/*
 * Copyright 1993,1994,1995 Emin Gun Sirer
 * MIPSI - Mips Instruction Set Simulator.
 */
#define _FILEHDR_H  1
#include <stdio.h>
#include <stdlib.h>
#define __mips 1
#define __mips__ 1
#include "MIPS/filehdr.h"
#include "MIPS/a.out.h"
#include "config.h"
#include "main.h"
#include "mem.h"

/*
 * format of bootable a.out file headers
 */
struct execinfo {
        struct filehdr fh;
        AOUTHDR ah;
};
extern int errno;


/* Read a MIPS executable file.  Return zero if successful, else non-zero */
extern int readaout(char *filename) {
    struct execinfo ei;
    FILE *fd;
    
    if((fd = fopen(filename, "r")) == NULL)
	error(TopLevel,"Cannot open file: %s\n", filename);

    /* read the fileheader and a.out header in one fell swoop */
    if (fread(&ei, 1, sizeof(ei), fd) != sizeof(ei)) {
	fclose(fd); error(TopLevel, "Bad header\n");
    }
    if((ei.fh.f_magic != MIPSEBMAGIC) && (ei.fh.f_magic != MIPSELMAGIC)) {
	fclose(fd); error(TopLevel, "File is not a binary executable\n");
    }
    pbreak = ROUND(ei.ah.bss_start + ei.ah.bsize,PGSZ); /* program break */
    pstaddress = ei.ah.entry; /* program starting address */
    R[REG_GP] = ei.ah.gp_value;

#if 0
printf("text_start:  0x%x    text_size: 0x%x\n", ei.ah.text_start, ei.ah.tsize);
printf("data_start:  0x%x    data_size: 0x%x\n", ei.ah.data_start, ei.ah.dsize);
printf("bss_start:   0x%x    bss_size:  0x%x\n", ei.ah.bss_start, ei.ah.bsize);
printf("entry point: 0x%x\n", ei.ah.entry);
printf("pbreak:      0x%x\n", pbreak);
printf("R[REG_GP]:   0x%x\n", ei.ah.gp_value);
#endif

    make_memory(ei.ah.tsize + 0x4000, pbreak - ei.ah.data_start);
    fseek(fd, N_TXTOFF(ei.fh, ei.ah), 0);
    
    {
    char *tseg,*dseg,*bseg;
    
    /* Read the text segment */
    tseg = (char *) malloc (ei.ah.tsize);
    if(fread(tseg, 1, ei.ah.tsize, fd) != 
       ei.ah.tsize) {
	fclose(fd); 
	error(TopLevel, "Cannot read entire text segment: %s\n", filename);
    }
    copy_from_buffer(tseg,ei.ah.text_start,ei.ah.tsize);
    free(tseg);

    /* Read the initialized data segment */
    dseg = (char *) malloc (ei.ah.dsize);

    if(fread(dseg, 1, ei.ah.dsize, fd) != 
       ei.ah.dsize) {
	fclose(fd);
	error(TopLevel, "Cannot read entire data segment: %s\n", filename);
    }
    copy_from_buffer(dseg,ei.ah.data_start,ei.ah.dsize);
    free(dseg);

    /* Now create some zero initialized memory */
    bseg = (char *) malloc (ei.ah.bsize);
    bzero(bseg, ei.ah.bsize);
    copy_from_buffer(bseg,ei.ah.bss_start,ei.ah.bsize);
    free(bseg);
    }
    fclose(fd);
    return 0;
    
}