218 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			218 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * Copyright (c) 2011 Aeroflex Gaisler
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|  *
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|  * BSD license:
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|  *
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|  * Permission is hereby granted, free of charge, to any person obtaining a copy
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|  * of this software and associated documentation files (the "Software"), to deal
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|  * in the Software without restriction, including without limitation the rights
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|  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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|  * copies of the Software, and to permit persons to whom the Software is
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|  * furnished to do so, subject to the following conditions:
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|  *
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|  * The above copyright notice and this permission notice shall be included in
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|  * all copies or substantial portions of the Software.
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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|  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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|  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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|  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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|  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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|  * THE SOFTWARE.
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|  */
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| 
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| 
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| #include <asm-leon/contextswitch.h>
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| #include <asm-leon/leonbare_kernel.h>
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| #include <asm-leon/leonbare_debug.h>
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| #include <asm-leon/stack.h>
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| #include <asm-leon/leonstack.h>
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| #include <asm-leon/irq.h>
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| 
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| struct leonbare_kernel leonbare_kernel;
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| 
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| /*
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|  * queue 0: [ <acc=2>],
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|  * queue 1: [ <acc=10>, <acc=8>,<acc=8>,<acc=1> ],
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|  * queue 2: [ ... ],
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|  * ...
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|  * queue n: [ ... ]
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|  *
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|  *  Seach through ready queue [0 - LEONBARE_RUNQ_READY_NR-1] for the
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|  *  first thread in a queue'ss head to discover
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|  *  leonbare_thread_tick_callback() will put threads that have their th_caccount
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|  *  consumed into the prepare-run queues. th_caccount is already initialized
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|  *  to the value for the next schedule round. So all there is to do is to
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|  *  move the to prepare-run queues to run queues [0 - LEONBARE_RUNQ_READY_NR-1].
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|  *  return the first thread in any queue, similary to leonbare_sched_next().
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|  *  Using LEONBARE_KR_RUNQ_WHICH and leonbare_thread.th_runq_which one can
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|  *  determine weather the thread is in a runqueue or a prepare-runqueue:
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|  *  LEONBARE_KR_RUNQ_WHICH == leonbare_thread.th_runq_which : thread in runqueue
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|  *  LEONBARE_KR_RUNQ_WHICH != leonbare_thread.th_runq_which : thread in prepare-runqueue
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|  *  after a leonbare_thread_tick_callback() or a run queue change, call
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|  *  leonbare_sched_update() to update LEONBARE_KR_NEXT and
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|  *  LEONBARE_KR_NEED_SCHEDULE
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|  */
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| int
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| leonbare_sched_update ()
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| {
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|   int idx;
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|   leonbare_thread_t n = 0;
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|   int i = 0;
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|   LEONBARE_VERIFYIRQDISABLED ();
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|   LEONBARE_VERIFYSCHED ();
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|   for (i = 0; i < LEONBARE_RUNQ_READY_NR; i++)
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|     {
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|       leonbare_thread_t c;
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|       if (!LBTAILQ_EMPTY (LEONBARE_KR_RUNQ (i)))
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| 	{
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| 	  n = LBTAILQ_FIRST (LEONBARE_KR_RUNQ (i));
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| 	  break;
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| 	}
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|     }
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|   if (!n)
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|     {
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|       for (idx = 0; idx < LEONBARE_RUNQ_READY_NR; idx++)
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| 	{
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| 	  struct leonbare_thread_queue *h0 =
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| 	    (struct leonbare_thread_queue *) LEONBARE_KR_RUNQ (idx);
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| 	  struct leonbare_thread_queue *h1 = (struct leonbare_thread_queue *)
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| 	    LEONBARE_KR_RUNQ (idx + LEONBARE_RUNQ_PREPARE_IDX);
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| 	  if (LBTAILQ_EMPTY (h1))
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| 	    {
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| 	      LBTAILQ_INIT (h0);
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| 	    }
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| 	  else
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| 	    {
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| 	      *h0 = *h1;
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| 	      if (LBTAILQ_FIRST (h0))
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| 		{
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| 		  LBTAILQ_FIRST (h0)->th_runq.tqe_prev = &(h0)->tqh_first;
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| 		}
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| 	      if (!n)
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| 		{
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| 		  n = LBTAILQ_FIRST (h0);
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| 		}
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| 	    }
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| 	}
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|       for (idx = 0; idx < LEONBARE_RUNQ_READY_NR; idx++)
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| 	{
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| 	  LBTAILQ_INIT (LEONBARE_KR_RUNQ (idx + LEONBARE_RUNQ_PREPARE_IDX));
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| 	}
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|       LEONBARE_KR_RUNQ_WHICH++;
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|       LEONBARE_VERIFYSCHED ();
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|       LEONBARE_PRINTQUEUES ();
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|     }
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|   LEONBARE_KR_NEXT = n;
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|   return (LEONBARE_KR_NEED_SCHEDULE);
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| }
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| 
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| /*  called in the timer irq handling. Decrements the 
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|  *  th_caccount field. On consumption of th_caccount the 
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|  *  thread will be removed from the ready queue nad placed into the
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|  *  prepare-runqueue for later readdition by leonbare_sched_readyprepare()
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|  *  called from gettimeofday.c's installed ticker_callback callback
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|  *  leonbare_thread_tick_callback() might change the kernel state in which case
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|  *  state on return from leonbare_thread_tick_callback() leonbare_thread_schedule_callback()
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|  *  will be called from rtrap_fast.S .
