| 0x0101 | `nx_fopen` | Opens the file at the _len_ bytes long path _path_ and writes a file descriptor to the referenced file into _fd_ (which needs to be a pointer). | path | len | *fd | | status | Implemented |
| 0x0102 | `nx_fclose` | Closes the file which is indicated by descriptor _fd_. This should always be called, otherwise the OS will have to unload files without knowledge of usage. | fd | | | | status | Implemented |
| 0x0103 | `nx_fread` | Reads at most _n_ bytes from a file given as descriptor _fd_ and at a specific position _offset_ into a given memory region _mem_. Returns the amount of bytes that were actually read. | fd | offset | mem | n | read_bytes | Implemented |
| 0x0104 | `nx_fwrite` | Writes at most _n_ bytes from a given memory region _mem_ into the file referenced by _fd_ at the given position _offset_, not inserting but either overwriting existing content or appending to the file. Returns the amount of bytes that were actually written. | fd | offset | mem | n | written_bytes | Implemented |
| 0x0105 | `nx_fdelete` | Completely delete the file or folder at a given path _path_, which is _len_ bytes long. | path | len | | | status | Implemented |
| 0x0106 | `nx_flist` | List all files and/or directories at the _len_ bytes long path _path_ and write their NULL-separated names into _mem_. When _mem_ is NULL, _needed_mem_ (which needs to be a pointer to an 32-bit integer) is filled with the appropriate value. | path | len | mem | *needed_mem | status | Implemented |
| 0x0107 | `nx_finfo` | Writes the information about the files attribute _attr_ into mem. Types of attributes are described below. | fd | attr | mem | | status | N/A |
| 0x0201 | `nx_mmap` | Maps _n_ 4KB pages to address _addr_. You can provide a bitmap of flags with the _flags_ argument. Which flags can be used, is described below. | addr | n | flags | | status | Implemented |
| 0x0202 | `nx_munmap` | Unmaps _n_ 4KB pages at address _addr_. | addr | n | | | status | Implemented |