Carloalberto Torghele

code question about AN3748

Discussion created by Carloalberto Torghele on Apr 22, 2010
Latest reply on May 4, 2010 by Carloalberto Torghele

Hi!

 

In the main file there is this definition of a function pointer:

 

void  (* const _UserEntry[])() @0x000011E4=    // modificato @0x000011C0=
{
  0x4E714EF9,           //asm NOP(0x4E71), asm JMP(0x4EF9)         
  _startup,
};

 

What does the code inside do?

If i look at the memory with the debugger, I see that at address 0x000011C0 there is

4E 71 4E F9 00 00 12 EC

I have never seen this syntax before but I assume that 0x4E714EF9 copy this value in the memory. What's the point of saving this value in memory? There is a comment with a jump. Does it jump to this value?

 

Where 00 00 12 EC come from? Is it the address of _startup?

 

I would be happy if anyone could explain me what this code does.

 

Thanks!

CA

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