[PATCH v3 04/21] DynamicTablesPkg: Add AmlRdSetEndTagChecksum()

["PierreGondois" <pierre.gondois@arm.com>]

From: Pierre Gondois <Pierre.Gondois@arm.com>

Add AmlRdSetEndTagChecksum(), setting the CheckSum value contained in a
Resource Data element.

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>
---
 .../AmlLib/ResourceData/AmlResourceData.c     | 33 +++++++++++++++++++
 .../AmlLib/ResourceData/AmlResourceData.h     | 21 ++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/DynamicTablesPkg/Library/Common/AmlLib/ResourceData/AmlResourceData.c b/DynamicTablesPkg/Library/Common/AmlLib/ResourceData/AmlResourceData.c
index 8b46c7232df3..41cf0bc45314 100644
--- a/DynamicTablesPkg/Library/Common/AmlLib/ResourceData/AmlResourceData.c
+++ b/DynamicTablesPkg/Library/Common/AmlLib/ResourceData/AmlResourceData.c
@@ -101,3 +101,36 @@ AmlRdGetSize (
   return ((ACPI_SMALL_RESOURCE_HEADER*)Header)->Bits.Length +
            sizeof (ACPI_SMALL_RESOURCE_HEADER);
 }
+
+/** Set the Checksum of an EndTag resource data.
+
+  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."
+
+  @param  [in]  Header     Pointer to the first byte of a resource data.
+  @param  [in]  CheckSum   Checksum value to set.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlRdSetEndTagChecksum (
+  IN  CONST AML_RD_HEADER   * Header,
+  IN        UINT8             CheckSum
+  )
+{
+  if ((Header == NULL)  ||
+      !AmlRdCompareDescId (
+        Header,
+        AML_RD_BUILD_SMALL_DESC_ID (ACPI_SMALL_END_TAG_DESCRIPTOR_NAME))) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  ((EFI_ACPI_END_TAG_DESCRIPTOR*)Header)->Checksum = CheckSum;
+  return EFI_SUCCESS;
+}
diff --git a/DynamicTablesPkg/Library/Common/AmlLib/ResourceData/AmlResourceData.h b/DynamicTablesPkg/Library/Common/AmlLib/ResourceData/AmlResourceData.h
index 48e4e2aaddb4..e478107dffbd 100644
--- a/DynamicTablesPkg/Library/Common/AmlLib/ResourceData/AmlResourceData.h
+++ b/DynamicTablesPkg/Library/Common/AmlLib/ResourceData/AmlResourceData.h
@@ -171,4 +171,25 @@ AmlRdGetSize (
   IN  CONST AML_RD_HEADER   * Header
   );
 
+/** Set the Checksum of an EndTag resource data.
+
+  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."
+
+  @param  [in]  Header     Pointer to the first byte of a resource data.
+  @param  [in]  CheckSum   Checksum value to set.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_INVALID_PARAMETER   Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlRdSetEndTagChecksum (
+  IN  CONST AML_RD_HEADER   * Header,
+  IN        UINT8             CheckSum
+  );
+
 #endif // AML_RESOURCE_DATA_H_
-- 
2.17.1