1 /* vi: set sw=4 ts=4: */
3 * Mini hwclock implementation for busybox
5 * Copyright (C) 2002 Robert Griebl <griebl@gmx.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <sys/utsname.h>
33 #include <sys/ioctl.h>
37 /* Copied from linux/rtc.h to eliminate the kernel dependancy */
38 struct linux_rtc_time {
51 #define RTC_SET_TIME _IOW('p', 0x0a, struct linux_rtc_time) /* Set RTC time */
52 #define RTC_RD_TIME _IOR('p', 0x09, struct linux_rtc_time) /* Read RTC time */
55 #ifdef CONFIG_FEATURE_HWCLOCK_LONGOPTIONS
71 time_t read_rtc ( int utc )
78 if (( rtc = open ( "/dev/rtc", O_RDONLY )) < 0 ) {
79 if (( rtc = open ( "/dev/misc/rtc", O_RDONLY )) < 0 )
80 bb_perror_msg_and_die ( "Could not access RTC" );
82 memset ( &tm, 0, sizeof( struct tm ));
83 if ( ioctl ( rtc, RTC_RD_TIME, &tm ) < 0 )
84 bb_perror_msg_and_die ( "Could not read time from RTC" );
85 tm. tm_isdst = -1; // not known
90 oldtz = getenv ( "TZ" );
91 setenv ( "TZ", "UTC 0", 1 );
99 setenv ( "TZ", oldtz, 1 );
107 void write_rtc ( time_t t, int utc )
112 if (( rtc = open ( "/dev/rtc", O_WRONLY )) < 0 ) {
113 if (( rtc = open ( "/dev/misc/rtc", O_WRONLY )) < 0 )
114 bb_perror_msg_and_die ( "Could not access RTC" );
119 tm = *( utc ? gmtime ( &t ) : localtime ( &t ));
124 if ( ioctl ( rtc, RTC_SET_TIME, &tm ) < 0 )
125 bb_perror_msg_and_die ( "Could not set the RTC time" );
130 int show_clock ( int utc )
136 t = read_rtc ( utc );
137 ptm = localtime ( &t ); /* Sets 'tzname[]' */
139 safe_strncpy ( buffer, ctime ( &t ), sizeof( buffer ));
141 buffer [bb_strlen ( buffer ) - 1] = 0;
143 //printf ( "%s %.6f seconds %s\n", buffer, 0.0, utc ? "" : ( ptm-> tm_isdst ? tzname [1] : tzname [0] ));
144 printf ( "%s %.6f seconds\n", buffer, 0.0 );
149 int to_sys_clock ( int utc )
151 struct timeval tv = { 0, 0 };
152 const struct timezone tz = { timezone/60 - 60*daylight, 0 };
154 tv. tv_sec = read_rtc ( utc );
156 if ( settimeofday ( &tv, &tz ))
157 bb_perror_msg_and_die ( "settimeofday() failed" );
162 int from_sys_clock ( int utc )
164 struct timeval tv = { 0, 0 };
165 struct timezone tz = { 0, 0 };
167 if ( gettimeofday ( &tv, &tz ))
168 bb_perror_msg_and_die ( "gettimeofday() failed" );
170 write_rtc ( tv. tv_sec, utc );
175 int check_utc ( void )
178 FILE *f = fopen ( "/etc/adjtime", "r" );
183 while ( fgets ( buffer, sizeof( buffer ), f )) {
184 int len = bb_strlen ( buffer );
186 while ( len && isspace ( buffer [len - 1] ))
191 if ( strncmp ( buffer, "UTC", 3 ) == 0 ) {
201 extern int hwclock_main ( int argc, char **argv )
204 enum OpMode mode = SHOW;
208 #ifdef CONFIG_FEATURE_HWCLOCK_LONGOPTIONS
209 struct option long_options[] = {
210 { "show", 0, 0, 'r' },
211 { "utc", 0, 0, 'u' },
212 { "localtime", 0, 0, 'l' },
213 { "hctosys", 0, 0, 's' },
214 { "systohc", 0, 0, 'w' },
218 while (( opt = getopt_long ( argc, argv, "rwsul", long_options, 0 )) != EOF ) {
220 while (( opt = getopt ( argc, argv, "rwsul" )) != EOF ) {
236 case 'l': // -l is not supported by the normal hwclock (only --localtime)
251 return from_sys_clock ( utc );
254 return to_sys_clock ( utc );
258 return show_clock ( utc );