330 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			330 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* 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 <string.h>
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| #include <unistd.h>
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| #include <assert.h>
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| #include <a.out.h>
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| #include <minix/com.h>
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| #include <minix/endpoint.h>
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| #include <minix/u64.h>
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| #include "proc.h"
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| #include "debug.h"
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| #include "clock.h"
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| 
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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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| /*===========================================================================*
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|  *				main                                         *
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|  *===========================================================================*/
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| PUBLIC int main(void)
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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;
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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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|   size_t argsz;			/* size of arguments passed to crtso on stack */
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| 
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|    /* Global value to test segment sanity. */
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|    magictest = MAGICTEST;
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|  
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|    DEBUGEXTRA(("main()\n"));
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| 
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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 = RTS_SLOT_FREE;		/* initialize free slot */
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| 	rp->p_magic = PMAGIC;
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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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| 	rp->p_scheduler = NULL;			/* no user space scheduler */
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| 	rp->p_priority = 0;		        /* no priority */
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| 	rp->p_quantum_size_ms = 0;	        /* no quantum size */
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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 = (sys_id_t) i;		/* priv structure index */
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| 	ppriv_addr[i] = sp;			/* priv ptr from number */
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| 	sp->s_sig_mgr = NONE;			/* clear signal managers */
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| 	sp->s_bak_sig_mgr = NONE;
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|   }
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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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| 
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|   /* Task stacks. */
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|   ktsb = (reg_t) t_stack;
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| 
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|   for (i=0; i < NR_BOOT_PROCS; ++i) {
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| 	int schedulable_proc;
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| 	proc_nr_t proc_nr;
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| 	int ipc_to_m, kcalls;
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| 
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| 	ip = &image[i];				/* process' attributes */
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| 	DEBUGEXTRA(("initializing %s... ", ip->proc_name));
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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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| 	make_zero64(rp->p_cpu_time_left);
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| 	strncpy(rp->p_name, ip->proc_name, P_NAME_LEN); /* set process name */
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| 
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| 	/* See if this process is immediately schedulable.
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| 	 * In that case, set its privileges now and allow it to run.
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| 	 * Only kernel tasks and the root system process get to run immediately.
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| 	 * All the other system processes are inhibited from running by the
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| 	 * RTS_NO_PRIV flag. They can only be scheduled once the root system
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| 	 * process has set their privileges.
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| 	 */
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| 	proc_nr = proc_nr(rp);
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| 	schedulable_proc = (iskerneln(proc_nr) || isrootsysn(proc_nr));
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| 	if(schedulable_proc) {
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| 	    /* Assign privilege structure. Force a static privilege id. */
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|             (void) get_priv(rp, static_priv_id(proc_nr));
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| 
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|             /* Priviliges for kernel tasks. */
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|             if(iskerneln(proc_nr)) {
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|                 /* Privilege flags. */
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|                 priv(rp)->s_flags = (proc_nr == IDLE ? IDL_F : TSK_F);
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|                 /* Allowed traps. */
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|                 priv(rp)->s_trap_mask = (proc_nr == CLOCK 
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|                     || proc_nr == SYSTEM  ? CSK_T : TSK_T);
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|                 ipc_to_m = TSK_M;                  /* allowed targets */
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|                 kcalls = TSK_KC;                   /* allowed kernel calls */
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|             }
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|             /* Priviliges for the root system process. */
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|             else if(isrootsysn(proc_nr)) {
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|                 priv(rp)->s_flags= RSYS_F;        /* privilege flags */
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|                 priv(rp)->s_trap_mask= SRV_T;     /* allowed traps */
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|                 ipc_to_m = SRV_M;                 /* allowed targets */
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|                 kcalls = SRV_KC;                  /* allowed kernel calls */
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|                 priv(rp)->s_sig_mgr = SRV_SM;     /* signal manager */
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|                 rp->p_priority = SRV_Q;	          /* priority queue */
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|                 rp->p_quantum_size_ms = SRV_QT;   /* quantum size */
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|             }
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|             /* Priviliges for ordinary process. */
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|             else {
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| 		NOT_REACHABLE;
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|             }
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| 
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|             /* Fill in target mask. */
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|             fill_sendto_mask(rp, ipc_to_m);
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| 
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|             /* Fill in kernel call mask. */
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|             for(j = 0; j < SYS_CALL_MASK_SIZE; j++) {
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|                 priv(rp)->s_k_call_mask[j] = (kcalls == NO_C ? 0 : (~0));
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|             }
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| 	}
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| 	else {
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| 	    /* Don't let the process run for now. */
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|             RTS_SET(rp, RTS_NO_PRIV | RTS_NO_QUANTUM);
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| 	}
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| 
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| 	if (iskerneln(proc_nr)) {		/* 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;	/* system/user processes */
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| 	}
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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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| 
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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 = (vir_clicks) (CLICK_CEIL(e_hdr.a_text) >> CLICK_SHIFT);
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| 	data_clicks = (vir_clicks) (CLICK_CEIL(e_hdr.a_data
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| 		+ e_hdr.a_bss) >> CLICK_SHIFT);
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| 	st_clicks = (vir_clicks) (CLICK_CEIL(e_hdr.a_total) >> CLICK_SHIFT);
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| 	if (!(e_hdr.a_flags & A_SEP))
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| 	{
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| 		data_clicks = (vir_clicks) (CLICK_CEIL(e_hdr.a_text +
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| 			e_hdr.a_data + e_hdr.a_bss) >> 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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| 
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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 = 0; /* we cannot start anything else */
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| 	rp->p_reg.psw = (iskerneln(proc_nr)) ? INIT_TASK_PSW : INIT_PSW;
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| 
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| 	/* Initialize the server stack pointer. Take it down three words
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| 	 * to give crtso.s something to use as "argc", "argv" and "envp".
