerequisites

Prerequisites

Host and runner

The current runtime requires:

• x86-64 Linux with glibc 2.34 or newer. A particular build can require a newer glibc; check its loader errors or ELF version requirements.
• A 64-bit Wine/Proton host process, including a compatible modern WoW64 setup for 32-bit Windows games.
• Working LD_PRELOAD support and access to LinUwUx.so inside any launcher sandbox.
• UMIP disabled and working CPUID faulting, either native or supplied by an appropriate emulation module.

The project README lists Valve Proton, Proton Experimental, GE-Proton, and UMU-managed builds as expected to work. Use a runner supported by your launcher. The old restriction to GE-Proton and CachyOS Proton no longer applies.

Native 32-bit Linux Wine processes cannot load this 64-bit library. A wrong ELF class warning from a helper does not by itself establish whether the actual game process loaded LinUwUx; see Troubleshooting.

Check CPU flags

Run on the host:

grep -m1 '^flags' /proc/cpuinfo | tr ' ' '\n' | grep -E '^(umip|cpuid_fault)$'

Result	Next step
umip appears	Disable UMIP using the kernel parameter below, then reboot.
cpuid_fault appears	Native CPUID faulting is advertised; an emulation module should not be needed.
cpuid_fault is absent	Check the emulation requirements for your CPU and kernel.
Neither flag appears	UMIP is not advertised, but CPUID faulting still needs checking.

Use the flags and runtime log rather than a CPU generation alone. The flag check does not prove that enabling CPUID faulting will succeed in the game process.

Disable UMIP

If umip is listed, add this parameter to your kernel command line using your distribution's bootloader instructions:

clearcpuid=514

Reboot, then check:

cat /proc/cmdline
grep -qw umip /proc/cpuinfo && echo 'UMIP is still enabled' || echo 'UMIP is not enabled'

514 is the x86 UMIP feature bit (16 * 32 + 2) in the kernel feature definitions. This changes the whole system. The kernel documents that clearcpuid taints the kernel. Remove the parameter and reboot to undo it.

Bootloader commands differ between distributions and installations. Use the instructions for the bootloader your machine actually uses.

CPUID emulation on AMD and Steam Deck

The project's CPU prerequisites describe cpuid_fault_emulation for AMD AM4 systems and Steam Deck when native CPUID faulting is missing. The module requires matching kernel headers, build tools, DKMS, and AMD virtualization enabled in firmware. Secure Boot installations need a module signed with an enrolled key.

LinUwUx's installer does not supply or install this module. Follow the module provider's instructions for your kernel and distribution. SteamOS users should use instructions that explicitly cover their current SteamOS release.

If you have installed the module, these commands help check its state:

uname -r
dkms status
lsmod | grep -w cpuid_fault_emulation

After a kernel update, confirm the module is built and loaded for the running kernel. A DKMS entry alone does not establish that it is loaded.

Containers

The environment running Wine must be able to read the library and satisfy its glibc requirements. A successful host installation does not establish either inside Flatpak or a nested Proton/UMU container. See Flatpak and containers.

Once the host is ready, continue with Install.