Bochs/bochs/gui/wxmain.cc

/////////////////////////////////////////////////////////////////
// $Id: wxmain.cc,v 1.24 2002-09-02 20:13:51 bdenney Exp $
/////////////////////////////////////////////////////////////////
//
// wxmain.cc implements the wxWindows frame, toolbar, menus, and dialogs.
// When the application starts, the user is given a chance to choose/edit/save
// a configuration.  When they decide to start the simulation, functions in
// main.cc are called in a separate thread to initialize and run the Bochs
// simulator.  
//
// Most ports to different platforms implement only the VGA window and
// toolbar buttons.  The wxWindows port is the first to implement both
// the VGA display and the configuration interface, so the boundaries
// between them are somewhat blurry.  See the extensive comments at
// the top of siminterface for the rationale behind this separation.
//
// The separation between wxmain.cc and wx.cc is as follows:
// - wxmain.cc implements a Bochs configuration interface (CI),
//   which is the wxWindows equivalent of control.cc.  wxmain creates
//   a frame with several menus and a toolbar, and allows the user to
//   choose the machine configuration and start the simulation.  Note
//   that wxmain.cc does NOT include bochs.h.  All interactions
//   between the CI and the simulator are through the siminterface
//   object.
// - wx.cc implements a VGA display screen using wxWindows.  It is 
//   is the wxWindows equivalent of x.cc, win32.cc, macos.cc, etc.
//   wx.cc includes bochs.h and has access to all Bochs devices.
//   The VGA panel accepts only paint, key, and mouse events.  As it
//   receives events, it builds BxEvents and places them into a 
//   thread-safe BxEvent queue.  The simulation thread periodically
//   processes events from the BxEvent queue (bx_gui_c::handle_events)
//   and notifies the appropriate emulated I/O device.
//
//////////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////////////////////
// includes
//////////////////////////////////////////////////////////////////////

// For compilers that support precompilation, includes "wx/wx.h".
#include <wx/wxprec.h>
#ifdef __BORLANDC__
#pragma hdrstop
#endif
#ifndef WX_PRECOMP
#include <wx/wx.h>
#endif
#include <wx/image.h>

#include "config.h"              // definitions based on configure script
#include "osdep.h"               // workarounds for missing stuff
#include "gui/siminterface.h"    // interface to the simulator
#include "bxversion.h"           // get version string
#include "wxmain.h"              // wxwindows shared stuff
#include "wxdialog.h"            // custom dialog boxes

// include XPM icons
#include "bitmaps/cdromd.xpm"
#include "bitmaps/copy.xpm"
#include "bitmaps/floppya.xpm"
#include "bitmaps/floppyb.xpm"
#include "bitmaps/paste.xpm"
#include "bitmaps/power.xpm"
#include "bitmaps/reset.xpm"
#include "bitmaps/snapshot.xpm"
#include "bitmaps/mouse.xpm"
#include "bitmaps/configbutton.xpm"
#include "bitmaps/userbutton.xpm"

// FIXME: ugly global variables that the bx_gui_c object in wx.cc can use
// to access the MyFrame and the MyPanel.
MyFrame *theFrame = NULL;
MyPanel *thePanel = NULL;

//////////////////////////////////////////////////////////////////////
// class declarations
//////////////////////////////////////////////////////////////////////

class MyApp: public wxApp
{
virtual bool OnInit();
};

// SimThread is the thread in which the Bochs simulator runs.  It is created
// by MyFrame::OnStartSim().  The SimThread::Entry() function calls a
// function in main.cc called bx_continue_after_config_interface() which
// initializes the devices and starts up the simulation.  All events from
// the simulator
class SimThread: public wxThread
{
  MyFrame *frame;

  // when the sim thread sends a synchronous event to the GUI thread, the
  // response is stored in sim2gui_mailbox.
  // FIXME: this would be cleaner and more reusable if I made a general
  // thread-safe mailbox class.
  BxEvent *sim2gui_mailbox;
  wxCriticalSection sim2gui_mailbox_lock;

public:
  SimThread (MyFrame *_frame) { frame = _frame; sim2gui_mailbox = NULL; }
  virtual ExitCode Entry ();
  void OnExit ();
  // called by the siminterface code, with the pointer to the sim thread
  // in the thisptr arg.
  static BxEvent *SiminterfaceCallback (void *thisptr, BxEvent *event);
  BxEvent *SiminterfaceCallback2 (BxEvent *event);
  // methods to coordinate synchronous response mailbox
  void ClearSyncResponse ();
  void SendSyncResponse (BxEvent *);
  BxEvent *GetSyncResponse ();
};


//////////////////////////////////////////////////////////////////////
// MyApp: the wxWindows application
//////////////////////////////////////////////////////////////////////

IMPLEMENT_APP(MyApp)

bool MyApp::OnInit()
{
  //wxLog::AddTraceMask (_T("mime"));
  bx_init_siminterface ();
  bx_init_main (argc, argv);
  MyFrame *frame = new MyFrame( "Bochs x86 Emulator", wxPoint(50,50), wxSize(450,340), wxMINIMIZE_BOX | wxSYSTEM_MENU | wxCAPTION );
  theFrame = frame;  // hack alert
  frame->Show( TRUE );
  SetTopWindow( frame );
  return TRUE;
}

//////////////////////////////////////////////////////////////////////
// MyFrame: the top level frame for the Bochs application
//////////////////////////////////////////////////////////////////////

BEGIN_EVENT_TABLE(MyFrame, wxFrame)
  EVT_MENU(ID_Config_New, MyFrame::OnConfigNew)
  EVT_MENU(ID_Config_Read, MyFrame::OnConfigRead)
  EVT_MENU(ID_Config_Save, MyFrame::OnConfigSave)
  EVT_MENU(ID_Quit, MyFrame::OnQuit)
  EVT_MENU(ID_Help_About, MyFrame::OnAbout)
  EVT_MENU(ID_Simulate_Start, MyFrame::OnStartSim)
  EVT_MENU(ID_Simulate_PauseResume, MyFrame::OnPauseResumeSim)
  EVT_MENU(ID_Simulate_Stop, MyFrame::OnKillSim)
  EVT_MENU(ID_Sim2CI_Event, MyFrame::OnSim2CIEvent)
  EVT_MENU(ID_Edit_HD_0, MyFrame::OnOtherEvent)
  EVT_MENU(ID_Edit_HD_1, MyFrame::OnOtherEvent)
  EVT_MENU(ID_Edit_Cdrom, MyFrame::OnOtherEvent)
  EVT_MENU(ID_Edit_Boot, MyFrame::OnEditBoot)
  EVT_MENU(ID_Edit_Memory, MyFrame::OnEditMemory)
  EVT_MENU(ID_Edit_Network, MyFrame::OnEditNet)
  EVT_MENU(ID_Log_Prefs, MyFrame::OnLogPrefs)
  // toolbar events
  EVT_TOOL(ID_Edit_FD_0, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Edit_FD_1, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Edit_Cdrom, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Toolbar_Reset, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Toolbar_Power, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Toolbar_Copy, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Toolbar_Paste, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Toolbar_Snapshot, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Toolbar_Config, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Toolbar_Mouse_en, MyFrame::OnToolbarClick)
  EVT_TOOL(ID_Toolbar_User, MyFrame::OnToolbarClick)
END_EVENT_TABLE()

//////////////////////////////////////////////////////////////////
// Menu layout (approximate)
//
// The actual menus will be changing so this probably isn't up
// to date, but having it in text form was useful in planning.
//////////////////////////////////////////////////////////////////
// - File
//   +----------------------+
//   | New Configuration    |
//   | Read Configuration   |
//   | Save Configuration   |
//   +----------------------+
//   | Quit                 |
//   +----------------------+
// - Edit
//   +----------------------+
//   | Floppy Disk 0...     |
//   | Floppy Disk 1...     |
//   | Hard Disk 0...       |
//   | Hard Disk 1...       |
//   | Cdrom...             |
//   | Boot...              |
//   | VGA...               |
//   | Memory...            |
//   | Sound...             |
//   | Networking...        |
//   | Keyboard...          |
//   | Other...             |
//   +----------------------+
// - Simulate
//   +----------------------+
//   | Start                |
//   | Pause/Resume         |
//   | Stop                 |
//   +----------------------+
//   | Speed...             |
//   +----------------------|
// - Debug
//   +----------------------|
//   | Show CPU             |
//   | Show Memory          |
//   | ? what else ?        |
//   +----------------------|
// - Event Log
//   +----------------------+
//   | View                 |
//   | Preferences...       |
//   | By Device...         |
//   +----------------------+
// - Help
//   +----------------------+
//   | About Bochs...       |
//   +----------------------+
//////////////////////////////////////////////////////////////////

MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size, const long style)
: wxFrame((wxFrame *)NULL, -1, title, pos, size, style)
{
  // init variables
  sim_thread = NULL;
  start_bochs_times = 0;

  // set up the gui
  menuConfiguration = new wxMenu;
  menuConfiguration->Append( ID_Config_New, "&New Configuration" );
  menuConfiguration->Append( ID_Config_Read, "&Read Configuration" );
  menuConfiguration->Append( ID_Config_Save, "&Save Configuration" );
  menuConfiguration->AppendSeparator ();
  menuConfiguration->Append (ID_Quit, "&Quit");

  menuEdit = new wxMenu;
  menuEdit->Append( ID_Edit_FD_0, "Floppy Disk &0..." );
  menuEdit->Append( ID_Edit_FD_1, "Floppy Disk &1..." );
  menuEdit->Append( ID_Edit_HD_0, "Hard Disk 0..." );
  menuEdit->Append( ID_Edit_HD_1, "Hard Disk 1..." );
  menuEdit->Append( ID_Edit_Cdrom, "Cdrom..." );
  menuEdit->Append( ID_Edit_Boot, "&Boot..." );
  menuEdit->Append( ID_Edit_Vga, "&VGA..." );
  menuEdit->Append( ID_Edit_Memory, "&Memory..." );
  menuEdit->Append( ID_Edit_Sound, "&Sound..." );
  menuEdit->Append( ID_Edit_Network, "&Network..." );
  menuEdit->Append( ID_Edit_Keyboard, "&Keyboard..." );
  menuEdit->Append( ID_Edit_Other, "&Other..." );

  menuSimulate = new wxMenu;
  menuSimulate->Append( ID_Simulate_Start, "&Start...");
  menuSimulate->Append( ID_Simulate_PauseResume, "&Pause...");
  menuSimulate->Append( ID_Simulate_Stop, "S&top...");
  menuSimulate->AppendSeparator ();
  menuSimulate->Append( ID_Simulate_Speed, "S&peed...");
  menuSimulate->Enable (ID_Simulate_PauseResume, FALSE);
  menuSimulate->Enable (ID_Simulate_Stop, FALSE);

  menuDebug = new wxMenu;
  menuDebug->Append (ID_Debug_ShowCpu, "Show &CPU");
  menuDebug->Append (ID_Debug_ShowMemory, "Show &memory");

  menuLog = new wxMenu;
  menuLog->Append (ID_Log_View, "&View");
  menuLog->Append (ID_Log_Prefs, "&Preferences...");
  menuLog->Append (ID_Log_PrefsDevice, "By &Device...");

  menuHelp = new wxMenu;
  menuHelp->Append( ID_Help_About, "&About..." );

  wxMenuBar *menuBar = new wxMenuBar;
  menuBar->Append( menuConfiguration, "&File" );
  menuBar->Append( menuEdit, "&Edit" );
  menuBar->Append( menuSimulate, "&Simulate" );
  menuBar->Append( menuDebug, "&Debug" );
  menuBar->Append( menuLog, "&Log" );
  menuBar->Append( menuHelp, "&Help" );
  SetMenuBar( menuBar );
  CreateStatusBar();
  SetStatusText( "Welcome to wxWindows!" );

  CreateToolBar(wxNO_BORDER|wxHORIZONTAL|wxTB_FLAT);
  wxToolBar *tb = GetToolBar();
  tb->SetToolBitmapSize(wxSize(16, 16));

  int currentX = 5;
#define BX_ADD_TOOL(id, xpm_name, tooltip) \
    do {tb->AddTool(id, wxBitmap(xpm_name), wxNullBitmap, FALSE, currentX, -1, (wxObject *)NULL, tooltip);  currentX += 34; } while (0)

  BX_ADD_TOOL(ID_Edit_FD_0, floppya_xpm, "Change Floppy A");
  BX_ADD_TOOL(ID_Edit_FD_1, floppyb_xpm, "Change Floppy B");
  BX_ADD_TOOL(ID_Edit_Cdrom, cdromd_xpm, "Change CDROM");
  BX_ADD_TOOL(ID_Toolbar_Reset, reset_xpm, "Reset the system");
  BX_ADD_TOOL(ID_Toolbar_Power, power_xpm, "Turn power on/off");

  BX_ADD_TOOL(ID_Toolbar_Copy, copy_xpm, "Copy to clipboard");
  BX_ADD_TOOL(ID_Toolbar_Paste, paste_xpm, "Paste from clipboard");
  BX_ADD_TOOL(ID_Toolbar_Snapshot, snapshot_xpm, "Save screen snapshot");
  BX_ADD_TOOL(ID_Toolbar_Config, configbutton_xpm, "Runtime Configuration");
  BX_ADD_TOOL(ID_Toolbar_Mouse_en, mouse_xpm, "Mouse Enable/Disable");
  BX_ADD_TOOL(ID_Toolbar_User, userbutton_xpm, "Keyboard shortcut");

  tb->Realize();

  // create a MyPanel that covers the whole frame
  panel = new MyPanel (this, -1);
  panel->SetBackgroundColour (wxColour (0,0,0));
  wxGridSizer *sz = new wxGridSizer (1, 1);
  sz->Add (panel, 0, wxGROW);
  SetAutoLayout (TRUE);
  SetSizer (sz);

  thePanel = panel;
}

void MyFrame::OnConfigNew(wxCommandEvent& WXUNUSED(event))
{
  int answer = wxMessageBox ("This will reset all settings back to their default values.\nAre you sure you want to do this?",
    "Are you sure?", wxYES_NO | wxCENTER);
  if (answer == wxYES) SIM->reset_all_param ();
}

void MyFrame::OnConfigRead(wxCommandEvent& WXUNUSED(event))
{
  panel->ReadConfiguration ();
}

void MyFrame::OnConfigSave(wxCommandEvent& WXUNUSED(event))
{
  panel->SaveConfiguration ();
}

void MyFrame::OnEditBoot(wxCommandEvent& WXUNUSED(event))
{
  int maxBootDevices = 3;
  int bootDevices = 0;
  wxString devices[maxBootDevices];
  int dev_id[maxBootDevices];
  bx_param_bool_c *floppy = (bx_param_bool_c *)
    SIM->get_param (BXP_FLOPPYA_DEVTYPE);
  bx_param_bool_c *hd = (bx_param_bool_c *)
    SIM->get_param (BXP_DISKC_PRESENT);
  bx_param_bool_c *cdrom = (bx_param_bool_c *)
    SIM->get_param (BXP_CDROM_PRESENT);
  wxASSERT (floppy->get_type () == BXT_PARAM_ENUM
      && hd->get_type () == BXT_PARAM_BOOL
      && cdrom->get_type () == BXT_PARAM_BOOL);
  if (floppy->get () != BX_FLOPPY_NONE) {
    devices[bootDevices] = wxT("First floppy drive");
    dev_id[bootDevices++] = BX_BOOT_FLOPPYA;
  }
  if (hd->get ()) {
    devices[bootDevices] = wxT("First hard drive");
    dev_id[bootDevices++] = BX_BOOT_DISKC;
  }
  if (cdrom->get ()) {
    devices[bootDevices] = wxT("CD-ROM drive");
    dev_id[bootDevices++] = BX_BOOT_CDROM;
  }
  if (bootDevices == 0) {
    wxMessageBox( "All the possible boot devices are disabled right now!\nYou must enable the first floppy drive, the first hard drive, or the CD-ROM.", "None enabled", wxOK | wxICON_ERROR );
    return;
  }
  int which = wxGetSingleChoiceIndex ("Select the device to boot from", "Boot Device", bootDevices, devices);
  if (which<0) return;  // cancelled
  bx_param_enum_c *bootdevice = (bx_param_enum_c *) 
    SIM->get_param(BXP_BOOTDRIVE);
  bootdevice->set (which);
}

void MyFrame::OnEditMemory(wxCommandEvent& WXUNUSED(event))
{
  ConfigMemoryDialog dlg (this, -1);
  bx_param_num_c *megs = (bx_param_num_c*) SIM->get_param(BXP_MEM_SIZE);
  bx_param_string_c *bios = (bx_param_string_c *) SIM->get_param (BXP_ROM_PATH);
  bx_param_num_c *biosaddr = (bx_param_num_c*) SIM->get_param(BXP_ROM_ADDRESS);
  bx_param_string_c *vgabios = (bx_param_string_c *) SIM->get_param (BXP_VGA_ROM_PATH);
  static bx_id optRomPathParams[] = {
    BXP_OPTROM1_PATH, BXP_OPTROM2_PATH, BXP_OPTROM3_PATH, BXP_OPTROM4_PATH
  };
  static bx_id optRomAddrParams[] = {
    BXP_OPTROM1_ADDRESS, BXP_OPTROM2_ADDRESS, BXP_OPTROM3_ADDRESS, BXP_OPTROM4_ADDRESS
  };
  bx_param_string_c *optromPath[CONFIG_MEMORY_N_ROMS];
  bx_param_num_c *optromAddr[CONFIG_MEMORY_N_ROMS];
  int rom;
  for (rom=0; rom<CONFIG_MEMORY_N_ROMS; rom++) {
    optromPath[rom] = (bx_param_string_c *) 
      SIM->get_param (optRomPathParams[rom]);
    optromAddr[rom] = (bx_param_num_c *) 
      SIM->get_param (optRomAddrParams[rom]);
  }
  dlg.SetSize (megs->get ());
  dlg.SetBios (wxString (bios->getptr ()));
  dlg.SetBiosAddr (biosaddr->get ());
  dlg.SetVgaBios (wxString (vgabios->getptr ()));
  for (rom=0; rom<CONFIG_MEMORY_N_ROMS; rom++) {
    dlg.SetRom (rom, wxString (optromPath[rom]->getptr ()));
    dlg.SetRomAddr (rom, optromAddr[rom]->get ());
  }
  int n = dlg.ShowModal ();
  if (n == wxOK) {
    char buf[1024];
    megs->set (dlg.GetSize ());
    safeWxStrcpy (buf, dlg.GetBios (), sizeof (buf));
    bios->set (buf);
    biosaddr->set (dlg.GetBiosAddr ());
    safeWxStrcpy (buf, dlg.GetVgaBios (), sizeof (buf));
    vgabios->set (buf);
    for (rom=0; rom<CONFIG_MEMORY_N_ROMS; rom++) {
      safeWxStrcpy (buf, dlg.GetRom (rom), sizeof (buf));
      optromPath[rom]->set (buf);
      optromAddr[rom]->set (dlg.GetRomAddr (rom));
    }
  }
}

void MyFrame::OnEditNet(wxCommandEvent& WXUNUSED(event))
{
  NetConfigDialog dlg (this, -1);
  bx_param_bool_c *present = (bx_param_bool_c*)SIM->get_param (BXP_NE2K_VALID);
  bx_param_num_c *io = (bx_param_num_c*)SIM->get_param (BXP_NE2K_IOADDR);
  bx_param_num_c *irq = (bx_param_num_c*)SIM->get_param (BXP_NE2K_IRQ);
  bx_param_string_c *mac = (bx_param_string_c*)
    SIM->get_param (BXP_NE2K_MACADDR);
  bx_param_string_c *module = (bx_param_string_c*)
    SIM->get_param (BXP_NE2K_ETHMOD);
  bx_param_string_c *device = (bx_param_string_c*)
    SIM->get_param (BXP_NE2K_ETHDEV);
  bx_param_string_c *script = (bx_param_string_c*)
    SIM->get_param (BXP_NE2K_SCRIPT);
  dlg.SetEnable (present->get ());
  dlg.SetIO (io->get ());
  dlg.SetIrq (irq->get ());
  dlg.SetMac ((unsigned char *) mac->getptr ());
  dlg.AddConn ("Null Packet Mover", "null");
#if defined(ETH_LINUX)
  dlg.AddConn ("Linux Socket Filter", "linux");
#endif
#if HAVE_ETHERTAP
  dlg.AddConn ("Ethertap", "tap");
#endif
#if HAVE_TUNTAP
  dlg.AddConn ("TUN/TAP", "tuntap");
#endif
#if defined(ETH_WIN32)
  dlg.AddConn ("Win32 packet mover", "win32");
#endif
#if defined(ETH_FBSD)
  dlg.AddConn ("Berkeley Packet Filter (FreeBSD, OpenBSD)", "fbsd");
#endif
#ifdef ETH_ARPBACK
  dlg.AddConn ("ARPback packet mover", "arpback");
#endif
  dlg.SetConn (module->getptr ());
  dlg.SetPhys (device->getptr ());
  dlg.SetScript (script->getptr ());
  int n = dlg.ShowModal ();
  if (n==wxOK) {
    present->set (dlg.GetEnable ());
    io->set (dlg.GetIO ());
    irq->set (dlg.GetIrq ());
    unsigned char tmp[6];
    dlg.GetMac (tmp);
    mac->set ((char *)tmp);
    module->set ((char *)dlg.GetConnData ());
    char buf[1024];
    wxString deviceString (dlg.GetPhys ());
    strncpy (buf, deviceString.c_str (), sizeof(buf));
    device->set (buf);
    wxString scriptString (dlg.GetScript ());
    strncpy (buf, scriptString.c_str (), sizeof(buf));
    script->set (buf);
  }
}

void MyFrame::OnLogPrefs(wxCommandEvent& WXUNUSED(event))
{
  // Ideally I would use the siminterface methods to fill in the fields
  // of the LogOptionsDialog, but in fact several things are hardcoded.
  // At least I can verify that the expected numbers are the same.
  wxASSERT (SIM->get_max_log_level() == LOG_OPTS_N_TYPES);
  LogOptionsDialog dlg (this, -1);

  // The inital values of the dialog are complicated.  If the panic action
  // for all modules is "ask", then clearly the inital value in the dialog
  // for panic action should be "ask".  This informs the user what the 
  // previous value was, and if they click Ok it won't do any harm.  But if
  // some devices are set to "ask" and others are set to "report", then the
  // initial value should be "no change".  With "no change", clicking on Ok
  // will not destroy the settings for individual devices.  You would only
  // start to see "no change" if you've been messing around in the advanced
  // menu already.
  for (int level=0; level<SIM->get_max_log_level(); level++) {
    int mod = 0;
    int first = SIM->get_log_action (mod, level);
    bool consensus = true;
    // now compare all others to first.  If all match, then use "first" as
    // the initial value.
    for (mod=1; mod<SIM->get_n_log_modules (); mod++) {
      if (first != SIM->get_log_action (mod, level)) {
	consensus = false;
	break;
      }
    }
    if (consensus)
      dlg.SetAction (level, first);
    else
      dlg.SetAction (level, LOG_OPTS_NO_CHANGE);
  }
  int n = dlg.ShowModal ();   // show the dialog!
  if (n == wxOK) {
    for (int level=0; level < SIM->get_max_log_level (); level++) {
      // ask the dialog what action the user chose for this type of event
      int action = dlg.GetAction (level);
      if (action != LOG_OPTS_NO_CHANGE) {
	// apply that action to all modules (devices)
	for (int i=0; i<SIM->get_n_log_modules (); i++)
	  SIM->set_log_action (i, level, action);
      }
    }
  }
}

void MyFrame::OnQuit(wxCommandEvent& event)
{
  Close( TRUE );
  OnKillSim (event);
#if 0
  if (SIM)
	SIM->quit_sim(0);  // give bochs a chance to shut down
#endif
}

void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
  wxString str;
  str.Printf ("Bochs x86 Emulator version %s (wxWindows port)", VER_STRING);
  wxMessageBox( str, "About Bochs", wxOK | wxICON_INFORMATION );
}

// update the menu items, status bar, etc.
void MyFrame::simStatusChanged (StatusChange change, Boolean popupNotify) {
  switch (change) {
    case Start:  // running
      menuSimulate->Enable (ID_Simulate_Start, FALSE);
      menuSimulate->Enable (ID_Simulate_PauseResume, TRUE);
      menuSimulate->Enable (ID_Simulate_Stop, TRUE);
      menuSimulate->SetLabel (ID_Simulate_PauseResume, "&Pause");
      break;
    case Stop: // not running
      menuSimulate->Enable (ID_Simulate_Start, TRUE);
      menuSimulate->Enable (ID_Simulate_PauseResume, FALSE);
      menuSimulate->Enable (ID_Simulate_Stop, FALSE);
      menuSimulate->SetLabel (ID_Simulate_PauseResume, "&Pause");
      // This should only be used if the simulation stops due to error.
      // Obviously if the user asked it to stop, they don't need to be told.
      if (popupNotify)
	    wxMessageBox("Bochs simulation has stopped.", "Bochs Stopped", 
		    wxOK | wxICON_INFORMATION);
      break;
    case Pause: // pause
      SetStatusText ("Pausing the Bochs simulation");
      menuSimulate->SetLabel (ID_Simulate_PauseResume, "&Resume");
      break;
    case Resume: // resume
      SetStatusText ("Resuming the Bochs simulation");
      menuSimulate->SetLabel (ID_Simulate_PauseResume, "&Pause");
      break;
  }
  bool canConfigure = (change == Stop);
  menuConfiguration->Enable (ID_Config_New, canConfigure);
  menuConfiguration->Enable (ID_Config_Read, canConfigure);
  menuEdit->Enable (ID_Edit_HD_0, canConfigure);
  menuEdit->Enable (ID_Edit_HD_1, canConfigure);
  menuEdit->Enable( ID_Edit_Boot, canConfigure);
  menuEdit->Enable( ID_Edit_Vga, canConfigure);
  menuEdit->Enable( ID_Edit_Memory, canConfigure);
  menuEdit->Enable( ID_Edit_Sound, canConfigure);
  menuEdit->Enable( ID_Edit_Network, canConfigure);
  menuEdit->Enable( ID_Edit_Keyboard, canConfigure);
  menuEdit->Enable( ID_Edit_Other, canConfigure);
  // during simulation, certain menu options like the floppy disk
  // can be modified under some circumstances.  A floppy drive can
  // only be edited if it was enabled at boot time.
  bx_param_c *param;
  param = SIM->get_param(BXP_FLOPPYA);
  menuEdit->Enable (ID_Edit_FD_0, canConfigure || param->get_enabled ());
  param = SIM->get_param(BXP_FLOPPYB);
  menuEdit->Enable (ID_Edit_FD_1, canConfigure || param->get_enabled ());
  param = SIM->get_param(BXP_CDROMD);
  menuEdit->Enable (ID_Edit_Cdrom, canConfigure || param->get_enabled ());
}

