Add support for AVR6 family

1 files changed, 267 insertions, 0 deletions

diff --git a/ld/emultempl/avrelf.em b/ld/emultempl/avrelf.em
new file mode 100644
index 0000000..ba595e9
--- /dev/null
+++ 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