--- /dev/null
+/* ELF support for BFD.
+ Copyright (C) 1991 Free Software Foundation, Inc.
+
+ Written by Fred Fish @ Cygnus Support, from information published
+ in "UNIX System V Release 4, Programmers Guide: ANSI C and
+ Programming Support Tools".
+
+This file is part of BFD, the Binary File Descriptor library.
+
+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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+
+ /****************************************
+
+ WARNING
+
+ This is only a partial ELF implementation,
+ incorporating only those parts that are
+ required to get gdb up and running. It is
+ expected that it will be expanded to a full
+ ELF implementation at some future date.
+
+ Unimplemented stubs call abort() to ensure
+ that they get proper attention if they are
+ ever called. The stubs are here since
+ this version was hacked from the COFF
+ version, and thus they will probably
+ go away or get expanded appropriately in a
+ future version.
+
+ fnf@cygnus.com
+
+ *****************************************/
+
+
+/* Problems and other issues to resolve.
+
+ (1) BFD expects there to be some fixed number of "sections" in
+ the object file. I.E. there is a "section_count" variable in the
+ bfd structure which contains the number of sections. However, ELF
+ supports multiple "views" of a file. In particular, with current
+ implementations, executable files typically have two tables, a
+ program header table and a section header table, both of which
+ partition the executable.
+
+ In ELF-speak, the "linking view" of the file uses the section header
+ table to access "sections" within the file, and the "execution view"
+ uses the program header table to access "segments" within the file.
+ "Segments" typically may contain all the data from one or more
+ "sections".
+
+ Note that the section header table is optional in ELF executables,
+ but it is this information that is most useful to gdb. If the
+ section header table is missing, then gdb should probably try
+ to make do with the program header table. (FIXME)
+
+*/
+
+#include <ansidecl.h>
+#include <sysdep.h>
+#include "bfd.h"
+#include "libbfd.h"
+#include "obstack.h"
+#include "elf-common.h"
+#include "elf-internal.h"
+#include "elf-external.h"
+
+/* Forward data declarations */
+extern bfd_target elf_little_vec, elf_big_vec;
+
+/* Translate an ELF header in external format into an ELF header in internal
+ format. */
+
+static void
+DEFUN(bfd_swap_ehdr_in,(abfd, src, dst),
+ bfd *abfd AND
+ Elf_External_Ehdr *src AND
+ Elf_Internal_Ehdr *dst)
+{
+ bcopy (src -> e_ident, dst -> e_ident, EI_NIDENT);
+ dst -> e_type = bfd_h_get_16 (abfd, (bfd_byte *) src -> e_type);
+ dst -> e_machine = bfd_h_get_16 (abfd, (bfd_byte *) src -> e_machine);
+ dst -> e_version = bfd_h_get_32 (abfd, (bfd_byte *) src -> e_version);
+ dst -> e_entry = bfd_h_get_32 (abfd, (bfd_byte *) src -> e_entry);
+ dst -> e_phoff = bfd_h_get_32 (abfd, (bfd_byte *) src -> e_phoff);
+ dst -> e_shoff = bfd_h_get_32 (abfd, (bfd_byte *) src -> e_shoff);
+ dst -> e_flags = bfd_h_get_32 (abfd, (bfd_byte *) src -> e_flags);
+ dst -> e_ehsize = bfd_h_get_16 (abfd, (bfd_byte *) src -> e_ehsize);
+ dst -> e_phentsize = bfd_h_get_16 (abfd, (bfd_byte *) src -> e_phentsize);
+ dst -> e_phnum = bfd_h_get_16 (abfd, (bfd_byte *) src -> e_phnum);
+ dst -> e_shentsize = bfd_h_get_16 (abfd, (bfd_byte *) src -> e_shentsize);
+ dst -> e_shnum = bfd_h_get_16 (abfd, (bfd_byte *) src -> e_shnum);
+ dst -> e_shstrndx = bfd_h_get_16 (abfd, (bfd_byte *) src -> e_shstrndx);
+}
+
+
