[patch] to ld: embedded relocs for m68k ELF, part 2 of 2
Michael Sokolov
msokolov@ivan.Harhan.ORG
Sun Sep 10 21:01:00 GMT 2000
Hi there,
Here is the ld part of the m68k ELF embedded relocs feature. It must be
installed after the bfd part in my previous posting.
--
Michael Sokolov Harhan Engineering Laboratory
Public Service Agent International Free Computing Task Force
International Engineering and Science Task Force
615 N GOOD LATIMER EXPY STE #4
DALLAS TX 75204-5852 USA
Phone: +1-214-824-7693 (Harhan Eng Lab office)
E-mail: msokolov@ivan.Harhan.ORG (ARPA TCP/SMTP) (UUCP coming soon)
2000-09-10 Michael Sokolov <msokolov@ivan.Harhan.ORG>
* emultempl/m68kelf.em: New file.
* emulparams/m68kelf.sh (EXTRA_EM_FILE): Use it.
* Makefile.am (em68kelf.c): Add dependency on m68kelf.em.
* Makefile.in: Regenerate.
*** /dev/null Sun Sep 10 22:19:55 2000
--- emultempl/m68kelf.em Sun Sep 10 15:35:44 2000
***************
*** 0 ****
--- 1,154 ----
+ # This shell script emits a C file. -*- C -*-
+ # Copyright (C) 2000 Free Software Foundation, Inc.
+ # Written by Michael Sokolov <msokolov@ivan.Harhan.ORG>, based on armelf.em
+ #
+ # 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ #
+
+ # This file is sourced from elf32.em, and defines extra m68k ELF
+ # specific routines.
+ #
+ cat >>e${EMULATION_NAME}.c <<EOF
+
+ static void m68k_elf_after_open PARAMS((void));
+ static void check_sections PARAMS ((bfd *, asection *, PTR));
+ static void m68k_elf_after_allocation PARAMS ((void));
+
+ /* This function is run after all the input files have been opened.
+ We create a .emreloc section for each input file with a non zero
+ .data section. The BFD backend will fill in these sections with
+ magic numbers which can be used to relocate the data section at run
+ time. */
+
+ static void
+ m68k_elf_after_open ()
+ {
+ bfd *abfd;
+
+ /* Call the standard elf routine. */
+ gld${EMULATION_NAME}_after_open ();
+
+ if (! command_line.embedded_relocs
+ || link_info.relocateable)
+ return;
+
+ for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link_next)
+ {
+ asection *datasec;
+
+ /* As first-order business, make sure that each input BFD is ELF. It
+ better be, as we are directly calling a ELF backend function. */
+ if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
+ einfo ("%F%B: all input objects must be ELF for --embedded-relocs\n");
+
+ datasec = bfd_get_section_by_name (abfd, ".data");
+
+ /* Note that we assume that the reloc_count field has already
+ been set up. We could call bfd_get_reloc_upper_bound, but
+ that returns the size of a memory buffer rather than a reloc
+ count. We do not want to call bfd_canonicalize_reloc,
+ because although it would always work it would force us to
+ read in the relocs into BFD canonical form, which would waste
+ a significant amount of time and memory. */
+ if (datasec != NULL && datasec->reloc_count > 0)
+ {
+ asection *relsec;
+
+ relsec = bfd_make_section (abfd, ".emreloc");
+ if (relsec == NULL
+ || ! bfd_set_section_flags (abfd, relsec,
+ (SEC_ALLOC
+ | SEC_LOAD
+ | SEC_HAS_CONTENTS
+ | SEC_IN_MEMORY))
+ || ! bfd_set_section_alignment (abfd, relsec, 2)
+ || ! bfd_set_section_size (abfd, relsec,
+ datasec->reloc_count * 12))
+ einfo ("%F%B: can not create .emreloc section: %E\n");
+ }
+
+ /* Double check that all other data sections are empty, as is
+ required for embedded PIC code. */
+ bfd_map_over_sections (abfd, check_sections, (PTR) datasec);
