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| author | Pierre Gondois <Pierre.Gondois@arm.com> | 2021-10-08 15:46:16 +0100 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2021-10-08 15:39:42 +0000 |
| commit | 74addfeab6d7f66800e430be078d6560c4edda53 (patch) | |
| tree | c452bb3cfc2673baba64ca1d9c1d4134ce0f4cd8 /DynamicTablesPkg | |
| parent | 28b2df475fb214d11ee50f5a924cedee671f0ba1 (diff) | |
| download | edk2-74addfeab6d7f66800e430be078d6560c4edda53.tar.gz edk2-74addfeab6d7f66800e430be078d6560c4edda53.tar.bz2 edk2-74addfeab6d7f66800e430be078d6560c4edda53.zip | |
DynamicTablesPkg: Add AmlSetRdListCheckSum()
Lists of Resource Data elements end with an EndTag (most of the time).
This function finds the EndTag (if present) in a list of Resource Data
elements and sets the checksum.
ACPI 6.4, s6.4.2.9 "End Tag":
"This checksum is generated such that adding it to the sum of all the data
bytes will produce a zero sum."
"If the checksum field is zero, the resource data is treated as if the
checksum operation succeeded. Configuration proceeds normally."
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
Diffstat (limited to 'DynamicTablesPkg')
| -rw-r--r-- | DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.c | 76 | ||||
| -rw-r--r-- | DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.h | 32 |
2 files changed, 108 insertions, 0 deletions
diff --git a/DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.c b/DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.c index 7ebd08f945..ef159e3b83 100644 --- a/DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.c +++ b/DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.c @@ -904,3 +904,79 @@ AmlPropagateInformation ( return EFI_SUCCESS;
}
+
+/** Find and set the EndTag's Checksum of a list of Resource Data elements.
+
+ Lists of Resource Data elements end with an EndTag (most of the time). This
+ function finds the EndTag (if present) in a list of Resource Data elements
+ and sets the checksum.
+
+ ACPI 6.4, s6.4.2.9 "End Tag":
+ "This checksum is generated such that adding it to the sum of all the data
+ bytes will produce a zero sum."
+ "If the checksum field is zero, the resource data is treated as if the
+ checksum operation succeeded. Configuration proceeds normally."
+
+ To avoid re-computing checksums, if a new resource data elements is
+ added/removed/modified in a list of resource data elements, the AmlLib
+ resets the checksum to 0.
+
+ @param [in] BufferOpNode Node having a list of Resource Data elements.
+ @param [in] CheckSum CheckSum to store in the EndTag.
+ To ignore/avoid computing the checksum,
+ give 0.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+ @retval EFI_NOT_FOUND No EndTag found.
+**/
+EFI_STATUS
+EFIAPI
+AmlSetRdListCheckSum (
+ IN AML_OBJECT_NODE * BufferOpNode,
+ IN UINT8 CheckSum
+ )
+{
+ EFI_STATUS Status;
+ AML_DATA_NODE * LastRdNode;
+ AML_RD_HEADER RdDataType;
+
+ if (!AmlNodeCompareOpCode (BufferOpNode, AML_BUFFER_OP, 0)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ // Get the last Resource data node in the variable list of
+ // argument of the BufferOp node.
+ LastRdNode = (AML_DATA_NODE*)AmlGetPreviousVariableArgument (
+ (AML_NODE_HEADER*)BufferOpNode,
+ NULL
+ );
+ if ((LastRdNode == NULL) ||
+ !IS_AML_DATA_NODE (LastRdNode) ||
+ (LastRdNode->DataType != EAmlNodeDataTypeResourceData)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Status = AmlGetResourceDataType (LastRdNode, &RdDataType);
+ if (EFI_ERROR (Status)) {
+ ASSERT (0);
+ return Status;
+ }
+
+ // Check the LastRdNode is an EndTag.
+ // It is possible to have only one Resource Data in a BufferOp with
+ // no EndTag. Return EFI_NOT_FOUND is such case.
+ if (!AmlRdCompareDescId (
+ &RdDataType,
+ AML_RD_BUILD_SMALL_DESC_ID (ACPI_SMALL_END_TAG_DESCRIPTOR_NAME))) {
+ ASSERT (0);
+ return EFI_NOT_FOUND;
+ }
+
+ Status = AmlRdSetEndTagChecksum (LastRdNode->Buffer, CheckSum);
+ ASSERT_EFI_ERROR (Status);
+
+ return Status;
+}
diff --git a/DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.h b/DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.h index c57d780140..4667f57d7f 100644 --- a/DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.h +++ b/DynamicTablesPkg/Library/Common/AmlLib/Utils/AmlUtility.h @@ -91,5 +91,37 @@ AmlPropagateInformation ( IN UINT8 NodeCount
);
+/** Find and set the EndTag's Checksum of a list of Resource Data elements.
+
+ Lists of Resource Data elements end with an EndTag (most of the time). This
+ function finds the EndTag (if present) in a list of Resource Data elements
+ and sets the checksum.
+
+ ACPI 6.4, s6.4.2.9 "End Tag":
+ "This checksum is generated such that adding it to the sum of all the data
+ bytes will produce a zero sum."
+ "If the checksum field is zero, the resource data is treated as if the
+ checksum operation succeeded. Configuration proceeds normally."
+
+ To avoid re-computing checksums, if a new resource data elements is
+ added/removed/modified in a list of resource data elements, the AmlLib
+ resets the checksum to 0.
+
+ @param [in] BufferOpNode Node having a list of Resource Data elements.
+ @param [in] CheckSum CheckSum to store in the EndTag.
+ To ignore/avoid computing the checksum,
+ give 0.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+ @retval EFI_NOT_FOUND No EndTag found.
+**/
+EFI_STATUS
+EFIAPI
+AmlSetRdListCheckSum (
+ IN AML_OBJECT_NODE * BufferOpNode,
+ IN UINT8 CheckSum
+ );
+
#endif // AML_UTILITY_H_
|