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| 	 */
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| 	if (isusern(proc_nr)) {		/* 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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| 		argsz = 3 * sizeof(reg_t);
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| 		rp->p_reg.sp -= argsz;
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| 		phys_memset(rp->p_reg.sp - 
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| 			(rp->p_memmap[S].mem_vir << CLICK_SHIFT) +
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| 			(rp->p_memmap[S].mem_phys << CLICK_SHIFT), 
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| 			0, argsz);
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| 	}
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| 
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| 	/* scheduling functions depend on proc_ptr pointing somewhere. */
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| 	if(!proc_ptr) proc_ptr = rp;
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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(ip->flags & PROC_FULLVM)
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| 		RTS_SET(rp, RTS_VMINHIBIT);
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| 
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| 	/* None of the kernel tasks run */
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| 	if (rp->p_nr < 0) RTS_SET(rp, RTS_PROC_STOP);
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| 	RTS_UNSET(rp, RTS_SLOT_FREE); /* remove RTS_SLOT_FREE and schedule */
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| 	alloc_segments(rp);
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| 	DEBUGEXTRA(("done\n"));
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|   }
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| 
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|   /* Architecture-dependent initialization. */
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|   DEBUGEXTRA(("arch_init()... "));
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|   arch_init();
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|   DEBUGEXTRA(("done\n"));
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| 
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|   /* System and processes initialization */
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|   DEBUGEXTRA(("system_init()... "));
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|   system_init();
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|   DEBUGEXTRA(("done\n"));
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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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| 
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|   vm_running = 0;
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|   krandom.random_sources = RANDOM_SOURCES;
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|   krandom.random_elements = RANDOM_ELEMENTS;
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| 
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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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| 
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|   /*
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|    * enable timer interrupts and clock task on the boot CPU
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|    */
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| 
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|   if (boot_cpu_init_timer(system_hz)) {
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| 	  panic( "FATAL : failed to initialize timer interrupts; "
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| 		"cannot continue without any clock source!");
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|   }
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| 
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| /* Warnings for sanity checks that take time. These warnings are printed
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|  * so it's a clear warning no full release should be done with them
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|  * enabled.
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|  */
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| #if DEBUG_PROC_CHECK
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|   FIXME("PROC check enabled");
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| #endif
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| 
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|   DEBUGEXTRA(("cycles_accounting_init()... "));
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|   cycles_accounting_init();
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|   DEBUGEXTRA(("done\n"));
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| 
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| #define IPCNAME(n) { \
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| 	assert((n) >= 0 && (n) <= IPCNO_HIGHEST); \
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| 	assert(!ipc_call_names[n]);	\
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| 	ipc_call_names[n] = #n; \
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| }
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| 
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|   IPCNAME(SEND);
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|   IPCNAME(RECEIVE);
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|   IPCNAME(SENDREC);
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|   IPCNAME(NOTIFY);
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|   IPCNAME(SENDNB);
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|   IPCNAME(SENDA);
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| 
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|   assert(runqueues_ok());
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| 
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|   switch_to_user();
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|   NOT_REACHABLE;
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|   return 1;
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| }
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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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|   printf("\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 2010, Vrije Universiteit, Amsterdam, The Netherlands\n",
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|       OS_RELEASE, OS_VERSION);
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|   printf("MINIX is open source software, see http://www.minix3.org\n");
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| }
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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(const 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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| 
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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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|   printf("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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| /*===========================================================================*
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|  *				shutdown 				     *
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|  *===========================================================================*/
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| PUBLIC void minix_shutdown(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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|   arch_stop_local_timer();
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|   intr_init(INTS_ORIG, 0);
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|   arch_shutdown(tp ? tmr_arg(tp)->ta_int : RBT_PANIC);
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| }
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| 
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