X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=MdePkg%2FInclude%2FIndustryStandard%2FElTorito.h;h=d8b1c27dfbe42e61911d5095419acac87a56243e;hb=1833218d9313d29499afdd81203decb9b5d9bf07;hp=b474dc9ba14768b5475b21e7ce66d218181c9b66;hpb=3052ec6b91ad4d7038d3f9a21f6da4fd260e4cc7;p=mirror_edk2.git

diff --git a/MdePkg/Include/IndustryStandard/ElTorito.h b/MdePkg/Include/IndustryStandard/ElTorito.h
index b474dc9ba1..d8b1c27dfb 100644
--- a/MdePkg/Include/IndustryStandard/ElTorito.h
+++ b/MdePkg/Include/IndustryStandard/ElTorito.h
@@ -19,9 +19,9 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #ifndef _ELTORITO_H_
 #define _ELTORITO_H_
 
-///
-/// CDROM_VOLUME_DESCRIPTOR.Types, defined in ISO 9660
-///
+//
+// CDROM_VOLUME_DESCRIPTOR.Types, defined in ISO 9660
+//
 #define CDVOL_TYPE_STANDARD 0x0
 #define CDVOL_TYPE_CODED    0x1
 #define CDVOL_TYPE_END      0xFF
@@ -58,12 +58,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #pragma pack(1)
 
 /// 
-/// El Torito Volume Descriptor
-/// Note that the CDROM_VOLUME_DESCRIPTOR does not match the ISO-9660
-/// descriptor.  For some reason descriptor used by El Torito is
-/// different, but they start the same.   The El Torito descriptor
-/// is left shifted 1 byte starting with the SystemId.  (Note this
-/// causes the field to get unaligned)
+/// CD-ROM Volume Descriptor
 /// 
 typedef union { 
   struct {
@@ -72,6 +67,9 @@ typedef union {
     CHAR8   Reserved[82];
   } Unknown;
 
+  ///
+  /// Boot Record Volume Descriptor, defined in "El Torito" Specification.
+  ///
   struct {
     UINT8   Type;            ///< Must be 0
     CHAR8   Id[5];           ///< "CD001" 
@@ -81,7 +79,10 @@ typedef union {
     UINT8   EltCatalog[4];   ///< Absolute pointer to first sector of Boot Catalog
     CHAR8   Unused2[13];     ///< Must be 0
   } BootRecordVolume;
-
+ 
+  ///
+  /// Primary Volumn Descriptor, defined in ISO 9660.
+  ///
   struct {
     UINT8   Type; 
     CHAR8   Id[5];           ///< "CD001"
@@ -107,7 +108,7 @@ typedef union {
   /// Catalog validation entry (Catalog header)
   ///
   struct {
-    UINT8   Indicator;
+    UINT8   Indicator;       ///< Must be 01
     UINT8   PlatformId;
     UINT16  Reserved;
     CHAR8   ManufacId[24];
@@ -119,12 +120,12 @@ typedef union {
   /// Initial/Default Entry or Section Entry
   ///
   struct {
-    UINT8   Indicator;
+    UINT8   Indicator;       ///< 88 = Bootable, 00 = Not Bootable
     UINT8   MediaType : 4;
-    UINT8   Reserved1 : 4;
+    UINT8   Reserved1 : 4;   ///< Must be 0
     UINT16  LoadSegment;
     UINT8   SystemType;
-    UINT8   Reserved2;
+    UINT8   Reserved2;       ///< Must be 0
     UINT16  SectorCount;
     UINT32  Lba;
   } Boot;
@@ -133,9 +134,9 @@ typedef union {
   /// Section Header Entry
   ///
   struct {
-    UINT8   Indicator;
+    UINT8   Indicator;       ///< 90 - Header, more header follw, 91 - Final Header
     UINT8   PlatformId;
-    UINT16  SectionEntries;
+    UINT16  SectionEntries;  ///< Number of section entries following this header
     CHAR8   Id[28];
   } Section;