I use the CPUID to get the CPU type, and try to use the RDMSR to get the CPU status, program can be compile under win2k, but the "access violation" error will popup.


why the BIOS can get the CPU current system speed & ratio ? it is calculate or inquire ? I try the RDTSC to calculate the CPU speed, but can not get the CPU ratio & current FSB.

who can tell me how to do this?
Posted on 2005-01-19 10:51:38 by metero
I use the CPUID to get the CPU type, and try to use the RDMSR to get the CPU status, program can be compile under win2k, but the "access violation" error will popup.


why the BIOS can get the CPU current system speed & ratio ? it is calculate or inquire ? I try the RDTSC to calculate the CPU speed, but can not get the CPU ratio & current FSB.

who can tell me how to do this?



You can only use RDMSR with privilege level 0.
Posted on 2005-01-19 16:18:09 by mark_larson
I just run at ring0,but I still can not run the code.
why?
Posted on 2005-01-20 06:33:09 by metero
I look on the intel document center,and search on the web, but can not found the BIOS read system speed & CPU ratio document :(
Posted on 2005-01-20 06:34:31 by metero