text: #ifndef DRAM_GUARD
  #define DRAM_GUARD
  
  #include<stdint.h>
  
  #define MM_LEN 1000
  
  uint8_t mm[MM_LEN];
  
  
  void write64bits_dram(uint64_t paddr, uint64_t data);
  
  uint64_t read64bits_dram(uint64_t paddr);
  
  
  // print tools
  void print_register();
  
  void print_stack();
  
  #endif