1# This shell script emits a C file. -*- C -*-
2#   Copyright (C) 2003-2016 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 powerpc32-elf
23# specific routines.
24#
25fragment <<EOF
26
27#include "libbfd.h"
28#include "elf32-ppc.h"
29#include "ldlex.h"
30#include "ldlang.h"
31
32#define is_ppc_elf(bfd) \
33  (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
34   && elf_object_id (bfd) == PPC32_ELF_DATA)
35
36/* Whether to run tls optimization.  */
37static int notlsopt = 0;
38
39/* Choose the correct place for .got.  */
40static int old_got = 0;
41
42static bfd_vma pagesize = 0;
43
44static struct ppc_elf_params params = { PLT_UNSET, -1, 0, 0, 0, 0, 0 };
45
46static void
47ppc_after_open_output (void)
48{
49  if (params.emit_stub_syms < 0)
50    params.emit_stub_syms = (link_info.emitrelocations
51			     || bfd_link_pic (&link_info));
52  if (pagesize == 0)
53    pagesize = config.commonpagesize;
54  params.pagesize_p2 = bfd_log2 (pagesize);
55  ppc_elf_link_params (&link_info, &params);
56}
57
58EOF
59
60# No --secure-plt, --bss-plt, or --sdata-got for vxworks.
61if test -z "$VXWORKS_BASE_EM_FILE" ; then
62  fragment <<EOF
63static void
64ppc_after_open (void)
65{
66  if (is_ppc_elf (link_info.output_bfd))
67    {
68      int new_plt;
69      int keep_new;
70      unsigned int num_plt;
71      unsigned int num_got;
72      lang_output_section_statement_type *os;
73      lang_output_section_statement_type *plt_os[2];
74      lang_output_section_statement_type *got_os[2];
75
76      new_plt = ppc_elf_select_plt_layout (link_info.output_bfd, &link_info);
77      if (new_plt < 0)
78	einfo ("%X%P: select_plt_layout problem %E\n");
79
80      num_got = 0;
81      num_plt = 0;
82      for (os = &lang_output_section_statement.head->output_section_statement;
83	   os != NULL;
84	   os = os->next)
85	{
86	  if (os->constraint == SPECIAL && strcmp (os->name, ".plt") == 0)
87	    {
88	      if (num_plt < 2)
89		plt_os[num_plt] = os;
90	      ++num_plt;
91	    }
92	  if (os->constraint == SPECIAL && strcmp (os->name, ".got") == 0)
93	    {
94	      if (num_got < 2)
95		got_os[num_got] = os;
96	      ++num_got;
97	    }
98	}
99
100      keep_new = new_plt == 1 ? 0 : -1;
101      if (num_plt == 2)
102	{
103	  plt_os[0]->constraint = keep_new;
104	  plt_os[1]->constraint = ~keep_new;
105	}
106      if (num_got == 2)
107	{
108	  if (old_got)
109	    keep_new = -1;
110	  got_os[0]->constraint = keep_new;
111	  got_os[1]->constraint = ~keep_new;
112	}
113    }
114
115  gld${EMULATION_NAME}_after_open ();
116}
117
118EOF
119fi
120fragment <<EOF
121static void
122ppc_before_allocation (void)
123{
124  if (is_ppc_elf (link_info.output_bfd))
125    {
126      if (ppc_elf_tls_setup (link_info.output_bfd, &link_info)
127	  && !notlsopt)
128	{
129	  if (!ppc_elf_tls_optimize (link_info.output_bfd, &link_info))
130	    {
131	      einfo ("%X%P: TLS problem %E\n");
132	      return;
133	    }
134	}
135    }
136
137  gld${EMULATION_NAME}_before_allocation ();
138
139  ppc_elf_maybe_strip_sdata_syms (&link_info);
140
141  if (RELAXATION_ENABLED)
142    params.branch_trampolines = 1;
143
144  /* Turn on relaxation if executable sections have addresses that
