1# This shell script emits a C file. -*- C -*-
2#   Copyright (C) 1991-2016 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 m68hc12-elf
23# and m68hc11-elf specific routines.  It is used to generate the
24# HC11/HC12 trampolines to call a far function by using a normal 'jsr/bsr'.
25#
26# - The HC11/HC12 relocations are checked to see if there is a
27#   R_M68HC11_16 relocation to a symbol marked with STO_M68HC12_FAR.
28#   This relocation cannot be made on the symbol but must be made on
29#   its trampoline
30#   The trampolines to generate are collected during this pass
31#   (See elf32_m68hc11_size_stubs)
32#
33# - The trampolines are generated in a ".tramp" section.  The generation
34#   takes care of HC11 and HC12 specificities.
35#   (See elf32_m68hc11_build_stubs)
36#
37# - During relocation the R_M68HC11_16 relocation to the far symbols
38#   are redirected to the trampoline that was generated.
39#
40# Copied from hppaelf and adapted for M68HC11/M68HC12 specific needs.
41#
42fragment <<EOF
43
44#include "ldctor.h"
45#include "elf32-m68hc1x.h"
46
47static asection *m68hc11elf_add_stub_section (const char *, asection *);
48
49/* Fake input file for stubs.  */
50static lang_input_statement_type *stub_file;
51
52/* By default the HC11/HC12 trampolines to call a far function using
53   a normal 'bsr' and 'jsr' convention are generated during the link.
54   The --no-trampoline option prevents that.  */
55static int no_trampoline = 0;
56
57/* Name of memory bank window in the MEMORY description.
58   This is set by --bank-window option.  */
59static const char* bank_window_name = 0;
60
61static void
62m68hc11_elf_${EMULATION_NAME}_before_allocation (void)
63{
64  lang_memory_region_type* region;
65  int ret;
66
67  gld${EMULATION_NAME}_before_allocation ();
68
69  /* If generating a relocatable output file, then we don't
70     have to generate the trampolines.  */
71  if (bfd_link_relocatable (&link_info))
72    return;
73
74  ret = elf32_m68hc11_setup_section_lists (link_info.output_bfd, &link_info);
75  if (ret != 0 && no_trampoline == 0)
76    {
77      if (ret < 0)
78	{
79	  einfo ("%X%P: can not size stub section: %E\n");
80	  return;
81	}
82
83      /* Call into the BFD backend to do the real work.  */
84      if (!elf32_m68hc11_size_stubs (link_info.output_bfd,
85				     stub_file->the_bfd,
86				     &link_info,
87				     &m68hc11elf_add_stub_section))
88	{
89	  einfo ("%X%P: can not size stub section: %E\n");
90	  return;
91	}
92    }
93
94  if (bank_window_name == 0)
95    return;
96
97  /* The 'bank_window_name' memory region is a special region that describes
98     the memory bank window to access to paged memory.  For 68HC12
99     this is fixed and should be:
100
101     window (rx) : ORIGIN = 0x8000, LENGTH = 16K
102
103     But for 68HC11 this is board specific.  The definition of such
104     memory region allows to control how this paged memory is accessed.  */
105  region = lang_memory_region_lookup (bank_window_name, FALSE);
106
107  /* Check the length to see if it was defined in the script.  */
108  if (region->length != 0)
109    {
110      struct m68hc11_page_info *pinfo;
111      unsigned i;
112
113      /* Get default values  */
114      m68hc11_elf_get_bank_parameters (&link_info);
115      pinfo = &m68hc11_elf_hash_table (&link_info)->pinfo;
116
117      /* And override them with the region definition.  */
118      pinfo->bank_size = region->length;
119      pinfo->bank_shift = 0;
120      for (i = pinfo->bank_size; i != 0; i >>= 1)
121	pinfo->bank_shift++;
122      pinfo->bank_shift--;
123      pinfo->bank_size = 1L << pinfo->bank_shift;
124      pinfo->bank_mask = (1 << pinfo->bank_shift) - 1;
125      pinfo->bank_physical = region->origin;
