diff options
Diffstat (limited to 'ld/emultempl')
| -rw-r--r-- | ld/emultempl/avrelf.em | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/ld/emultempl/avrelf.em b/ld/emultempl/avrelf.em new file mode 100644 index 0000000000..ba595e9309 --- /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 |