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|  */
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| int
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| leonbare_thread_tick_callback ()
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| {
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|   LEONBARE_PROTECT_DECL (flags);
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|   unsigned int r;
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|   volatile leonbare_thread_t c = LEONBARE_KR_CURRENT;
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|   leonbare_thread_t i;
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|   LBDEBUG_FNCALL;
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|   if (c && LEONBARE_KR_IS_PREEMPTION)
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|     {
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| 
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|       LEONBARE_PROTECT_KERNEL_START ();
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|       {
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| 
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| 	LEONBARE_VERIFYIRQDISABLED ();
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| 	LEONBARE_VERIFYSCHED ();
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| 
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| 	if ((--c->th_caccount) < 0)
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| 	  {
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| 	    LBDEBUG_HEADER_PRINTF (LBDEBUG_QUEUE_NR, "remove %s(%x)\n",
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| 				   LEONBARE_TH_NAME_DBG (c), c);
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| 	    LBTAILQ_REMOVE (LEONBARE_KR_RUNQ (c->th_runq_idx), c, th_runq);
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| 	    LBTAILQ_INSERT_TAIL (LEONBARE_KR_RUNQ
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| 				 (c->th_runq_idx + LEONBARE_RUNQ_PREPARE_IDX),
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| 				 c, th_runq);
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| 	    c->th_caccount = c->th_account;
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| 	    c->th_runq_which++;
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| 	  }
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| 	else
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| 	  {
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| 	    /* todo: round robbin scheme */
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| 	  }
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|       }
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|       LEONBARE_PROTECT_KERNEL_END ();
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|     }
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|   r = leonbare_sched_update ();
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|   return r;
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| }
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| 
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| /* called from rtrap_fast.S's installed schedule_callback callback */
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| int
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| leonbare_thread_schedule_callback (struct leonbare_pt_regs *ptregs)
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| {
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|   unsigned int retval;
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|   LBDEBUG_FNCALL;
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|   if (LEONBARE_KR_IS_IN_KERNEL == 0 && LEONBARE_KR_NEED_SCHEDULE)
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|     {
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| 
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|       leonbare_sched ();
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| 
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|       //KERNEL_ENTER;
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|       //KERNEL_EXIT(LEONBARE_KR_NEED_SCHEDULE, retval);
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|     }
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|   LBDEBUG_FNEXIT;
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| }
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| 
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| 
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| struct leonbare_thread _thread_main;
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| int
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| leonbare_thread_init ()
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| {
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|   int i;
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|   LBDEBUG_FNCALL;
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| 
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|   memset ((void *) &_thread_main, 0, sizeof (_thread_main));
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|   _thread_main.th_reentp = _impure_ptr;
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|   _thread_main.th_name = "<main>";
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|   _thread_main.th_runq_idx = 0;
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|   _thread_main.th_pri_idx = 0;
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|   _thread_main.th_account = 0;
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| 
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|   LBTAILQ_INIT (LEONBARE_KR_ALLQ);
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|   for (i = 0; i < LEONBARE_RUNQ_NR; i++)
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|     {
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|       LBTAILQ_INIT (LEONBARE_KR_RUNQ (i));
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|     }
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|   LBTAILQ_INIT (LEONBARE_KR_ALLM);
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| 
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|   /* queues */
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|   LBTAILQ_INSERT_TAIL (LEONBARE_KR_ALLQ, &_thread_main, th_allq);
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| 
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|   /* inseart into ready queue 0 at head */
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|   LBTAILQ_INSERT_HEAD (LEONBARE_KR_RUNQ (_thread_main.th_runq_idx),
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| 		       &_thread_main, th_runq);
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| 
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|   LEONBARE_KR_CURRENT = &_thread_main;
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|   LEONBARE_KR_IS_IN_KERNEL = 0;
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| 
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|   leonbare_init_ticks ();
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|   schedule_callback = (schedulehandler) leonbare_thread_schedule_callback;
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|   ticker_callback = (tickerhandler) leonbare_thread_tick_callback;
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| 
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|   /* disable later */
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|   LEONBARE_KR_IS_PREEMPTION = 1;
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| 
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| 
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|   LBDEBUG_FNEXIT;
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| }
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