/* Reads and returns the current value of DR4. This function is only available on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on X64. */
UINTN EFIAPI AsmReadDr4(VOID)
/* Reads and returns the current value of DR4. This function is only available on IA-32 and X64. This returns a 32-bit value on IA-32 and a 64-bit value on X64. */
UINTN EFIAPI AsmReadDr4(VOID)
{
  UINTN  Data;
  __asm__ __volatile__ (
    "mov  %%dr4, %0"
    : "=r" (Data)
  );
  return Data;
}