Bochs/bochs/README-wxWindows

Readme for wxWindows Interface
updated Thu Aug 29 10:43:37 EDT 2002

Contributors to wxWindows port:
  Don Becker (Psyon)
  Bryce Denney
  Dave Poirier
  Volker Ruppert

wxWindows Configuration Interface

The wxWindows port began in June 2001 around the time of Bochs 1.2.1.  Dave
Poirier and Bryce Denney started adding a wxWindows configuration interface.
We made some progress, but stopped after a while.  Then in March/April 2002
Bryce and Psyon revived the wxWindows branch and turned it into a (mostly)
usable interface.  Psyon did most of the work to get text and graphics 
working, and Bryce worked on event passing between threads, and keyboard
mapping.

The wxWindows window appears first.  This WILL BE where you can choose a preset
configuration or create one from scratch, then edit the bochsrc options using
the GUI.  Then, by clicking on Simulate:Start, you can start up the Bochs
simulation.  The VGA display is implemented in wxWindows.

WARNING: Don't expect perfect code yet!

Regarding wxWindows versions, we started out with 2.2.9 but then found
a reason or two to switch to 2.3.2.  (I have forgotten exactly what
they were.)  In addition, I made a keyboard patch to wxWindows itself,
which they accepted for the next version, that allows us to get raw
keycodes out of the library in addition to wxwindows translated keys.
Bochs will work with or without it, but you'll find that the keyboard
mapping is much better with the patch, which is called
patches/patch.wx-raw-keycodes.

So the ideal wxWindows version is 2.3.2+patch.wx-raw-keycodes.
To apply the patch, go to the main wx____-2.3.2 directory and
type "patch -p1 < THIS_PATCH_FILE".

Bryce has been developing in linux, where a "configure --with-wx;make"
should work fine.

To build in MS VC++:
- edit .conf.win32-vcpp and add "--with-wx" to the configure line. 
  If you want different configure options from what you see, change them
  too.
- in cygwin, do "sh .conf.win32-vcpp" to run configure
- unzip build/win32/wxworkspace.zip into the main directory.
  For cygwin: unzip build/win32/wxworkspace.zip
  or use winzip or whatever else.
- open up bochs.dsw, the workspace file
- edit project settings so that VC++ can find the wxWindows include
  files and libraries on your system.  I installed them in
  d:/wx/wx232/include and d:/wx/wx232/lib.  Specifically, edit
  - Project>Settings>C/C++>Category=Preprocessor: include directories.
  - Project>Settings>Link>Category=Input: additional library path.
- build

Note that the project is set up for wxWindows 2.3.2, and the only 
configuration that I've used is called Win32 Debug.  To use on 
other wxwindows versions, you will have to change some of the names
of the libraries to include.  Use the samples that came with that
version of wxwindows for reference.

What works right now (September 2002):
- cd to a directory with a bochsrc and disk images in it
- start up bochs.  You get a small window with a File, Edit, Simulate,
  Debug, Log, Help menus.  The empty black rectangle is where the
  simulation will be displayed.
- choose File:Read Configuration and select the bochsrc file you want
  to read.
- use the choices on the Edit menu to adjust settings.
- choose "Start" on the Simulate menu.  Bochs starts running in the
  You can pause it, resume it, or kill it on the Simulate menu.
  Most toolbar buttons work.
- You can pause, resume, and stop the simulation too.  If you start
  a new simulation, it's possible that things may not work quite right.  
  The initialization and re-initialization process needs work.
- Debug:Show CPU displays all the CPU registers.  When Bochs is compiled
  with debugging support, this screen has Continue, Stop, and Step 
  buttons to let you control the simulation.  Debug:Show Keyboard shows 
  some of the internal state of the Bochs keyboard in a dialog box.
  Both dialog boxes are updated periodically during simulation.

To do:
- configure script must be able to check that wxwindows is actually 
  installed.
- if you stop and start a second simulation, tons of parameters get 
  redefined and it's a big mess.
- now that ParamDialog works, I may rewrite some of the other dialogs 
  as subclasses of ParamDialog.  This would lead to more compact code,
  and fewer bugs.
- configure time dialog
  - need to think about dialog layout 
  - setting of IPS (controls how much time the PIT associates with each 
    instruction for purposes of sending timer interrupts).  How can we
    name this?  instructions per simulated second.
  - enable realtime pit, realtime pit settings (?)
  - enable/disable X windows idle hack
  - report instructions per wall clock second in real time
- decide which settings can be adjusted at runtime, and figure out how
  to disable the others.  Do we need a set_enable() on the parameters
  themselves?
- the power button has always "turned off" the power.  Make it also
  turn ON the power.  I think a few little green LEDs are in order.
- floppy config screen: on win32, both not present and ejected are selected
  at first.
- log events
  - Later: allow viewing of current log messages.  Maybe this is a dialog that
    we append to, or maybe it should periodically display the last 1K of the
    log file (might be faster in high volume situations).
  - Later: should we allow multiple log files with different settings? for
    example dump cpu events to cpulog.txt and keyboard events to
    keyboardlog.txt?
- debugger
  - bug: it's possible to make the GUI stop responding to mouse and keyboard
    input if you click the continue button in the debugger twice in very
    close succession.  I don't know why yet.
  - probably the layout will be similar to BFE at first
  - need to show disassembly of the next instruction to be executed
- clean up the biggest memory leaks and init/cleanup code.  The gui allows you
  to kill the simulator and restart, but it doesn't do well after the first
  time.  Valgrind should help with memory leak debugging, though until
  recently it couldn't run multithreaded programes.
- disk change dialogs for floppy and cdrom need work.
  http://sourceforge.net/tracker/index.php?func=detail&aid=545414&group_id=12580&atid=112580
-------------

