1# This shell script emits a C file. -*- C -*-
2#   Copyright (C) 2006-2014 Free Software Foundation, Inc.
3#
4# This file is part of the GNU Binutils.
5#
6# This program is free software; you can redistribute it and/or modify
7# it under the terms of the GNU General Public License as published by
8# the Free Software Foundation; either version 3 of the License, or
9# (at your option) any later version.
10#
11# This program is distributed in the hope that it will be useful,
12# but WITHOUT ANY WARRANTY; without even the implied warranty of
13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14# GNU General Public License for more details.
15#
16# You should have received a copy of the GNU General Public License
17# along with this program; if not, write to the Free Software
18# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19# MA 02110-1301, USA.
20
21
22# This file is sourced from elf32.em, and defines extra avr-elf specific
23# routines.  It is used to generate the trampolines for the avr6 family
24# of devices where one needs to address the issue that it is not possible
25# to reach the whole program memory by using 16 bit pointers.
26
27fragment <<EOF
28
29#include "elf32-avr.h"
30#include "ldctor.h"
31
32/* The fake file and it's corresponding section meant to hold
33   the linker stubs if needed.  */
34
35static lang_input_statement_type *stub_file;
36static asection *avr_stub_section;
37
38/* Variables set by the command-line parameters and transfered
39   to the bfd without use of global shared variables.  */
40
41static bfd_boolean avr_no_stubs = FALSE;
42static bfd_boolean avr_debug_relax = FALSE;
43static bfd_boolean avr_debug_stubs = FALSE;
44static bfd_boolean avr_replace_call_ret_sequences = TRUE;
45static bfd_vma avr_pc_wrap_around = 0x10000000;
46
47/* Transfers information to the bfd frontend.  */
48
49static void
50avr_elf_set_global_bfd_parameters (void)
51{
52  elf32_avr_setup_params (& link_info,
53                          stub_file->the_bfd,
54                          avr_stub_section,
55                          avr_no_stubs,
56                          avr_debug_stubs,
57                          avr_debug_relax,
58                          avr_pc_wrap_around,
59                          avr_replace_call_ret_sequences);
60}
61
62
63/* Makes a conservative estimate of the trampoline section size that could
64   be corrected later on.  */
65
66static void
67avr_elf_${EMULATION_NAME}_before_allocation (void)
68{
69  int ret;
70
71  gld${EMULATION_NAME}_before_allocation ();
72
73  /* We only need stubs for avr6, avrxmega6, and avrxmega7. */
74  if (strcmp ("${EMULATION_NAME}","avr6")
75      && strcmp ("${EMULATION_NAME}","avrxmega6")
76      && strcmp ("${EMULATION_NAME}","avrxmega7") )
77    avr_no_stubs = TRUE;
78
79  avr_elf_set_global_bfd_parameters ();
80
81  /* If generating a relocatable output file, then
82     we don't  have to generate the trampolines.  */
83  if (link_info.relocatable)
84    avr_no_stubs = TRUE;
85
86  if (avr_no_stubs)
87    return;
88
89  ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info);
90
91  if (ret < 0)
92    einfo ("%X%P: can not setup the input section list: %E\n");
93
94  if (ret <= 0)
95    return;
96
97  /* Call into the BFD backend to do the real "stub"-work.  */
98  if (! elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE))
99    einfo ("%X%P: can not size stub section: %E\n");
100}
101
102/* This is called before the input files are opened.  We create a new
103   fake input file to hold the stub section and generate the section itself.  */
104
105static void
106avr_elf_create_output_section_statements (void)
107{
108  flagword flags;
109
110  stub_file = lang_add_input_file ("linker stubs",
111                                   lang_input_file_is_fake_enum,
112                                   NULL);
113
114  stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
115  if (stub_file->the_bfd == NULL
116      || !bfd_set_arch_mach (stub_file->the_bfd,
117                             bfd_get_arch (link_info.output_bfd),
118                             bfd_get_mach (link_info.output_bfd)))
119    {
120      einfo ("%X%P: can not create stub BFD %E\n");
121      return;
122    }
123
124  /* Now we add the stub section.  */
125
126  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
127           | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
128  avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
129							 ".trampolines",
130							 flags);
131  if (avr_stub_section == NULL)
132    goto err_ret;
133
