elf2ecoff.c

一个2.4.21版本的嵌入式linux内核

/*
 * Copyright (c) 1995
 *	Ted Lemon (hereinafter referred to as the author)
 *
 * 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/* elf2ecoff.c

   This program converts an elf executable to an ECOFF executable.
   No symbol table is retained.   This is useful primarily in building
   net-bootable kernels for machines (e.g., DECstation and Alpha) which
   only support the ECOFF object file format. */

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <elf.h>
#include <limits.h>
#include <netinet/in.h>
#include <stdlib.h>

#include "ecoff.h"

/*
 * Some extra ELF definitions
 */
#define PT_MIPS_REGINFO 0x70000000	/* Register usage information */

/* -------------------------------------------------------------------- */

struct sect {
	unsigned long vaddr;
	unsigned long len;
};

int *symTypeTable;
int must_convert_endian = 0;
int format_bigendian = 0;

static void copy(int out, int in, off_t offset, off_t size)
{
	char ibuf[4096];
	int remaining, cur, count;

	/* Go to the start of the ELF symbol table... */
	if (lseek(in, offset, SEEK_SET) < 0) {
		perror("copy: lseek");
		exit(1);
	}

	remaining = size;
	while (remaining) {
		cur = remaining;
		if (cur > sizeof(ibuf))
			cur = sizeof(ibuf);
		remaining -= cur;
		if ((count = read(in, ibuf, cur)) != cur) {
			fprintf(stderr, "copy: read: %s\n",
				count ? strerror(errno) :
				"premature end of file");
			exit(1);
		}
		if ((count = write(out, ibuf, cur)) != cur) {
			perror("copy: write");
			exit(1);
		}
	}
}

/*
 * Combine two segments, which must be contiguous.   If pad is true, it's
 * okay for there to be padding between.
 */
static void combine(struct sect *base, struct sect *new, int pad)
{
	if (!base->len)
		*base = *new;
	else if (new->len) {
		if (base->vaddr + base->len != new->vaddr) {
			if (pad)
				base->len = new->vaddr - base->vaddr;
			else {
				fprintf(stderr,
					"Non-contiguous data can't be converted.\n");
				exit(1);
			}
		}
		base->len += new->len;
	}
}

static int phcmp(const void *v1, const void *v2)
{
	const Elf32_Phdr *h1 = v1;
	const Elf32_Phdr *h2 = v2;

	if (h1->p_vaddr > h2->p_vaddr)
		return 1;
	else if (h1->p_vaddr < h2->p_vaddr)
		return -1;
	else
		return 0;
}

static char *saveRead(int file, off_t offset, off_t len, char *name)
{
	char *tmp;
	int count;
	off_t off;
	if ((off = lseek(file, offset, SEEK_SET)) < 0) {
		fprintf(stderr, "%s: fseek: %s\n", name, strerror(errno));
		exit(1);
	}
	if (!(tmp = (char *) malloc(len))) {
		fprintf(stderr, "%s: Can't allocate %ld bytes.\n", name,
			len);
		exit(1);
	}
	count = read(file, tmp, len);
	if (count != len) {
		fprintf(stderr, "%s: read: %s.\n",
			name,
			count ? strerror(errno) : "End of file reached");
		exit(1);
	}
	return tmp;
}

#define swab16(x) \
	((unsigned short)( \
		(((unsigned short)(x) & (unsigned short)0x00ffU) << 8) | \
		(((unsigned short)(x) & (unsigned short)0xff00U) >> 8) ))

#define swab32(x) \
	((unsigned int)( \
		(((unsigned int)(x) & (unsigned int)0x000000ffUL) << 24) | \
		(((unsigned int)(x) & (unsigned int)0x0000ff00UL) <<  8) | \
		(((unsigned int)(x) & (unsigned int)0x00ff0000UL) >>  8) | \
		(((unsigned int)(x) & (unsigned int)0xff000000UL) >> 24) ))

static void convert_elf_hdr(Elf32_Ehdr * e)
{
	e->e_type = swab16(e->e_type);
	e->e_machine = swab16(e->e_machine);
	e->e_version = swab32(e->e_version);
	e->e_entry = swab32(e->e_entry);
	e->e_phoff = swab32(e->e_phoff);
	e->e_shoff = swab32(e->e_shoff);
	e->e_flags = swab32(e->e_flags);
	e->e_ehsize = swab16(e->e_ehsize);
	e->e_phentsize = swab16(e->e_phentsize);
	e->e_phnum = swab16(e->e_phnum);
	e->e_shentsize = swab16(e->e_shentsize);
	e->e_shnum = swab16(e->e_shnum);
	e->e_shstrndx = swab16(e->e_shstrndx);
}

static void convert_elf_phdrs(Elf32_Phdr * p, int num)
{
	int i;

	for (i = 0; i < num; i++, p++) {
		p->p_type = swab32(p->p_type);
		p->p_offset = swab32(p->p_offset);
		p->p_vaddr = swab32(p->p_vaddr);
		p->p_paddr = swab32(p->p_paddr);
		p->p_filesz = swab32(p->p_filesz);
		p->p_memsz = swab32(p->p_memsz);
		p->p_flags = swab32(p->p_flags);
		p->p_align = swab32(p->p_align);
	}

