typedef struct _KUMS_CONTEXT_HEADER { unsigned __int64 P1Home; unsigned __int64 P2Home; unsigned __int64 P3Home; unsigned __int64 P4Home; void *StackTop; unsigned __int64 StackSize; unsigned __int64 RspOffset; unsigned __int64 Rip; XSAVE_FORMAT *FltSave; union { struct { unsigned __int64 Volatile : 1; unsigned __int64 Reserved : 63; }; unsigned __int64 Flags; }; KTRAP_FRAME *TrapFrame; KEXCEPTION_FRAME *ExceptionFrame; KTHREAD *SourceThread; unsigned __int64 Return; } KUMS_CONTEXT_HEADER, *PKUMS_CONTEXT_HEADER;