boot-timestamps.c revision c51d84dc09476d9c06b8aac726220bf3c7d62e8d
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2012 Lennart Poettering
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 <unistd.h>
#include "boot-timestamps.h"
#include "acpi-fpdt.h"
#include "efivars.h"
int boot_timestamps(const dual_timestamp *n, dual_timestamp *firmware, dual_timestamp *loader) {
usec_t x, y, a;
int r;
dual_timestamp _n;
assert(firmware);
assert(loader);
if (!n) {
dual_timestamp_get(&_n);
n = &_n;
}
r = acpi_get_boot_usec(&x, &y);
if (r < 0) {
r = efi_loader_get_boot_usec(&x, &y);
if (r < 0)
return r;
}
/* Let's convert this to timestamps where the firmware
* began/loader began working. To make this more confusing:
* since usec_t is unsigned and the kernel's monotonic clock
* begins at kernel initialization we'll actually initialize
* the monotonic timestamps here as negative of the actual
* value. */
firmware->monotonic = y;
loader->monotonic = y - x;
a = n->monotonic + firmware->monotonic;
firmware->realtime = n->realtime > a ? n->realtime - a : 0;
a = n->monotonic + loader->monotonic;
loader->realtime = n->realtime > a ? n->realtime - a : 0;
return 0;
}