`cpuid` 명령을 사용하여 Linux에서 CPU 정보에 액세스하는 방법은 무엇입니까?

<code class="c">unsigned int __get_cpuid_max(unsigned int __ext, unsigned int *__sig);
int __get_cpuid(unsigned int __level, unsigned int *__eax, unsigned int *__ebx, unsigned int *__ecx, unsigned int *__edx);</code>

<code class="c">#include <stdio.h>
#include <cpuid.h>

int main() {
  unsigned int eax, ebx, ecx, edx;

  // Get maximum supported CPUID level
  unsigned int max_level = __get_cpuid_max(0x0, NULL);

  // Iterate over different CPUID levels
  for (unsigned int level = 0; level <= max_level; level++) {
    // Retrieve CPUID data for the current level
    __get_cpuid(level, &eax, &ebx, &ecx, &edx);

    printf("Level %u: EAX=%u, EBX=%u, ECX=%u, EDX=%u\n", level, eax, ebx, ecx, edx);
  }

  return 0;
}</code>