FileSystem on LPC43XX cortex M0

Hi there,

I am trying to access a memory SD card using keil fileSystem library on a LPC4337.
I am using keil MDK5 and all software component needed for a FileSystem firmware.

I can run FileSystem example for LPC4357 processor (works perfectly).
I can run FileSystem library using my own board and my own firmware if SD Card is accessed by cortex M4 core.

But I am not able to access it with Cortex M0 core.

each time I called any fileSystem functions (finit, fmount, etc.) firmware hangs ..

All my init functions are done by cortex M4 core before starting M0 core

I try to called finit before starting M0 core.
If I do that, when I call finit with M0 core, it hangs.
If M4 didnt called any fileSystem function,
finit doesnt hang when called by M0 core but fmount does ..

Here is my main code for M0 core

void main(void){
FILE *f;
fsStatus stat;

SystemInit();

stat = finit("M0:");
if (stat == fsOK) {
stat = fmount("M0:");
//code
}else{
//code
}
//code
}

/* M4 sets pll at 204 MHz */
#define CPU_SPEED_AFTER_CONFIGURATION (204000000UL)

__weak
void SystemInit (void)  {
        SystemCoreClock = CPU_SPEED_AFTER_CONFIGURATION;
}

Is it possible to use fileSystem library component with M0 core ?
If so, what did I missed ?

Thank you =)