1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
|
# This shell script emits a C file. -*- C -*-
# Copyright (C) 2006-2015 Free Software Foundation, Inc.
#
# This file is part of the GNU Binutils.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
# MA 02110-1301, USA.
# This file is sourced from elf32.em, and defines extra avr-elf specific
# routines. It is used to generate the trampolines for the avr6 family
# of devices where one needs to address the issue that it is not possible
# to reach the whole program memory by using 16 bit pointers.
fragment <<EOF
#include "elf32-avr.h"
#include "ldctor.h"
#include "elf/avr.h"
/* The fake file and it's corresponding section meant to hold
the linker stubs if needed. */
static lang_input_statement_type *stub_file;
static asection *avr_stub_section;
/* Variables set by the command-line parameters and transfered
to the bfd without use of global shared variables. */
static bfd_boolean avr_no_stubs = FALSE;
static bfd_boolean avr_debug_relax = FALSE;
static bfd_boolean avr_debug_stubs = FALSE;
static bfd_boolean avr_replace_call_ret_sequences = TRUE;
static bfd_vma avr_pc_wrap_around = 0x10000000;
/* Transfers information to the bfd frontend. */
static void
avr_elf_set_global_bfd_parameters (void)
{
elf32_avr_setup_params (& link_info,
stub_file->the_bfd,
avr_stub_section,
avr_no_stubs,
avr_debug_stubs,
avr_debug_relax,
avr_pc_wrap_around,
avr_replace_call_ret_sequences);
}
/* Makes a conservative estimate of the trampoline section size that could
be corrected later on. */
static void
avr_elf_${EMULATION_NAME}_before_allocation (void)
{
int ret;
gld${EMULATION_NAME}_before_allocation ();
/* We only need stubs for avr6, avrxmega6, and avrxmega7. */
if (strcmp ("${EMULATION_NAME}","avr6")
&& strcmp ("${EMULATION_NAME}","avrxmega6")
&& strcmp ("${EMULATION_NAME}","avrxmega7") )
avr_no_stubs = TRUE;
avr_elf_set_global_bfd_parameters ();
/* If generating a relocatable output file, then
we don't have to generate the trampolines. */
if (link_info.relocatable)
avr_no_stubs = TRUE;
if (avr_no_stubs)
return;
ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info);
if (ret < 0)
einfo ("%X%P: can not setup the input section list: %E\n");
if (ret <= 0)
return;
/* Call into the BFD backend to do the real "stub"-work. */
if (! elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE))
einfo ("%X%P: can not size stub section: %E\n");
}
/* This is called before the input files are opened. We create a new
fake input file to hold the stub section and generate the section itself. */
static void
avr_elf_create_output_section_statements (void)
{
flagword flags;
stub_file = lang_add_input_file ("linker stubs",
lang_input_file_is_fake_enum,
NULL);
stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
if (stub_file->the_bfd == NULL
|| !bfd_set_arch_mach (stub_file->the_bfd,
bfd_get_arch (link_info.output_bfd),
bfd_get_mach (link_info.output_bfd)))
{
einfo ("%X%P: can not create stub BFD %E\n");
return;
}
/* Now we add the stub section. */
flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
| SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
".trampolines",
flags);
if (avr_stub_section == NULL)
goto err_ret;
avr_stub_section->alignment_power = 1;
ldlang_add_file (stub_file);
return;
err_ret:
einfo ("%X%P: can not make stub section: %E\n");
return;
}
/* Re-calculates the size of the stubs so that we won't waste space. */
static void
avr_elf_after_allocation (void)
{
if (!avr_no_stubs && ! RELAXATION_ENABLED)
{
/* If relaxing, elf32_avr_size_stubs will be called from
elf32_avr_relax_section. */
if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE))
