Adds a Target Device section to TOOLCHAIN.md with specs gathered over
SSH from the Anbernic RG35XX Plus. Confirms the device runs Ubuntu 22.04
with all required shared libraries (SDL2, FFmpeg) pre-installed, making
the Buildroot toolchain unnecessary. Updates Possible Approaches to
reflect that native arm64 container builds are confirmed working.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The Docker/Buildroot toolchain produces 32-bit ARM binaries but the
RG35XX target runs a 64-bit aarch64 userland. Add docs/TOOLCHAIN.md
covering the full pipeline, config details, patches, and three possible
approaches to fix the architecture mismatch.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
