GP2X/FPC Issues

[savage]

Where are you running this code that crashes?

You need to tell the compiler that this is a console Application otherwise the calls to *writeln* will AV. Which is what I am seeing.

The following works for me on Windows.

[pascal]
program Thread;

{$APPTYPE CONSOLE}

uses
sdl;

var
thread : PSDL_Thread;
returnValue : Integer;

function thread_func( aData : pointer ) : integer; cdecl;
begin
// do threading here
WriteLn( 'Start Thread' );
SDL_Delay( 5000 );
WriteLn( 'End Thread' );

result := 1; // thread leaves and return this value
end;

begin
returnValue := 0;

thread := SDL_CreateThread( @thread_func, nil );

SDL_WaitThread( thread, returnValue );
WriteLn( 'Thread returns code ', returnValue );
SDL_Quit;
WriteLn( 'ByeBye ' );
end.
[/pascal]

On other platforms you may have to specifcy the *cdecl* call and the pointer parameter as well to avoid the AV.

As for timers, the following example works for me....
[pascal]
program SDLTimers;

{$APPTYPE CONSOLE}

uses
SysUtils,
sdl;

var
Timer1 : PSDL_TimerID;
Timer2 : PSDL_TimerID;
Param1 : Integer;
Param2 : Integer;

function CallTimer1( interval : UInt32; param : Pointer ) : UInt32; cdecl;
var
pParam : PInteger;
begin
pParam := PInteger( param );
WriteLn( 'Parameter = ' + IntToStr( pParam^ ) + ' in CallTimer1' );
Result := interval;
end;

function CallTimer2( interval : UInt32; param : Pointer ) : UInt32; cdecl;
var
pParam : PInteger;
begin
pParam := PInteger( param );
WriteLn( 'Parameter = ' + IntToStr( pParam^ ) + ' in CallTimer2' );
Result := interval;
end;

begin
if ( SDL_Init( SDL_INIT_TIMER ) <> 0 ) then
WriteLn( 'Cannot initalize SDL' );

// Adding Timers
WriteLn( 'Adding Timers +' );
Param1 := 12;
Param2 := 15;
Timer1 := SDL_AddTimer( 500, CallTimer1, @Param1 );
Timer2 := SDL_AddTimer( 1200, CallTimer2, @Param2 );

WriteLn( 'SDL_Delay 30 secs, so we can see the timers in operation' );
SDL_Delay( 30000 );

WriteLn( 'Removing Timers -' );
SDL_RemoveTimer( Timer2 );
SDL_RemoveTimer( Timer1 );

WriteLn( 'Ciao ' );
ReadLn;
SDL_Quit;
end.
[/pascal]

Does it work for you?

[savage]

Btw, I tested both of these apps with Delphi and FreePascal on Windows. Hopefully they should work exactly as advertised on other platforms.

[paul_nicholls]

Hi Thomas
I googled for 'MPEGerror.h and found this file:

http://svn.icculus.org/*checkout*/sm...Gerror.h?rev=2

So it sounds like something else is causing this class to be used to produce the error.

I did try adding SDL_INIT_TIMER to my SDL_Init() call, but it still crashes on my GP2X

I haven't tried running it using gdb again with the SDL_INIT_TIMER to see if it is the same error as before though...

cheers,
Paul.

[KidPaddle]

Hi,

@savage
My sample crashed only on GP2X, on Windows it works perfectly. I will try your sample today.

@Paul
You got nearly the same stack trace, only a few higher level calls are missing, but after calling SDL_CreateThread, it crashed in function __pthread_initialize_manager ().

Thomas

[KidPaddle]

Hi savage,

if have tested both samples from you, under windows it works perfect, on gp2x it crashed always in function __pthread_initialize_manager.

Cheers,
Thomas

[savage]

I've posted a message about it on the main SDL mailing list, so will see what they come back with.

[KidPaddle]

Thanks for open a post on libsdl mailing list, but i believe it has nothing to do with sdl.

I have installed the official gph sdk and compiled the thread sample. After executing on gp2x i got following debugger output:

Starting program: /mnt/sd/Test/fpc/fpc4gp2x/fpcthread.gpe

Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? ()
(gdb) info stack
#0  0x00000000 in ?? ()
#1  0x00075ecc in ptmalloc_init () at malloc.c:1760
#2  0x00077630 in malloc_hook_ini (sz=792, caller=0x75b6c) at malloc.c:1856
#3  0x000774ac in __libc_malloc (bytes=989568) at malloc.c:2797
#4  0x0004da7c in SDL_CreateThread &#40;fn=0x8118 <THREAD_FUNC>, data=0x0&#41; at SDL_thread.c&#58;228
#5  0x000081e4 in main &#40;&#41; at fpcthread.dpr&#58;26

As you can see, the gph sdk has more debug symbols insight, so we got a better error location.

I wrote a smaller sample, like this:

program fpcmalloc;
{$IFNDEF FPC}
  {$APPTYPE CONSOLE}
{$ENDIF}

function  malloc(aSize : Integer): Pointer; cdecl; external;
procedure free(aPtr : Pointer); cdecl; external;

var
  MemPtr           : Pointer;
begin
  WriteLn('Alloc 792 Bytes');
  MemPtr := Malloc(792);

  WriteLn('Release 792 Bytes');
  Free(MemPtr);
  
  WriteLn('ByeBye');
end.

The output under gp2x is:

Starting program: /mnt/sd/Test/fpc/fpc4gp2x/fpcmalloc.gpe
Alloc 792 Bytes

Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? ()
(gdb) info stack
#0  0x00000000 in ?? ()
#1  0x00034f70 in ptmalloc_init () at malloc.c:1756
#2  0x0003670c in malloc_hook_ini (sz=792, caller=0x0) at malloc.c:1856
#3  0x00036588 in __libc_malloc (bytes=230028) at malloc.c:2797
#4  0x00008168 in main () at fpcmalloc.dpr:13

I don't know if I'm right, but i look at ptmalloc_init ();

Cheers,
Thomas

[savage]

So do you think the problem is in the FreePascal memory allocation?
That it is incompatible with how GP2X expects it?

[KidPaddle]

I don't know. Using GetMem/FreeMem works, maybe there is something wrong with static linking of libc, but that is guessed.

Thomas

[gigantor77]

Hi all!
I used the fpc4gp2x from eonclash.com and got the same problem...crash when trying to use the mixer, when statically linking. All the graphics & joystick stuff works find though...thanks Paul :-)

I noticed that the Eugene Proshkin's Blocks program is dynamically linked and the sound is working fine.

However I couldnt work out how to dynamically link from his compiler files. Has anyone been able to dynamically link using fpc4gp2x on Windows? I keep getting all sorts of linking errors.