Posted on November 10, 2017 at 13:18I am accessing an illegal memory location, but it does no generate MemManage fault or HardFault. Here's the compiling code that demonstrate the issue.
&sharpdefine SCB_SHCSR (*((volatile unsigned long*) 0xE000ED24)) //System handler control and state register
void MemManage_Handler(void)
{
__asm(
'MOV R4, 0x77777777\n\t'
'MOV R5, 0x77777777\n\t'
);
}
void HardFault_Handler(void)
{
__asm(
'MOV R4, 0x77777777\n\t'
'MOV R5, 0x77777777\n\t'
);
}
int main(void)
{
SCB_SHCSR = 0x00010000; // enable MemManage Fault
__asm(
'LDR R0, =0xE0100000\n\t'
'MOV R1, 0x77777777\n\t'
'STR R1, [R0,&sharp0]'
);
return (1);
}
void SystemInit(void)
{}
So, 0xE0100000 is an illegal memory location and does not allow to read/write. But in main function I am writing at that location but it does not generate any fault i.e. MemManage or hardfault handler is not executed. Why is that?
It does however shows this error message: *** error 65: access violation at 0xE0100000 : no 'write' permission.
#stm32f103rb #stm32 #keil #cortex-m3 #memory-protection
