tools/tests/jitter/cpu_number.s

   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