CCS: CCS: C++ (g++) program crash in mallo_r during startup

Andreas Terstegge

Other Parts Discussed in Thread: ENERGIA

Tool/software: Code Composer Studio

Hello!

I am using CCSv7 and a MSP432 launchpad (black) for C++ development. I am using gcc/g++ (4.9.3), which comes along with CCS (and I checked that it is the latest version available from the CCS App Center).
I also tried out newer compilers (g++ 6.2.4) with no success.

I have stripped down my problem to the following simple file:

#include "msp.h"

class A {
public:
    A() {}
    virtual ~A() {}
};

A mya;

int main(void)
{
    return 0;
}

When I run this program on the MSP432 lauchpad, it immediately crashes during the start-up code. I started with a fresh CCS C Project, and renamed main.c to main.cpp. I also added the libstdc++.a library in the linker configuration. The program compiles and uploads without errors.

Some further investigations showed that the crash happens in malloc_r, when accessing an invalid address (something like 0xD000xxxx).

Can someone help me to fix this problem? I guess it has to do with the linker script (heap size?) or some other general issue concerning the gcc startup code in case of global CTORs/DTORs.

Since CCS is not providing a "New C++ Project" functionality, I am also not sure about the general C++ support in CCS.

Energia is heavily using C++, and strangely the program above works without problems in energia (which I can not use, because I don't want/need the multithreading stuff, which is mandatory there...).

Any help is highly welcome!

BR, Andreas

over 8 years ago

Chester Gillon over 8 years ago

Guru 92251 points

Andreas Terstegge said:
Since CCS is not providing a "New C++ Project" functionality, I am also not sure about the general C++ support in CCS.

The thread Global constructors in a C++ project with GCC on the MSP432 found there was a bug in the CCS default msp432p401r.lds linker script which placed the stack incorrectly, leading to a crash during start-up.

Suggest you first check if your linker script contains the same problem as detailed in the referenced thread.

Andreas Terstegge over 8 years ago in reply to Chester Gillon

Intellectual 280 points

Hello!

Thank you very much - the wrong SP was indeed part of the problem. I changed
my linker script accordingly!

But to make my program work, I had add some more code in the startup routine:

void Reset_Handler(void)
{
    uint32_t *pui32Src, *pui32Dest;

    //
    // Copy the data segment initializers from flash to SRAM.
    //
    pui32Src = &__data_load__;
    for(pui32Dest = &__data_start__; pui32Dest < &__data_end__; )
    {
        *pui32Dest++ = *pui32Src++;
    }

    /* Call system initialization routine */
    SystemInit();

    /* Jump to the main initialization routine. */
    _mainCRTStartup();
}

Somehow the data segment is not inizialized, and has to be copied to SRAM. I found this fix in the
following link (was reported for Tiva-C): http://processors.wiki.ti.com/index.php/Using_GCC_with_Tiva_in_CCSv6

I am not sure if this could also be fixed in the linker script, or if I could have fixed it in a more elegant way.
Any ideas?

BR, Andreas

Chester Gillon over 8 years ago in reply to Andreas Terstegge

Guru 92251 points

Andreas Terstegge said:
I am not sure if this could also be fixed in the linker script, or if I could have fixed it in a more elegant way.
Any ideas?

You have fixed the code in the correct way. I found that I previously reported the problem in msp432_startup_ccs_gcc.c in CCS 6.1.0.00104 is missing code to copy the data segment initializers from flash to SRAM.

Having just created a new project in CCS 7.0.0.00042 for a MSP432P401R, the default startup_msp432p401r_gcc.c added to the project by CCS is still missing the code in Reset_Handler() to copy the data segment initializers from flash to SRAM.

Andreas Terstegge over 8 years ago in reply to Chester Gillon

Intellectual 280 points

Maybe you could also add code to initialize the bss segment:

     // Copy the data segment initializers from flash to SRAM.
    pui32Src = &__data_load__;
    for(pui32Dest = &__data_start__; pui32Dest < &__data_end__; ) {
        *pui32Dest++ = *pui32Src++;
    }

    // Copy zeros in bss segment
    for (pui32Src = &__bss_start__; pui32Src < &__bss_end__;) {
        *pui32Src++ = 0;
    }

Andreas Terstegge over 8 years ago in reply to Andreas Terstegge

Intellectual 280 points

Not to forget the external decls:

extern uint32_t __data_load__;
extern uint32_t __data_start__;
extern uint32_t __data_end__;
extern uint32_t __bss_start__;
extern uint32_t __bss_end__;
extern uint32_t __StackTop;

Chester Gillon over 8 years ago in reply to Andreas Terstegge

Guru 92251 points

Andreas Terstegge said:
Maybe you could also add code to initialize the bss segment:

The _mainCRTStartup() function, which is called from Reset_Handler(), zeros the .bss section. Therefore, it is unnecessary to zero the .bss segment directly in Reset_Handler().

[Earlier versions of startup_msp432p401r_gcc.c called main() directly from Reset_Handler(), and therefore the .bss segment was initialized in Reset_Handler(). _mainCRTStartup() initializes the .bss segment and performs other start-up code such as calling global constructors before finally calling main()]

Andreas Terstegge over 8 years ago in reply to Chester Gillon

Intellectual 280 points

Ah okay. So I will take out the code for bss initialization !

BTW: Do you know where to get the source of the mainCRTstartup code?
It comes as a lib with gcc, right?

BR, Andreas

Chester Gillon over 8 years ago in reply to Andreas Terstegge

Guru 92251 points

Andreas Terstegge said:
BTW: Do you know where to get the source of the mainCRTstartup code?
It comes as a lib with gcc, right?

I got the source of the mainCRTstartup code from the GCC source package.

If you are using GCC v4.9.3, there is a link to the source package on https://launchpad.net/gcc-arm-embedded/4.9/4.9-2015-q3-update

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CCS: CCS: C++ (g++) program crash in mallo_r during startup