[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit

Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/app/busybox/src/util-linux/hwclock.c b/ap/app/busybox/src/util-linux/hwclock.c
new file mode 100644
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--- /dev/null
+++ b/ap/app/busybox/src/util-linux/hwclock.c
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+/* 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);
+	strchrnul(cp, '\n')[0] = '\0';
+#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 - 60*daylight;
+	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)
+		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
+	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;
+}