typedef struct _WHEA_ERROR_PACKET
{
     ULONG Signature;
     ULONG Flags;
     UINT64 Size;
     UINT64 RawDataLength;
     UINT64 Context;
     WHEA_ERROR_TYPE ErrorType;
     WHEA_ERROR_SEVERITY ErrorSeverity;
     ULONG ErrorSourceId;
     WHEA_ERROR_SOURCE_TYPE ErrorSourceType;
     ULONG Reserved1;
     ULONG Version;
     UINT64 Cpu;
     BYTE u[208];
     WHEA_ERROR_STATUS_FORMAT RawDataFormat;
     ULONG Reserved2;
     UCHAR RawData[1];
} WHEA_ERROR_PACKET, *PWHEA_ERROR_PACKET;

Windows Vista Kernel Structures