0 Replies Latest reply on Aug 10, 2015 8:03 AM by edris

    read msr (IA32_ENERGY_PERF_BIAS )

    edris

      hi

      I want to read msr register (IA32_ENERGY_PERF_BIAS(1B0H) ) in assembly with "rdmsr" instruction but have a run time error (Segmentation fault (core dumped)).

      I execute my code by root.

      -------------------- it's my code -----------------

      .file    "tst.c"

          .section    .rodata

      .LC0:

          .string    "result %u\n"

          .text

          .globl    main

          .type    main, @function

      main:

      .LFB0:

          .cfi_startproc

          pushq    %rbp

          .cfi_def_cfa_offset 16

          .cfi_offset 6, -16

          movq    %rsp, %rbp

          movq    $0,%rax

          movq    $0,%rdx

          movl    $0x1b0,%ecx

          rdmsr

          .cfi_def_cfa_register 6

          subq    $16, %rsp

          movl    %ecx, -4(%rbp)

          movl    $.LC0, %eax

          movl    -4(%rbp), %edx

          movl    %edx, %esi

          movq    %rax, %rdi

          movl    $0, %eax

          call    printf

          movl    $0, %eax

          leave

          .cfi_def_cfa 7, 8

          ret

          .cfi_endproc

      .LFE0:

          .size    main, .-main

          .ident    "GCC: (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3"

          .section    .note.GNU-stack,"",@progbits