126      pinfo->bank_physical_end = region->origin + pinfo->bank_size;
127
128      if (pinfo->bank_size != region->length)
129	{
130	  einfo (_("warning: the size of the 'window' memory region "
131		   "is not a power of 2\n"));
132	  einfo (_("warning: its size %d is truncated to %d\n"),
133		 region->length, pinfo->bank_size);
134	}
135    }
136}
137
138/* This is called before the input files are opened.  We create a new
139   fake input file to hold the stub sections.  */
140
141static void
142m68hc11elf_create_output_section_statements (void)
143{
144  stub_file = lang_add_input_file ("linker stubs",
145				   lang_input_file_is_fake_enum,
146				   NULL);
147  stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
148  if (stub_file->the_bfd == NULL
149      || !bfd_set_arch_mach (stub_file->the_bfd,
150			     bfd_get_arch (link_info.output_bfd),
151			     bfd_get_mach (link_info.output_bfd)))
152    {
153      einfo ("%X%P: can not create BFD %E\n");
154      return;
155    }
156
157  ldlang_add_file (stub_file);
158}
159
160
161struct hook_stub_info
162{
163  lang_statement_list_type add;
164  asection *input_section;
165};
166
167/* Traverse the linker tree to find the spot where the stub goes.  */
168
169static bfd_boolean
170hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
171{
172  lang_statement_union_type *l;
173  bfd_boolean ret;
174
175  for (; (l = *lp) != NULL; lp = &l->header.next)
176    {
177      switch (l->header.type)
178	{
179	case lang_constructors_statement_enum:
180	  ret = hook_in_stub (info, &constructor_list.head);
181	  if (ret)
182	    return ret;
183	  break;
184
185	case lang_output_section_statement_enum:
186	  ret = hook_in_stub (info,
187			      &l->output_section_statement.children.head);
188	  if (ret)
189	    return ret;
190	  break;
191
192	case lang_wild_statement_enum:
193	  ret = hook_in_stub (info, &l->wild_statement.children.head);
194	  if (ret)
195	    return ret;
196	  break;
197
198	case lang_group_statement_enum:
199	  ret = hook_in_stub (info, &l->group_statement.children.head);
200	  if (ret)
201	    return ret;
202	  break;
203
204	case lang_input_section_enum:
205	  if (l->input_section.section == info->input_section
206	      || strcmp (bfd_get_section_name (l->input_section.section->owner,
207					       l->input_section.section),
208			 bfd_get_section_name (info->input_section->owner,
209					       info->input_section)) == 0)
210	    {
211	      /* We've found our section.  Insert the stub immediately
212		 before its associated input section.  */
213	      *lp = info->add.head;
214	      *(info->add.tail) = l;
215	      return TRUE;
216	    }
217	  break;
218
219	case lang_data_statement_enum:
220	case lang_reloc_statement_enum:
221	case lang_object_symbols_statement_enum:
222	case lang_output_statement_enum:
223	case lang_target_statement_enum:
224	case lang_input_statement_enum:
225	case lang_assignment_statement_enum:
226	case lang_padding_statement_enum:
227	case lang_address_statement_enum:
228	case lang_fill_statement_enum:
229	  break;
230
231	default:
232	  FAIL ();
233	  break;
234	}
235    }
236  return FALSE;
237}
238
239
240/* Call-back for elf32_m68hc11_size_stubs.  */
241
242/* Create a new stub section, and arrange for it to be linked
243   immediately before INPUT_SECTION.  */
244
245static asection *
246m68hc11elf_add_stub_section (const char *stub_sec_name,
247			     asection *tramp_section)
248{
249  asection *stub_sec;
250  flagword flags;
251  asection *output_section;
252  lang_output_section_statement_type *os;
253  struct hook_stub_info info;
254
255  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
256	   | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
