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main.c

Go to the documentation of this file.

/*
 Copyright (c) 1992-1993 The Regents of the University of California.
 All rights reserved.  See copyright.h for copyright notice and limitation 
 of liability and disclaimer of warranty provisions.
 */

#include "copyright.h"

/* MIPS instruction interpreter */

#include <stdio.h>
#include <filehdr.h>
#include <scnhdr.h>
#include <syms.h>
#include <ldfcn.h>
#include "int.h"

static FILE *fp;
static LDFILE *ldptr;
static SCNHDR texthead, rdatahead, datahead, sdatahead, sbsshead, bsshead;

static char filename[1000] = "a.out";   /* default a.out file */
static char self[256];                  /* name of invoking program */

char mem[MEMSIZE];              /* main memory. use malloc later */
int TRACE, Traptrace, Regtrace;
int NROWS=64, ASSOC=1, LINESIZE=4, RAND=0, LRD=0;

extern char *strcpy();

main(argc, argv)
int argc;
char *argv[];
{
        register char *s;
        char *fakeargv[3];

        strcpy(self, argv[0]);
        while  ( argc > 1  &&  argv[1][0] == '-' )
        {
                --argc; ++argv;
                for  ( s=argv[0]+1; *s != '\0'; ++s )
                        switch  ( *s )
                        {
                                case 't':  TRACE = 1; break;
                                case 'T':  Traptrace = 1; break;
                                case 'r':  Regtrace = 1; break;
                                case 'm':
                                        NROWS = atoi(*++argv);
                                        ASSOC = atoi(*++argv);
                                        LINESIZE = atoi(*++argv);
                                        RAND = ((*++argv)[0] == 'r');
                                        LRD = ((*argv)[0] == 'l')
                                           && ((*argv)[1] == 'r')
                                           && ((*argv)[2] == 'd');
                                        argc -= 4;
                                        break;
                        }
        }

        if (argc >= 2)
                strcpy(filename, argv[1]);
        fp = fopen(filename, "r");
        if (fp == NULL)
        {
                fprintf(stderr, "%s: Could not open '%s'\n", self, filename);
                exit(0);
        }
        fclose(fp);
        load_program(filename);
        if  ( argv[1] == NULL )
        {
                fakeargv[1] = "a.out";
                fakeargv[2] = NULL;
                argv = fakeargv;
                ++argc;
        }
        runprogram(memoffset, argc-1, argv+1); /* where things normally start */
}

char *string(s)
char *s;
{
        char *p;
        extern char *malloc();

        p = malloc((unsigned) strlen(s)+1);
        strcpy(p, s);
        return p;
}

load_program(filename)
char *filename;
{
        register int pc, i, j, strindex, stl;
        char str[1111];
        int rc1, rc2;

        ldptr = ldopen(filename, NULL);
        if  ( ldptr == NULL )
        {
                fprintf(stderr, "%s: Load read error on %s\n", self, filename);
                exit(0);
        }
        if  ( TYPE(ldptr) != 0x162 )
        {
                fprintf(stderr,
                        "big-endian object file (little-endian interp)\n");
                exit(0);
        }

#define LOADSECTION(head)       \
        if  ( head.s_scnptr != 0 ) \
        { \
                /* printf("loading %s\n", head.s_name); /* */ \
                pc = head.s_vaddr; \
                FSEEK(ldptr, head.s_scnptr, 0); \
                for  ( i=0; i<head.s_size; ++i ) \
                        *(char *) ((mem-memoffset)+pc++) = getc(fp); \
                if (pc-memoffset >= MEMSIZE) \
                        { printf("MEMSIZE too small. Fix and recompile.\n"); \
                        exit(1); } \
        }

        if  ( ldnshread(ldptr, ".text", &texthead) != 1 )
                printf("text section header missing\n");
        else
                LOADSECTION(texthead)

        if  ( ldnshread(ldptr, ".rdata", &rdatahead) != 1 )
                printf("rdata section header missing\n");
        else
                LOADSECTION(rdatahead)

        if  ( ldnshread(ldptr, ".data", &datahead) != 1 )
                printf("data section header missing\n");
        else
                LOADSECTION(datahead)

        if  ( ldnshread(ldptr, ".sdata", &sdatahead) != 1 )
                printf("sdata section header missing\n");
        else
                LOADSECTION(sdatahead)

        if  ( ldnshread(ldptr, ".sbss", &sbsshead) != 1 )
                printf("sbss section header missing\n");
        else
                LOADSECTION(sbsshead)

        if  ( ldnshread(ldptr, ".bss", &bsshead) != 1 )
                printf("bss section header missing\n");
        else
                LOADSECTION(bsshead)

        /* BSS is already zeroed (statically-allocated mem) */
        /* this version ignores relocation info */
}


int *m_alloc(n)
int n;
{
        extern char *malloc();

        return (int *) (int) malloc((unsigned) n);
}

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