Function 68, subfunction 4 - write to MSR-register.
MSR = Model Specific Register; the complete list of MSR-registers
of a processor is included to the documentation on it (for example,
IA-32 Intel Architecture Software Developer's Manual,
Volume 3, Appendix B); each processor family has its own subset
of the MSR-registers.
Parameters:
- eax = 68 - function number
- ebx = 4 - subfunction number
- ecx is ignored
- edx = MSR address
- esi:edi = high:low dword
Returned value:
- ebx:eax = copy of esi:edi
Замечания:
- If ecx contains nonexistent or not implemented for this processor
MSR, processor will generate an exception in the kernel, which
will kill the thread.
- Previously it is necessary to check, whether MSRs are supported
as a whole, with the instruction 'cpuid'. Otherwise processor
will generate other exception in the kernel, which will anyway
kill the thread.