+/* Translate an ELF section header table entry in external format into an
+ ELF section header table entry in internal format. */
+
+static void
+DEFUN(bfd_swap_shdr_in,(abfd, src, dst),
+ bfd *abfd AND
+ Elf_External_Shdr *src AND
+ Elf_Internal_Shdr *dst)
+{
+ dst -> sh_name = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_name);
+ dst -> sh_type = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_type);
+ dst -> sh_flags = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_flags);
+ dst -> sh_addr = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_addr);
+ dst -> sh_offset = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_offset);
+ dst -> sh_size = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_size);
+ dst -> sh_link = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_link);
+ dst -> sh_info = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_info);
+ dst -> sh_addralign = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_addralign);
+ dst -> sh_entsize = bfd_h_get_32 (abfd, (bfd_byte *) src -> sh_entsize);
+}
+
+
+/* Create a new bfd section from an ELF section header. */
+
+static boolean
+DEFUN(bfd_section_from_shdr, (abfd, hdr, shstrtab),
+ bfd *abfd AND
+ Elf_Internal_Shdr *hdr AND
+ char *shstrtab)
+{
+ asection *newsect;
+ char *name;
+
+ name = hdr -> sh_name ? shstrtab + hdr -> sh_name : "unnamed";
+ newsect = bfd_make_section (abfd, name);
+ newsect -> vma = hdr -> sh_addr;
+ newsect -> size = hdr -> sh_size;
+ if (!(hdr -> sh_type == SHT_NOBITS))
+ {
+ newsect -> filepos = hdr -> sh_offset;
+ newsect -> flags |= SEC_HAS_CONTENTS;
+ }
+ if (hdr -> sh_flags & SHF_ALLOC)
+ {
+ newsect -> flags |= SEC_ALLOC;
+ if (hdr -> sh_type != SHT_NOBITS)
+ {
+ newsect -> flags |= SEC_LOAD;
+ }
+ }
+ if (!(hdr -> sh_flags & SHF_WRITE))
+ {
+ newsect -> flags |= SEC_READONLY;
+ }
+ if (hdr -> sh_flags & SHF_EXECINSTR)
+ {
+ newsect -> flags |= SEC_CODE; /* FIXME: may only contain SOME code */
+ }
+ if (hdr -> sh_type == SHT_SYMTAB)
+ {
+ abfd -> flags |= HAS_SYMS;
+ }
+
+ return (true);
+}
+
+/* Begin processing a given object.
+
+ First we validate the file by reading in the ELF header and checking
+ the magic number.
+
+ */
+
+static bfd_target *
+DEFUN (elf_object_p, (abfd), bfd *abfd)
+{
+ Elf_External_Ehdr x_ehdr; /* Elf file header, external form */
+ Elf_Internal_Ehdr i_ehdr; /* Elf file header, internal form */
+ Elf_External_Shdr *x_shdr; /* Section header table, external form */
+ Elf_Internal_Shdr *i_shdr; /* Section header table, internal form */
+ int shindex;
+ char *shstrtab; /* Internal copy of section header stringtab */
+ int shstrtabsize; /* Size of section header string table */
+
+ /* Read in the ELF header in external format. */
+
+ if (bfd_read ((PTR) &x_ehdr, sizeof (x_ehdr), 1, abfd) != sizeof (x_ehdr))
+ {
+ bfd_error = system_call_error;
+ return (NULL);
+ }
+
+ /* Now check to see if we have a valid ELF file, and one that BFD can
+ make use of. The magic number must match, the address size ('class')
+ and byte-swapping must match our XVEC entry, and it must have a
+ section header table (FIXME: See comments re sections at top of this
+ file). */
+
+ if (x_ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
+ x_ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
+ x_ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
+ x_ehdr.e_ident[EI_MAG3] != ELFMAG3)
+ {
+wrong:
+ bfd_error = wrong_format;
+ return (NULL);
+ }
+
+ /* FIXME, Check EI_VERSION here ! */
+
+ switch (x_ehdr.e_ident[EI_CLASS]) {
+ case ELFCLASSNONE: /* address size not specified */
