1 /* vi: set sw=4 ts=4: */
3 * Mini hwclock implementation for busybox
5 * Copyright (C) 2002 Robert Griebl <griebl@gmx.de>
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
10 //#include <sys/ioctl.h>
11 #include <sys/utsname.h>
15 /* Copied from linux/rtc.h to eliminate the kernel dependency */
16 struct linux_rtc_time {
28 #define RTC_SET_TIME _IOW('p', 0x0a, struct linux_rtc_time) /* Set RTC time */
29 #define RTC_RD_TIME _IOR('p', 0x09, struct linux_rtc_time) /* Read RTC time */
31 #if ENABLE_FEATURE_HWCLOCK_LONG_OPTIONS
37 static const char *rtcname;
39 static int xopen_rtc(int flags)
44 rtc = open("/dev/rtc", flags);
47 rtc = open("/dev/rtc0", flags);
50 rtcname = "/dev/misc/rtc";
52 return xopen(rtcname, flags);
55 static time_t read_rtc(int utc)
60 int rtc = xopen_rtc(O_RDONLY);
62 memset(&tm, 0, sizeof(struct tm));
63 if (ioctl(rtc, RTC_RD_TIME, &tm) < 0)
64 bb_perror_msg_and_die("cannot read time from RTC");
65 tm.tm_isdst = -1; /* not known */
71 setenv("TZ", "UTC 0", 1);
79 setenv("TZ", oldtz, 1);
87 static void write_rtc(time_t t, int utc)
90 int rtc = xopen_rtc(O_WRONLY);
92 tm = *(utc ? gmtime(&t) : localtime(&t));
95 if (ioctl(rtc, RTC_SET_TIME, &tm) < 0)
96 bb_perror_msg_and_die("cannot set the RTC time");
101 static int show_clock(int utc)
105 RESERVE_CONFIG_BUFFER(buffer, 64);
108 ptm = localtime(&t); /* Sets 'tzname[]' */
110 safe_strncpy(buffer, ctime(&t), 64);
112 buffer[strlen(buffer) - 1] = 0;
114 //printf("%s %.6f seconds %s\n", buffer, 0.0, utc ? "" : (ptm->tm_isdst ? tzname[1] : tzname[0]));
115 printf( "%s %.6f seconds\n", buffer, 0.0);
116 RELEASE_CONFIG_BUFFER(buffer);
121 static int to_sys_clock(int utc)
123 struct timeval tv = { 0, 0 };
124 const struct timezone tz = { timezone/60 - 60*daylight, 0 };
126 tv.tv_sec = read_rtc(utc);
128 if (settimeofday(&tv, &tz))
129 bb_perror_msg_and_die("settimeofday() failed");
134 static int from_sys_clock(int utc)
136 struct timeval tv = { 0, 0 };
137 struct timezone tz = { 0, 0 };
139 if (gettimeofday(&tv, &tz))
140 bb_perror_msg_and_die("gettimeofday() failed");
142 write_rtc(tv.tv_sec, utc);
146 #ifdef CONFIG_FEATURE_HWCLOCK_ADJTIME_FHS
147 # define ADJTIME_PATH "/var/lib/hwclock/adjtime"
149 # define ADJTIME_PATH "/etc/adjtime"
151 static int check_utc(void)
154 FILE *f = fopen(ADJTIME_PATH, "r");
157 RESERVE_CONFIG_BUFFER(buffer, 128);
159 while (fgets(buffer, sizeof(buffer), f)) {
160 int len = strlen(buffer);
162 while (len && isspace(buffer[len - 1]))
167 if (strncmp(buffer, "UTC", 3) == 0) {
173 RELEASE_CONFIG_BUFFER(buffer);
178 #define HWCLOCK_OPT_LOCALTIME 0x01
179 #define HWCLOCK_OPT_UTC 0x02
180 #define HWCLOCK_OPT_SHOW 0x04
181 #define HWCLOCK_OPT_HCTOSYS 0x08
182 #define HWCLOCK_OPT_SYSTOHC 0x10
183 #define HWCLOCK_OPT_RTCFILE 0x20
185 int hwclock_main(int argc, char **argv );
186 int hwclock_main(int argc, char **argv )
191 #if ENABLE_FEATURE_HWCLOCK_LONG_OPTIONS
192 static const struct option hwclock_long_options[] = {
193 { "localtime", 0, 0, 'l' },
194 { "utc", 0, 0, 'u' },
195 { "show", 0, 0, 'r' },
196 { "hctosys", 0, 0, 's' },
197 { "systohc", 0, 0, 'w' },
198 { "file", 1, 0, 'f' },
201 applet_long_options = hwclock_long_options;
203 opt_complementary = "?:r--ws:w--rs:s--wr:l--u:u--l";
204 opt = getopt32(argc, argv, "lurswf:", &rtcname);
206 /* If -u or -l wasn't given check if we are using utc */
207 if (opt & (HWCLOCK_OPT_UTC | HWCLOCK_OPT_LOCALTIME))
208 utc = opt & HWCLOCK_OPT_UTC;
212 if (opt & HWCLOCK_OPT_HCTOSYS) {
213 return to_sys_clock(utc);
215 else if (opt & HWCLOCK_OPT_SYSTOHC) {
216 return from_sys_clock(utc);
218 /* default HWCLOCK_OPT_SHOW */
219 return show_clock(utc);