nios II help please

Hello

I'm a newbie in FPGAs, please help me for NIOS II project

I have 3 memorys

app_mem from 0x0000 to 0x57FF

boot_loader from 0x8000 to 0xAFFF

boot_ram from 0xC000 to 0XCFFF

where app_mem and boot_loader are ROM, boot_ram is RAM

I write this bootloader where jump from boot_loader to app_mem on address 0x0034

int main()

{

__asm("call 0x0034");

return 0;

}

my app_mem is programed with simple function start main on addr 0x0034

int main()

{

printf("Hello from Nios II!\n");

return 0;

}

when i run debuger to debug boot_loader on instruction call debuger is paused without errors, when i run instruction simulator, debuger says :

Error! : Failed memory access in component cpu_0 - Reading data 0x3030 from unin

itialized memory (addr = 0x22)

Error! : Simulation failed in component cpu_0 at instruction 663653 (PC=0x818c i

nstr=0x10c0002b).

where is the problem?

helpme to repair this problem please

very thanks