123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687 |
- /*
- * Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or any later version.
- *
- * This program 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
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
- FILE_LICENCE(GPL2_OR_LATER);
-
- #include <stddef.h>
- #include <ipxe/timer.h>
-
- #include <linux_api.h>
-
- /** @file
- *
- * iPXE timer API for linux
- *
- */
-
- /**
- * Delay for a fixed number of microseconds
- *
- * @v usecs Number of microseconds for which to delay
- */
- static void linux_udelay(unsigned long usecs)
- {
- linux_usleep(usecs);
- }
-
- /**
- * Get number of ticks per second
- *
- * @ret ticks_per_sec Number of ticks per second
- */
- static unsigned long linux_ticks_per_sec(void)
- {
- return 1000;
- }
-
- /**
- * Get current system time in ticks
- *
- * linux doesn't provide an easy access to jiffies so implement it by measuring
- * the time since the first call to this function.
- *
- * Since this function is used to seed the (non-cryptographic) random
- * number generator, we round the start time down to the nearest whole
- * second. This minimises the chances of generating identical RNG
- * sequences (and hence identical TCP port numbers, etc) on
- * consecutive invocations of iPXE.
- *
- * @ret ticks Current time, in ticks
- */
- static unsigned long linux_currticks(void)
- {
- static struct timeval start;
- static int initialized = 0;
-
- if (! initialized) {
- linux_gettimeofday(&start, NULL);
- initialized = 1;
- }
-
- struct timeval now;
- linux_gettimeofday(&now, NULL);
-
- unsigned long ticks = (now.tv_sec - start.tv_sec) * linux_ticks_per_sec();
- ticks += now.tv_usec / (long)(1000000 / linux_ticks_per_sec());
-
- return ticks;
- }
-
- PROVIDE_TIMER(linux, udelay, linux_udelay);
- PROVIDE_TIMER(linux, currticks, linux_currticks);
- PROVIDE_TIMER(linux, ticks_per_sec, linux_ticks_per_sec);
|