Synchronize function's comments with UEFI specification.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@6058 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 19 insertions, 7 deletions

diff --git a/MdePkg/Include/Protocol/VariableWrite.h b/MdePkg/Include/Protocol/VariableWrite.h
index 802026b739..d8d81076dc 100644
--- a/MdePkg/Include/Protocol/VariableWrite.h
+++ b/MdePkg/Include/Protocol/VariableWrite.h
@@ -1,13 +1,25 @@
 /** @file

   Variable Write Architectural Protocol as defined in PI Specification VOLUME 2 DXE

 

-  This code is used to produce the UEFI 2.0 runtime variable services

-

-  The SetVariable () UEFI 2.0 services may be updated to the EFI system table and the 

-  EFI_VARIABLE_WRITE_ARCH_PROTOCOL_GUID protocol is registered with a NULL pointer.

-

-  No CRC of the EFI system table is required, as it is done in the DXE core.

-

+  This provides the services required to set nonvolatile environment variables. 

+  This protocol must be produced by a runtime DXE driver and may be consumed only 

+  by the DXE Foundation.

+

+  The DXE driver that produces this protocol must be a runtime driver. This driver 

+  may update the SetVariable() field of the UEFI Runtime Services Table.

+  

+  After the UEFI Runtime Services Table has been initialized, the driver must 

+  install the EFI_VARIABLE_WRITE_ARCH_PROTOCOL_GUID on a new handle with a NULL 

+  interface pointer. The installation of this protocol informs the DXE Foundation 

+  that the write services for nonvolatile environment variables are now available 

+  and that the DXE Foundation must update the 32-bit CRC of the UEFI Runtime Services 

+  Table. The full complement of environment variable services are not available 

+  until both this protocol and EFI_VARIABLE_ARCH_PROTOCOL are installed. DXE drivers 

+  that require read-only access or read/write access to volatile environment variables

+  must have the EFI_VARIABLE_WRITE_ARCH_PROTOCOL in their dependency expressions.

+  DXE drivers that require write access to nonvolatile environment variables must 

+  have this architectural protocol in their dependency expressions.  

+  

   Copyright (c) 2006 - 2008, Intel Corporation                                                         

   All rights reserved. This program and the accompanying materials                          

   are licensed and made available under the terms and conditions of the BSD License