IA32 EFER

From Thought dump
Jump to navigation Jump to search

MSR 0xc0000080IA32_EFER

Usable if (CPUID.80000001H:EDX.[20] || CPUID.80000001H:EDX.[29])
Bit Name Label Ops Description
0 SYSCALL Enable IA32_EFER.SCE R/W Enables SYSCALL/SYSRET instructions in 64-bit mode.
1 Reserved
2
3
4
5
6
7
8 IA-32e Mode Enable IA32_EFER.LME R/W Enables IA-32e mode operation.
9 Reserved
10 IA-32e Mode Active IA32_EFER.LMA R Indicates IA-32e mode is active when set.
11 Execute Disable Bit Enable IA32_EFER.NXE R/W
Reserved

From Intel SDM [1]