xref: /netbsd-src/external/gpl3/binutils/dist/ld/emultempl/m68hc1xelf.em (revision bbde328be4e75ea9ad02e9715ea13ca54b797ada)
1# This shell script emits a C file. -*- C -*-
2#   Copyright 1991, 1993, 1994, 1997, 1999, 2000, 2001, 2002, 2003, 2007,
3#   2008 Free Software Foundation, Inc.
4#
5# This file is part of the GNU Binutils.
6#
7# This program is free software; you can redistribute it and/or modify
8# it under the terms of the GNU General Public License as published by
9# the Free Software Foundation; either version 3 of the License, or
10# (at your option) any later version.
11#
12# This program is distributed in the hope that it will be useful,
13# but WITHOUT ANY WARRANTY; without even the implied warranty of
14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15# GNU General Public License for more details.
16#
17# You should have received a copy of the GNU General Public License
18# along with this program; if not, write to the Free Software
19# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20# MA 02110-1301, USA.
21#
22
23# This file is sourced from elf32.em, and defines extra m68hc12-elf
24# and m68hc11-elf specific routines.  It is used to generate the
25# HC11/HC12 trampolines to call a far function by using a normal 'jsr/bsr'.
26#
27# - The HC11/HC12 relocations are checked to see if there is a
28#   R_M68HC11_16 relocation to a symbol marked with STO_M68HC12_FAR.
29#   This relocation cannot be made on the symbol but must be made on
30#   its trampoline
31#   The trampolines to generate are collected during this pass
32#   (See elf32_m68hc11_size_stubs)
33#
34# - The trampolines are generated in a ".tramp" section.  The generation
35#   takes care of HC11 and HC12 specificities.
36#   (See elf32_m68hc11_build_stubs)
37#
38# - During relocation the R_M68HC11_16 relocation to the far symbols
39#   are redirected to the trampoline that was generated.
40#
41# Copied from hppaelf and adapted for M68HC11/M68HC12 specific needs.
42#
43fragment <<EOF
44
45#include "ldctor.h"
46#include "elf32-m68hc1x.h"
47
48static asection *m68hc11elf_add_stub_section (const char *, asection *);
49
50/* Fake input file for stubs.  */
51static lang_input_statement_type *stub_file;
52
53/* By default the HC11/HC12 trampolines to call a far function using
54   a normal 'bsr' and 'jsr' convention are generated during the link.
55   The --no-trampoline option prevents that.  */
56static int no_trampoline = 0;
57
58/* Name of memory bank window in the MEMORY description.
59   This is set by --bank-window option.  */
60static const char* bank_window_name = 0;
61
62static void
63m68hc11_elf_${EMULATION_NAME}_before_allocation (void)
64{
65  lang_memory_region_type* region;
66  int ret;
67
68  gld${EMULATION_NAME}_before_allocation ();
69
70  /* If generating a relocatable output file, then we don't
71     have to generate the trampolines.  */
72  if (link_info.relocatable)
73    return;
74
75  ret = elf32_m68hc11_setup_section_lists (link_info.output_bfd, &link_info);
76  if (ret != 0 && no_trampoline == 0)
77    {
78      if (ret < 0)
79	{
80	  einfo ("%X%P: can not size stub section: %E\n");
81	  return;
82	}
83
84      /* Call into the BFD backend to do the real work.  */
85      if (!elf32_m68hc11_size_stubs (link_info.output_bfd,
86				     stub_file->the_bfd,
87				     &link_info,
88				     &m68hc11elf_add_stub_section))
89	{
90	  einfo ("%X%P: can not size stub section: %E\n");
91	  return;
92	}
93    }
94
95  if (bank_window_name == 0)
96    return;
97
98  /* The 'bank_window_name' memory region is a special region that describes
99     the memory bank window to access to paged memory.  For 68HC12
100     this is fixed and should be:
101
102     window (rx) : ORIGIN = 0x8000, LENGTH = 16K
103
104     But for 68HC11 this is board specific.  The definition of such
105     memory region allows to control how this paged memory is accessed.  */
106  region = lang_memory_region_lookup (bank_window_name, FALSE);
107
108  /* Check the length to see if it was defined in the script.  */
109  if (region->length != 0)
110    {
