Base class for serial devices such as terminals. More...
#include <serial.hh>
Public Member Functions | |
| SerialDevice (const SerialDeviceParams *p) | |
| ~SerialDevice () | |
| void | regInterfaceCallback (const std::function< void()> &callback) |
| Register a data available callback into the host interface layer. More... | |
| virtual bool | dataAvailable () const =0 |
| Check if there is pending data from the serial device. More... | |
| virtual void | writeData (uint8_t c)=0 |
| Transmit a character from the host interface to the device. More... | |
| virtual uint8_t | readData ()=0 |
| Read a character from the device. More... | |
 Public Member Functions inherited from SimObject | |
| const Params * | params () const |
| SimObject (const Params *_params) | |
| virtual | ~SimObject () |
| virtual const std::string | name () const |
| virtual void | init () |
| init() is called after all C++ SimObjects have been created and all ports are connected. More... | |
| virtual void | loadState (CheckpointIn &cp) |
| loadState() is called on each SimObject when restoring from a checkpoint. More... | |
| virtual void | initState () |
| initState() is called on each SimObject when not restoring from a checkpoint. More... | |
| virtual void | regProbePoints () |
| Register probe points for this object. More... | |
| virtual void | regProbeListeners () |
| Register probe listeners for this object. More... | |
| ProbeManager * | getProbeManager () |
| Get the probe manager for this object. More... | |
| virtual Port & | getPort (const std::string &if_name, PortID idx=InvalidPortID) |
| Get a port with a given name and index. More... | |
| virtual void | startup () |
| startup() is the final initialization call before simulation. More... | |
| DrainState | drain () override |
| Provide a default implementation of the drain interface for objects that don't need draining. More... | |
| virtual void | memWriteback () |
| Write back dirty buffers to memory using functional writes. More... | |
| virtual void | memInvalidate () |
| Invalidate the contents of memory buffers. More... | |
| void | serialize (CheckpointOut &cp) const override |
| Serialize an object. More... | |
| void | unserialize (CheckpointIn &cp) override |
| Unserialize an object. More... | |
| Public Member Functions inherited from EventManager | |
| EventQueue * | eventQueue () const |
| void | schedule (Event &event, Tick when) |
| void | deschedule (Event &event) |
| void | reschedule (Event &event, Tick when, bool always=false) |
| void | schedule (Event *event, Tick when) |
| void | deschedule (Event *event) |
| void | reschedule (Event *event, Tick when, bool always=false) |
| void | wakeupEventQueue (Tick when=(Tick) -1) |
| This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers. More... | |
| void | setCurTick (Tick newVal) |
| EventManager (EventManager &em) | |
| Event manger manages events in the event queue. More... | |
| EventManager (EventManager *em) | |
| EventManager (EventQueue *eq) | |
| Public Member Functions inherited from Serializable | |
| Serializable () | |
| virtual | ~Serializable () |
| void | serializeSection (CheckpointOut &cp, const char *name) const |
| Serialize an object into a new section. More... | |
| void | serializeSection (CheckpointOut &cp, const std::string &name) const |
| void | unserializeSection (CheckpointIn &cp, const char *name) |
| Unserialize an a child object. More... | |
| void | unserializeSection (CheckpointIn &cp, const std::string &name) |
| Public Member Functions inherited from Drainable | |
| DrainState | drainState () const |
| Return the current drain state of an object. More... | |
| virtual void | notifyFork () |
| Notify a child process of a fork. More... | |
| Public Member Functions inherited from Stats::Group | |
| Group (Group *parent, const char *name=nullptr) | |
| Construct a new statistics group. More... | |
| virtual | ~Group () |
| virtual void | regStats () |
| Callback to set stat parameters. More... | |
| virtual void | resetStats () |
| Callback to reset stats. More... | |
| virtual void | preDumpStats () |
| Callback before stats are dumped. More... | |
| void | addStat (Stats::Info *info) |
| Register a stat with this group. More... | |
| const std::map< std::string, Group * > & | getStatGroups () const |
| Get all child groups associated with this object. More... | |
| const std::vector< Info * > & | getStats () const |
| Get all stats associated with this object. More... | |
| void | addStatGroup (const char *name, Group *block) |
| Add a stat block as a child of this block. More... | |
| const Info * | resolveStat (std::string name) const |
| Resolve a stat by its name within this group. More... | |
| Group ()=delete | |
| Group (const Group &)=delete | |
| Group & | operator= (const Group &)=delete |
Protected Member Functions | |
| void | notifyInterface () |
| Notify the host interface of pending data. More... | |
| Protected Member Functions inherited from Drainable | |
| Drainable () | |
| virtual | ~Drainable () |
| virtual void | drainResume () |
| Resume execution after a successful drain. More... | |
| void | signalDrainDone () const |
| Signal that an object is drained. More... | |
Private Attributes | |
| std::function< void()> | interfaceCallback |
| Currently regisxtered host interface layer callback. More... | |
Additional Inherited Members | |
| Public Types inherited from SimObject | |
| typedef SimObjectParams | Params |
| Static Public Member Functions inherited from SimObject | |
| static void | serializeAll (CheckpointOut &cp) |
| Serialize all SimObjects in the system. More... | |
| static SimObject * | find (const char *name) |
| Find the SimObject with the given name and return a pointer to it. More... | |
| Static Public Member Functions inherited from Serializable | |
| static const std::string & | currentSection () |
| Gets the fully-qualified name of the active section. More... | |
| static void | serializeAll (const std::string &cpt_dir) |
| Serializes all the SimObjects. More... | |
| static void | unserializeGlobals (CheckpointIn &cp) |
| Protected Attributes inherited from SimObject | |
| const SimObjectParams * | _params |
| Cached copy of the object parameters. More... | |
| Protected Attributes inherited from EventManager | |
| EventQueue * | eventq |
| A pointer to this object's event queue. More... | |
Detailed Description
Base class for serial devices such as terminals.
