236 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			236 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
/* This file contains the main program of MINIX as well as its shutdown code.
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 * The routine main() initializes the system and starts the ball rolling by
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 * setting up the process table, interrupt vectors, and scheduling each task 
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 * to run to initialize itself.
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 * The routine shutdown() does the opposite and brings down MINIX. 
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 *
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 * The entries into this file are:
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 *   main:	    	MINIX main program
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 *   prepare_shutdown:	prepare to take MINIX down
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 */
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#include "kernel.h"
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#include <signal.h>
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#include <string.h>
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#include <unistd.h>
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#include <a.out.h>
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#include <minix/callnr.h>
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#include <minix/com.h>
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#include <minix/endpoint.h>
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#include "proc.h"
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/* Prototype declarations for PRIVATE functions. */
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FORWARD _PROTOTYPE( void announce, (void));	
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/*===========================================================================*
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 *				main                                         *
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 *===========================================================================*/
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PUBLIC void main()
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{
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/* Start the ball rolling. */
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  struct boot_image *ip;	/* boot image pointer */
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  register struct proc *rp;	/* process pointer */
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  register struct priv *sp;	/* privilege structure pointer */
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  register int i, j, s;
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  int hdrindex;			/* index to array of a.out headers */
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  phys_clicks text_base;
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  vir_clicks text_clicks, data_clicks, st_clicks;
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  reg_t ktsb;			/* kernel task stack base */
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  struct exec e_hdr;		/* for a copy of an a.out header */
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  /* Clear the process table. Anounce each slot as empty and set up mappings 
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   * for proc_addr() and proc_nr() macros. Do the same for the table with 
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   * privilege structures for the system processes. 
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   */
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  for (rp = BEG_PROC_ADDR, i = -NR_TASKS; rp < END_PROC_ADDR; ++rp, ++i) {
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  	rp->p_rts_flags = SLOT_FREE;		/* initialize free slot */
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	rp->p_nr = i;				/* proc number from ptr */
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	rp->p_endpoint = _ENDPOINT(0, rp->p_nr); /* generation no. 0 */
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        (pproc_addr + NR_TASKS)[i] = rp;        /* proc ptr from number */
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  }
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  for (sp = BEG_PRIV_ADDR, i = 0; sp < END_PRIV_ADDR; ++sp, ++i) {
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	sp->s_proc_nr = NONE;			/* initialize as free */
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	sp->s_id = i;				/* priv structure index */
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	ppriv_addr[i] = sp;			/* priv ptr from number */
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  }
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  /* Set up proc table entries for processes in boot image.  The stacks of the
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   * kernel tasks are initialized to an array in data space.  The stacks
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   * of the servers have been added to the data segment by the monitor, so
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   * the stack pointer is set to the end of the data segment.  All the
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   * processes are in low memory on the 8086.  On the 386 only the kernel
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   * is in low memory, the rest is loaded in extended memory.
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   */
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  /* Task stacks. */
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  ktsb = (reg_t) t_stack;
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  for (i=0; i < NR_BOOT_PROCS; ++i) {
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	int ci;
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	bitchunk_t fv;
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	ip = &image[i];				/* process' attributes */
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	rp = proc_addr(ip->proc_nr);		/* get process pointer */
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	ip->endpoint = rp->p_endpoint;		/* ipc endpoint */
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	rp->p_max_priority = ip->priority;	/* max scheduling priority */
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	rp->p_priority = ip->priority;		/* current priority */
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	rp->p_quantum_size = ip->quantum;	/* quantum size in ticks */
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	rp->p_ticks_left = ip->quantum;		/* current credit */
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	strncpy(rp->p_name, ip->proc_name, P_NAME_LEN); /* set process name */
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	(void) get_priv(rp, (ip->flags & SYS_PROC));    /* assign structure */
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	priv(rp)->s_flags = ip->flags;			/* process flags */
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	priv(rp)->s_trap_mask = ip->trap_mask;		/* allowed traps */
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	/* Initialize call mask bitmap from unordered set.
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	 * A single SYS_ALL_CALLS is a special case - it
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	 * means all calls are allowed.
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	 */
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	if(ip->nr_k_calls == 1 && ip->k_calls[0] == SYS_ALL_CALLS)
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		fv = ~0;		/* fill call mask */
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	else
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		fv = 0;			/* clear call mask */
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	for(ci = 0; ci < CALL_MASK_SIZE; ci++) 	/* fill or clear call mask */
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		priv(rp)->s_k_call_mask[ci] = fv;
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	if(!fv)			/* not all full? enter calls bit by bit */
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		for(ci = 0; ci < ip->nr_k_calls; ci++)
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			SET_BIT(priv(rp)->s_k_call_mask,
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				ip->k_calls[ci]-KERNEL_CALL);
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	priv(rp)->s_ipc_to.chunk[0] = ip->ipc_to;	/* restrict targets */
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	for (j=0; j<BITMAP_CHUNKS(NR_SYS_PROCS); j++) {
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		rp->p_priv->s_ipc_sendrec.chunk[j] = ~0L;
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	}
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	unset_sys_bit(rp->p_priv->s_ipc_sendrec, USER_PRIV_ID);
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	if (iskerneln(proc_nr(rp))) {		/* part of the kernel? */ 
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		if (ip->stksize > 0) {		/* HARDWARE stack size is 0 */
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			rp->p_priv->s_stack_guard = (reg_t *) ktsb;
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			*rp->p_priv->s_stack_guard = STACK_GUARD;
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		}
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		ktsb += ip->stksize;	/* point to high end of stack */
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		rp->p_reg.sp = ktsb;	/* this task's initial stack ptr */
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		hdrindex = 0;		/* all use the first a.out header */
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	} else {
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		hdrindex = 1 + i-NR_TASKS;	/* servers, drivers, INIT */
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	}
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	/* Architecture-specific way to find out aout header of this
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	 * boot process.
