/* $NetBSD: elf.c,v 1.14 2011/10/01 15:59:00 chs Exp $ */
/*-
* Copyright (c) 1998 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Leo Weppelman.
*
* 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.
*/
#ifdef TOSTOOLS
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include "exec_elf.h"
#define MALLOC(x) malloc(x)
#else
#include <lib/libsa/stand.h>
#include <atari_stand.h>
#include <libkern.h>
#include <sys/exec_elf.h>
#define MALLOC(x) alloc(x)
#endif
#include "libtos.h"
#include "tosdefs.h"
#include "kparamb.h"
#include "cread.h"
/*
* Load an elf image.
* Exit codes:
* -1 : Not an ELF file.
* 0 : OK
* error# : Error during load (*errp might contain error string).
*/
#define ELFMAGIC ((ELFMAG0 << 24) | (ELFMAG1 << 16) | \
(ELFMAG2 << 8) | ELFMAG3)
int
elf_load(int fd, osdsc_t *od, char **errp, int loadsyms)
{
int i,j;
int err;
Elf32_Ehdr ehdr;
Elf32_Phdr *phdrs;
Elf32_Word ident, symsize, symstart;
long kernsize;
*errp = NULL;
lseek(fd, (off_t)0, SEEK_SET);
if (read(fd, (char *)&ehdr, sizeof(ehdr)) != sizeof(ehdr))
return -1;
memcpy(&ident, ehdr.e_ident, sizeof ident);
if (ident != ELFMAGIC)
return -1;
/*
* calculate highest used address
*/
i = ehdr.e_phnum * sizeof(Elf32_Phdr);
err = 1;
if ((phdrs = (Elf32_Phdr *)MALLOC(i)) == NULL)
goto error;
err = 2;
if (read(fd, phdrs, i) != i)
goto error;
kernsize = 0;
for (i = 0; i < ehdr.e_phnum; i++) {
Elf32_Word sum;
sum = phdrs[i].p_vaddr + phdrs[i].p_memsz;
if ((phdrs[i].p_flags & (PF_W|PF_X)) && (sum > kernsize))
kernsize = sum;
}
/*
* look for symbols and calculate the size
* XXX: This increases the load time by a factor 2 for gzipped
* images!
*/
symsize = 0;
symstart = 0;
if (loadsyms) {
i = ehdr.e_shnum + 1;
err = 3;
if (lseek(fd, (off_t)ehdr.e_shoff, SEEK_SET) != ehdr.e_shoff)
goto error;
while (--i) {
Elf32_Shdr shdr;
err = 4;
if (read(fd, &shdr, sizeof(shdr)) != sizeof(shdr))
goto error;
if ((shdr.sh_type == SHT_SYMTAB) || (shdr.sh_type == SHT_STRTAB))
symsize += shdr.sh_size;
}
}
if (symsize) {
symstart = kernsize;
kernsize += symsize + sizeof(ehdr) + ehdr.e_shnum*sizeof(Elf32_Shdr);
}
/*
* Extract various sizes from the kernel executable
*/
od->k_esym = symsize ? kernsize : 0;
od->ksize = kernsize;
od->kentry = ehdr.e_entry;
err = 5;
if ((od->kstart = (u_char *)MALLOC(od->ksize)) == NULL)
goto error;
/*
* Read text & data, clear bss
*/
for (i = 0; i < ehdr.e_phnum; i++) {
u_char *p;
Elf32_Phdr *php = &phdrs[i];
if (php->p_flags & (PF_W|PF_X)) {
err = 6;
if (lseek(fd, (off_t)php->p_offset, SEEK_SET) != php->p_offset)
goto error;
p = (u_char *)(od->kstart) + php->p_vaddr;
err = 7;
if (read(fd, p, php->p_filesz) != php->p_filesz)
goto error;
if (php->p_memsz > php->p_filesz)
memset(p + php->p_filesz, 0, php->p_memsz - php->p_filesz);
}
}
/*
* Read symbols and strings
*/
if (symsize) {
u_char *p, *symtab;
int nhdrs;
Elf32_Shdr *shp;
symtab = od->kstart + symstart;
p = symtab + sizeof(ehdr);
nhdrs = ehdr.e_shnum;
err = 8;
if (lseek(fd, (off_t)ehdr.e_shoff, SEEK_SET) != ehdr.e_shoff)
goto error;
err = 9;
if (read(fd, p, nhdrs * sizeof(*shp)) != nhdrs * sizeof(*shp))
goto error;
shp = (Elf32_Shdr*)p;
p += nhdrs * sizeof(*shp);
for (i = 0; i < nhdrs; i++) {
if (shp[i].sh_type == SHT_SYMTAB) {
if (shp[i].sh_offset == 0)
continue;
/* Got the symbol table. */
err = 10;
if (lseek(fd, (off_t)shp[i].sh_offset, SEEK_SET) !=
shp[i].sh_offset)
goto error;
err = 11;
if (read(fd, p, shp[i].sh_size) != shp[i].sh_size)
goto error;
shp[i].sh_offset = p - symtab;
/* Find the string table to go with it. */
j = shp[i].sh_link;
if (shp[j].sh_offset == 0)
continue;
p += shp[i].sh_size;
err = 12;
if (lseek(fd, (off_t)shp[j].sh_offset, SEEK_SET) !=
shp[j].sh_offset)
goto error;
err = 13;
if (read(fd, p, shp[j].sh_size) != shp[j].sh_size)
goto error;
shp[j].sh_offset = p - symtab;
/* There should only be one symbol table. */
break;
}
}
ehdr.e_shoff = sizeof(ehdr);
memcpy(symtab, &ehdr, sizeof(ehdr));
}
return 0;
error:
#ifdef TOSTOOLS
{
static char *errs[] = {
/* 1 */ "Cannot malloc Elf phdr storage space",
/* 2 */ "Cannot read Elf32_Phdrs",
/* 3 */ "Cannot seek to e_shoff location",
/* 4 */ "Cannot read Elf32_shdr",
/* 5 */ "Cannot malloc kernel image space",
/* 6 */ "Seek error while reading text segment\n",
/* 7 */ "Read error in text segment\n",
/* 8 */ "Error seeking to section headers",
/* 9 */ "Error reading section headers",
/* 10 */ "Error seeking to symbols",
/* 11 */ "Error reading symbols",
/* 12 */ "Error seeking to string table",
/* 13 */ "Error reading strings"
};
*errp = errs[err];
}
#endif /* TOSTOOLS */
return err;
}
