mirror of
https://github.com/sheumann/hush.git
synced 2024-08-14 11:28:58 +00:00
function old new delta unix_do_one 548 540 -8 process_timer_stats 508 500 -8 process_irq_counts 532 524 -8 lpd_main 839 831 -8 hwclock_main 502 494 -8 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/6 up/down: 0/-50) Total: -40 bytes Signed-off-by: Ron Yorston <rmy@tigress.co.uk> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
337 lines
9.3 KiB
C
337 lines
9.3 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Mini hwclock implementation for busybox
|
|
*
|
|
* Copyright (C) 2002 Robert Griebl <griebl@gmx.de>
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
|
|
*/
|
|
|
|
#include "libbb.h"
|
|
/* After libbb.h, since it needs sys/types.h on some systems */
|
|
#include <sys/utsname.h>
|
|
#include "rtc_.h"
|
|
|
|
/* diff code is disabled: it's not sys/hw clock diff, it's some useless
|
|
* "time between hwclock was started and we saw CMOS tick" quantity.
|
|
* It's useless since hwclock is started at a random moment,
|
|
* thus the quantity is also random, useless. Showing 0.000000 does not
|
|
* deprive us from any useful info.
|
|
*
|
|
* SHOW_HWCLOCK_DIFF code in this file shows the difference between system
|
|
* and hw clock. It is useful, but not compatible with standard hwclock.
|
|
* Thus disabled.
|
|
*/
|
|
#define SHOW_HWCLOCK_DIFF 0
|
|
|
|
|
|
#if !SHOW_HWCLOCK_DIFF
|
|
# define read_rtc(pp_rtcname, sys_tv, utc) read_rtc(pp_rtcname, utc)
|
|
#endif
|
|
static time_t read_rtc(const char **pp_rtcname, struct timeval *sys_tv, int utc)
|
|
{
|
|
struct tm tm_time;
|
|
int fd;
|
|
|
|
fd = rtc_xopen(pp_rtcname, O_RDONLY);
|
|
|
|
rtc_read_tm(&tm_time, fd);
|
|
|
|
#if SHOW_HWCLOCK_DIFF
|
|
{
|
|
int before = tm_time.tm_sec;
|
|
while (1) {
|
|
rtc_read_tm(&tm_time, fd);
|
|
gettimeofday(sys_tv, NULL);
|
|
if (before != (int)tm_time.tm_sec)
|
|
break;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (ENABLE_FEATURE_CLEAN_UP)
|
|
close(fd);
|
|
|
|
return rtc_tm2time(&tm_time, utc);
|
|
}
|
|
|
|
static void show_clock(const char **pp_rtcname, int utc)
|
|
{
|
|
#if SHOW_HWCLOCK_DIFF
|
|
struct timeval sys_tv;
|
|
#endif
|
|
time_t t = read_rtc(pp_rtcname, &sys_tv, utc);
|
|
|
|
#if ENABLE_LOCALE_SUPPORT
|
|
/* Standard hwclock uses locale-specific output format */
|
|
char cp[64];
|
|
struct tm *ptm = localtime(&t);
|
|
strftime(cp, sizeof(cp), "%c", ptm);
|
|
#else
|
|
char *cp = ctime(&t);
|
|
chomp(cp);
|
|
#endif
|
|
|
|
#if !SHOW_HWCLOCK_DIFF
|
|
printf("%s 0.000000 seconds\n", cp);
|
|
#else
|
|
{
|
|
long diff = sys_tv.tv_sec - t;
|
|
if (diff < 0 /*&& tv.tv_usec != 0*/) {
|
|
/* Why we need diff++? */
|
|
/* diff >= 0 is ok: | diff < 0, can't just use tv.tv_usec: */
|
|
/* 45.520820 | 43.520820 */
|
|
/* - 44.000000 | - 45.000000 */
|
|
/* = 1.520820 | = -1.479180, not -2.520820! */
|
|
diff++;
|
|
/* Should be 1000000 - tv.tv_usec, but then we must check tv.tv_usec != 0 */
|
|
sys_tv.tv_usec = 999999 - sys_tv.tv_usec;
|
|
}
|
|
printf("%s %ld.%06lu seconds\n", cp, diff, (unsigned long)sys_tv.tv_usec);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static void to_sys_clock(const char **pp_rtcname, int utc)
|
|
{
|
|
struct timeval tv;
|
|
struct timezone tz;
|
|
|
|
tz.tz_minuteswest = timezone/60;
|
|
/* ^^^ used to also subtract 60*daylight, but it's wrong:
|
|
* daylight!=0 means "this timezone has some DST
|
|
* during the year", not "DST is in effect now".