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	 */
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	arch_get_aout_headers(hdrindex, &e_hdr);
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	/* Convert addresses to clicks and build process memory map */
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	text_base = e_hdr.a_syms >> CLICK_SHIFT;
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	text_clicks = (e_hdr.a_text + CLICK_SIZE-1) >> CLICK_SHIFT;
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	data_clicks = (e_hdr.a_data+e_hdr.a_bss + CLICK_SIZE-1) >> CLICK_SHIFT;
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	st_clicks= (e_hdr.a_total + CLICK_SIZE-1) >> CLICK_SHIFT;
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	if (!(e_hdr.a_flags & A_SEP))
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	{
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		data_clicks= (e_hdr.a_text+e_hdr.a_data+e_hdr.a_bss +
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			CLICK_SIZE-1) >> CLICK_SHIFT;
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		text_clicks = 0;	   /* common I&D */
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	}
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	rp->p_memmap[T].mem_phys = text_base;
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	rp->p_memmap[T].mem_len  = text_clicks;
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	rp->p_memmap[D].mem_phys = text_base + text_clicks;
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	rp->p_memmap[D].mem_len  = data_clicks;
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	rp->p_memmap[S].mem_phys = text_base + text_clicks + st_clicks;
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	rp->p_memmap[S].mem_vir  = st_clicks;
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	rp->p_memmap[S].mem_len  = 0;
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	/* Set initial register values.  The processor status word for tasks 
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	 * is different from that of other processes because tasks can
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	 * access I/O; this is not allowed to less-privileged processes 
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	 */
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	rp->p_reg.pc = (reg_t) ip->initial_pc;
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	rp->p_reg.psw = (iskernelp(rp)) ? INIT_TASK_PSW : INIT_PSW;
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	/* Initialize the server stack pointer. Take it down one word
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	 * to give crtso.s something to use as "argc".
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	 */
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	if (isusern(proc_nr(rp))) {		/* user-space process? */ 
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		rp->p_reg.sp = (rp->p_memmap[S].mem_vir +
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				rp->p_memmap[S].mem_len) << CLICK_SHIFT;
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		rp->p_reg.sp -= sizeof(reg_t);
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	}
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	/* If this process has its own page table, VM will set the
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	 * PT up and manage it. VM will signal the kernel when it has
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	 * done this; until then, don't let it run.
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	 */
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	if(priv(rp)->s_flags & PROC_FULLVM)
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		RTS_SET(rp, VMINHIBIT);
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	/* Set ready. The HARDWARE task is never ready. */
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	if (rp->p_nr == HARDWARE) RTS_SET(rp, NO_PRIORITY);
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	RTS_UNSET(rp, SLOT_FREE); /* remove SLOT_FREE and schedule */
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	/* Code and data segments must be allocated in protected mode. */
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	alloc_segments(rp);
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  }
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#if SPROFILE
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  sprofiling = 0;      /* we're not profiling until instructed to */
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#endif /* SPROFILE */
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  cprof_procs_no = 0;  /* init nr of hash table slots used */
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  vm_running = 0;
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  /* MINIX is now ready. All boot image processes are on the ready queue.
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   * Return to the assembly code to start running the current process. 
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   */
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  bill_ptr = proc_addr(IDLE);		/* it has to point somewhere */
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  announce();				/* print MINIX startup banner */
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  restart();
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}
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/*===========================================================================*
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 *				announce				     *
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 *===========================================================================*/
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PRIVATE void announce(void)
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{
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  /* Display the MINIX startup banner. */
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  kprintf("\nMINIX %s.%s. "
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#ifdef _SVN_REVISION
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	"(" _SVN_REVISION ")\n"
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#endif
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      "Copyright 2006, Vrije Universiteit, Amsterdam, The Netherlands\n",
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      OS_RELEASE, OS_VERSION);
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}
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/*===========================================================================*
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 *				prepare_shutdown			     *
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 *===========================================================================*/
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PUBLIC void prepare_shutdown(how)
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int how;
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{
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/* This function prepares to shutdown MINIX. */
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  static timer_t shutdown_timer;
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  register struct proc *rp; 
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  message m;
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  /* Continue after 1 second, to give processes a chance to get scheduled to 
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   * do shutdown work.  Set a watchog timer to call shutdown(). The timer 
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   * argument passes the shutdown status. 
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   */
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  kprintf("MINIX will now be shut down ...\n");
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  tmr_arg(&shutdown_timer)->ta_int = how;
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  set_timer(&shutdown_timer, get_uptime() + system_hz, minix_shutdown);
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}
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/*===========================================================================*
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 *				shutdown 				     *
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 *===========================================================================*/
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PUBLIC void minix_shutdown(tp)
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timer_t *tp;
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{
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/* This function is called from prepare_shutdown or stop_sequence to bring 
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 * down MINIX. How to shutdown is in the argument: RBT_HALT (return to the
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 * monitor), RBT_MONITOR (execute given code), RBT_RESET (hard reset). 
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 */
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  intr_init(INTS_ORIG);
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  clock_stop();
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  arch_shutdown(tp ? tmr_arg(tp)->ta_int : RBT_PANIC);
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}
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