145     might make branches overflow.  */
146  else if (!RELAXATION_DISABLED_BY_USER)
147    {
148      bfd_vma low = (bfd_vma) -1;
149      bfd_vma high = 0;
150      asection *o;
151
152      /* Run lang_size_sections (if not already done).  */
153      if (expld.phase != lang_mark_phase_enum)
154	{
155	  expld.phase = lang_mark_phase_enum;
156	  expld.dataseg.phase = exp_dataseg_none;
157	  one_lang_size_sections_pass (NULL, FALSE);
158	  lang_reset_memory_regions ();
159	}
160
161      for (o = link_info.output_bfd->sections; o != NULL; o = o->next)
162	{
163	  if ((o->flags & (SEC_ALLOC | SEC_CODE)) != (SEC_ALLOC | SEC_CODE))
164	    continue;
165	  if (o->rawsize == 0)
166	    continue;
167	  if (low > o->vma)
168	    low = o->vma;
169	  if (high < o->vma + o->rawsize - 1)
170	    high = o->vma + o->rawsize - 1;
171	}
172      if (high > low && high - low > (1 << 25) - 1)
173	params.branch_trampolines = 1;
174    }
175
176  if (params.branch_trampolines
177      || params.ppc476_workaround
178      || params.pic_fixup > 0)
179    ENABLE_RELAXATION;
180}
181
182/* Replaces default zero fill padding in executable sections with
183   "ba 0" instructions.  This works around the ppc476 icache bug if we
184   have a function pointer tail call near the end of a page, some
185   small amount of padding, then the function called at the beginning
186   of the next page.  If the "ba 0" is ever executed we should hit a
187   segv, so it's almost as good as an illegal instruction (zero).  */
188
189static void
190no_zero_padding (lang_statement_union_type *l)
191{
192  if (l->header.type == lang_padding_statement_enum
193      && l->padding_statement.size != 0
194      && l->padding_statement.output_section != NULL
195      && (l->padding_statement.output_section->flags & SEC_CODE) != 0
196      && l->padding_statement.fill->size == 0)
197    {
198      struct _ppc_fill_type
199      {
200	size_t size;
201	unsigned char data[4];
202      };
203      static struct _ppc_fill_type fill_be = { 4, {0x48, 0, 0, 2} };
204      static struct _ppc_fill_type fill_le = { 4, {2, 0, 0, 0x48} };
205
206      if (bfd_big_endian (link_info.output_bfd))
207	l->padding_statement.fill = (struct _fill_type *) &fill_be;
208      else
209	l->padding_statement.fill = (struct _fill_type *) &fill_le;
210    }
211}
212
213static void
214ppc_finish (void)
215{
216  if (params.ppc476_workaround)
217    lang_for_each_statement (no_zero_padding);
218  finish_default ();
219}
220
221EOF
222
223if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
224  fragment <<EOF
225/* Special handling for embedded SPU executables.  */
226extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
227static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
228
229static bfd_boolean
230ppc_recognized_file (lang_input_statement_type *entry)
231{
232  if (embedded_spu_file (entry, "-m32"))
233    return TRUE;
234
235  return gld${EMULATION_NAME}_load_symbols (entry);
236}
237
238EOF
239LDEMUL_RECOGNIZED_FILE=ppc_recognized_file
240fi
241
242# Define some shell vars to insert bits of code into the standard elf
243# parse_args and list_options functions.
