sim/rx/load.c

   1 /* load.c --- loading object files into the RX simulator.
   2
   3 Copyright (C) 2005, 2007, 2008, 2009 Free Software Foundation, Inc.
   4 Contributed by Red Hat, Inc.
   5
   6 This file is part of the GNU simulators.
   7
   8 This program is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3 of the License, or
  11 (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25
  26 #include "bfd.h"
  27 #include "libbfd.h"
  28 #include "cpu.h"
  29 #include "mem.h"
  30 #include "elf/internal.h"
  31 #include "elf/common.h"
  32
  33 /* A note about endianness and swapping...
  34
  35    The RX chip is CISC-like in that the opcodes are variable length
  36    and are read as a stream of bytes.  However, the chip itself shares
  37    the code prefetch block with the data fetch block, so when it's
  38    configured for big endian mode, the memory fetched for opcodes is
  39    word-swapped.  To compensate for this, the ELF file has the code
  40    sections pre-swapped.  Our BFD knows this, and for the convenience
  41    of all the other tools, hides this swapping at a very low level.
  42    I.e.  it swaps words on the way out and on the way back in.
  43
  44    Fortunately the iovector routines are unaffected by this, so we
  45    can use them to read in the segments directly, without having
  46    to worry about byte swapping anything.
  47
  48    However, our opcode decoder and disassemblers need to swap the data
  49    after reading it from the chip memory, just like the chip does.
  50    All in all, the code words are swapped four times between the
  51    assembler and our decoder.
  52
  53    If the chip is running in little-endian mode, no swapping is done
  54    anywhere.  Note also that the *operands* within opcodes are always
  55    encoded in little-endian format.  */
  56
  57 void
  58 rx_load (bfd *prog)
  59 {
  60   unsigned long highest_addr_loaded = 0;
  61   Elf_Internal_Phdr * phdrs;
  62   long sizeof_phdrs;
  63   int num_headers;
  64   int i;
  65
  66   rx_big_endian = bfd_big_endian (prog);
  67
  68   /* Note we load by ELF program header not by BFD sections.
  69      This is because BFD sections get their information from
  70      the ELF section structure, which only includes a VMA value
  71      and not an LMA value.  */
  72   sizeof_phdrs = bfd_get_elf_phdr_upper_bound (prog);
  73   if (sizeof_phdrs == 0)
  74     {
  75       fprintf (stderr, "Failed to get size of program headers\n");
  76       return;
  77     }
  78   phdrs = malloc (sizeof_phdrs);
  79   if (phdrs == NULL)
  80     {
  81       fprintf (stderr, "Failed allocate memory to hold program headers\n");
  82       return;
  83     }
  84   num_headers = bfd_get_elf_phdrs (prog, phdrs);
  85   if (num_headers < 1)
  86     {
  87       fprintf (stderr, "Failed to read program headers\n");
  88       return;
  89     }
  90
  91   for (i = 0; i < num_headers; i++)
  92     {
  93       Elf_Internal_Phdr * p = phdrs + i;
  94       char *buf;
  95       bfd_vma size;
  96       bfd_vma base;
  97       file_ptr offset;
  98
  99       size = p->p_filesz;
 100       if (size <= 0)
 101         continue;
 102
 103       base = p->p_paddr;
 104       if (verbose > 1)
 105         fprintf (stderr, "[load segment: lma=%08x vma=%08x size=%08x]\n",
 106                  (int) base, (int) p->p_vaddr, (int) size);
 107
 108       buf = malloc (size);
 109       if (buf == NULL)
 110         {
 111           fprintf (stderr, "Failed to allocate buffer to hold program segment\n");
 112           continue;
 113         }
 114
 115       offset = p->p_offset;
 116       if (prog->iovec->bseek (prog, offset, SEEK_SET) != 0)
 117         {
 118           fprintf (stderr, "Failed to seek to offset %lx\n", (long) offset);
 119           continue;
 120         }
 121       if (prog->iovec->bread (prog, buf, size) != size)
 122         {
 123           fprintf (stderr, "Failed to read %lx bytes\n", size);
 124           continue;
 125         }
 126
 127       mem_put_blk (base, buf, size);
 128       free (buf);
 129       if (highest_addr_loaded < base + size - 1 && size >= 4)
 130         highest_addr_loaded = base + size - 1;
 131     }
 132
 133   free (phdrs);
 134
 135   regs.r_pc = prog->start_address;
 136
 137   if (strcmp (bfd_get_target (prog), "srec") == 0
 138       || regs.r_pc == 0)
 139     {
 140       regs.r_pc = mem_get_si (0xfffffffc);
 141       heaptop = heapbottom = 0;
 142     }
 143
 144   if (verbose > 1)
 145     fprintf (stderr, "[start pc=%08x %s]\n",
 146              (unsigned int) regs.r_pc,
 147              rx_big_endian ? "BE" : "LE");
 148 }