main_TcpNet throws PAbt

Hi,

My application is running from 0x20000 started by a 2nd stage bootloader located at 0x00000.

When my application is started by the bootloader, the function call main_TcpNet throws a PAbt exception after a while. Sometimes the exception occurs nearly immediately, sometimes the application runs for several minutes. I removed everything else from my application to track the cause of the PAbt. Now the init task only starts the TCP task and the tick-timer task before the init terminates. I don't have to establish a connection or do anything to cause the PAbt exception.

In the following cases the application runs without throwing an exception:

1) The application without the tcp-task calling main_TcpNet runs without any problems.

2) When no network cable is connected the application runs without any problems.

3) When I start the application directly without running through the bootloader everything works fine.

I also have reduced the bootloader to the one only command to call the application at 0x20000.

My reduced bootloader.c:

#define APPL_RUN_ADDR           0x00020000

typedef void (*FP)(void);

void run_appl()
{
    FP fp;

    VICIntEnClr = 0xFFFFFFFF; // Disable all interrupt
    fp = (FP)APPL_RUN_ADDR;
    (*fp)();
}

int main(void)
{
    run_appl();
}

This exception I can observe at my own Hardware as well as with the MBC2300 Evalboard.

I'm using the following environment:

IDE-Version:
µVision V4.71.2.0
Copyright (C) 2013 ARM Ltd and ARM Germany GmbH. All rights reserved.

Tool Version Numbers:
Toolchain:          MDK-ARM Professional   Version: 4.71.0.0
Toolchain Path:     C:\Keil\ARM\ARMCC\bin\ 
C Compiler:         Armcc.Exe              V5.03.0.69
Assembler:          Armasm.Exe             V5.03.0.69
Linker/Locator:     ArmLink.Exe            V5.03.0.69
Librarian:          ArmAr.Exe              V5.03.0.69
Hex Converter:      FromElf.Exe            V5.03.0.69
CPU DLL:            SARM.DLL               V4.71.0.0
Dialog DLL:         DARMP.DLL              V1.51
Target DLL:         ULP2ARM.DLL            V2.20.2.0
Dialog DLL:         TARMP.DLL              V1.51

Can anyone give me a clue, where I have missed something, or what can the cause of that exception?

I've run out ideas right now.

Thanks in advance
Hubert