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.
11 #include <sys/ioctl.h>
12 #include <sys/utsname.h>
23 /* Copied from linux/rtc.h to eliminate the kernel dependency */
24 struct linux_rtc_time {
36 #define RTC_SET_TIME _IOW('p', 0x0a, struct linux_rtc_time) /* Set RTC time */
37 #define RTC_RD_TIME _IOR('p', 0x09, struct linux_rtc_time) /* Read RTC time */
39 #if ENABLE_FEATURE_HWCLOCK_LONG_OPTIONS
45 static time_t read_rtc(int utc)
52 if (( rtc = open ( "/dev/rtc", O_RDONLY )) < 0 ) {
53 if (( rtc = open ( "/dev/misc/rtc", O_RDONLY )) < 0 )
54 bb_perror_msg_and_die ( "Could not access RTC" );
56 memset ( &tm, 0, sizeof( struct tm ));
57 if ( ioctl ( rtc, RTC_RD_TIME, &tm ) < 0 )
58 bb_perror_msg_and_die ( "Could not read time from RTC" );
59 tm.tm_isdst = -1; /* not known */
64 oldtz = getenv ( "TZ" );
65 setenv ( "TZ", "UTC 0", 1 );
73 setenv ( "TZ", oldtz, 1 );
81 static void write_rtc(time_t t, int utc)
86 if (( rtc = open ( "/dev/rtc", O_WRONLY )) < 0 ) {
87 if (( rtc = open ( "/dev/misc/rtc", O_WRONLY )) < 0 )
88 bb_perror_msg_and_die ( "Could not access RTC" );
91 tm = *( utc ? gmtime ( &t ) : localtime ( &t ));
94 if ( ioctl ( rtc, RTC_SET_TIME, &tm ) < 0 )
95 bb_perror_msg_and_die ( "Could not set the RTC time" );
100 static int show_clock(int utc)
104 RESERVE_CONFIG_BUFFER(buffer, 64);
106 t = read_rtc ( utc );
107 ptm = localtime ( &t ); /* Sets 'tzname[]' */
109 safe_strncpy ( buffer, ctime ( &t ), 64);
111 buffer [strlen ( buffer ) - 1] = 0;
113 //printf ( "%s %.6f seconds %s\n", buffer, 0.0, utc ? "" : ( ptm-> tm_isdst ? tzname [1] : tzname [0] ));
114 printf ( "%s %.6f seconds\n", buffer, 0.0 );
115 RELEASE_CONFIG_BUFFER(buffer);
120 static int to_sys_clock(int utc)
122 struct timeval tv = { 0, 0 };
123 const struct timezone tz = { timezone/60 - 60*daylight, 0 };
125 tv.tv_sec = read_rtc ( utc );
127 if ( settimeofday ( &tv, &tz ))
128 bb_perror_msg_and_die ( "settimeofday() failed" );
133 static int from_sys_clock(int utc)
135 struct timeval tv = { 0, 0 };
136 struct timezone tz = { 0, 0 };
138 if ( gettimeofday ( &tv, &tz ))
139 bb_perror_msg_and_die ( "gettimeofday() failed" );
141 write_rtc ( tv.tv_sec, utc );
145 #ifdef CONFIG_FEATURE_HWCLOCK_ADJTIME_FHS
146 # define ADJTIME_PATH "/var/lib/hwclock/adjtime"
148 # define ADJTIME_PATH "/etc/adjtime"
150 static int check_utc(void)
153 FILE *f = fopen ( ADJTIME_PATH, "r" );
156 RESERVE_CONFIG_BUFFER(buffer, 128);
158 while ( fgets ( buffer, sizeof( buffer ), f )) {
159 int len = strlen ( buffer );
161 while ( len && isspace ( buffer [len - 1] ))
166 if ( strncmp ( buffer, "UTC", 3 ) == 0 ) {
172 RELEASE_CONFIG_BUFFER(buffer);
177 #define HWCLOCK_OPT_LOCALTIME 0x01
178 #define HWCLOCK_OPT_UTC 0x02
179 #define HWCLOCK_OPT_SHOW 0x04
180 #define HWCLOCK_OPT_HCTOSYS 0x08
181 #define HWCLOCK_OPT_SYSTOHC 0x10
183 int hwclock_main ( int argc, char **argv )
188 #if ENABLE_FEATURE_HWCLOCK_LONG_OPTIONS
189 static const struct option hwclock_long_options[] = {
190 { "localtime", 0, 0, 'l' },
191 { "utc", 0, 0, 'u' },
192 { "show", 0, 0, 'r' },
193 { "hctosys", 0, 0, 's' },
194 { "systohc", 0, 0, 'w' },
197 bb_applet_long_options = hwclock_long_options;
200 bb_opt_complementally = "?:r--ws:w--rs:s--wr:l--u:u--l";
201 opt = bb_getopt_ulflags(argc, argv, "lursw");
203 /* If -u or -l wasn't given check if we are using utc */
204 if (opt & (HWCLOCK_OPT_UTC | HWCLOCK_OPT_LOCALTIME))
205 utc = opt & HWCLOCK_OPT_UTC;
209 if (opt & HWCLOCK_OPT_HCTOSYS) {
210 return to_sys_clock ( utc );
212 else if (opt & HWCLOCK_OPT_SYSTOHC) {
213 return from_sys_clock ( utc );
215 /* default HWCLOCK_OPT_SHOW */
216 return show_clock ( utc );