|
|
*/
|
|
tz.tz_dsttime = 0;
|
|
|
|
tv.tv_sec = read_rtc(pp_rtcname, NULL, utc);
|
|
tv.tv_usec = 0;
|
|
if (settimeofday(&tv, &tz))
|
|
bb_perror_msg_and_die("settimeofday");
|
|
}
|
|
|
|
static void from_sys_clock(const char **pp_rtcname, int utc)
|
|
{
|
|
#if 1
|
|
struct timeval tv;
|
|
struct tm tm_time;
|
|
int rtc;
|
|
|
|
rtc = rtc_xopen(pp_rtcname, O_WRONLY);
|
|
gettimeofday(&tv, NULL);
|
|
/* Prepare tm_time */
|
|
if (sizeof(time_t) == sizeof(tv.tv_sec)) {
|
|
if (utc)
|
|
gmtime_r((time_t*)&tv.tv_sec, &tm_time);
|
|
else
|
|
localtime_r((time_t*)&tv.tv_sec, &tm_time);
|
|
} else {
|
|
time_t t = tv.tv_sec;
|
|
if (utc)
|
|
gmtime_r(&t, &tm_time);
|
|
else
|
|
localtime_r(&t, &tm_time);
|
|
}
|
|
#else
|
|
/* Bloated code which tries to set hw clock with better precision.
|
|
* On x86, even though code does set hw clock within <1ms of exact
|
|
* whole seconds, apparently hw clock (at least on some machines)
|
|
* doesn't reset internal fractional seconds to 0,
|
|
* making all this a pointless excercise.
|
|
*/
|
|
/* If we see that we are N usec away from whole second,
|
|
* we'll sleep for N-ADJ usecs. ADJ corrects for the fact
|
|
* that CPU is not infinitely fast.
|
|
* On infinitely fast CPU, next wakeup would be
|
|
* on (exactly_next_whole_second - ADJ). On real CPUs,
|
|
* this difference between current time and whole second
|
|
* is less than ADJ (assuming system isn't heavily loaded).
|
|
*/
|
|
/* Small value of 256us gives very precise sync for 2+ GHz CPUs.
|
|
* Slower CPUs will fail to sync and will go to bigger
|
|
* ADJ values. qemu-emulated armv4tl with ~100 MHz
|
|
* performance ends up using ADJ ~= 4*1024 and it takes
|
|
* 2+ secs (2 tries with successively larger ADJ)
|
|
* to sync. Even straced one on the same qemu (very slow)
|
|
* takes only 4 tries.
