!404 Update en/readme/liteipc_driver.md.

Merge pull request !404 from Christopher Tom/updateipc

en/readme/liteipc_driver.md

@@ -40,7 +40,7 @@ SpecialObj
 ObjContent
 | SpecialObj type | Member | Type        | Description |
 | --------------- | ------ | ----------- | ----------- |
-| OBJ_FD          | fd     | UINT32      | Currently does nothing. |
+| OBJ_FD          | fd     | UINT32      | File descriptor referring to the file description to be sent. |
 | OBJ_PTR         | ptr    | BuffPtr     | Auxiliary data to be sent (not limited by IPC_MSG_DATA_SZ_MAX). |
 | OBJ_SVC         | svc    | SvcIdentity | A service to give the recipient permission to send requests to. |
 
@@ -65,7 +65,7 @@ IpcContent
 
     Trying to reply to a message sent more than LITEIPC_TIMEOUT_NS nanoseconds ago (currently 5 seconds) returns with error **ETIME**.
 
-  The message is copied into memory allocated from the IPC memory area of the process for the recipient task specified by target.handle.  Returns with error **ENOMEM** if the memory cannot be allocated.   Special objects in offsets are then processed.  **OBJ_PTR** objects' data is copied into memory allocated from the recipient's IPC memory area, discards the message and returns with error **EINVAL** if unable to allocate enough memory.  **OBJ_SVC** objects grant the recipient access rights to the service specified by the object if the sender already has access and the service is set as an IPC task (see IPC_SET_IPC_THREAD), discards the message and returns with error **EACCES** if the sender doesn't have access or **EINVAL** if the service isn't running.  Access rights are not revokable, on error any access rights granted before the special object which caused the error will remain.  The message is then added to the tail end of the recipient's list of received messages, the recipient is woken and the scheduler is called.
+  The message is copied into memory allocated from the IPC memory area of the process for the recipient task specified by target.handle.  Returns with error **ENOMEM** if the memory cannot be allocated.   Special objects in offsets are then processed.  For each **OBJ_FD**, a file descriptor that refers to the specified file description is created for the recipient and the recipient's copy of the **OBJ_FD** is updated with the new file descriptor, discards the message and returns with error **EPERM** if the sender doesn't have permission to create the file descriptor, **EBADF** for a bad file descriptor, or **ESRCH** for other problem creating the file descriptor.  **OBJ_PTR** objects' data is copied into memory allocated from the recipient's IPC memory area, discards the message and returns with error **EINVAL** if unable to allocate enough memory.  **OBJ_SVC** objects grant the recipient access rights to the service specified by the object if the sender already has access and the service is set as an IPC task (see IPC_SET_IPC_THREAD), discards the message and returns with error **EACCES** if the sender doesn't have access or **EINVAL** if the service isn't running.  Access rights are not revokable, on error any access rights granted before the special object which caused the error will remain.  The message is then added to the tail end of the recipient's list of received messages, the recipient is woken and the scheduler is called.
 - The **BUFF_FREE** flag indicates a request to free the memory used by the buffToFree message so it can be used again later for receiving messages.  Returns with error **EFAULT** if buffToFree doesn't point to a received message.  Returns with error **EINVAL** if an invalid address.
 - The **RECV** flag indicates a request to receive a message.
   - If the **SEND** flag is set the task will wait for a message for up to LITEIPC_TIMEOUT_MS milliseconds (currently 5 seconds).  Returns with error **ETIME** on timeout.  Messages with a type of **MT_REQUEST** and **MT_REPLY** or **MT_FAILED_REPLY** type messages which don't match outMsg (matching timestamp or matching code and target.token depending on kernel configuration) are discarded (resets timer).  Sets inMsg to point at the received message and removes it from the list of received messages for **MT_REPLY** or **MT_DEATH_NOTIFY** type messages.  Note that receiving  a **MT_DEATH_NOTIFY** makes it impossible to receive the reply so send/receive requests shouldn't be used by services which might receive death notifications.  Discards the message and returns with error **ENOENT** without changing inMsg if the received message has type **MT_FAILED_REPLY**.
@@ -86,7 +86,7 @@ The `IPC_CMS_CMD` request provides various service related utility functions to
 - **CMS_ADD_ACCESS** gives the task specified by the taskID member access rights to the service specified by the serviceHandle member.
 
 LiteIPC includes utility functions for the kernel to manage the IPC system.  
-`LiteIpcInit` initializes the IPC system and must be called before it can be used.  
+`OsLiteIpcInit` initializes the IPC system and must be called before it can be used.  
 `LiteIpcPoolInit` performs basic initialization of a ProcIpcInfo.  Called by the kernel on task creation to initialize the IPC variables in the task's control block.  
 `LiteIpcPoolReInit` initializes the IPC variables of a child task from it's parent's task.  Called by the kernel on the creation of child tasks for basic initialization.  
 `LiteIpcPoolDelete` removes a process' IPC memory pool allocated by memory mapping and all the process' access rights.  Called by the kernel on process deletion for automatic memory and IPC resource management.