+ goto wrong; /* No support if can't tell address size */
+ case ELFCLASS32: /* 32-bit addresses */
+ break;
+ case ELFCLASS64: /* 64-bit addresses */
+ goto wrong; /* FIXME: 64 bits not yet supported */
+ default:
+ goto wrong; /* No support if unknown address class */
+ }
+
+ /* Switch xvec to match the specified byte order. */
+ switch (x_ehdr.e_ident[EI_DATA]) {
+ case ELFDATA2MSB: /* Big-endian */
+ abfd->xvec = &elf_big_vec;
+ break;
+ case ELFDATA2LSB: /* Little-endian */
+ abfd->xvec = &elf_little_vec;
+ case ELFDATANONE: /* No data encoding specified */
+ default: /* Unknown data encoding specified */
+ goto wrong;
+ }
+
+ /* Now that we know the byte order, swap in the rest of the header */
+ bfd_swap_ehdr_in (abfd, &x_ehdr, &i_ehdr);
+ if (x_ehdr.e_shoff == 0)
+ goto wrong;
+
+ if (i_ehdr.e_type == ET_EXEC || i_ehdr.e_type == ET_DYN)
+ {
+ abfd -> flags |= EXEC_P;
+ }
+
+ /* Allocate space for copies of the section header table in external
+ and internal form, seek to the section header table in the file,
+ read it in, and convert it to internal form. As a simple sanity
+ check, verify that the what BFD thinks is the size of each section
+ header table entry actually matches the size recorded in the file. */
+
+ if (i_ehdr.e_shentsize != sizeof (*x_shdr))
+ goto wrong;
+ if ((x_shdr = (Elf_External_Shdr *)
+ bfd_alloc (abfd, sizeof (*x_shdr) * i_ehdr.e_shnum)) == NULL)
+ {
+ bfd_error = no_memory;
+ return (NULL);
+ }
+ if ((i_shdr = (Elf_Internal_Shdr *)
+ bfd_alloc (abfd, sizeof (*i_shdr) * i_ehdr.e_shnum)) == NULL)
+ {
+ bfd_error = no_memory;
+ return (NULL);
+ }
+ if (bfd_seek (abfd, i_ehdr.e_shoff, SEEK_SET) == -1)
+ {
+ bfd_error = system_call_error;
+ return (NULL);
+ }
+ for (shindex = 0; shindex < i_ehdr.e_shnum; shindex++)
+ {
+ if (bfd_read ((PTR) (x_shdr + shindex), sizeof (*x_shdr), 1, abfd)
+ != sizeof (*x_shdr))
+ {
+ bfd_error = system_call_error;
+ return (NULL);
+ }
+ bfd_swap_shdr_in (abfd, x_shdr + shindex, i_shdr + shindex);
+ }
+
+ /* Read in the string table containing the names of the sections. We
+ will need the base pointer to this table later. */
+
+ shstrtabsize = i_shdr[i_ehdr.e_shstrndx].sh_size;
+ if ((shstrtab = bfd_alloc (abfd, shstrtabsize)) == NULL)
+ {
+ bfd_error = no_memory;
+ return (NULL);
+ }
+ if (bfd_seek (abfd, i_shdr[i_ehdr.e_shstrndx].sh_offset, SEEK_SET) == -1)
+ {
+ bfd_error = system_call_error;
+ return (NULL);
+ }
+ if (bfd_read ((PTR) shstrtab, shstrtabsize, 1, abfd) != shstrtabsize)
+ {
+ bfd_error = system_call_error;
+ return (NULL);
+ }
+
+ /* Once all of the section headers have been read and converted, we
+ can start processing them. */
+
+ for (shindex = 0; shindex < i_ehdr.e_shnum; shindex++)
+ {
+ bfd_section_from_shdr (abfd, i_shdr + shindex, shstrtab);
+ }
+
+ return (abfd->xvec);
+}
+
+static boolean
+DEFUN (elf_mkobject, (abfd), bfd *abfd)
+{
+ fprintf (stderr, "elf_mkobject unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (false);
+}
+
+static boolean
+DEFUN (elf_write_object_contents, (abfd), bfd *abfd)
+{
+ fprintf (stderr, "elf_write_object_contents unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (false);
+}
+
+static boolean
+DEFUN (elf_set_section_contents, (abfd, section, location, offset, count),
+ bfd *abfd AND
+ sec_ptr section AND
+ PTR location AND
+ file_ptr offset AND
+ bfd_size_type count)
+{
+ fprintf (stderr, "elf_set_section_contents unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (false);
+}
+
+#define elf_new_section_hook _bfd_dummy_new_section_hook