134  avr_stub_section->alignment_power = 1;
135
136  ldlang_add_file (stub_file);
137
138  return;
139
140  err_ret:
141   einfo ("%X%P: can not make stub section: %E\n");
142   return;
143}
144
145/* Re-calculates the size of the stubs so that we won't waste space.  */
146
147static void
148avr_elf_after_allocation (void)
149{
150  if (!avr_no_stubs && ! RELAXATION_ENABLED)
151    {
152      /* If relaxing, elf32_avr_size_stubs will be called from
153	 elf32_avr_relax_section.  */
154      if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE))
155	einfo ("%X%P: can not size stub section: %E\n");
156    }
157
158  gld${EMULATION_NAME}_after_allocation ();
159
160  /* Now build the linker stubs.  */
161  if (!avr_no_stubs)
162    {
163      if (!elf32_avr_build_stubs (&link_info))
164	einfo ("%X%P: can not build stubs: %E\n");
165    }
166}
167
168static void
169avr_elf_before_parse (void)
170{
171  /* Don't create a demand-paged executable, since this feature isn't
172     meaningful in AVR. */
173  config.magic_demand_paged = FALSE;
174
175  gld${EMULATION_NAME}_before_parse ();
176}
177
178EOF
179
180
181PARSE_AND_LIST_PROLOGUE='
182
183#define OPTION_NO_CALL_RET_REPLACEMENT 301
184#define OPTION_PMEM_WRAP_AROUND        302
185#define OPTION_NO_STUBS                303
186#define OPTION_DEBUG_STUBS             304
187#define OPTION_DEBUG_RELAX             305
188'
189
190PARSE_AND_LIST_LONGOPTS='
191  { "no-call-ret-replacement", no_argument,
192     NULL, OPTION_NO_CALL_RET_REPLACEMENT},
193  { "pmem-wrap-around", required_argument,
194    NULL, OPTION_PMEM_WRAP_AROUND},
195  { "no-stubs", no_argument,
196    NULL, OPTION_NO_STUBS},
197  { "debug-stubs", no_argument,
198    NULL, OPTION_DEBUG_STUBS},
199  { "debug-relax", no_argument,
200    NULL, OPTION_DEBUG_RELAX},
201'
202
203PARSE_AND_LIST_OPTIONS='
204  fprintf (file, _("  --pmem-wrap-around=<val>    "
205		   "Make the linker relaxation machine assume that a\n"
206		   "                              "
207		   "  program counter wrap-around occures at address\n"
208		   "                              "
209		   "  <val>.  Supported values: 8k, 16k, 32k and 64k.\n"));
210  fprintf (file, _("  --no-call-ret-replacement   "
211		   "The relaxation machine normally will\n"
212		   "                              "
213		   "  substitute two immediately following call/ret\n"
214		   "                              "
215		   "  instructions by a single jump instruction.\n"
216		   "                              "
217		   "  This option disables this optimization.\n"));
218  fprintf (file, _("  --no-stubs                  "
219		   "If the linker detects to attempt to access\n"
220		   "                              "
221		   "  an instruction beyond 128k by a reloc that\n"
222		   "                              "
223		   "  is limited to 128k max, it inserts a jump\n"
224		   "                              "
225		   "  stub. You can de-active this with this switch.\n"));
226  fprintf (file, _("  --debug-stubs               "
227		   "Used for debugging avr-ld.\n"));
228  fprintf (file, _("  --debug-relax               "
229		   "Used for debugging avr-ld.\n"));
230'
231
232PARSE_AND_LIST_ARGS_CASES='
233
234    case OPTION_PMEM_WRAP_AROUND:
235      {
236        /* This variable is defined in the bfd library.  */
237        if ((!strcmp (optarg,"32k"))      || (!strcmp (optarg,"32K")))
238          avr_pc_wrap_around = 32768;
239        else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K")))
240          avr_pc_wrap_around = 8192;
241        else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K")))
242          avr_pc_wrap_around = 16384;
243        else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K")))
244          avr_pc_wrap_around = 0x10000;
245        else
246          return FALSE;
247      }
248      break;
249
250    case OPTION_DEBUG_STUBS:
251      avr_debug_stubs = TRUE;
252      break;
253
254    case OPTION_DEBUG_RELAX:
255      avr_debug_relax = TRUE;
256      break;
257
258    case OPTION_NO_STUBS:
259      avr_no_stubs = TRUE;
260      break;
261
262    case OPTION_NO_CALL_RET_REPLACEMENT:
263      {
264        /* This variable is defined in the bfd library.  */
265        avr_replace_call_ret_sequences = FALSE;
266      }
267      break;
268'
269
270#
271# Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation
272#
273LDEMUL_BEFORE_PARSE=avr_elf_before_parse
274LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation
275LDEMUL_AFTER_ALLOCATION=avr_elf_after_allocation
276LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements
277