|
|
*/
|
|
#define TWEAK_USEC 256
|
|
unsigned adj = TWEAK_USEC;
|
|
struct tm tm_time;
|
|
struct timeval tv;
|
|
int rtc = rtc_xopen(pp_rtcname, O_WRONLY);
|
|
|
|
/* Try to catch the moment when whole second is close */
|
|
while (1) {
|
|
unsigned rem_usec;
|
|
time_t t;
|
|
|
|
gettimeofday(&tv, NULL);
|
|
|
|
t = tv.tv_sec;
|
|
rem_usec = 1000000 - tv.tv_usec;
|
|
if (rem_usec < adj) {
|
|
/* Close enough */
|
|
small_rem:
|
|
t++;
|
|
}
|
|
|
|
/* Prepare tm_time from t */
|
|
if (utc)
|
|
gmtime_r(&t, &tm_time); /* may read /etc/xxx (it takes time) */
|
|
else
|
|
localtime_r(&t, &tm_time); /* same */
|
|
|
|
if (adj >= 32*1024) {
|
|
break; /* 32 ms diff and still no luck?? give up trying to sync */
|
|
}
|
|
|
|
/* gmtime/localtime took some time, re-get cur time */
|
|
gettimeofday(&tv, NULL);
|
|
|
|
if (tv.tv_sec < t /* we are still in old second */
|
|
|| (tv.tv_sec == t && tv.tv_usec < adj) /* not too far into next second */
|
|
) {
|
|
break; /* good, we are in sync! */
|
|
}
|
|
|
|
rem_usec = 1000000 - tv.tv_usec;
|
|
if (rem_usec < adj) {
|
|
t = tv.tv_sec;
|
|
goto small_rem; /* already close to next sec, don't sleep */
|
|
}
|
|
|
|
/* Try to sync up by sleeping */
|
|
usleep(rem_usec - adj);
|
|
|
|
/* Jump to 1ms diff, then increase fast (x2): EVERY loop
|
|
* takes ~1 sec, people won't like slowly converging code here!
|
|
*/
|
|
//bb_error_msg("adj:%d tv.tv_usec:%d", adj, (int)tv.tv_usec);
|
|
if (adj < 512)
|
|
adj = 512;
|
|
/* ... and if last "overshoot" does not look insanely big,
|
|
* just use it as adj increment. This makes convergence faster.
|
|
*/
|
|
if (tv.tv_usec < adj * 8) {
|
|
adj += tv.tv_usec;
|
|
continue;
|
|
}
|
|
adj *= 2;
|
|
}
|
|
/* Debug aid to find "optimal" TWEAK_USEC with nearly exact sync.
|
|
* Look for a value which makes tv_usec close to 999999 or 0.
|
|
* For 2.20GHz Intel Core 2: optimal TWEAK_USEC ~= 200
|
|
*/
|
|
//bb_error_msg("tv.tv_usec:%d", (int)tv.tv_usec);
|
|
#endif
|
|
|
|
tm_time.tm_isdst = 0;
|
|
xioctl(rtc, RTC_SET_TIME, &tm_time);
|
|
|
|
if (ENABLE_FEATURE_CLEAN_UP)
|
|
close(rtc);
|
|
}
|
|
|
|
/*
|
|
* At system boot, kernel may set system time from RTC,
|
|
* but it knows nothing about timezones. If RTC is in local time,
|
|
* then system time is wrong - it is offset by timezone.
|
|
* This option corrects system time if RTC is in local time,
|
|
* and (always) sets in-kernel timezone.
|
|
*
|
|
* This is an alternate option to --hctosys that does not read the
|
|
* hardware clock.