void MyFrame::OnStartSim(wxCommandEvent& WXUNUSED(event))
{
  wxCriticalSectionLocker lock(sim_thread_lock);
  if (sim_thread != NULL) {
	wxMessageBox (
	  "Can't start Bochs simulator, because it is already running",
	  "Already Running", wxOK | wxICON_ERROR);
	return;
  }
  wxLogStatus ("Starting a Bochs simulation");
  start_bochs_times++;
  if (start_bochs_times>1) {
	wxMessageBox (
	"You have already started the simulator once this session. Due to memory leaks and bugs in init code, you may get unstable behavior.",
	"2nd time warning", wxOK | wxICON_WARNING);
  }
  num_events = 0;  // clear the queue of events for bochs to handle
  sim_thread = new SimThread (this);
  sim_thread->Create ();
  sim_thread->Run ();                                                        
  wxLogDebug ("Simulator thread has started.");
  // set up callback for events from simulator thread
  SIM->set_notify_callback (&SimThread::SiminterfaceCallback, sim_thread);
  simStatusChanged (Start);
}

void MyFrame::OnPauseResumeSim(wxCommandEvent& WXUNUSED(event))
{
  wxCriticalSectionLocker lock(sim_thread_lock);
  if (sim_thread) {
    if (sim_thread->IsPaused ()) {
      simStatusChanged (Resume);
	  sim_thread->Resume ();
	} else {
      simStatusChanged (Pause);
	  sim_thread->Pause ();
	}
  }
}

void MyFrame::OnKillSim(wxCommandEvent& WXUNUSED(event))
{
  // DON'T use a critical section here.  Delete implicitly calls
  // OnSimThreadExit, which also tries to lock sim_thread_lock.
  // If we grab the lock at this level, deadlock results.
  wxLogDebug ("OnKillSim()");
  if (sim_thread) {
    sim_thread->Delete ();
    // Next time the simulator reaches bx_real_sim_c::periodic() it
    // will quit.  This is better than killing the thread because it
    // gives it a chance to clean up after itself.
  }
}

void
MyFrame::OnSimThreadExit () {
  wxCriticalSectionLocker lock (sim_thread_lock);
  sim_thread = NULL; 
}

int 
MyFrame::HandleAskParamString (bx_param_string_c *param)
{
  wxLogDebug ("HandleAskParamString start");
  bx_param_num_c *opt = param->get_options ();
  wxASSERT (opt != NULL);
  int n_opt = opt->get ();
  char *msg = param->get_ask_format ();
  if (!msg) msg = param->get_description ();
  char *newval = NULL;
  wxDialog *dialog = NULL;
  if (n_opt & param->BX_IS_FILENAME) {
    // use file open dialog
	long style = 
	  (n_opt & param->BX_SAVE_FILE_DIALOG) ? wxSAVE|wxOVERWRITE_PROMPT : wxOPEN;
        wxLogDebug ("HandleAskParamString: create dialog");
	wxFileDialog *fdialog = new wxFileDialog (this, msg, "", "", "*.*", style);
        wxLogDebug ("HandleAskParamString: before showmodal");
	if (fdialog->ShowModal() == wxID_OK)
	  newval = (char *)fdialog->GetPath().c_str ();
        wxLogDebug ("HandleAskParamString: after showmodal");
	dialog = fdialog; // so I can delete it
  } else {
    // use simple string dialog
	long style = wxOK|wxCANCEL;
	wxTextEntryDialog *tdialog = new wxTextEntryDialog (this, msg, "Enter new value", wxString(param->getptr ()), style);
	if (tdialog->ShowModal() == wxID_OK)
	  newval = (char *)tdialog->GetValue().c_str ();
	dialog = tdialog; // so I can delete it
  }
  // newval points to memory inside the dialog.  As soon as dialog is deleted,
  // newval points to junk.  So be sure to copy the text out before deleting
  // it!
  if (newval && strlen(newval)>0) {
	// change floppy path to this value.
	wxLogDebug ("Setting param %s to '%s'", param->get_name (), newval);
	param->set (newval);
	delete dialog;
	return 1;
  }
  delete dialog;
  return -1;
}

// This is called when the simulator needs to ask the user to choose
// a value or setting.  For example, when the user indicates that he wants
// to change the floppy disk image for drive A, an ask-param event is created
// with the parameter id set to BXP_FLOPPYA_PATH.  The simulator blocks until
// the gui has displayed a dialog and received a selection from the user.
// In the current implemention, the GUI will look up the parameter's 
// data structure using SIM->get_param() and then call the set method on the
// parameter to change the param.  The return value only needs to return
// success or failure (failure = cancelled, or not implemented).
// Returns 1 if the user chose a value and the param was modified.
// Returns 0 if the user cancelled.
// Returns -1 if the gui doesn't know how to ask for that param.
int 
MyFrame::HandleAskParam (BxEvent *event)
{
  wxASSERT (event->type == BX_SYNC_EVT_ASK_PARAM);

