Add details comments for the code flow to initialize Unicode Collation (2) support.

[mirror_edk2.git] / FatPkg / EnhancedFatDxe / UnicodeCollation.c

diff --git a/FatPkg/EnhancedFatDxe/UnicodeCollation.c b/FatPkg/EnhancedFatDxe/UnicodeCollation.c
index 4a849af2eb642e013345d686cc537128a8388ab4..9e5db7b96714abc2d80a6db95bdd03ebc4918f71 100644 (file)
--- a/FatPkg/EnhancedFatDxe/UnicodeCollation.c
+++ b/FatPkg/EnhancedFatDxe/UnicodeCollation.c
@@ -162,6 +162,12 @@ InitializeUnicodeCollationSupportWithConfig (
 /**\r
   Initialize Unicode Collation support.\r
 \r
+  This function searches Initialized Unicode Collation support based on PCDs:\r
+  PcdUnicodeCollation2Support and PcdUnicodeCollationSupport.\r
+  It first tries to locate Unicode Collation 2 protocol and matches it with current\r
+  platform language code. If for any reason the first attempt fails, it then tries to\r
+  use Unicode Collation Protocol.\r
+\r
   @param  AgentHandle          The handle used to open Unicode Collation (2) protocol.\r
 \r
   @retval EFI_SUCCESS          The Unicode Collation (2) protocol has been successfully located.\r
@@ -177,10 +183,18 @@ InitializeUnicodeCollationSupport (
   EFI_STATUS       Status;\r
 \r
   Status = EFI_UNSUPPORTED;\r
+\r
+  //\r
+  // First try to use RFC 3066 Unicode Collation 2 Protocol.\r
+  //\r
   if (FeaturePcdGet (PcdUnicodeCollation2Support)) {\r
     Status = InitializeUnicodeCollationSupportWithConfig (AgentHandle, &mRfc3066Lang);\r
   }\r
 \r
+  //\r
+  // If the attempt to use Unicode Collation 2 Protocol fails, then we fall back\r
+  // on the ISO 639-2 Unicode Collation Protocol.\r
+  //\r
   if (FeaturePcdGet (PcdUnicodeCollationSupport) && EFI_ERROR (Status)) {\r
     Status = InitializeUnicodeCollationSupportWithConfig (AgentHandle, &mIso639Lang);\r
   }\r