NASM 2.05 based x86 Instruction Reference[ch294]

A.5.270 RDMSR: Read Model-Specific Registers RDMSR ; 0F 32 [PENT,PRIV] RDMSR reads the processor Model-Specific Register (MSR) whose index is stored in ECX, and stores the result in EDX:EAX. See also WRMSR (section A.5.329).