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authorNick Clifton <nickc@redhat.com>2006-05-24 07:36:12 +0000
committerNick Clifton <nickc@redhat.com>2006-05-24 07:36:12 +0000
commit28c9d252b48e5c262359910389f157de087060d6 (patch)
tree8a03a8b466f84f1857399df1447d6f74e5a1cd5e /ld/emultempl/avrelf.em
parentf607ec8858a8ce6a1a821257d657db95ee47af2a (diff)
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Add support for AVR6 family
Diffstat (limited to 'ld/emultempl/avrelf.em')
-rw-r--r--ld/emultempl/avrelf.em267
1 files changed, 267 insertions, 0 deletions
diff --git a/ld/emultempl/avrelf.em b/ld/emultempl/avrelf.em
new file mode 100644
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+++ b/ld/emultempl/avrelf.em
@@ -0,0 +1,267 @@
+# This shell script emits a C file. -*- C -*-
+# Copyright 2006
+# Free Software Foundation, Inc.
+#
+# This file is part of GLD, the Gnu Linker.
+#
+# 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 2 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 devices where one needs to address the issue that it is not possible
+# to reach the whole program memory by using 16 bit pointers.
+
+cat >>e${EMULATION_NAME}.c <<EOF
+
+#include "elf32-avr.h"
+#include "ldctor.h"
+
+/* The fake file and it's corresponding section meant to hold
+ the linker stubs if needed. */
+
+static lang_input_statement_type *stub_file;
+static asection *avr_stub_section;
+
+/* Variables set by the command-line parameters and transfered
+ to the bfd without use of global shared variables. */
+
+static bfd_boolean avr_no_stubs = FALSE;
+static bfd_boolean avr_debug_relax = FALSE;
+static bfd_boolean avr_debug_stubs = FALSE;
+static bfd_boolean avr_replace_call_ret_sequences = TRUE;
+static bfd_vma avr_pc_wrap_around = 0x10000000;
+
+/* Transfers information to the bfd frontend. */
+
+static void
+avr_elf_set_global_bfd_parameters (void)
+{
+ elf32_avr_setup_params (& link_info,
+ stub_file->the_bfd,
+ avr_stub_section,
+ avr_no_stubs,
+ avr_debug_stubs,
+ avr_debug_relax,
+ avr_pc_wrap_around,
+ avr_replace_call_ret_sequences);
+}
+
+
+/* Makes a conservative estimate of the trampoline section size that could
+ be corrected later on. */
+
+static void
+avr_elf_${EMULATION_NAME}_before_allocation (void)
+{
+ int ret;
+
+ gld${EMULATION_NAME}_before_allocation ();
+
+ /* We only need stubs for the avr6 family. */
+ if (strcmp ("${EMULATION_NAME}","avr6"))
+ 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 (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 (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", output_bfd);
+ if (stub_file->the_bfd == NULL
+ || !bfd_set_arch_mach (stub_file->the_bfd,
+ bfd_get_arch (output_bfd),
+ bfd_get_mach (output_bfd)))
+ {
+ einfo ("%X%P: can not create stub BFD %E\n");
+ return;
+ }
+
+ /* Now we add the stub section. */
+
+ avr_stub_section = bfd_make_section_anyway (stub_file->the_bfd,
+ ".trampolines");
+ if (avr_stub_section == NULL)
+ goto err_ret;
+
+ flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
+ | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
+ if (!bfd_set_section_flags (stub_file->the_bfd, avr_stub_section, flags))
+ 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_finish (void)
+{
+ if (!avr_no_stubs)
+ {
+ /* Now build the linker stubs. */
+ if (stub_file->the_bfd->sections != NULL)
+ {
+ /* Call again the trampoline analyzer to initialize the trampoline
+ stubs with the correct symbol addresses. Since there could have
+ been relaxation, the symbol addresses that were found during
+ first call may no longer be correct. */
+ if (!elf32_avr_size_stubs (output_bfd, &link_info, FALSE))
+ {
+ einfo ("%X%P: can not size stub section: %E\n");
+ return;
+ }
+
+ if (!elf32_avr_build_stubs (&link_info))
+ einfo ("%X%P: can not build stubs: %E\n");
+ }
+ }
+
+ gld${EMULATION_NAME}_finish ();
+}
+
+
+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 are 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,"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_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation
+LDEMUL_FINISH=avr_elf_finish
+LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements