support acpi firmware performance data (FPDT)

Prefer firmware-provided performance data over loader-exported ones; if
ACPI data is available, always use it, otherwise try to read the loader
data.

The firmware-provided variables start at the time the first EFI image
is executed and end when the operating system exits the boot services;
the (loader) time calculated in systemd-analyze increases.

1 files changed, 26 insertions, 0 deletions

diff --git a/src/shared/acpi-fpdt.h b/src/shared/acpi-fpdt.h
new file mode 100644
index 0000000000..fc4fe6f10f
--- /dev/null
+++ b/src/shared/acpi-fpdt.h
@@ -0,0 +1,26 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Kay Sievers
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <time-util.h>
+
+int acpi_get_boot_usec(usec_t *loader_start, usec_t *loader_exit);