case EfiBootServicesCode:\r
case EfiBootServicesData:\r
case EfiConventionalMemory:\r
+ //\r
+ // The memory of EfiRuntimeServicesCode and EfiRuntimeServicesData are\r
+ // usable memory for legacy OS.\r
+ // In ACPI specification, EfiRuntimeServiceCode and EfiRuntimeServiceData\r
+ // should be mapped to AddressRangeReserved. This statement is for UEFI OS, not for legacy OS.\r
+ //\r
case EfiRuntimeServicesCode:\r
case EfiRuntimeServicesData:\r
return EfiAcpiAddressRangeMemory;\r