54 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			54 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* The kernel call implemented in this file:
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|  *   m_type:	SYS_SETTIME
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|  *
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|  * The parameters for this kernel call are:
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|  *    m4_l2:	T_SETTIME_NOW
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|  *    m4_l3:	T_CLOCK_ID
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|  *    m4_ll1:	T_TIME_SEC
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|  *    m4_l5:	T_TIME_NSEC
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|  */
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| 
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| #include "kernel/system.h"
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| #include <minix/endpoint.h>
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| #include <time.h>
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| 
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| /*===========================================================================*
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|  *				do_settime				     *
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|  *===========================================================================*/
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| int do_settime(struct proc * caller, message * m_ptr)
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| {
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|   clock_t newclock;
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|   int32_t ticks;
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|   time_t timediff, timediff_ticks;
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| 
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|   if (m_ptr->T_CLOCK_ID != CLOCK_REALTIME) /* only realtime can change */
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| 	return EINVAL;
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| 
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|   if (m_ptr->T_SETTIME_NOW == 0) { /* user just wants to adjtime() */
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| 	/* convert delta value from seconds and nseconds to ticks */
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| 	ticks = (m_ptr->T_TIME_SEC * system_hz) +
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| 				(m_ptr->T_TIME_NSEC/(1000000000/system_hz));
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| 	set_adjtime_delta(ticks);
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| 	return(OK);
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|   } /* else user wants to set the time */
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| 
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|   timediff = m_ptr->T_TIME_SEC - boottime;
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|   timediff_ticks = timediff * system_hz;
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| 
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|   /* prevent a negative value for realtime */
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|   if (m_ptr->T_TIME_SEC <= boottime ||
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|       timediff_ticks < LONG_MIN/2 || timediff_ticks > LONG_MAX/2) {
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|   	/* boottime was likely wrong, try to correct it. */
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| 	boottime = m_ptr->T_TIME_SEC;
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| 	set_realtime(1);
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| 	return(OK);
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|   }
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| 
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|   /* calculate the new value of realtime in ticks */
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|   newclock = timediff_ticks + (m_ptr->T_TIME_NSEC/(1000000000/system_hz));
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| 
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|   set_realtime(newclock);
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| 
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|   return(OK);
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| }
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