244#
245PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
246#define OPTION_NO_TLS_OPT		321
247#define OPTION_NO_TLS_GET_ADDR_OPT	(OPTION_NO_TLS_OPT + 1)
248#define OPTION_NEW_PLT			(OPTION_NO_TLS_GET_ADDR_OPT + 1)
249#define OPTION_OLD_PLT			(OPTION_NEW_PLT + 1)
250#define OPTION_OLD_GOT			(OPTION_OLD_PLT + 1)
251#define OPTION_STUBSYMS			(OPTION_OLD_GOT + 1)
252#define OPTION_NO_STUBSYMS		(OPTION_STUBSYMS + 1)
253#define OPTION_PPC476_WORKAROUND	(OPTION_NO_STUBSYMS + 1)
254#define OPTION_NO_PPC476_WORKAROUND	(OPTION_PPC476_WORKAROUND + 1)
255#define OPTION_NO_PICFIXUP		(OPTION_NO_PPC476_WORKAROUND + 1)
256'
257
258PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
259  { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
260  { "no-emit-stub-syms", no_argument, NULL, OPTION_NO_STUBSYMS },
261  { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
262  { "no-tls-get-addr-optimize", no_argument, NULL, OPTION_NO_TLS_GET_ADDR_OPT },'
263if test -z "$VXWORKS_BASE_EM_FILE" ; then
264  PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
265  { "secure-plt", no_argument, NULL, OPTION_NEW_PLT },
266  { "bss-plt", no_argument, NULL, OPTION_OLD_PLT },
267  { "sdata-got", no_argument, NULL, OPTION_OLD_GOT },'
268fi
269PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
270  { "ppc476-workaround", optional_argument, NULL, OPTION_PPC476_WORKAROUND },
271  { "no-ppc476-workaround", no_argument, NULL, OPTION_NO_PPC476_WORKAROUND },
272  { "no-pic-fixup", no_argument, NULL, OPTION_NO_PICFIXUP },
273'
274
275PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
276  fprintf (file, _("\
277  --emit-stub-syms            Label linker stubs with a symbol.\n\
278  --no-emit-stub-syms         Don'\''t label linker stubs with a symbol.\n\
279  --no-tls-optimize           Don'\''t try to optimize TLS accesses.\n\
280  --no-tls-get-addr-optimize  Don'\''t use a special __tls_get_addr call.\n'
281if test -z "$VXWORKS_BASE_EM_FILE" ; then
282  PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
283  --secure-plt                Use new-style PLT if possible.\n\
284  --bss-plt                   Force old-style BSS PLT.\n\
285  --sdata-got                 Force GOT location just before .sdata.\n'
286fi
287PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
288  --ppc476-workaround [=pagesize]\n\
289                              Avoid a cache bug on ppc476.\n\
290  --no-ppc476-workaround      Disable workaround.\n\
291  --no-pic-fixup              Don'\''t edit non-pic to pic.\n"
292		   ));
293'
294
295PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
296    case OPTION_STUBSYMS:
297      params.emit_stub_syms = 1;
298      break;
299
300    case OPTION_NO_STUBSYMS:
301      params.emit_stub_syms = 0;
302      break;
303
304    case OPTION_NO_TLS_OPT:
305      notlsopt = 1;
306      break;
307
308    case OPTION_NO_TLS_GET_ADDR_OPT:
309      params.no_tls_get_addr_opt = 1;
310      break;
311
312    case OPTION_NEW_PLT:
313      params.plt_style = PLT_NEW;
314      break;
315
316    case OPTION_OLD_PLT:
317      params.plt_style = PLT_OLD;
318      break;
319
320    case OPTION_OLD_GOT:
321      old_got = 1;
322      break;
323
324    case OPTION_TRADITIONAL_FORMAT:
325      notlsopt = 1;
326      params.no_tls_get_addr_opt = 1;
327      return FALSE;
328
329    case OPTION_PPC476_WORKAROUND:
330      params.ppc476_workaround = 1;
331      if (optarg != NULL)
332	{
333	  char *end;
334	  pagesize = strtoul (optarg, &end, 0);
335	  if (*end
336	      || (pagesize < 4096 && pagesize != 0)
337	      || pagesize != (pagesize & -pagesize))
338	    einfo (_("%P%F: invalid pagesize `%s'\''\n"), optarg);
339	}
340      break;
341
342    case OPTION_NO_PPC476_WORKAROUND:
343      params.ppc476_workaround = 0;
344      break;
345
346    case OPTION_NO_PICFIXUP:
347      params.pic_fixup = -1;
348      break;
349'
350
351# Put these extra ppc32elf routines in ld_${EMULATION_NAME}_emulation
352#
353LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_after_open_output
354if test -z "$VXWORKS_BASE_EM_FILE" ; then
355  LDEMUL_AFTER_OPEN=ppc_after_open
356fi
357LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
358LDEMUL_FINISH=ppc_finish
359