SyspartGetSystemPartition

INT64 __fastcall SyspartGetSystemPartition(WCHAR *String, UINT64 Size, UINT64 *BytesWritten){
  unsigned int v4; 
  INT64 result; 
  v4 = Size;
  result = SiQuerySystemInformationString(98i64, String, (unsigned int)Size, BytesWritten);
  if( (int)(result + 0x80000000) >= 0 && (_DWORD)result != -1073741789 )
    return SiGetSystemDeviceName(
             (__int64(__fastcall *)(_QWORD, void **))SiGetSystemPartition,
             String,
             v4,
             (unsigned int *)BytesWritten);
  return result;
}

Referenced by:

BiMapEfiDeviceForSpaces
CmpMountPreloadedHives