This patch adds time stamp infrastructure using the TSC. It attempts to
determine TSC frequency inside virtual machines, but not on read hardware.
Signed-off-by: Alexander Graf <g...@amazon.com>
---
.../BaseDebugBootlog/DebugBootlogX86.c | 50 +++++++++++++++++++
1 file changed, 50 insertions(+)
create mode 100644 MdePkg/Library/BaseDebugBootlog/DebugBootlogX86.c
diff --git a/MdePkg/Library/BaseDebugBootlog/DebugBootlogX86.c
b/MdePkg/Library/BaseDebugBootlog/DebugBootlogX86.c
new file mode 100644
index 0000000000..1b6f677ce8
--- /dev/null
+++ b/MdePkg/Library/BaseDebugBootlog/DebugBootlogX86.c
@@ -0,0 +1,50 @@
+/** @file
+ Base Debug library instance for a RAM based boot log
+ It provides functions to store debug messages in RAM and make them available
as
+ Bootlog Configuration Table.
+
+ Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
+ Copyright (c) 2022, Amazon Development Center Germany GmbH.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "BaseDebugBootlog.h"
+
+UINT64
+EFIAPI
+BaseDebugLibBootlogTicksPerSecond (
+ VOID
+ )
+{
+ UINT32 MaxLeaf = 0;
+ UINT32 TscKhz = 0;
+
+ /* Look up VMware's TSC leaf first */
+ AsmCpuid (0x40000000, &MaxLeaf, NULL, NULL, NULL);
+ if (MaxLeaf >= 0x40000010 && MaxLeaf < 0x50000000) {
+ /* We're in a VM that supports the TSC leaf. */
+ AsmCpuid (0x40000010, &TscKhz, NULL, NULL, NULL);
+
+ return (UINT64)TscKhz * 1000;
+ }
+
+ /*
+ * The natural fallback path here would be to leverage TimerLib's
+ * GetPerformanceCounterProperties(), but TimerLib uses DebugLib
+ * so we can not use it. Let's leave TSC frequency extraction to
+ * post processing for now.
+ */
+
+ return 0;
+}
+
+UINT64
+EFIAPI
+BaseDebugLibBootlogTicks (
+ VOID
+ )
+{
+ return AsmReadTsc();
+}
+
--
2.28.0.394.ge197136389
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879
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