This class provides a unified interface that all serial (RS232 or similar) devices must implement. A device can be wired to exactly one host serial interface (serial port model).
SerialDevices are passive devices that are driven by the serial interface using the writeData(c) (the interface sends a character) and readData() (the interface reads a character) methods. Serial devices need to override these methods to communicate with the host interface layer.
To implement basic flow control, serial devices must implement the dataAvailable() method. This method returns true if a valid character can be read using the readData() method. When data becomes available, the serial device must call the notifyInterface() method to send a callback to the interface layer.
To send a character (host to device), the interface layer calls writeData(char) to send a character to the serial device.
To read a character (device to host), the interface layer calls dataAvailable() to determine if there is a character pending. If there is data available, it immediately calls readData() to get the character. The receive loop in the serial device typically looks like this:
To avoid polling, the interface layer may register a data available callback using the regInterfaceCallback() method. The device uses this callback to notify the interface layer whenever there is new data pending. Note that devices will normally only notify the interface layer when there is a state transition in the device. E.g., the dataAvailable() transitions from false to true. This means that there can be multiple pending characters when the interface layer receives the callback.
Constructor & Destructor Documentation
◆ SerialDevice()
◆ ~SerialDevice()
Member Function Documentation
◆ dataAvailable()
|
pure virtual |
Check if there is pending data from the serial device.
- Returns
- true if there is data pending that can be read using the readData() method.
Implemented in SerialNullDevice, and Terminal.
Referenced by notifyInterface(), SimpleUart::read(), Pl011::read(), Uart8250::read(), VirtIOConsole::TermRecvQueue::trySend(), Pl011::write(), and Uart8250::write().
◆ notifyInterface()
|
protected |
Notify the host interface of pending data.
Definition at line 64 of file serial.cc.
References dataAvailable(), and interfaceCallback.
Referenced by Terminal::data().
◆ readData()
|
pure virtual |
Read a character from the device.
- Returns
- Character from the device's output buffer, undefined if no data is pending.
Implemented in SerialNullDevice, and Terminal.
Referenced by SimpleUart::read(), Pl011::read(), Uart8250::read(), and VirtIOConsole::TermRecvQueue::trySend().
◆ regInterfaceCallback()
| void SerialDevice::regInterfaceCallback | ( | const std::function< void()> & | callback | ) |
Register a data available callback into the host interface layer.
Serial devices need to call the underlying host interface layer to inform it of state change such as pending data that can be read from the device by the interface layer using the readData() method. The interface layer may use this method to register a callback that informs it of pending data.
- Parameters
-
c Callback from interface layer.
Definition at line 53 of file serial.cc.
References fatal_if, and interfaceCallback.
Referenced by Uart::Uart(), and VirtIOConsole::VirtIOConsole().
◆ writeData()
|
pure virtual |
Transmit a character from the host interface to the device.
- Parameters
-
c Received data.
Implemented in SerialNullDevice, and Terminal.
Referenced by SimpleUart::write(), Pl011::write(), and Uart8250::write().
Member Data Documentation
◆ interfaceCallback
|
private |
Currently regisxtered host interface layer callback.
Definition at line 140 of file serial.hh.
Referenced by notifyInterface(), and regInterfaceCallback().
The documentation for this class was generated from the following files: