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