  bx_param_c *param = event->u.param.param;
  Raise ();  // bring window to front so that you will see the dialog
  switch (param->get_type ())
  {
  case BXT_PARAM_STRING:
    return HandleAskParamString ((bx_param_string_c *)param);
  default:
    {
	  wxString msg;
	  msg.Printf ("ask param for parameter type %d is not implemented in wxWindows");
	  wxMessageBox( msg, "not implemented", wxOK | wxICON_ERROR );
	  return -1;
	}
  }
#if 0
  switch (param) {
  case BXP_FLOPPYA_PATH:
  case BXP_FLOPPYB_PATH:
  case BXP_DISKC_PATH:
  case BXP_DISKD_PATH:
  case BXP_CDROM_PATH:
	{
	  Raise();  // bring window to front so dialog shows
	  char *msg;
	  if (param==BXP_FLOPPYA_PATH || param==BXP_FLOPPYB_PATH)
	    msg = "Choose new floppy disk image file";
      else if (param==BXP_DISKC_PATH || param==BXP_DISKD_PATH)
	    msg = "Choose new hard disk image file";
      else if (param==BXP_CDROM_PATH)
	    msg = "Choose new CDROM image file";
	  else
	    msg = "Choose new image file";
	  wxFileDialog dialog(this, msg, "", "", "*.*", 0);
	  int ret = dialog.ShowModal();
	  if (ret == wxID_OK)
	  {
	    char *newpath = (char *)dialog.GetPath().c_str ();
	    if (newpath && strlen(newpath)>0) {
	      // change floppy path to this value.
	      bx_param_string_c *Opath = SIM->get_param_string (param);
	      assert (Opath != NULL);
	      wxLogDebug ("Setting floppy %c path to '%s'", 
		    param == BXP_FLOPPYA_PATH ? 'A' : 'B',
		    newpath);
	      Opath->set (newpath);
	      return 1;
	    }
	  }
	  return 0;
	}
  default:
	wxLogError ("HandleAskParam: parameter %d, not implemented", event->u.param.id);
  }
#endif
  return -1;  // could not display
}

// This is called from the wxWindows GUI thread, when a Sim2CI event
// is found.  (It got there via wxPostEvent in SiminterfaceCallback2, which is
// executed in the simulator Thread.)
void 
MyFrame::OnSim2CIEvent (wxCommandEvent& event)
{
  wxLogDebug ("received a bochs event in the GUI thread");
  BxEvent *be = (BxEvent *) event.GetEventObject ();
  wxLogDebug ("event type = %d", (int) be->type);
  // all cases should return.  sync event handlers MUST send back a 
  // response.
  switch (be->type) {
  case BX_SYNC_EVT_ASK_PARAM:
    wxLogDebug ("before HandleAskParam");
    be->retcode = HandleAskParam (be);
    wxLogDebug ("after HandleAskParam");
    // sync must return something; just return a copy of the event.
    sim_thread->SendSyncResponse(be);
    wxLogDebug ("after SendSyncResponse");
    return;
  case BX_SYNC_EVT_LOG_ASK:
  case BX_ASYNC_EVT_LOG_MSG:
    {
    wxLogDebug ("log msg: level=%d, prefix='%s', msg='%s'",
	be->u.logmsg.level,
	be->u.logmsg.prefix,
	be->u.logmsg.msg);
    if (be->type == BX_ASYNC_EVT_LOG_MSG) {
      // don't ask for user response
      return;
    }
    wxString levelName (SIM->get_log_level_name (be->u.logmsg.level));
    LogMsgAskDialog dlg (this, -1, levelName);  // panic, error, etc.
#if !BX_DEBUGGER
    dlg.EnableButton (dlg.DEBUG, FALSE);
#endif
    dlg.SetContext (be->u.logmsg.prefix);
    dlg.SetMessage (be->u.logmsg.msg);
    int n = dlg.ShowModal ();
    Boolean dontAsk = dlg.GetDontAsk ();
    // turn the return value into the constant that logfunctions::ask is
    // expecting.  0=continue, 1=continue but ignore future messages from this
    // device, 2=die, 3=dump core, 4=debugger. FIXME: yuck. replace hardcoded
    // constants in logfunctions::ask with enum or defined constant.
    if (n==0) {
      n = dontAsk? 1 : 0; 
    } else {
      n=n+1;
    }
    be->retcode = n;
    wxLogDebug ("you chose %d", n);
    sim_thread->SendSyncResponse (be);
    return;
    }
  default:
    wxLogDebug ("OnSim2CIEvent: event type %d ignored", (int)be->type);
	// assume it's a synchronous event and send back a response, to avoid
	// potential deadlock.
    sim_thread->SendSyncResponse(be);
	return;
  }
  // it is critical to send a response back eventually since the sim thread
  // is blocking.
  wxASSERT_MSG (0, "switch stmt should have returned");
}

void 
MyFrame::OnOtherEvent (wxCommandEvent& event)
{
  int id = event.GetId ();
  printf ("event id=%d\n", id);
  switch (id) {
    case ID_Edit_HD_0: editHDConfig (0); break;
    case ID_Edit_HD_1: editHDConfig (1); break;
    case ID_Edit_Cdrom: editCdromConfig (); break;
  }
}

bool
MyFrame::editFloppyValidate (FloppyConfigDialog *dialog)
{
  // haven't done anything with this 'feature'
  return true;
}

void MyFrame::editFloppyConfig (int drive)
{
  FloppyConfigDialog dlg (this, -1);
  dlg.SetDriveName (wxString (drive==0? BX_FLOPPY0_NAME : BX_FLOPPY1_NAME));
  dlg.SetCapacityChoices (n_floppy_type_names, floppy_type_names);
  bx_list_c *list = (bx_list_c*) SIM->get_param ((drive==0)? BXP_FLOPPYA : BXP_FLOPPYB);
  if (!list) { wxLogError ("floppy object param is null"); return; }
  bx_param_filename_c *fname = (bx_param_filename_c*) list->get(0);
  bx_param_enum_c *disktype = (bx_param_enum_c *) list->get(1);
  bx_param_enum_c *status = (bx_param_enum_c *) list->get(2);
  if (fname->get_type () != BXT_PARAM_STRING
      || disktype->get_type () != BXT_PARAM_ENUM 
      || status->get_type() != BXT_PARAM_ENUM) {
    wxLogError ("floppy params have wrong type");
    return;
  }
  dlg.AddRadio ("Not Present", "");
  dlg.AddRadio ("Ejected", "none");
  dlg.AddRadio ("Physical floppy drive /dev/fd0", "/dev/fd0");
  dlg.AddRadio ("Physical floppy drive /dev/fd1", "/dev/fd1");
  dlg.SetCapacity (disktype->get () - disktype->get_min ());
  dlg.SetFilename (fname->getptr ());
  dlg.SetValidateFunc (editFloppyValidate);
  if (disktype->get() == BX_FLOPPY_NONE) {
    dlg.SetRadio (0);
  } else if (!strcmp ("none", fname->getptr ())) {
    dlg.SetRadio (1);
  } else {
    // otherwise the SetFilename() should have done the right thing.
  }
  int n = dlg.ShowModal ();
  printf ("floppy config returned %d\n", n);
  if (n==wxID_OK) {
    char filename[1024];
    wxString fn (dlg.GetFilename ());
    strncpy (filename, fn.c_str (), sizeof(filename));
    printf ("filename is '%s'\n", filename);
    printf ("capacity = %d (%s)\n", dlg.GetCapacity(), floppy_type_names[dlg.GetCapacity ()]);
    fname->set (filename);
    disktype->set (disktype->get_min () + dlg.GetCapacity ());
    if (dlg.GetRadio () == 0)
      disktype->set (BX_FLOPPY_NONE);
  }
}

