1# This shell script emits a C file. -*- C -*-
2#   Copyright (C) 1991-2020 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 elf.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 (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour)
70    return;
71
72  /* If generating a relocatable output file, then we don't
73     have to generate the trampolines.  */
74  if (bfd_link_relocatable (&link_info))
75    return;
76
77  ret = elf32_m68hc11_setup_section_lists (link_info.output_bfd, &link_info);
78  if (ret != 0 && no_trampoline == 0)
79    {
80      if (ret < 0)
81	{
82	  einfo (_("%X%P: can not size stub section: %E\n"));
83	  return;
84	}
85
86      /* Call into the BFD backend to do the real work.  */
87      if (!elf32_m68hc11_size_stubs (link_info.output_bfd,
88				     stub_file->the_bfd,
89				     &link_info,
90				     &m68hc11elf_add_stub_section))
91	{
92	  einfo (_("%X%P: can not size stub section: %E\n"));
93	  return;
94	}
95    }
96
97  if (bank_window_name == 0)
98    return;
99
100  /* The 'bank_window_name' memory region is a special region that describes
101     the memory bank window to access to paged memory.  For 68HC12
102     this is fixed and should be:
103
104     window (rx) : ORIGIN = 0x8000, LENGTH = 16K
105
106     But for 68HC11 this is board specific.  The definition of such
107     memory region allows to control how this paged memory is accessed.  */
108  region = lang_memory_region_lookup (bank_window_name, FALSE);
109
110  /* Check the length to see if it was defined in the script.  */
111  if (region->length != 0)
112    {
113      struct m68hc11_page_info *pinfo;
114      unsigned i;
115
116      /* Get default values  */
117      m68hc11_elf_get_bank_parameters (&link_info);
118      pinfo = &m68hc11_elf_hash_table (&link_info)->pinfo;
119
120      /* And override them with the region definition.  */
121      pinfo->bank_size = region->length;
122      pinfo->bank_shift = 0;
123      for (i = pinfo->bank_size; i != 0; i >>= 1)
124	pinfo->bank_shift++;
125      pinfo->bank_shift--;
126      pinfo->bank_size = 1L << pinfo->bank_shift;
127      pinfo->bank_mask = (1 << pinfo->bank_shift) - 1;
128      pinfo->bank_physical = region->origin;
129      pinfo->bank_physical_end = region->origin + pinfo->bank_size;
130
131      if (pinfo->bank_size != region->length)
132	{
133	  einfo (_("%P: warning: the size of the 'window' memory region "
134		   "is not a power of 2; its size %d is truncated to %d\n"),
135		 region->length, pinfo->bank_size);
136	}
137    }
138}
139
140/* This is called before the input files are opened.  We create a new
141   fake input file to hold the stub sections.  */
142
143static void
144m68hc11elf_create_output_section_statements (void)
145{
146  if (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour)
147    {
148      einfo (_("%X%P: changing output format whilst linking "
149	       "is not supported\n"));
150      return;
151    }
152
153  stub_file = lang_add_input_file ("linker stubs",
154				   lang_input_file_is_fake_enum,
155				   NULL);
156  stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
157  if (stub_file->the_bfd == NULL
158      || !bfd_set_arch_mach (stub_file->the_bfd,
159			     bfd_get_arch (link_info.output_bfd),
160			     bfd_get_mach (link_info.output_bfd)))
161    {
162      einfo (_("%F%P: can not create BFD: %E\n"));
163      return;
164    }
165
166  ldlang_add_file (stub_file);
167}
168
169
170struct hook_stub_info
171{
172  lang_statement_list_type add;
173  asection *input_section;
174};
175
176/* Traverse the linker tree to find the spot where the stub goes.  */
177
178static bfd_boolean
179hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
180{
181  lang_statement_union_type *l;
182  bfd_boolean ret;
183
184  for (; (l = *lp) != NULL; lp = &l->header.next)
185    {
186      switch (l->header.type)
187	{
188	case lang_constructors_statement_enum:
189	  ret = hook_in_stub (info, &constructor_list.head);
190	  if (ret)
191	    return ret;
192	  break;
193
194	case lang_output_section_statement_enum:
195	  ret = hook_in_stub (info,
196			      &l->output_section_statement.children.head);
197	  if (ret)
198	    return ret;
199	  break;
200
201	case lang_wild_statement_enum:
202	  ret = hook_in_stub (info, &l->wild_statement.children.head);
203	  if (ret)
204	    return ret;
205	  break;
206
207	case lang_group_statement_enum:
208	  ret = hook_in_stub (info, &l->group_statement.children.head);
209	  if (ret)
210	    return ret;
211	  break;
212
213	case lang_input_section_enum:
214	  if (l->input_section.section == info->input_section
215	      || strcmp (bfd_section_name (l->input_section.section),