|
|
*/
|
|
static void set_system_clock_timezone(int utc)
|
|
{
|
|
struct timeval tv;
|
|
struct tm *broken;
|
|
struct timezone tz;
|
|
|
|
gettimeofday(&tv, NULL);
|
|
broken = localtime(&tv.tv_sec);
|
|
tz.tz_minuteswest = timezone / 60;
|
|
if (broken->tm_isdst > 0)
|
|
tz.tz_minuteswest -= 60;
|
|
tz.tz_dsttime = 0;
|
|
gettimeofday(&tv, NULL);
|
|
if (!utc)
|
|
tv.tv_sec += tz.tz_minuteswest * 60;
|
|
if (settimeofday(&tv, &tz))
|
|
bb_perror_msg_and_die("settimeofday");
|
|
}
|
|
|
|
//usage:#define hwclock_trivial_usage
|
|
//usage: IF_FEATURE_HWCLOCK_LONG_OPTIONS(
|
|
//usage: "[-r|--show] [-s|--hctosys] [-w|--systohc] [-t|--systz]"
|
|
//usage: " [-l|--localtime] [-u|--utc]"
|
|
//usage: " [-f|--rtc FILE]"
|
|
//usage: )
|
|
//usage: IF_NOT_FEATURE_HWCLOCK_LONG_OPTIONS(
|
|
//usage: "[-r] [-s] [-w] [-t] [-l] [-u] [-f FILE]"
|
|
//usage: )
|
|
//usage:#define hwclock_full_usage "\n\n"
|
|
//usage: "Query and set hardware clock (RTC)\n"
|
|
//usage: "\n -r Show hardware clock time"
|
|
//usage: "\n -s Set system time from hardware clock"
|
|
//usage: "\n -w Set hardware clock from system time"
|
|
//usage: "\n -t Set in-kernel timezone, correct system time"
|
|
//usage: "\n if hardware clock is in local time"
|
|
//usage: "\n -u Assume hardware clock is kept in UTC"
|
|
//usage: "\n -l Assume hardware clock is kept in local time"
|
|
//usage: "\n -f FILE Use specified device (e.g. /dev/rtc2)"
|
|
|
|
#define HWCLOCK_OPT_LOCALTIME 0x01
|
|
#define HWCLOCK_OPT_UTC 0x02
|
|
#define HWCLOCK_OPT_SHOW 0x04
|
|
#define HWCLOCK_OPT_HCTOSYS 0x08
|
|
#define HWCLOCK_OPT_SYSTOHC 0x10
|
|
#define HWCLOCK_OPT_SYSTZ 0x20
|
|
#define HWCLOCK_OPT_RTCFILE 0x40
|
|
|
|
int hwclock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
|
int hwclock_main(int argc UNUSED_PARAM, char **argv)
|
|
{
|
|
const char *rtcname = NULL;
|
|
unsigned opt;
|
|
int utc;
|
|
|
|
#if ENABLE_FEATURE_HWCLOCK_LONG_OPTIONS
|
|
static const char hwclock_longopts[] ALIGN1 =
|
|
"localtime\0" No_argument "l" /* short opt is non-standard */
|
|
"utc\0" No_argument "u"
|
|
"show\0" No_argument "r"
|
|
"hctosys\0" No_argument "s"
|
|
"systohc\0" No_argument "w"
|
|
"systz\0" No_argument "t" /* short opt is non-standard */
|
|
"rtc\0" Required_argument "f"
|
|
;
|
|
applet_long_options = hwclock_longopts;
|
|
#endif
|
|
|
|
/* Initialize "timezone" (libc global variable) */
|
|
tzset();
|
|
|
|
opt_complementary = "r--wst:w--rst:s--wrt:t--rsw:l--u:u--l";
|
|
opt = getopt32(argv, "lurswtf:", &rtcname);
|
|
|
|
/* If -u or -l wasn't given check if we are using utc */
|
|
if (opt & (HWCLOCK_OPT_UTC | HWCLOCK_OPT_LOCALTIME))
|
|
utc = (opt & HWCLOCK_OPT_UTC);
|
|
else
|
|
utc = rtc_adjtime_is_utc();
|
|
|
|
if (opt & HWCLOCK_OPT_HCTOSYS)
|
|
to_sys_clock(&rtcname, utc);
|
|
else if (opt & HWCLOCK_OPT_SYSTOHC)
|
|
from_sys_clock(&rtcname, utc);
|
|
else if (opt & HWCLOCK_OPT_SYSTZ)
|
|
set_system_clock_timezone(utc);
|
|
else
|
|
/* default HWCLOCK_OPT_SHOW */
|
|
show_clock(&rtcname, utc);
|
|
|
|
return 0;
|
|
}
|