einfo ("%X%P: can not size stub section: %E\n");
}
gld${EMULATION_NAME}_after_allocation ();
/* Now build the linker stubs. */
if (!avr_no_stubs)
{
if (!elf32_avr_build_stubs (&link_info))
einfo ("%X%P: can not build stubs: %E\n");
}
}
static void
avr_elf_before_parse (void)
{
/* Don't create a demand-paged executable, since this feature isn't
meaningful in AVR. */
config.magic_demand_paged = FALSE;
gld${EMULATION_NAME}_before_parse ();
}
static void
avr_finish (void)
{
bfd *abfd;
bfd_boolean avr_link_relax;
if (link_info.relocatable)
{
avr_link_relax = TRUE;
for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link.next)
{
/* Don't let the linker stubs prevent the final object being
marked as link-relax ready. */
if ((elf_elfheader (abfd)->e_flags
& EF_AVR_LINKRELAX_PREPARED) == 0
&& abfd != stub_file->the_bfd)
{
avr_link_relax = FALSE;
break;
}
}
}
else
{
avr_link_relax = RELAXATION_ENABLED;
}
abfd = link_info.output_bfd;
if (avr_link_relax)
elf_elfheader (abfd)->e_flags |= EF_AVR_LINKRELAX_PREPARED;
else
elf_elfheader (abfd)->e_flags &= ~EF_AVR_LINKRELAX_PREPARED;
finish_default ();
}
EOF
PARSE_AND_LIST_PROLOGUE='
#define OPTION_NO_CALL_RET_REPLACEMENT 301
#define OPTION_PMEM_WRAP_AROUND 302
#define OPTION_NO_STUBS 303
#define OPTION_DEBUG_STUBS 304
#define OPTION_DEBUG_RELAX 305
'
PARSE_AND_LIST_LONGOPTS='
{ "no-call-ret-replacement", no_argument,
NULL, OPTION_NO_CALL_RET_REPLACEMENT},
{ "pmem-wrap-around", required_argument,
NULL, OPTION_PMEM_WRAP_AROUND},
{ "no-stubs", no_argument,
NULL, OPTION_NO_STUBS},
{ "debug-stubs", no_argument,
NULL, OPTION_DEBUG_STUBS},
{ "debug-relax", no_argument,
NULL, OPTION_DEBUG_RELAX},
'
PARSE_AND_LIST_OPTIONS='
fprintf (file, _(" --pmem-wrap-around=<val> "
"Make the linker relaxation machine assume that a\n"
" "
" program counter wrap-around occures at address\n"
" "
" <val>. Supported values: 8k, 16k, 32k and 64k.\n"));
fprintf (file, _(" --no-call-ret-replacement "
"The relaxation machine normally will\n"
" "
" substitute two immediately following call/ret\n"
" "
" instructions by a single jump instruction.\n"
" "
" This option disables this optimization.\n"));
fprintf (file, _(" --no-stubs "
"If the linker detects to attempt to access\n"
" "
" an instruction beyond 128k by a reloc that\n"
" "
" is limited to 128k max, it inserts a jump\n"
" "
" stub. You can de-active this with this switch.\n"));
fprintf (file, _(" --debug-stubs "
"Used for debugging avr-ld.\n"));
fprintf (file, _(" --debug-relax "
"Used for debugging avr-ld.\n"));
'
PARSE_AND_LIST_ARGS_CASES='
case OPTION_PMEM_WRAP_AROUND:
{
/* This variable is defined in the bfd library. */
if ((!strcmp (optarg,"32k")) || (!strcmp (optarg,"32K")))
avr_pc_wrap_around = 32768;
else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K")))
avr_pc_wrap_around = 8192;
else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K")))
avr_pc_wrap_around = 16384;
else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K")))
avr_pc_wrap_around = 0x10000;
else
return FALSE;
}
break;
case OPTION_DEBUG_STUBS:
avr_debug_stubs = TRUE;
break;
case OPTION_DEBUG_RELAX:
avr_debug_relax = TRUE;
break;
case OPTION_NO_STUBS:
avr_no_stubs = TRUE;
break;
case OPTION_NO_CALL_RET_REPLACEMENT:
{
/* This variable is defined in the bfd library. */
avr_replace_call_ret_sequences = FALSE;
}
break;
'
#
# Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation
#
LDEMUL_BEFORE_PARSE=avr_elf_before_parse
LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation
LDEMUL_AFTER_ALLOCATION=avr_elf_after_allocation
LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements
LDEMUL_FINISH=avr_finish
|
