1. Download assemble_xsr2.py from Github
2. IF onenand is split into onenand_a and onenand_b, combine the bin files and the oob files
3. Use the following command

   python .\assemble_xsr2.py onenand.bin output_dir

4. In the output directory, select the largest partition and use TestDisk

NOTE: If TestDisk says that the partition(s) can't be recovered, try [UNDELETE] instead of Analyze.