1.text 2/* 3 * Taken from Libc 4 */ 5.globl _cpu_number 6_cpu_number: 7#if defined(__x86_64__) 8 push %rbp 9 mov %rsp,%rbp 10 sub $16,%rsp // space to read IDTR 11 12 sidt (%rsp) // store limit:base on stack 13 movw (%rsp), %rax // get limit 14 and $0xfff, %rax // mask off lower 12 bits to return 15 16 mov %rbp,%rsp 17 pop %rbp 18 ret 19#elif defined(__i386__) 20 push %ebp 21 mov %esp,%ebp 22 sub $8, %esp // space to read IDTR 23 24 sidt (%esp) // store limit:base on stack 25 movw (%esp), %ax // get limit 26 and $0xfff, %eax // mask off lower 12 bits to return 27 28 mov %ebp,%esp 29 pop %ebp 30 ret 31#else 32#error Unsupported architecture 33#endif 34