111      struct m68hc11_page_info *pinfo;
112      unsigned i;
113
114      /* Get default values  */
115      m68hc11_elf_get_bank_parameters (&link_info);
116      pinfo = &m68hc11_elf_hash_table (&link_info)->pinfo;
117
118      /* And override them with the region definition.  */
119      pinfo->bank_size = region->length;
120      pinfo->bank_shift = 0;
121      for (i = pinfo->bank_size; i != 0; i >>= 1)
122	pinfo->bank_shift++;
123      pinfo->bank_shift--;
124      pinfo->bank_size = 1L << pinfo->bank_shift;
125      pinfo->bank_mask = (1 << pinfo->bank_shift) - 1;
126      pinfo->bank_physical = region->origin;
127      pinfo->bank_physical_end = region->origin + pinfo->bank_size;
128
129      if (pinfo->bank_size != region->length)
130	{
131	  einfo (_("warning: the size of the 'window' memory region "
132		   "is not a power of 2\n"));
133	  einfo (_("warning: its size %d is truncated to %d\n"),
134		 region->length, pinfo->bank_size);
135	}
136    }
137}
138
139/* This is called before the input files are opened.  We create a new
140   fake input file to hold the stub sections.  */
141
142static void
143m68hc11elf_create_output_section_statements (void)
144{
145  stub_file = lang_add_input_file ("linker stubs",
146				   lang_input_file_is_fake_enum,
147				   NULL);
148  stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
149  if (stub_file->the_bfd == NULL
150      || !bfd_set_arch_mach (stub_file->the_bfd,
151			     bfd_get_arch (link_info.output_bfd),
152			     bfd_get_mach (link_info.output_bfd)))
153    {
154      einfo ("%X%P: can not create BFD %E\n");
155      return;
156    }
157
158  ldlang_add_file (stub_file);
159}
160
161
162struct hook_stub_info
163{
164  lang_statement_list_type add;
165  asection *input_section;
166};
167
168/* Traverse the linker tree to find the spot where the stub goes.  */
169
170static bfd_boolean
171hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
172{
173  lang_statement_union_type *l;
174  bfd_boolean ret;
175
176  for (; (l = *lp) != NULL; lp = &l->header.next)
177    {
178      switch (l->header.type)
179	{
180	case lang_constructors_statement_enum:
181	  ret = hook_in_stub (info, &constructor_list.head);
182	  if (ret)
183	    return ret;
184	  break;
185
186	case lang_output_section_statement_enum:
187	  ret = hook_in_stub (info,
188			      &l->output_section_statement.children.head);
189	  if (ret)
190	    return ret;
191	  break;
192
193	case lang_wild_statement_enum:
194	  ret = hook_in_stub (info, &l->wild_statement.children.head);
195	  if (ret)
196	    return ret;
197	  break;
198
199	case lang_group_statement_enum:
200	  ret = hook_in_stub (info, &l->group_statement.children.head);
201	  if (ret)
202	    return ret;
203	  break;
204
205	case lang_input_section_enum:
206	  if (l->input_section.section == info->input_section
207	      || strcmp (bfd_get_section_name (output_section,
208					       l->input_section.section),
209			 bfd_get_section_name (output_section,
210					       info->input_section)) == 0)
211	    {
212	      /* We've found our section.  Insert the stub immediately
213		 before its associated input section.  */
214	      *lp = info->add.head;
215	      *(info->add.tail) = l;
216	      return TRUE;
217	    }
218	  break;
219
220	case lang_data_statement_enum:
221	case lang_reloc_statement_enum:
222	case lang_object_symbols_statement_enum:
223	case lang_output_statement_enum:
224	case lang_target_statement_enum:
225	case lang_input_statement_enum:
226	case lang_assignment_statement_enum:
227	case lang_padding_statement_enum:
228	case lang_address_statement_enum:
229	case lang_fill_statement_enum:
230	  break;
231
232	default:
233	  FAIL ();
234	  break;
235	}
236    }
237  return FALSE;
238}
239
240
241/* Call-back for elf32_m68hc11_size_stubs.  */
242
243/* Create a new stub section, and arrange for it to be linked
244   immediately before INPUT_SECTION.  */
245
246static asection *
247m68hc11elf_add_stub_section (const char *stub_sec_name,
248			     asection *tramp_section)
249{
250  asection *stub_sec;
251  flagword flags;
