IntelFrameworkModulePkg: add comments to clarify runtime memory usage for legacy OS.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Elvin Li <elvin.li@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17135 6f19259b-4bc3-4df7-8a09-765794883524

diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
index 6c2688b4a423cf7e5e0db2fd1d5c375f9d342a77..5575d2ec8eb9f8907eded90a2df1b4ff1cacc792 100644 (file)
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
@@ -1613,6 +1613,12 @@ EfiMemoryTypeToE820Type (
   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