------------------------------------------------------

Random notes follow

Added some sketches.  I'm thinking that the control
panel will be able to basically show one of these screens at a time.  When
you first start you would see ChooseConfigScreen which chooses between the
configurations that you have loaded recently (which it would remember
by the pathname of their bochsrc).  Whether you choose an existing 
configuration to be loaded or a new one, when you click Ok you go to
the first configuration screen, ConfigDiskScreen.

Each of the configuration screens takes up the whole control panel window.
We could use tabs on the top and/or "<-Prev" and "Next->" buttons to make
it quick to navigate the configuration screens.  Each screen should
probably have a Prev, Next, Revert to Saved, and Accept button.
The menu choices like Disk..., VGA..., etc. just switch directly to
that tab.


------------------------------------------------------
Notes:

events from gui to sim:
- [async] key pressed or released
- [async] mouse motion with button state
- [sync] query parameter
- [sync] change parameter
- [async] start, pause, stop, reset simulation.  Can be implemented
  as changing a parameter.
- [async] request notification when some param changes

events from sim to gui:
- [async] log message to be displayed (or not)
- [async] ask user how to proceed (like panic: action=ask)
- [async] param value changed
- make my thread sleep for X microseconds  (call wxThread::sleep then return)

In a synchronous event, the event object will contain space for the entire
response.  The sender allocates memory for the event and builds it.  The
receiver fills in blanks in the event structure (or could overwrite parts)
and returns the same event pointer as a response.  For async events, probably
the sender will allocate and the receiver will have to delete it.

implement the floppyA and floppyB change buttons using new event
structure.  How should it work?

vga gui detects a click on floppyA bitmap
construct a BxEvent type BX_EVT_ASK_PARAM
post the event to the wxwindows gui thread (somehow) and block for response
when it arrives in the gui thread, show a modal dialog box
get the answer back to the simulator thread


right now, this is working ok within the simulator thread using
wxMutexGuiEnter/Leave.  Still I'm going to change it so that the
siminterface.cc code builds an event structure and the gui code
fills in the blank in the structure, instead of the stupid 
notify_get_int_arg stuff.


Starting and Killing Threads

When a detachable (default) thread finishes (returns from its Entry()
function), wxwindows frees the memory associated with that thread.  
Unless the thread is never going to end, it is potentially dangerous to have a
pointer to it at all.  Even if you try to "check if it's alive" first, you may
be dereferencing the pointer after it has already been deleted, leading to it
claiming to be alive when it's not, or a segfault.  To solve this, the approach
used in the wxwindows threads example is to have code in the thread's OnExit()
method remove the thread's pointer from the list of usable threads.  In
addition, any references or changes to the list of threads is controlled by a
critical section to ensure that it stays correct.  This post finally 
explained what I was seeing.

+-----------------------
| From: Pieter van der Meulen (pgmvdm@yahoo.com)
|  Subject: Re: Thread Sample program - bug 
|  Newsgroups: comp.soft-sys.wxwindows
|  Date: 2001-06-28 17:51:35 PST 
| 
| 
| At 06:24 PM 6/28/2001, you wrote:
| >Hi,
| >I have wxWindows 2.2.7 (wxMSW) installed.
| >
| >I just found in the thread.cpp sample code this section:
| >
| ><code>
| >void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
| >{
| >     size_t count = wxGetApp().m_threads.Count();
| >     for ( size_t i = 0; i < count; i++ )
| >     {
| >===>        wxGetApp().m_threads[0]->Delete();    <=====
| >     }
| >
| >     Close(TRUE);
| >}
| ></code>
| >The indecated line should probably rather have a
| >m_threads[i]     rather than     m_threads[0] .
| 
| No, it should not, although it is not immediately obvious. When Delete() is 
| called, the thread will eventually delete itself, but not before it calls 
| MyThread::Exit(), which will remove itself from m_threads[] using 
| wxArray::Remove(this). wxArray::Remove (RemoveAt) will compact the array to 
| remove the element, it is now size-1. After this wxThread::Delete() returns.
| 
| 
| >I have have a further question to this:
| >Does this mean that a detached thread created with new
| >HAS to be deleted  manually ?  Or is this only in case it might still
| >be running?
| 
| Firstly, you must create every detached thread using new since it will 
| delete itself, literally calling delete this.
| Calling wxThread::Delete() is a correct way to terminate a thread, but 
| manually deleting (using delete) a detached wxThread object is not. 
| wxThread::Delete() will ask the thread to exit, the thread should check for 
| this in wxThread::Entry() regularly using wxThread::TestDestroy() and exit 
| when asked to do so.
| 
| >(In general I have a unsatisfied felling about when delete is
| >neccessary and when not -- "I only know, it's not , if the class is
| >derived from wxWindows")
| 
| For wxThreads: joinable threads must be deleted (when allocated on the 
| heap), detached threads may never be deleted. For other classes, consult 
| the documentation ;)
| 
| 
| >Thanks for some feedback,
| >Sebastian
| 
| Regards,
| 
| Pieter.
+-----------------------

tracking some kind of deadlock bug in Linux.

seems to be in ReadMailcap, src/unix/mimetypes.cpp in wxwindows sources
src/unix/mimetype.cpp:2312

SOLUTION: compile with -pthread on every compile and link line.



----------------------------------------------
Suggested solution for putting sizers inside a scrolled window

From: Thaddaeus Frogley (codemonkey_uk@users.sourceforge.net)
Subject: RE: Using sizers inside of a scrolled window 
Newsgroups: comp.soft-sys.wxwindows
Date: 2001-10-02 02:41:04 PST 

I have solved that same problem (scrolled windows / sizers) like so:

In the constructor for your wxFrame derived class,

//create a scrolling window
myScrolledWindow = new wxScrolledWindow(this, -1);

//in the scolling window, create a panel
myMainPanel = new wxPanel(myScrolledWindow, -1);        

//place controls in the panel, laying them out with sizers

//...

myMainPanel->SetAutoLayout( TRUE );
myMainPanel->SetSizer( sizer );
sizer->Fit( myMainPanel );
sizer->SetSizeHints( myMainPanel );

//set the scroll bars lengths based on the size of the inner panel
wxSize size = myMainPanel->GetBestSize();
myScrolledWindow->SetScrollbars( 1, 1, size.GetWidth(), size.GetHeight() );

//calculate the size of the window, and set it appropriately
size.Set(size.GetWidth()+16,size.GetHeight()+16);
        
//Get the physical size of the display in pixels.
int displaySizeX,displaySizeY;
wxDisplaySize(&displaySizeX,&displaySizeY);

//clamp window size to % of screen
if (size.GetWidth()>displaySizeX*0.75){
        size.SetWidth(displaySizeX*0.75);
}
if (size.GetHeight()>displaySizeY*0.75){
        size.SetHeight(displaySizeY*0.75);
}

SetClientSize(size);



-----------------
How to make wxChoice as wide as the longest string in the choice box?

From: Vadim Zeitlin (Vadim.zeitlin@dptmaths.ens-cachan.fr)
Subject: Re: wxChoice 
Newsgroups: comp.soft-sys.wxwindows
Date: 2001-09-18 04:41:07 PST 


On Sat, 15 Sep 2001 15:39:45 +0200 Merlijn Blaauw <merlijn@student-kmt.hku.nl> wrote:

MB> Also, I 
MB> would like the widget's parent window to change size (width) to fit the 
MB> widget's new content aswell.

 You'll have to do it manually by calculating the length of the string you
add to the control (use wxClientDC(combobox) and set correct font before
calling GetTextExtent()!) and resizing the control to be slightly larger
(yes, I know it's not nice at all but I don't see any other way to do it).

 Regards,
VZ

---------
Hold on, this is even better!

From: Yann Rouillard (Y.Rouillard@exeter.ac.uk)
Subject: wxChoice and wxADJUST_MINSIZE 
Newsgroups: comp.soft-sys.wxwindows
Date: 2002-07-18 08:28:31 PST 

I am trying to use a wxChoice widget in a little panel. The text length of
the choices in the wxChoice can change so I used the wxADJUST_MINSIZE to
have its width correctly set. 

> the manual for wxSizer::Add() says:
Finally, you can also specify wxADJUST_MINSIZE flag to make the minimal size of
the control dynamically adjust to the value returned by its GetBestSize()
method - this allows, for example, for correct relayouting of a static text
control even if its text is changed during run-time.

relayouting?  sounds like s/size/layout/g gone wrong.

Call Add() with wxADJUST_MINSIZE flag!