216			 bfd_section_name (info->input_section)) == 0)
217	    {
218	      /* We've found our section.  Insert the stub immediately
219		 before its associated input section.  */
220	      *lp = info->add.head;
221	      *(info->add.tail) = l;
222	      return TRUE;
223	    }
224	  break;
225
226	case lang_data_statement_enum:
227	case lang_reloc_statement_enum:
228	case lang_object_symbols_statement_enum:
229	case lang_output_statement_enum:
230	case lang_target_statement_enum:
231	case lang_input_statement_enum:
232	case lang_assignment_statement_enum:
233	case lang_padding_statement_enum:
234	case lang_address_statement_enum:
235	case lang_fill_statement_enum:
236	  break;
237
238	default:
239	  FAIL ();
240	  break;
241	}
242    }
243  return FALSE;
244}
245
246
247/* Call-back for elf32_m68hc11_size_stubs.  */
248
249/* Create a new stub section, and arrange for it to be linked
250   immediately before INPUT_SECTION.  */
251
252static asection *
253m68hc11elf_add_stub_section (const char *stub_sec_name,
254			     asection *tramp_section)
255{
256  asection *stub_sec;
257  flagword flags;
258  asection *output_section;
259  lang_output_section_statement_type *os;
260  struct hook_stub_info info;
261
262  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
263	   | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
264  stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
265						 stub_sec_name, flags);
266  if (stub_sec == NULL)
267    goto err_ret;
268
269  output_section = tramp_section->output_section;
270  os = lang_output_section_get (output_section);
271
272  /* Try to put the new section at the same place as an existing
273     .tramp section.  Such .tramp section exists in most cases and
274     contains the trampoline code.  This way we put the generated trampoline
275     at the correct place.  */
276  info.input_section = tramp_section;
277  lang_list_init (&info.add);
278  lang_add_section (&info.add, stub_sec, NULL, os);
279
280  if (info.add.head == NULL)
281    goto err_ret;
282
283  if (hook_in_stub (&info, &os->children.head))
284    return stub_sec;
285
286 err_ret:
287  einfo (_("%X%P: can not make stub section: %E\n"));
288  return NULL;
289}
290
291/* For the 68HC12 we use this opportunity to build linker stubs.  */
292
293static void
294m68hc11elf_after_allocation (void)
295{
296  if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour)
297    {
298      /* Now build the linker stubs.  */
299      if (stub_file->the_bfd->sections != NULL)
300	{
301	  /* Call again the trampoline analyzer to initialize the trampoline
302	     stubs with the correct symbol addresses.  Since there could have
303	     been relaxation, the symbol addresses that were found during
304	     first call may no longer be correct.  */
305	  if (!elf32_m68hc11_size_stubs (link_info.output_bfd,
306					 stub_file->the_bfd,
307					 &link_info, 0))
308	    {
309	      einfo (_("%X%P: can not size stub section: %E\n"));
310	      return;
311	    }
312	  if (!elf32_m68hc11_build_stubs (link_info.output_bfd, &link_info))
313	    einfo (_("%X%P: can not build stubs: %E\n"));
314	}
315    }
316
317  gld${EMULATION_NAME}_after_allocation ();
318}
319
320EOF
321
322# Define some shell vars to insert bits of code into the standard elf
323# parse_args and list_options functions.
324#
325PARSE_AND_LIST_PROLOGUE='
326#define OPTION_NO_TRAMPOLINE		300
327#define OPTION_BANK_WINDOW		301
328'
329
330# The options are repeated below so that no abbreviations are allowed.
331# Otherwise -s matches stub-group-size
332PARSE_AND_LIST_LONGOPTS='
333  { "no-trampoline", no_argument, NULL, OPTION_NO_TRAMPOLINE },
334  { "bank-window",   required_argument, NULL, OPTION_BANK_WINDOW },
335'
336
337PARSE_AND_LIST_OPTIONS='
338  fprintf (file, _(
339"  --no-trampoline             Do not generate the far trampolines used to call\n"
340"                                a far function using 'jsr' or 'bsr'\n"));
341  fprintf (file, _(
342"  --bank-window NAME          Specify the name of the memory region describing\n"
343"                                the layout of the memory bank window\n"));
344'
345
346PARSE_AND_LIST_ARGS_CASES='
347    case OPTION_NO_TRAMPOLINE:
348      no_trampoline = 1;
349      break;
350    case OPTION_BANK_WINDOW:
351      bank_window_name = optarg;
352      break;
353'
354
355# Put these extra m68hc11elf routines in ld_${EMULATION_NAME}_emulation
356#
357LDEMUL_BEFORE_ALLOCATION=m68hc11_elf_${EMULATION_NAME}_before_allocation
358LDEMUL_AFTER_ALLOCATION=m68hc11elf_after_allocation
359LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=m68hc11elf_create_output_section_statements
360