48 lines
982 B
C
48 lines
982 B
C
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/*
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Manipulating the Program Counter
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*/
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/* $Header$ */
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#include <em_abs.h>
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#include "global.h"
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#include "alloc.h"
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#include "trap.h"
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#include "text.h"
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#include "read.h"
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#include "proctab.h"
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#include "warn.h"
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init_text() {
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DB = i2p(NTEXT); /* set Descriptor Base */
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NProc = NPROC; /* set Number of Proc. Descriptors */
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PI = -1; /* initialize Procedure Identifier */
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PC = 0; /* initialize Program Counter */
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text = Malloc((size)p2i(DB), "text space");
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}
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/************************************************************************
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* Program Counter division *
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************************************************************************
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* *
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* newPC(p) - check and adjust PC. *
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* *
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************************************************************************/
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newPC(p)
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ptr p;
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{
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register struct proc *pr = &proctab[PI];
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if (p >= DB) {
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wtrap(WPCOVFL, EBADPC);
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}
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if (p < pr->pr_ep || p >= pr->pr_ff) {
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wtrap(WPCPROC, EBADPC);
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}
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PC = p;
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}
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