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authorRobert Griebl2002-07-21 16:50:49 +0000
committerRobert Griebl2002-07-21 16:50:49 +0000
commit1cd044549531ef1c4016ec3c60652dad95b1617f (patch)
treed552f7d94cac8240a89a5e498b73c0c60299de2c /util-linux/hwclock.c
parentfc78b795758ad04caeadfbb2bbb75e6cefa03785 (diff)
downloadbusybox-1cd044549531ef1c4016ec3c60652dad95b1617f.zip
busybox-1cd044549531ef1c4016ec3c60652dad95b1617f.tar.gz
Initial checkin of a very primitive hwclock replacement
Diffstat (limited to 'util-linux/hwclock.c')
-rw-r--r--util-linux/hwclock.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/util-linux/hwclock.c b/util-linux/hwclock.c
new file mode 100644
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--- /dev/null
+++ b/util-linux/hwclock.c
@@ -0,0 +1,229 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * really dumb hwclock implementation for busybox
+ * Copyright (C) 2002 Robert Griebl <griebl@gmx.de>
+ *
+ */
+
+
+#include <sys/utsname.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <string.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <sys/time.h>
+#include <time.h>
+#include <linux/rtc.h>
+#include <sys/ioctl.h>
+#include "busybox.h"
+
+#ifdef CONFIG_FEATURE_HWCLOCK_LONGOPTIONS
+# ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+# endif
+#endif
+
+#include <getopt.h>
+
+
+enum OpMode {
+ SHOW,
+ SYSTOHC,
+ HCTOSYS
+};
+
+
+time_t read_rtc ( int utc )
+{
+ int rtc;
+ struct tm tm;
+ char *oldtz = 0;
+ time_t t = 0;
+
+ if (( rtc = open ( "/dev/rtc", O_RDONLY )) < 0 ) {
+ if (( rtc = open ( "/dev/misc/rtc", O_RDONLY )) < 0 )
+ perror_msg_and_die ( "Could not access RTC" );
+ }
+ memset ( &tm, 0, sizeof( struct tm ));
+ if ( ioctl ( rtc, RTC_RD_TIME, &tm ) < 0 )
+ perror_msg_and_die ( "Could not read time from RTC" );
+ tm. tm_isdst = -1; // not known
+
+ close ( rtc );
+
+ if ( utc ) {
+ oldtz = getenv ( "TZ" );
+ setenv ( "TZ", "UTC 0", 1 );
+ tzset ( );
+ }
+
+ t = mktime ( &tm );
+
+ if ( utc ) {
+ if ( oldtz )
+ setenv ( "TZ", oldtz, 1 );
+ else
+ unsetenv ( "TZ" );
+ tzset ( );
+ }
+ return t;
+}
+
+void write_rtc ( time_t t, int utc )
+{
+ int rtc;
+ struct tm tm;
+
+ if (( rtc = open ( "/dev/rtc", O_WRONLY )) < 0 ) {
+ if (( rtc = open ( "/dev/misc/rtc", O_WRONLY )) < 0 )
+ perror_msg_and_die ( "Could not access RTC" );
+ }
+
+ printf ( "1\n" );
+
+ tm = *( utc ? gmtime ( &t ) : localtime ( &t ));
+ tm. tm_isdst = 0;
+
+ printf ( "2\n") ;
+
+ if ( ioctl ( rtc, RTC_SET_TIME, &tm ) < 0 )
+ perror_msg_and_die ( "Could not set the RTC time" );
+
+ close ( rtc );
+}
+
+int show_clock ( int utc )
+{
+ struct tm *ptm;
+ time_t t;
+ char buffer [64];
+
+ t = read_rtc ( utc );
+ ptm = localtime ( &t ); /* Sets 'tzname[]' */
+
+ safe_strncpy ( buffer, ctime ( &t ), sizeof( buffer ));
+ if ( buffer [0] )
+ buffer [xstrlen ( buffer ) - 1] = 0;
+
+ //printf ( "%s %.6f seconds %s\n", buffer, 0.0, utc ? "" : ( ptm-> tm_isdst ? tzname [1] : tzname [0] ));
+ printf ( "%s %.6f seconds\n", buffer, 0.0 );
+
+ return 0;
+}
+
+int to_sys_clock ( int utc )
+{
+ struct timeval tv = { 0, 0 };
+ const struct timezone tz = { timezone/60 - 60*daylight, 0 };
+
+ tv. tv_sec = read_rtc ( utc );
+
+ if ( settimeofday ( &tv, &tz ))
+ perror_msg_and_die ( "settimeofday() failed" );
+
+ return 0;
+}
+
+int from_sys_clock ( int utc )
+{
+ struct timeval tv = { 0, 0 };
+ struct timezone tz = { 0, 0 };
+
+ if ( gettimeofday ( &tv, &tz ))
+ perror_msg_and_die ( "gettimeofday() failed" );
+
+ write_rtc ( tv. tv_sec, utc );
+ return 0;
+}
+
+
+int check_utc ( void )
+{
+ int utc = 0;
+ FILE *f = fopen ( "/etc/adjtime", "r" );
+
+ if ( f ) {
+ char buffer [128];
+
+ while ( fgets ( buffer, sizeof( buffer ), f )) {
+ int len = xstrlen ( buffer );
+
+ while ( len && isspace ( buffer [len - 1] ))
+ len--;
+
+ buffer [len] = 0;
+
+ if ( strncmp ( buffer, "UTC", 3 ) == 0 ) {
+ utc = 1;
+ break;
+ }
+ }
+ fclose ( f );
+ }
+ return utc;
+}
+
+extern int hwclock_main ( int argc, char **argv )
+{
+ int opt;
+ enum OpMode mode = SHOW;
+ int utc = 0;
+ int utc_arg = 0;
+
+#ifdef CONFIG_FEATURE_HWCLOCK_LONGOPTIONS
+ struct option long_options[] = {
+ { "show", 0, 0, 'r' },
+ { "utc", 0, 0, 'u' },
+ { "localtime", 0, 0, 'l' },
+ { "hctosys", 0, 0, 's' },
+ { "systohc", 0, 0, 'w' },
+ { 0, 0, 0, 0 }
+ };
+
+ while (( opt = getopt_long ( argc, argv, "rwsul", long_options, 0 )) != EOF ) {
+#else
+ while (( opt = getopt ( argc, argv, "rwsul" )) != EOF ) {
+#endif
+ switch ( opt ) {
+ case 'r':
+ mode = SHOW;
+ break;
+ case 'w':
+ mode = SYSTOHC;
+ break;
+ case 's':
+ mode = HCTOSYS;
+ break;
+ case 'u':
+ utc = 1;
+ utc_arg = 1;
+ break;
+ case 'l': // -l is not supported by the normal hwclock (only --localtime)
+ utc = 0;
+ utc_arg = 1;
+ break;
+ default:
+ show_usage();
+ break;
+ }
+ }
+
+ if ( !utc_arg )
+ utc = check_utc ( );
+
+ switch ( mode ) {
+ case SYSTOHC:
+ return from_sys_clock ( utc );
+
+ case HCTOSYS:
+ return to_sys_clock ( utc );
+
+ case SHOW:
+ default:
+ return show_clock ( utc );
+ }
+}
+
+