+#define elf_core_file_failing_command _bfd_dummy_core_file_failing_command
+#define elf_core_file_failing_signal _bfd_dummy_core_file_failing_signal
+#define elf_core_file_matches_executable_p _bfd_dummy_core_file_matches_executable_p
+#define elf_slurp_armap bfd_false
+#define elf_slurp_extended_name_table _bfd_slurp_extended_name_table
+#define elf_truncate_arname bfd_dont_truncate_arname
+#define elf_openr_next_archived_file bfd_generic_openr_next_archived_file
+#define elf_generic_stat_arch_elt bfd_generic_stat_arch_elt
+#define elf_get_section_contents bfd_generic_get_section_contents
+#define elf_close_and_cleanup bfd_generic_close_and_cleanup
+
+#define elf_bfd_debug_info_start bfd_void
+#define elf_bfd_debug_info_end bfd_void
+#define elf_bfd_debug_info_accumulate (PROTO(void,(*),(bfd*, struct sec *))) bfd_void
+
+#define elf_write_armap bfd_false
+
+
+static unsigned int
+elf_get_symtab_upper_bound(abfd)
+bfd *abfd;
+{
+ fprintf (stderr, "elf_get_symtab_upper_bound unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (0);
+}
+
+static unsigned int
+elf_get_reloc_upper_bound (abfd, asect)
+bfd *abfd;
+sec_ptr asect;
+{
+ fprintf (stderr, "elf_get_reloc_upper_bound unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (0);
+}
+
+static unsigned int
+elf_canonicalize_reloc (abfd, section, relptr, symbols)
+bfd *abfd;
+sec_ptr section;
+arelent **relptr;
+asymbol **symbols;
+{
+ fprintf (stderr, "elf_canonicalize_reloc unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (0);
+}
+
+static unsigned int
+elf_get_symtab (abfd, alocation)
+bfd *abfd;
+asymbol **alocation;
+{
+ fprintf (stderr, "elf_get_symtab unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (0);
+}
+
+static asymbol *
+elf_make_empty_symbol(abfd)
+bfd *abfd;
+{
+ fprintf (stderr, "elf_make_empty_symbol unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (NULL);
+}
+
+static void
+DEFUN (elf_print_symbol,(ignore_abfd, filep, symbol, how),
+ bfd *ignore_abfd AND
+ PTR filep AND
+ asymbol *symbol AND
+ bfd_print_symbol_enum_type how)
+{
+ fprintf (stderr, "elf_print_symbol unimplemented\n");
+ fflush (stderr);
+ abort ();
+}
+
+static alent *
+DEFUN (elf_get_lineno,(ignore_abfd, symbol),
+ bfd *ignore_abfd AND
+ asymbol *symbol)
+{
+ fprintf (stderr, "elf_get_lineno unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (NULL);
+}
+
+static boolean
+DEFUN (elf_set_arch_mach,(abfd, arch, machine),
+ bfd *abfd AND
+ enum bfd_architecture arch AND
+ unsigned long machine)
+{
+ fprintf (stderr, "elf_set_arch_mach unimplemented\n");
+ fflush (stderr);
+ /* Allow any architecture to be supported by the elf backend */
+ return bfd_default_set_arch_mach(abfd, arch, machine);
+}
+
+static boolean
+DEFUN (elf_find_nearest_line,(abfd,
+ section,
+ symbols,
+ offset,
+ filename_ptr,
+ functionname_ptr,
+ line_ptr),
+ bfd *abfd AND
+ asection *section AND
+ asymbol **symbols AND
+ bfd_vma offset AND
+ CONST char **filename_ptr AND
+ CONST char **functionname_ptr AND
+ unsigned int *line_ptr)
+{
+ fprintf (stderr, "elf_find_nearest_line unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (false);
+}
+
+static int
+DEFUN (elf_sizeof_headers, (abfd, reloc),
+ bfd *abfd AND
+ boolean reloc)
+{
+ fprintf (stderr, "elf_sizeof_headers unimplemented\n");
+ fflush (stderr);
+ abort ();
+ return (0);
+}
+
+/* This structure contains everything that BFD knows about a target.
+ It includes things like its byte order, name, what routines to call
+ to do various operations, etc. Every BFD points to a target structure
+ with its "xvec" member.