+ }
+ }
+
+ /* Check that of the data sections, only the .data section has
+ relocs. This is called via bfd_map_over_sections. */
+
+ static void
+ check_sections (abfd, sec, datasec)
+ bfd *abfd;
+ asection *sec;
+ PTR datasec;
+ {
+ if ((bfd_get_section_flags (abfd, sec) & SEC_DATA)
+ && sec != (asection *) datasec
+ && sec->reloc_count != 0)
+ einfo ("%B%X: section %s has relocs; can not use --embedded-relocs\n",
+ abfd, bfd_get_section_name (abfd, sec));
+ }
+
+ /* This function is called after the section sizes and offsets have
+ been set. If we are generating embedded relocs, it calls a special
+ BFD backend routine to do the work. */
+
+ static void
+ m68k_elf_after_allocation ()
+ {
+ bfd *abfd;
+
+ /* Call the standard elf routine. */
+ gld${EMULATION_NAME}_before_allocation ();
+
+ if (! command_line.embedded_relocs
+ || link_info.relocateable)
+ return;
+
+ for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link_next)
+ {
+ asection *datasec, *relsec;
+ char *errmsg;
+
+ datasec = bfd_get_section_by_name (abfd, ".data");
+
+ if (datasec == NULL || datasec->reloc_count == 0)
+ continue;
+
+ relsec = bfd_get_section_by_name (abfd, ".emreloc");
+ ASSERT (relsec != NULL);
+
+ if (! bfd_m68k_elf32_create_embedded_relocs (abfd, &link_info,
+ datasec, relsec,
+ &errmsg))
+ {
+ if (errmsg == NULL)
+ einfo ("%B%X: can not create runtime reloc information: %E\n",
+ abfd);
+ else
+ einfo ("%X%B: can not create runtime reloc information: %s\n",
+ abfd, errmsg);
+ }
+ }
+ }
+
+ EOF
+
+ # We have our own after_open and after_allocation functions, but they call
+ # the standard routines, so give them a different name.
+ LDEMUL_AFTER_OPEN=m68k_elf_after_open
+ LDEMUL_AFTER_ALLOCATION=m68k_elf_after_allocation
Index: emulparams/m68kelf.sh
===================================================================
RCS file: /cvs/src/src/ld/emulparams/m68kelf.sh,v
retrieving revision 1.1.1.1
diff -c -r1.1.1.1 m68kelf.sh
*** m68kelf.sh 1999/05/03 07:29:07 1.1.1.1
--- m68kelf.sh 2000/09/11 03:54:50
***************
*** 7,10 ****
--- 7,11 ----
MACHINE=
NOP=0x4e75
TEMPLATE_NAME=elf32
+ EXTRA_EM_FILE=m68kelf
GENERATE_SHLIB_SCRIPT=yes
Index: Makefile.am
===================================================================
RCS file: /cvs/src/src/ld/Makefile.am,v
retrieving revision 1.46
diff -c -r1.46 Makefile.am
*** Makefile.am 2000/09/07 19:52:17 1.46
--- Makefile.am 2000/09/11 03:54:57
***************
*** 615,621 ****
$(srcdir)/emultempl/m68kcoff.em $(srcdir)/scripttempl/m68kcoff.sc ${GEN_DEPENDS}
${GENSCRIPTS} m68kcoff "$(tdir_m68kcoff)"
em68kelf.c: $(srcdir)/emulparams/m68kelf.sh \
! $(srcdir)/emultempl/elf32.em $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
${GENSCRIPTS} m68kelf "$(tdir_m68kelf)"
em68klinux.c: $(srcdir)/emulparams/m68klinux.sh \
$(srcdir)/emultempl/linux.em $(srcdir)/scripttempl/aout.sc ${GEN_DEPENDS}
--- 615,622 ----
$(srcdir)/emultempl/m68kcoff.em $(srcdir)/scripttempl/m68kcoff.sc ${GEN_DEPENDS}
${GENSCRIPTS} m68kcoff "$(tdir_m68kcoff)"
em68kelf.c: $(srcdir)/emulparams/m68kelf.sh \
! $(srcdir)/emultempl/elf32.em $(srcdir)/emultempl/m68kelf.em \
! $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
${GENSCRIPTS} m68kelf "$(tdir_m68kelf)"
em68klinux.c: $(srcdir)/emulparams/m68klinux.sh \
$(srcdir)/emultempl/linux.em $(srcdir)/scripttempl/aout.sc ${GEN_DEPENDS}
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