void MyFrame::editHDConfig (int drive)
{
  HDConfigDialog dlg (this, -1);
  dlg.SetDriveName (drive==0? BX_HARD_DISK0_NAME : BX_HARD_DISK1_NAME);
  bx_list_c *list = (bx_list_c*) SIM->get_param ((drive==0)? BXP_DISKC : BXP_DISKD);
  if (!list) { wxLogError ("HD object param is null"); return; }
  bx_param_filename_c *fname = (bx_param_filename_c*) list->get(0);
  bx_param_num_c *cyl = (bx_param_num_c *) list->get(1);
  bx_param_num_c *heads = (bx_param_num_c *) list->get(2);
  bx_param_num_c *spt = (bx_param_num_c *) list->get(3);
  bx_param_bool_c *present = (bx_param_bool_c *)
    SIM->get_param (drive==0? BXP_DISKC_PRESENT : BXP_DISKD_PRESENT);
  wxASSERT (fname->get_type () == BXT_PARAM_STRING
      && cyl->get_type () == BXT_PARAM_NUM 
      && heads->get_type () == BXT_PARAM_NUM 
      && spt->get_type() == BXT_PARAM_NUM
      && present->get_type() == BXT_PARAM_BOOL);
  dlg.SetFilename (fname->getptr ());
  dlg.SetGeomRange (0, cyl->get_min(), cyl->get_max ());
  dlg.SetGeomRange (1, heads->get_min(), heads->get_max ());
  dlg.SetGeomRange (2, spt->get_min(), spt->get_max ());
  dlg.SetGeom (0, cyl->get ());
  dlg.SetGeom (1, heads->get ());
  dlg.SetGeom (2, spt->get ());
  dlg.SetEnable (present->get ());
  int n = dlg.ShowModal ();
  printf ("HD config returned %d\n", n);
  if (n==wxID_OK) {
    char filename[1024];
    wxString fn (dlg.GetFilename ());
    strncpy (filename, fn.c_str (), sizeof (filename));
    printf ("filename is '%s'\n", filename);
    fname->set (filename);
    cyl->set (dlg.GetGeom (0));
    heads->set (dlg.GetGeom (1));
    spt->set (dlg.GetGeom (2));
    present->set (dlg.GetEnable ());
    printf ("present=%d cyl=%d heads=%d spt=%d\n", present->get (), cyl->get(), heads->get(), spt->get());
    if (drive==1 && present->get ()) {
      // check that diskD and cdrom are not enabled at the same time
      bx_param_bool_c *cdromd = (bx_param_bool_c*)
	SIM->get_param(BXP_CDROM_PRESENT);
      if (cdromd->get ()) {
	wxString msg;
	msg.Printf ("You cannot have both %s and %s enabled. Disabling %s.",
	    BX_HARD_DISK1_NAME, BX_CDROM_NAME, BX_CDROM_NAME);
	wxMessageBox( msg, "Device conflict", wxOK | wxICON_ERROR );
	cdromd->set (0);
      }
    }
  }
}

void MyFrame::editCdromConfig ()
{
  CdromConfigDialog dlg (this, -1);
  dlg.SetDriveName (BX_CDROM_NAME);
  bx_param_filename_c *fname = 
    (bx_param_filename_c*) SIM->get_param(BXP_CDROM_PATH);
  bx_param_bool_c *present =
    (bx_param_bool_c*) SIM->get_param(BXP_CDROM_PRESENT);
  bx_param_enum_c *status =
    (bx_param_enum_c*) SIM->get_param(BXP_CDROM_STATUS);
  wxASSERT (fname->get_type () == BXT_PARAM_STRING
      && present->get_type () == BXT_PARAM_BOOL
      && status->get_type () == BXT_PARAM_ENUM);
  dlg.AddRadio ("Physical CD-ROM drive /dev/cdrom", "/dev/cdrom");
  dlg.SetEnable (present->get () ? TRUE : FALSE);
  dlg.SetFilename (fname->getptr ());
  dlg.SetEjected (status->get () == BX_EJECTED);
  int n = dlg.ShowModal ();
  printf ("cdrom config returned %d\n", n);
  if (n==wxID_OK) {
    char filename[1024];
    wxString fn (dlg.GetFilename ());
    strncpy (filename, fn.c_str (), sizeof(filename));
    fname->set (filename);
    present->set (dlg.GetEnable ());
    status->set (dlg.GetEjected () ? BX_EJECTED : BX_INSERTED);
    printf ("filename is '%s'\n", filename);
    printf ("enabled=%d ejected=%d\n", present->get(), status->get());
    // cdrom and hard disk D cannot both be enabled.
    if (present->get ()) {
      bx_param_bool_c *diskd = (bx_param_bool_c*)
	SIM->get_param(BXP_DISKD_PRESENT);
      if (diskd->get ()) {
	wxString msg;
	msg.Printf ("You cannot have both %s and %s enabled. Disabling %s.",
	    BX_CDROM_NAME, BX_HARD_DISK1_NAME, BX_HARD_DISK1_NAME);
	wxMessageBox( msg, "Device conflict", wxOK | wxICON_ERROR );
	diskd->set (0);
      }
    }
  }
}

void MyFrame::OnToolbarClick(wxCommandEvent& event)
{
  wxLogDebug ("clicked toolbar thingy");
  bx_toolbar_buttons which = BX_TOOLBAR_UNDEFINED;
  int id = event.GetId ();
  switch (id) {
    case ID_Toolbar_Power:which = BX_TOOLBAR_POWER; break;
    case ID_Toolbar_Reset: which = BX_TOOLBAR_RESET; break;
    case ID_Edit_FD_0: 
      // floppy config dialog box
      editFloppyConfig (0);
      break;
    case ID_Edit_FD_1: 
      // floppy config dialog box
      editFloppyConfig (1);
      break;
    case ID_Edit_Cdrom: which = BX_TOOLBAR_CDROMD; break;
    case ID_Toolbar_Copy: which = BX_TOOLBAR_COPY; break;
    case ID_Toolbar_Paste: which = BX_TOOLBAR_PASTE; break;
    case ID_Toolbar_Snapshot: which = BX_TOOLBAR_SNAPSHOT; break;
    case ID_Toolbar_Config: which = BX_TOOLBAR_CONFIG; break;
    case ID_Toolbar_Mouse_en: which = BX_TOOLBAR_MOUSE_EN; break;
    case ID_Toolbar_User: which = BX_TOOLBAR_USER; break;
    default:
      wxLogError ("unknown toolbar id %d", id);
  }
  if (num_events < MAX_EVENTS) {
    event_queue[num_events].type = BX_ASYNC_EVT_TOOLBAR;
    event_queue[num_events].u.toolbar.button = which;
    num_events++;
  }
}