+
+ There are two such structures here: one for big-endian machines and
+ one for little-endian machines. */
+
+bfd_target elf_big_vec =
+{
+ /* name: identify kind of target */
+ "elf-big",
+
+ /* flavour: general indication about file */
+ bfd_target_elf_flavour_enum,
+
+ /* byteorder_big_p: data is big endian */
+ true,
+
+ /* header_byteorder_big_p: header is also big endian */
+ true,
+
+ /* object_flags: mask of all file flags */
+ (HAS_RELOC | EXEC_P | HAS_LINENO | HAS_DEBUG | HAS_SYMS | HAS_LOCALS |
+ DYNAMIC | WP_TEXT),
+
+ /* section_flags: mask of all section flags */
+ (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC | SEC_READONLY |
+ SEC_DATA),
+
+ /* ar_pad_char: pad character for filenames within an archive header
+ FIXME: this really has nothing to do with ELF, this is a characteristic
+ of the archiver and/or os and should be independently tunable */
+ '/',
+
+ /* ar_max_namelen: maximum number of characters in an archive header
+ FIXME: this really has nothing to do with ELF, this is a characteristic
+ of the archiver and should be independently tunable. This value is
+ a WAG (wild a** guess) */
+ 15,
+
+ /* align_power_min: minimum alignment restriction for any section
+ FIXME: this value may be target machine dependent */
+ 3,
+
+ /* Routines to byte-swap various sized integers from the data sections */
+ _do_getb64, _do_putb64, _do_getb32, _do_putb32, _do_getb16, _do_putb16,
+
+ /* Routines to byte-swap various sized integers from the file headers */
+ _do_getb64, _do_putb64, _do_getb32, _do_putb32, _do_getb16, _do_putb16,
+
+ /* bfd_check_format: check the format of a file being read */
+ { _bfd_dummy_target,
+ elf_object_p,
+ bfd_generic_archive_p,
+ _bfd_dummy_target
+ },
+
+ /* bfd_set_format: set the format of a file being written */
+ { bfd_false,
+ elf_mkobject,
+ _bfd_generic_mkarchive,
+ bfd_false
+ },
+
+ /* bfd_write_contents: write cached information into a file being written */
+ { bfd_false,
+ elf_write_object_contents,
+ _bfd_write_archive_contents,
+ bfd_false
+ },
+
+ /* Initialize a jump table with the standard macro. All names start
+ with "elf" */
+ JUMP_TABLE(elf),
+
+ /* SWAP_TABLE */
+ NULL, NULL, NULL
+};
+
+bfd_target elf_little_vec =
+{
+ /* name: identify kind of target */
+ "elf-little",
+
+ /* flavour: general indication about file */
+ bfd_target_elf_flavour_enum,
+
+ /* byteorder_big_p: data is big endian */
+ false, /* Nope -- this one's little endian */
+
+ /* header_byteorder_big_p: header is also big endian */
+ false, /* Nope -- this one's little endian */
+
+ /* object_flags: mask of all file flags */
+ (HAS_RELOC | EXEC_P | HAS_LINENO | HAS_DEBUG | HAS_SYMS | HAS_LOCALS |
+ DYNAMIC | WP_TEXT),
+
+ /* section_flags: mask of all section flags */
+ (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC | SEC_READONLY |
+ SEC_DATA),
+
+ /* ar_pad_char: pad character for filenames within an archive header
+ FIXME: this really has nothing to do with ELF, this is a characteristic
+ of the archiver and/or os and should be independently tunable */
+ '/',
+
+ /* ar_max_namelen: maximum number of characters in an archive header
+ FIXME: this really has nothing to do with ELF, this is a characteristic
+ of the archiver and should be independently tunable. This value is
+ a WAG (wild a** guess) */
+ 15,
+
+ /* align_power_min: minimum alignment restriction for any section
+ FIXME: this value may be target machine dependent */
+ 3,
+
+ /* Routines to byte-swap various sized integers from the data sections */
+ _do_getl64, _do_putl64, _do_getl32, _do_putl32, _do_getl16, _do_putl16,
+
+ /* Routines to byte-swap various sized integers from the file headers */
+ _do_getl64, _do_putl64, _do_getl32, _do_putl32, _do_getl16, _do_putl16,
+
+ /* bfd_check_format: check the format of a file being read */
+ { _bfd_dummy_target,
+ elf_object_p,
+ bfd_generic_archive_p,
+ _bfd_dummy_target
+ },
+
+ /* bfd_set_format: set the format of a file being written */
+ { bfd_false,
+ elf_mkobject,
+ _bfd_generic_mkarchive,
+ bfd_false
+ },
+
+ /* bfd_write_contents: write cached information into a file being written */
+ { bfd_false,
+ elf_write_object_contents,
+ _bfd_write_archive_contents,
+ bfd_false
+ },
+
+ /* Initialize a jump table with the standard macro. All names start
+ with "elf" */
+ JUMP_TABLE(elf),
+
+ /* SWAP_TABLE */
+ NULL, NULL, NULL
+};
projects / binutils-gdb.git / commitdiff