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