docs: documented ramfs and the vfs strutures

.wiki/Kernel-documentation.md

@@ -284,6 +284,143 @@ More information can be found on the limine project's [GitHub](https://github.co
 
 ## drivers
 
+### fs/ramfs.h
+**Warning:** This is a filesystem specific driver, by this it should only be accessed by the vfs.
+
+The ramfs (ram-filesystem) is not a filesystem in the common sense.
+All data that is stored in ramfs is stored in the virtual file systems cache.
+This means that all data in ramfs is temporary and erased after a reboot.
+
+#### `ramfs_file_delete(node)` - function (void)
+Frees the files cache space. This won't delete the node in the vfs.
+
+#### `ramfs_file_write(node, size, buffer_in)` - function (void)
+If this file has some cache space allocated, it will be freed.
+Then there will be some cache space (**_size_** bytes) allocated and **_size_** bytes from **_buffer_in_** copied into the cache.
+
+This use of the vfs cache isn't a great solution and should be reworked.
+
+#### `ramfs_file_read(node, size, buffer_out)` - function (void)
+Copies **_size_** bytes from the files' cache to **_buffer_out_**.
+This won't copy more bytes than the allocated cache space is big.
+
+### fs/vfs.h
+
+**VFS** stands for _Virtual File System_ and is an abstraction,
+that kinda merges all mounted filesystems into one.
+It provides a general API for dealing with files, and handles all fs specific stuff in the background.
+This VFS is node based, meaning, that every file, directory, mount point, etc is represented as a node in memory.
+Nodes have a type and a fs.
+Nodes can have children and next and previous nodes.
+
+Example node relations:
+```
++-----------+
+| Root Node | <---------+
++-----------+           |
+    |                   |
+[Childs]            [Parent]
+    |     +-------------+---------------+
+    v    /              |                \
++-------+            +-------+            +-------+
+| Child | --[Next]-> | Child | --[Next]-> | Child |
+|   1   | <-[Prev]-- |   2   | <-[Prev]-- |   3   |  ...
++-------+            +-------+            +-------+
+    |
+[Childs]
+    |     
+    v   
+   ...
+```
+
+If a node is accessed it is linked as the first node in the childs order, to make name resolving process faster.
+
+#### `VFS_MAX_NAME_LENGTH` - macro
+The maximum length of a nodes name.
+Bigger names will be cut of at the end.
+
+#### `fs_type_E` - enum
+This enum specifies all supported filesystems:
+  - **RAMFS** - A filesystem, that is bound very tight to the vfs and is completely in the RAM.
+
+#### `vfs_node_type_E` - enum
+This enum specifies all types a node can have:
+  - **Directory** - A directory can contain other nodes
+  - **File** - A file can hold data
+  - **Mount Point** - A mount point is like a directory, but in the vfs backend this resolves to the root of a filesystem
+  - **Block Device** - Neither used nor implemented yet
+
+#### `fs_T` - struct
+This struct specifies a filesystem instance.
+
+| Name      | Type        | Description                                                 |
+|-----------|-------------|-------------------------------------------------------------|
+| type      | fs_type_E   | The type of the filesystem                                  |
+| root_node | vfs_node_T* | A pointer to the vfs node of the filesystems root directory |
+
+#### `vfs_node_cache_T` - struct
+The current node caching system is just a small placeholder that will be reworked soon.
+
+| Name        | Type        | Description                                         |
+|-------------|-------------|-----------------------------------------------------|
+| buffer      | void*       | The actual buffer, where data is cached             |
+| buffer_size | uint64_t    | The size of _buffer_                                |
+| reclaimable | bool        | Not used atm, but could be important after refactor |
+| node        | vfs_node_T* | The node, that the cache belongs to                 |
+
+
+#### `vfs_node_T` - struct
+
+| Name       | Type             | Description                                    |
+|------------|------------------|------------------------------------------------|
+| name       | char[]           | The name of the node                           |
+| type       | vfs_node_type_E  | The type of the node                           |
+| cache      | vfs_node_cache_T | The nodes cache segment                        |
+| size       | uint64_t         | The nodes size                                 |
+| specific   | void*            | General purpose pointer (details below)        |
+| filesystem | fs_T*            | The filesystem this node actually lies in      |
+| prev       | vfs_node_T*      | The previous node                              |
+| next       | vfs_node_T*      | The next node                                  |
+| parent     | vfs_node_T*      | The parent node (has to be dir or mount point) |
+| childs     | vfs_node_T*      | The first child node                           |
+
+##### specific
+The usage of this value is specific to th nodes type:
+  - **Directories:** NULL
+  - **Files:** NULL
+  - **Mount points:** a pointer to the mounted filesystem.
+  - **Block devices:** NULL
+
+#### `g_root_fs` - global variable
+The systems root filesystem.
+Every node resolve will start at this filesystem.
+
+#### `vfs_node_cache_create(node, size)` - function (vfs_node_cache_T*)
+
+#### `vfs_node_cache_destruct(node_cache)` - function (void)
+
+#### `vfs_node_create(parent, name, type, specific)` - function (vfs_node_T*)
+
+#### `vfs_node_destruct(node)` - function (void)
+
+#### `vfs_node_dump_info(node, indent)` - function (void)
+
+#### `vfs_node_resolve_child(node, child_name)` - function (vfs_node_T*)
+
+#### `vfs_file_create(filesystem, path)` - function (vfs_node_T*)
+
+#### `vfs_file_delete(file)` - function (void)
+
+#### `vfs_file_write(file, position, size, buffer_in)` - function (void)
+
+#### `vfs_file_read(file, position, size, buffer_out)` - function (void)
+
+#### `vfs_init(boot_info)` - function (void)
+
+#### `vfs_resolve_path(filesystem, path)` - function (vfs_node_T*)
+
+#### `vfs_unpack_archive_ustar(node, archive)` - function (void)
+
 ### graphics/color.h
 
 #### `color_palette_E` - enum