/*      $NetBSD: coffhdrfix.c,v 1.2 2008/04/28 20:23:18 martin Exp $    */

/*-
 * Copyright (c) 2004 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/* fixup GNU binutils file offset error. */

#include <stdio.h>
#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/mman.h>

typedef uint8_t Coff_Byte;
typedef uint8_t Coff_Half[2];
typedef uint8_t Coff_Word[4];

#define ECOFF_OMAGIC            0407
#define ECOFF_MAGIC_MIPSEB      0x0160

struct coff_filehdr {
        Coff_Half       f_magic;
        Coff_Half       f_nscns;
        Coff_Word       f_timdat;
        Coff_Word       f_symptr;
        Coff_Word       f_nsyms;
        Coff_Half       f_opthdr;
        Coff_Half       f_flags;
};

struct coff_aouthdr {
        Coff_Half       a_magic;
        Coff_Half       a_vstamp;
        Coff_Word       a_tsize;
        Coff_Word       a_dsize;
        Coff_Word       a_bsize;
        Coff_Word       a_entry;
        Coff_Word       a_tstart;
        Coff_Word       a_dstart;
};

#define COFF_GET_HALF(w)        ((w)[1] | ((w)[0] << 8))
#define COFF_SET_HALF(w,v)      ((w)[1] = (uint8_t)(v),                 \
                                (w)[0] = (uint8_t)((v) >> 8))
#define COFF_GET_WORD(w)        ((w)[3] | ((w)[2] << 8) |               \
                                ((w)[1] << 16) | ((w)[0] << 24))
#define COFF_SET_WORD(w,v)      ((w)[3] = (uint8_t)(v),                 \
                                (w)[2] = (uint8_t)((v) >> 8),           \
                                (w)[1] = (uint8_t)((v) >> 16),          \
                                (w)[0] = (uint8_t)((v) >> 24))

#define FILHSZ  sizeof(struct coff_filehdr)
#define SCNHSZ  40

int
main(int argc, char *argp[])
{
        int fd, fdout, fileoff, i;
        struct coff_filehdr file;
        struct coff_aouthdr aout;
        char fname[256];
        char buf[1024];

        if (argc < 3)
                return 0;

        if ((fd = open(argp[1], O_RDWR)) < 0) {
                perror(0);
                return 0;
        }
        read(fd, &file, sizeof file);
        read(fd, &aout, sizeof aout);

        if (COFF_GET_HALF(file.f_magic) != ECOFF_MAGIC_MIPSEB) {
                fprintf (stderr, "not COFF file.\n");
                return 0;
        }
        if (COFF_GET_HALF(aout.a_magic) != ECOFF_OMAGIC) {
                fprintf (stderr, "not OMAGIC.\n");
                return 0;
        }
        fprintf(stderr, "File: magic: 0x%04x flags: 0x%04x\n",
            COFF_GET_HALF(file.f_magic), COFF_GET_HALF(file.f_flags));
        fprintf(stderr, "Aout: magic: 0x%04x vstamp: %d\n",
            COFF_GET_HALF(aout.a_magic), COFF_GET_HALF(aout.a_vstamp));

        fileoff = (FILHSZ +
            COFF_GET_HALF(file.f_opthdr) +
            COFF_GET_HALF(file.f_nscns) * SCNHSZ + 7) & ~7;
        fprintf(stderr, "File offset: 0x%x\n", fileoff);
        close(fd);

        if ((fdout = open(argp[2], O_CREAT | O_TRUNC | O_RDWR, 0644)) < 0) {
                perror (0);
                return 0;
        }
        fd = open(argp[1], O_RDWR);
        read(fd, buf, fileoff);
        write(fdout, buf, fileoff);
        lseek(fd, 8, SEEK_CUR);
        while ((i = read(fd, buf, 1024)) > 0)
                write(fdout, buf, i);
        close(fd);
        close(fdout);

        return 0;
}