}

static void convert_elf_shdrs(Elf32_Shdr * s, int num)
{
	int i;

	for (i = 0; i < num; i++, s++) {
		s->sh_name = swab32(s->sh_name);
		s->sh_type = swab32(s->sh_type);
		s->sh_flags = swab32(s->sh_flags);
		s->sh_addr = swab32(s->sh_addr);
		s->sh_offset = swab32(s->sh_offset);
		s->sh_size = swab32(s->sh_size);
		s->sh_link = swab32(s->sh_link);
		s->sh_info = swab32(s->sh_info);
		s->sh_addralign = swab32(s->sh_addralign);
		s->sh_entsize = swab32(s->sh_entsize);
	}
}

static void convert_ecoff_filehdr(struct filehdr *f)
{
	f->f_magic = swab16(f->f_magic);
	f->f_nscns = swab16(f->f_nscns);
	f->f_timdat = swab32(f->f_timdat);
	f->f_symptr = swab32(f->f_symptr);
	f->f_nsyms = swab32(f->f_nsyms);
	f->f_opthdr = swab16(f->f_opthdr);
	f->f_flags = swab16(f->f_flags);
}

static void convert_ecoff_aouthdr(struct aouthdr *a)
{
	a->magic = swab16(a->magic);
	a->vstamp = swab16(a->vstamp);
	a->tsize = swab32(a->tsize);
	a->dsize = swab32(a->dsize);
	a->bsize = swab32(a->bsize);
	a->entry = swab32(a->entry);
	a->text_start = swab32(a->text_start);
	a->data_start = swab32(a->data_start);
	a->bss_start = swab32(a->bss_start);
	a->gprmask = swab32(a->gprmask);
	a->cprmask[0] = swab32(a->cprmask[0]);
	a->cprmask[1] = swab32(a->cprmask[1]);
	a->cprmask[2] = swab32(a->cprmask[2]);
	a->cprmask[3] = swab32(a->cprmask[3]);
	a->gp_value = swab32(a->gp_value);
}

static void convert_ecoff_esecs(struct scnhdr *s, int num)
{
	int i;

	for (i = 0; i < num; i++, s++) {
		s->s_paddr = swab32(s->s_paddr);
		s->s_vaddr = swab32(s->s_vaddr);
		s->s_size = swab32(s->s_size);
		s->s_scnptr = swab32(s->s_scnptr);
		s->s_relptr = swab32(s->s_relptr);
		s->s_lnnoptr = swab32(s->s_lnnoptr);
		s->s_nreloc = swab16(s->s_nreloc);
		s->s_nlnno = swab16(s->s_nlnno);
		s->s_flags = swab32(s->s_flags);
	}
}

int main(int argc, char *argv[])
{
	Elf32_Ehdr ex;
	Elf32_Phdr *ph;
	Elf32_Shdr *sh;
	char *shstrtab;
	int i, pad;
	struct sect text, data, bss;
	struct filehdr efh;
	struct aouthdr eah;
	struct scnhdr esecs[6];
	int infile, outfile;
	unsigned long cur_vma = ULONG_MAX;
	int addflag = 0;
	int nosecs;

	text.len = data.len = bss.len = 0;
	text.vaddr = data.vaddr = bss.vaddr = 0;

	/* Check args... */
	if (argc < 3 || argc > 4) {
	      usage:
		fprintf(stderr,
			"usage: elf2aout <elf executable> <a.out executable> [-a]\n");
		exit(1);
	}
	if (argc == 4) {
		if (strcmp(argv[3], "-a"))
			goto usage;
		addflag = 1;
	}

	/* Try the input file... */
	if ((infile = open(argv[1], O_RDONLY)) < 0) {
		fprintf(stderr, "Can't open %s for read: %s\n",
			argv[1], strerror(errno));
		exit(1);
	}

	/* Read the header, which is at the beginning of the file... */
	i = read(infile, &ex, sizeof(ex));
	if (i != sizeof(ex)) {
		fprintf(stderr, "ex: %s: %s.\n", argv[1],