252  asection *output_section;
253  const char *secname;
254  lang_output_section_statement_type *os;
255  struct hook_stub_info info;
256
257  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
258	   | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
259  stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
260						 stub_sec_name, flags);
261  if (stub_sec == NULL)
262    goto err_ret;
263
264  output_section = tramp_section->output_section;
265  secname = bfd_get_section_name (output_section->owner, output_section);
266  os = lang_output_section_find (secname);
267
268  /* Try to put the new section at the same place as an existing
269     .tramp section.  Such .tramp section exists in most cases and
270     contains the trampoline code.  This way we put the generated trampoline
271     at the correct place.  */
272  info.input_section = tramp_section;
273  lang_list_init (&info.add);
274  lang_add_section (&info.add, stub_sec, os);
275
276  if (info.add.head == NULL)
277    goto err_ret;
278
279  if (hook_in_stub (&info, &os->children.head))
280    return stub_sec;
281
282 err_ret:
283  einfo ("%X%P: can not make stub section: %E\n");
284  return NULL;
285}
286
287/* Final emulation specific call.  For the 68HC12 we use this opportunity
288   to build linker stubs.  */
289
290static void
291m68hc11elf_finish (void)
292{
293  /* Now build the linker stubs.  */
294  if (stub_file->the_bfd->sections != NULL)
295    {
296      /* Call again the trampoline analyzer to initialize the trampoline
297	 stubs with the correct symbol addresses.  Since there could have
298	 been relaxation, the symbol addresses that were found during
299	 first call may no longer be correct.  */
300      if (!elf32_m68hc11_size_stubs (link_info.output_bfd,
301				     stub_file->the_bfd,
302				     &link_info, 0))
303	{
304	  einfo ("%X%P: can not size stub section: %E\n");
305	  return;
306	}
307      if (!elf32_m68hc11_build_stubs (link_info.output_bfd, &link_info))
308	einfo ("%X%P: can not build stubs: %E\n");
309    }
310
311  gld${EMULATION_NAME}_finish ();
312}
313
314
315/* Avoid processing the fake stub_file in vercheck, stat_needed and
316   check_needed routines.  */
317
318static void (*real_func) (lang_input_statement_type *);
319
320static void m68hc11_for_each_input_file_wrapper (lang_input_statement_type *l)
321{
322  if (l != stub_file)
323    (*real_func) (l);
324}
325
326static void
327m68hc11_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
328{
329  real_func = func;
330  lang_for_each_input_file (&m68hc11_for_each_input_file_wrapper);
331}
332
333#define lang_for_each_input_file m68hc11_lang_for_each_input_file
334
335EOF
336
337# Define some shell vars to insert bits of code into the standard elf
338# parse_args and list_options functions.
339#
340PARSE_AND_LIST_PROLOGUE='
341#define OPTION_NO_TRAMPOLINE		300
342#define OPTION_BANK_WINDOW		301
343'
344
345# The options are repeated below so that no abbreviations are allowed.
346# Otherwise -s matches stub-group-size
347PARSE_AND_LIST_LONGOPTS='
348  { "no-trampoline", no_argument, NULL, OPTION_NO_TRAMPOLINE },
349  { "bank-window",   required_argument, NULL, OPTION_BANK_WINDOW },
350'
351
352PARSE_AND_LIST_OPTIONS='
353  fprintf (file, _(
354"  --no-trampoline             Do not generate the far trampolines used to call\n"
355"                                a far function using 'jsr' or 'bsr'.\n"
356"  --bank-window NAME          Specify the name of the memory region describing\n"
357"                                the layout of the memory bank window.\n"
358		   ));
359'
360
361PARSE_AND_LIST_ARGS_CASES='
362    case OPTION_NO_TRAMPOLINE:
363      no_trampoline = 1;
364      break;
365    case OPTION_BANK_WINDOW:
366      bank_window_name = optarg;
367      break;
368'
369
370# Put these extra m68hc11elf routines in ld_${EMULATION_NAME}_emulation
371#
372LDEMUL_BEFORE_ALLOCATION=m68hc11_elf_${EMULATION_NAME}_before_allocation
373LDEMUL_FINISH=m68hc11elf_finish
374LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=m68hc11elf_create_output_section_statements
375