Solo Enables Static Musl Binaries to Load Glibc-Linked GPU Drivers on Linux

Bridging Musl and Glibc for Static Binaries

Solo introduces a method for musl-linked static Linux binaries to dynamically load shared objects that are linked against glibc. This capability is particularly relevant for applications requiring access to GPU drivers, which are typically provided by the host system as glibc-linked shared libraries. Previously, fully static musl binaries could not normally use dlopen() to load these drivers.

Technical Implementation

The tool provides a dlfcn-style source API, backed by its own ELF loader, which supports x86-64 and aarch64 architectures. It also includes a glibc ABI bridge implemented on top of musl. This architecture allows a single static executable to utilize existing graphics drivers installed on the machine without requiring containers, AppImages, or a second libc within the process.

Vulkan Proof-of-Concept and Testing

A proof-of-concept demonstrates a fully static executable loading an unmodified host Vulkan driver, running a compute shader, and writing the result to a PNG image. This has been tested on AMD (radv, radeonsi), Intel, and NVIDIA GPUs under Linux, as well as on Apple M1 under Asahi Linux. Continuous integration (CI) processes validate Solo by loading shared libraries from the 1,000 most-installed Debian packages, totaling over 2,100 host objects, on both x86-64 and aarch64 architectures with every commit.

Deployment and Verification

Users can obtain a prebuilt binary to test the Vulkan demo, which discovers distro-installed Vulkan ICDs and produces a 512x512 RGBA image. The tool also allows forcing a particular driver. Verification steps are provided to confirm that the executable itself remains dynamically unlinked, showing no INTERP section or dynamic section when inspected with readelf.