DynamicTablesPkg: AML Code generation for Resource data EndTag

Add a helper function AmlCodeGenEndTag() to generate AML Resource Data
EndTag. The EndTag resource data is automatically generated by the ASL
compiler at the end of a list of resource data elements. Therefore, an
equivalent function is not present in ASL.

However, AmlCodeGenEndTag() is useful when generating AML code for the
ResourceTemplate() macro.

Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
This commit is contained in:
Pierre Gondois
2021-10-08 15:46:22 +01:00
committed by mergify[bot]
parent f995f8672b
commit 9454d1ebcb
2 changed files with 156 additions and 0 deletions

View File

@@ -104,4 +104,47 @@ AmlCodeGenRdRegister (
OUT AML_DATA_NODE_HANDLE *NewRdNode OPTIONAL
);
/** Code generation for the EndTag resource data.
The EndTag resource data is automatically generated by the ASL compiler
at the end of a list of resource data elements. Thus, it doesn't have
a corresponding ASL function.
This function allocates memory to create a data node. It is the caller's
responsibility to either:
- attach this node to an AML tree;
- delete this node.
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] CheckSum CheckSum to store in the EndTag.
To ignore/avoid computing the checksum,
give 0.
@param [in] ParentNode If not NULL, add the generated node
to the end of the variable list of
argument of the ParentNode.
The ParentNode must not initially contain
an EndTag resource data element.
@param [out] NewRdNode If success, contains the generated node.
@retval EFI_SUCCESS The function completed successfully.
@retval EFI_INVALID_PARAMETER Invalid parameter.
@retval EFI_OUT_OF_RESOURCES Could not allocate memory.
**/
EFI_STATUS
EFIAPI
AmlCodeGenEndTag (
IN UINT8 CheckSum, OPTIONAL
IN AML_OBJECT_NODE * ParentNode, OPTIONAL
OUT AML_DATA_NODE ** NewRdNode OPTIONAL
);
#endif // AML_RESOURCE_DATA_CODE_GEN_H_