From: Shumin Qiu <shumin.qiu@intel.com>
Date: Fri, 23 Aug 2013 08:37:31 +0000 (+0000)
Subject: Update SetVariable() function description  for the clarification of requirements... 
X-Git-Tag: edk2-stable201903~12309
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=ce1d1c9a5fb422f41e240d9b13a6c14c9cffa468

Update SetVariable() function description  for the clarification of requirements to update timestamp associated with authenticated variable.

Signed-off-by: Shumin Qiu <shumin.qiu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14597 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/MdePkg/Include/Uefi/UefiSpec.h b/MdePkg/Include/Uefi/UefiSpec.h
index a39b4b8960..b44463104d 100644
--- a/MdePkg/Include/Uefi/UefiSpec.h
+++ b/MdePkg/Include/Uefi/UefiSpec.h
@@ -662,8 +662,15 @@ EFI_STATUS
                                  then EFI_INVALID_PARAMETER is returned.
   @param  VendorGuid             A unique identifier for the vendor.
   @param  Attributes             Attributes bitmask to set for the variable.
-  @param  DataSize               The size in bytes of the Data buffer. A size of zero causes the
-                                 variable to be deleted.
+  @param  DataSize               The size in bytes of the Data buffer. Unless the EFI_VARIABLE_APPEND_WRITE, 
+                                 EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS, or 
+                                 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS attribute is set, a size of zero 
+                                 causes the variable to be deleted. When the EFI_VARIABLE_APPEND_WRITE attribute is 
+                                 set, then a SetVariable() call with a DataSize of zero will not cause any change to 
+                                 the variable value (the timestamp associated with the variable may be updated however 
+                                 even if no new data value is provided,see the description of the 
+                                 EFI_VARIABLE_AUTHENTICATION_2 descriptor below. In this case the DataSize will not 
+                                 be zero since the EFI_VARIABLE_AUTHENTICATION_2 descriptor will be populated). 
   @param  Data                   The contents for the variable.
 
   @retval EFI_SUCCESS            The firmware has successfully stored the variable and its data as
@@ -675,9 +682,10 @@ EFI_STATUS
   @retval EFI_DEVICE_ERROR       The variable could not be retrieved due to a hardware error.
   @retval EFI_WRITE_PROTECTED    The variable in question is read-only.
   @retval EFI_WRITE_PROTECTED    The variable in question cannot be deleted.
-  @retval EFI_SECURITY_VIOLATION The variable could not be written due to EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS
-                                 set but the AuthInfo does NOT pass the validation check carried out
-                                 by the firmware.
+  @retval EFI_SECURITY_VIOLATION The variable could not be written due to EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS 
+                                 or EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACESS being set, but the AuthInfo 
+                                 does NOT pass the validation check carried out by the firmware.
+  
   @retval EFI_NOT_FOUND          The variable trying to be updated or deleted was not found.
 
 **/