nvopen-tools

Reverse-engineered tools for NVIDIA binary formats.

Fat Binary Tools

Complete toolkit for manipulating NVIDIA .nv_fatbin sections found in CUDA libraries.

Tools:

• fatbin_dump - Analyze and extract entries from fat binaries
• fatbin_unpack - Extract all entries with metadata manifest
• fatbin_extract_ptx - Extract PTX source code organized by SM architecture
• fatbin_simple_repack - Repack cubin files with ZSTD compression (levels 1-22)
• fatbin_repack - Rebuild fat binary from manifest preserving metadata

Features:

• 100% cuobjdump compatible
• Supports SM 75-121 architectures
• Variable-length headers (64/80/112 bytes)
• ZSTD compression with 87-92% compression ratios
• Handles ELF, PTX, and LTOIR entries
• Tested with 5700+ entry binaries

Build:

cd fatbin
make

Quick Example:

# Extract .nv_fatbin from library
objcopy --dump-section .nv_fatbin=output.fatbin libcublasLt.so

# Analyze
./fatbin_dump output.fatbin --list-elf

# Extract all entries
./fatbin_unpack output.fatbin /tmp/extracted

# Repack with better compression
cd /tmp/extracted
ls *.cubin | xargs /path/to/fatbin_simple_repack -c 19 repacked.bin

See fatbin/README.md for complete documentation.

Documentation

• fatbin/FORMAT_SPECIFICATION.md - Complete fat binary format documentation
• fatbin/nvFatbin.h - nvFatbin API reference

License

MIT