257  stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
258						 stub_sec_name, flags);
259  if (stub_sec == NULL)
260    goto err_ret;
261
262  output_section = tramp_section->output_section;
263  os = lang_output_section_get (output_section);
264
265  /* Try to put the new section at the same place as an existing
266     .tramp section.  Such .tramp section exists in most cases and
267     contains the trampoline code.  This way we put the generated trampoline
268     at the correct place.  */
269  info.input_section = tramp_section;
270  lang_list_init (&info.add);
271  lang_add_section (&info.add, stub_sec, NULL, os);
272
273  if (info.add.head == NULL)
274    goto err_ret;
275
276  if (hook_in_stub (&info, &os->children.head))
277    return stub_sec;
278
279 err_ret:
280  einfo ("%X%P: can not make stub section: %E\n");
281  return NULL;
282}
283
284/* For the 68HC12 we use this opportunity to build linker stubs.  */
285
286static void
287m68hc11elf_after_allocation (void)
288{
289  /* Now build the linker stubs.  */
290  if (stub_file->the_bfd->sections != NULL)
291    {
292      /* Call again the trampoline analyzer to initialize the trampoline
293	 stubs with the correct symbol addresses.  Since there could have
294	 been relaxation, the symbol addresses that were found during
295	 first call may no longer be correct.  */
296      if (!elf32_m68hc11_size_stubs (link_info.output_bfd,
297				     stub_file->the_bfd,
298				     &link_info, 0))
299	{
300	  einfo ("%X%P: can not size stub section: %E\n");
301	  return;
302	}
303      if (!elf32_m68hc11_build_stubs (link_info.output_bfd, &link_info))
304	einfo ("%X%P: can not build stubs: %E\n");
305    }
306
307  gld${EMULATION_NAME}_after_allocation ();
308}
309
310
311/* Avoid processing the fake stub_file in vercheck, stat_needed and
312   check_needed routines.  */
313
314static void (*real_func) (lang_input_statement_type *);
315
316static void m68hc11_for_each_input_file_wrapper (lang_input_statement_type *l)
317{
318  if (l != stub_file)
319    (*real_func) (l);
320}
321
322static void
323m68hc11_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
324{
325  real_func = func;
326  lang_for_each_input_file (&m68hc11_for_each_input_file_wrapper);
327}
328
329#define lang_for_each_input_file m68hc11_lang_for_each_input_file
330
331EOF
332
333# Define some shell vars to insert bits of code into the standard elf
334# parse_args and list_options functions.
335#
336PARSE_AND_LIST_PROLOGUE='
337#define OPTION_NO_TRAMPOLINE		300
338#define OPTION_BANK_WINDOW		301
339'
340
341# The options are repeated below so that no abbreviations are allowed.
342# Otherwise -s matches stub-group-size
343PARSE_AND_LIST_LONGOPTS='
344  { "no-trampoline", no_argument, NULL, OPTION_NO_TRAMPOLINE },
345  { "bank-window",   required_argument, NULL, OPTION_BANK_WINDOW },
346'
347
348PARSE_AND_LIST_OPTIONS='
349  fprintf (file, _(
350"  --no-trampoline             Do not generate the far trampolines used to call\n"
351"                                a far function using 'jsr' or 'bsr'.\n"
352"  --bank-window NAME          Specify the name of the memory region describing\n"
353"                                the layout of the memory bank window.\n"
354		   ));
355'
356
357PARSE_AND_LIST_ARGS_CASES='
358    case OPTION_NO_TRAMPOLINE:
359      no_trampoline = 1;
360      break;
361    case OPTION_BANK_WINDOW:
362      bank_window_name = optarg;
363      break;
364'
365
366# Put these extra m68hc11elf routines in ld_${EMULATION_NAME}_emulation
367#
368LDEMUL_BEFORE_ALLOCATION=m68hc11_elf_${EMULATION_NAME}_before_allocation
369LDEMUL_AFTER_ALLOCATION=m68hc11elf_after_allocation
370LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=m68hc11elf_create_output_section_statements
371