Mezzano: Operating system written in Common Lisp
Some starting points:USB mass storage driver: https://github.com/froggey/Mezzano/blob/master/drivers/usb/m...ext4 file system (read-only): https://github.com/froggey/Mezzano/blob/master/file/ext4.lis...TCP network stack: https://github.com/froggey/Mezzano/blob/master/net/tcp.lisp