//////////////////////////////////////////////////////////////////////
// Simulation Thread
//////////////////////////////////////////////////////////////////////

void *
SimThread::Entry (void)
{     
  int argc=1;
  char *argv[] = {"bochs"};
  // run all the rest of the Bochs simulator code.  This function will
  // run forever, unless a "kill_bochs_request" is issued.  The shutdown
  // procedure is as follows:
  //   - user selects "Kill Simulation" or GUI decides to kill bochs
  //   - GUI calls sim_thread->Delete ()
  //   - sim continues to run until the next time it reaches SIM->periodic().
  //   - SIM->periodic() sends a synchronous tick event to the GUI, which
  //     finally calls TestDestroy() and realizes it needs to stop.  It
  //     sets the sync event return code to -1.  SIM->periodic() sets the
  //     kill_bochs_request flag in cpu #0.
  //   - cpu loop notices kill_bochs_request and returns to main.cc:
  //     bx_continue_after_config_interface(), which notices the
  //     kill_bochs_request and returns back to this Entry() function.
  //   - Entry() exits and the thread stops. Whew.
  wxLogDebug ("in SimThread, starting at bx_continue_after_config_interface");
  static jmp_buf context;  // this must not go out of scope. maybe static not needed
  if (setjmp (context) == 0) {
	SIM->set_quit_context (&context);
    bx_continue_after_config_interface (argc, argv);
    wxLogDebug ("in SimThread, bx_continue_after_config_interface exited normally");
  } else {
    wxLogDebug ("in SimThread, bx_continue_after_config_interface exited by longjmp");
  }
  wxMutexGuiEnter();
  theFrame->simStatusChanged (theFrame->Stop, true);
  wxMutexGuiLeave();
  return NULL;
}

void
SimThread::OnExit ()
{
  // notify the MyFrame that the bochs thread has died.  I can't adjust
  // the sim_thread directly because it's private.
  frame->OnSimThreadExit ();
  // don't use this SimThread's callback function anymore.
  SIM->set_notify_callback (NULL, NULL);
}

// Event handler function for BxEvents coming from the simulator.
// This function is declared static so that I can get a usable
// function pointer for it.  The function pointer is passed to
// SIM->set_notify_callback so that the siminterface can call this
// function when it needs to contact the gui.  It will always be
// called with a pointer to the SimThread as the first argument, and
// it will be called from the simulator thread, not the GUI thread.
BxEvent *
SimThread::SiminterfaceCallback (void *thisptr, BxEvent *event)
{
  SimThread *me = (SimThread *)thisptr;
  // call the normal non-static method now that we know the this pointer.
  return me->SiminterfaceCallback2 (event);
}

// callback function for sim thread events.  This is called from
// the sim thread, not the GUI thread.  So any GUI actions must be
// thread safe.  Most events are handled by packaging up the event
// in a wxEvent of some kind, and posting it to the GUI thread for
// processing.
BxEvent *
SimThread::SiminterfaceCallback2 (BxEvent *event)
{
  //wxLogDebug ("SiminterfaceCallback with event type=%d", (int)event->type);
  event->retcode = 0;  // default return code
  int async = BX_EVT_IS_ASYNC(event->type);
  if (!async) {
    // for synchronous events, clear away any previous response.  There
	// can only be one synchronous event pending at a time.
    ClearSyncResponse ();
	event->retcode = -1;   // default to error
  }

  // tick event must be handled right here in the bochs thread.
  if (event->type == BX_SYNC_EVT_TICK) {
	if (TestDestroy ()) {
	  // tell simulator to quit
	  event->retcode = -1;
	} else {
	  event->retcode = 0;
	}
	return event;
  }

  //encapsulate the bxevent in a wxwindows event
  wxCommandEvent wxevent (wxEVT_COMMAND_MENU_SELECTED, ID_Sim2CI_Event);
  wxevent.SetEventObject ((wxEvent *)event);
  wxLogDebug ("Sending an event to the window");
  wxPostEvent (frame, wxevent);
  // if it is an asynchronous event, return immediately
  if (async) return NULL;
  wxLogDebug ("SiminterfaceCallback2: synchronous event; waiting for response");
  // now wait forever for the GUI to post a response.
  BxEvent *response = NULL;
  while (response == NULL) {
	response = GetSyncResponse ();
	if (!response) {
	  wxLogDebug ("no sync response yet, waiting");
	  this->Sleep(500);
	}
  }
  wxASSERT (response != NULL);
  return response;
}

void 
SimThread::ClearSyncResponse ()
{
  wxCriticalSectionLocker lock(sim2gui_mailbox_lock);
  if (sim2gui_mailbox != NULL) {
    wxLogDebug ("WARNING: ClearSyncResponse is throwing away an event that was previously in the mailbox");
  }
  sim2gui_mailbox = NULL;
}

void 
SimThread::SendSyncResponse (BxEvent *event)
{
  wxCriticalSectionLocker lock(sim2gui_mailbox_lock);
  if (sim2gui_mailbox != NULL) {
    wxLogDebug ("WARNING: SendSyncResponse is throwing away an event that was previously in the mailbox");
  }
  sim2gui_mailbox = event;
}

BxEvent *
SimThread::GetSyncResponse ()
{
  wxCriticalSectionLocker lock(sim2gui_mailbox_lock);
  BxEvent *event = sim2gui_mailbox;
  sim2gui_mailbox = NULL;
  return event;
}

///////////////////////////////////////////////////////////////////
// utility
///////////////////////////////////////////////////////////////////
void 
safeWxStrcpy (char *dest, wxString src, int destlen)
{
  wxString tmp (src);
  strncpy (dest, tmp.c_str (), destlen);
}