From 8da8daafc9055ce83804fcc65d0f4cf01b2ca6fe Mon Sep 17 00:00:00 2001
From: Krzysztof Koch <krzysztof.koch@arm.com>
Date: Thu, 16 May 2019 01:43:35 -0700
Subject: [PATCH] ShellPkg: acpiview: Add GT Frame Number validation to GTDT
 parser

The ACPI 6.2 specification mandates that the Generic Timer (GT) Block
Timer Structures must have a frame number in the range 0-7.

Update the GTDT parser to warn if this condition is violated.

Signed-off-by: Krzysztof Koch <krzysztof.koch@arm.com>
Reviewed-by: Zhichao Gao <zhichao.gao@intel.com>
---
 .../Parsers/Gtdt/GtdtParser.c                 | 47 ++++++++++++++++++-
 1 file changed, 45 insertions(+), 2 deletions(-)

diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Gtdt/GtdtParser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Gtdt/GtdtParser.c
index f31c4a2761..1b7e56486c 100644
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Gtdt/GtdtParser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Gtdt/GtdtParser.c
@@ -1,7 +1,7 @@
 /** @file
   GTDT table parser
 
-  Copyright (c) 2016 - 2018, ARM Limited. All rights reserved.
+  Copyright (c) 2016 - 2019, ARM Limited. All rights reserved.
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
   @par Reference(s):
@@ -38,6 +38,21 @@ ValidateGtBlockTimerCount (
   IN VOID*  Context
   );
 
+/**
+  This function validates the GT Frame Number.
+
+  @param [in] Ptr     Pointer to the start of the field data.
+  @param [in] Context Pointer to context specific information e.g. this
+                      could be a pointer to the ACPI table header.
+**/
+STATIC
+VOID
+EFIAPI
+ValidateGtFrameNumber (
+  IN UINT8* Ptr,
+  IN VOID*  Context
+  );
+
 /**
   An ACPI_PARSER array describing the ACPI GTDT Table.
 **/
@@ -92,7 +107,7 @@ STATIC CONST ACPI_PARSER GtBlockParser[] = {
   An ACPI_PARSER array describing the GT Block timer.
 **/
 STATIC CONST ACPI_PARSER GtBlockTimerParser[] = {
-  {L"Frame Number", 1, 0, L"%d", NULL, NULL, NULL, NULL},
+  {L"Frame Number", 1, 0, L"%d", NULL, NULL, ValidateGtFrameNumber, NULL},
   {L"Reserved", 3, 1, L"%x %x %x", Dump3Chars, NULL, NULL, NULL},
   {L"Physical address (CntBaseX)", 8, 4, L"0x%lx", NULL, NULL, NULL, NULL},
   {L"Physical address (CntEL0BaseX)", 8, 12, L"0x%lx", NULL, NULL, NULL,
@@ -145,6 +160,34 @@ ValidateGtBlockTimerCount (
   }
 }
 
+/**
+  This function validates the GT Frame Number.
+
+  @param [in] Ptr     Pointer to the start of the field data.
+  @param [in] Context Pointer to context specific information e.g. this
+                      could be a pointer to the ACPI table header.
+**/
+STATIC
+VOID
+EFIAPI
+ValidateGtFrameNumber (
+  IN UINT8* Ptr,
+  IN VOID*  Context
+  )
+{
+  UINT8 FrameNumber;
+
+  FrameNumber = *(UINT8*)Ptr;
+
+  if (FrameNumber > 7) {
+    IncrementErrorCount ();
+    Print (
+      L"\nERROR: GT Frame Number = %d. GT Frame Number must be in range 0-7.",
+      FrameNumber
+      );
+  }
+}
+
 /**
   This function parses the Platform GT Block.
 
-- 
2.39.2