/* This file is part of SIS (SPARC/RISCV instruction simulator)
Copyright (C) 2019 Free Software Foundation, Inc.
Contributed by Jiri Gaisler, Sweden.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Very simple ELF program loader, only tested with RTEMS */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef WIN32
#include <winsock.h>
#else
#include <netinet/in.h>
#endif
#include <elf.h>
#include <ctype.h>
#include "sis.h"
struct elf_file
{
FILE *fp;
Elf32_Ehdr ehdr;
char *strtab;
int arch;
int cpu;
int be;
};
static struct elf_file efile;
static int
read_elf_header (FILE * fp)
{
Elf32_Ehdr ehdr;
fseek (fp, 0, SEEK_SET);
if (fread (&ehdr, sizeof (ehdr), 1, fp) != 1)
{
return (-1);
}
efile.fp = fp;
if ((ehdr.e_ident[EI_MAG0] != 0x7f) ||
strncmp ((char *) &ehdr.e_ident[EI_MAG1], "ELF", 3) != 0)
{
return (-1);
}
if (ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
{
efile.be = 1;
ehdr.e_entry = ntohl (ehdr.e_entry);
ehdr.e_shoff = ntohl (ehdr.e_shoff);
ehdr.e_phoff = ntohl (ehdr.e_phoff);
ehdr.e_phnum = ntohs (ehdr.e_phnum);
ehdr.e_shnum = ntohs (ehdr.e_shnum);
ehdr.e_phentsize = ntohs (ehdr.e_phentsize);
ehdr.e_shentsize = ntohs (ehdr.e_shentsize);
ehdr.e_shstrndx = ntohs (ehdr.e_shstrndx);
ehdr.e_machine = ntohs (ehdr.e_machine);
}
switch (ehdr.e_machine)
{
case EM_SPARC:
if (sis_verbose)
printf ("SPARC executable\n");
efile.arch = CPU_ERC32;
efile.cpu = CPU_ERC32;
break;
case EM_RISCV:
if (sis_verbose)
printf ("RISCV executable\n");
efile.arch = CPU_RISCV;
efile.cpu = CPU_RISCV;
break;
default:
printf ("Unknown architecture (%d)\n", ehdr.e_machine);
return (-1);
}
if (ehdr.e_ident[EI_CLASS] != 1)
{
printf ("Only 32-bit ELF supported!\n");
return (-1);
}
efile.ehdr = ehdr;
ebase.cpu = efile.cpu;
return (ehdr.e_entry);
}
static int
read_elf_body ()
{
Elf32_Ehdr ehdr = efile.ehdr;
Elf32_Shdr sh, ssh;
Elf32_Phdr ph[16];
char *strtab;
char *mem;
uint32 *memw, i, j, k, vaddr;
int be = efile.be;
FILE *fp = efile.fp;
fseek (fp, ehdr.e_shoff + ((ehdr.e_shstrndx) * ehdr.e_shentsize), SEEK_SET);
if ((!fp) || (fread (&ssh, sizeof (ssh), 1, fp) != 1))
{
return (-1);
}
/* endian swap if big-endian target */
if (be)
{
ssh.sh_name = ntohl (ssh.sh_name);
ssh.sh_type = ntohl (ssh.sh_type);
ssh.sh_offset = ntohl (ssh.sh_offset);
ssh.sh_size = ntohl (ssh.sh_size);
}
strtab = (char *) malloc (ssh.sh_size);
fseek (fp, ssh.sh_offset, SEEK_SET);
if (fread (strtab, ssh.sh_size, 1, fp) != 1)
{
return (-1);
}
for (i = 0; i < ehdr.e_phnum; i++)
{
fseek (fp, ehdr.e_phoff + (i * ehdr.e_phentsize), SEEK_SET);
if (fread (&ph[i], ehdr.e_phentsize, 1, fp) != 1)
{
return (-1);
}
if (be)
{
ph[i].p_type = ntohl (ph[i].p_type);
ph[i].p_offset = ntohl (ph[i].p_offset);
ph[i].p_vaddr = ntohl (ph[i].p_vaddr);
ph[i].p_paddr = ntohl (ph[i].p_paddr);
ph[i].p_filesz = ntohl (ph[i].p_filesz);
ph[i].p_memsz = ntohl (ph[i].p_memsz);
}
}
for (i = 1; i < ehdr.e_shnum; i++)
{
fseek (fp, ehdr.e_shoff + (i * ehdr.e_shentsize), SEEK_SET);
if (fread (&sh, sizeof (sh), 1, fp) != 1)
{
return (-1);
}
if (be)
{
sh.sh_name = ntohl (sh.sh_name);
sh.sh_addr = ntohl (sh.sh_addr);
sh.sh_size = ntohl (sh.sh_size);
sh.sh_type = ntohl (sh.sh_type);
sh.sh_offset = ntohl (sh.sh_offset);
sh.sh_flags = ntohl (sh.sh_flags);
}
if ((sh.sh_type != SHT_NOBITS) && (sh.sh_size)
&& (sh.sh_flags & SHF_ALLOC))
{
for (k = 0; k < ehdr.e_phnum; k++)
{
if ((sh.sh_addr >= ph[k].p_vaddr) &&
((sh.sh_addr + sh.sh_size) <=
(ph[k].p_vaddr + ph[k].p_filesz)))
{
vaddr = sh.sh_addr;
sh.sh_addr = sh.sh_addr - ph[k].p_vaddr + ph[k].p_paddr;
break;
}
}
if (sis_verbose)
printf ("section: %s at 0x%x, size %d bytes\n",
&strtab[sh.sh_name], sh.sh_addr, sh.sh_size);
mem = calloc (sh.sh_size / 4 + 1, 4);
if (mem != NULL)
{
if ((sh.sh_type == SHT_PROGBITS)
|| (sh.sh_type == SHT_INIT_ARRAY)
|| (sh.sh_type == SHT_FINI_ARRAY))
{
fseek (fp, sh.sh_offset, SEEK_SET);
if (fread (mem, sh.sh_size, 1, fp) != 1)
{
return (-1);
}
memw = (unsigned int *) mem;
if (be)
for (j = 0; j < (sh.sh_size) / 4 + 1; j++)
memw[j] = ntohl (memw[j]);
ms->sis_memory_write (sh.sh_addr, mem,
(sh.sh_size / 4 + 1) * 4);
}
}
else
{
return (-1);
}
free (mem);
}
}
free (strtab);
return (ehdr.e_entry);
}
int
elf_load (char *fname, int load)
{
FILE *fp;
int res;
if ((fp = fopen (fname, "rb")) == NULL)
{
printf ("file not found\n");
return (-1);
}
res = read_elf_header (fp);
if (res < 0)
printf ("File read error\n");
if (load && (res >= 0))
{
res = read_elf_body ();
if (res < 0)
printf ("File read error\n");
else
printf (" Loaded %s, entry 0x%08x\n", fname, res);
fclose (efile.fp);
}
return res;
}
