/* ARM Symbian OS target support. Copyright (C) 2008-2019 Free Software Foundation, Inc. This file is part of GDB. 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 3 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, see <http://www.gnu.org/licenses/>. */ #include "defs.h" #include "frame.h" #include "objfiles.h" #include "osabi.h" #include "solib.h" #include "solib-target.h" #include "target.h" #include "elf-bfd.h" /* If PC is in a DLL import stub, return the address of the `real' function belonging to the stub. */ static CORE_ADDR arm_symbian_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) { struct gdbarch *gdbarch; enum bfd_endian byte_order; ULONGEST insn; CORE_ADDR dest; gdb_byte buf[4]; if (!in_plt_section (pc)) return 0; if (target_read_memory (pc, buf, 4) != 0) return 0; gdbarch = get_frame_arch (frame); byte_order = gdbarch_byte_order (gdbarch); /* ldr pc, [pc, #-4]. */ insn = extract_unsigned_integer (buf, 4, byte_order); if (insn != 0xe51ff004) return 0; if (target_read_memory (pc + 4, buf, 4) != 0) return 0; dest = extract_unsigned_integer (buf, 4, byte_order); return gdbarch_addr_bits_remove (gdbarch, dest); } static void arm_symbian_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { /* Shared library handling. */ set_gdbarch_skip_trampoline_code (gdbarch, arm_symbian_skip_trampoline_code); /* On this target, the toolchain outputs ELF files, with `sym' for filename extension (e.g., `FOO.sym'); these are post-linker processed into PE-ish DLLs (e.g., `FOO.dll'), and it's these that are actually copied to and run on the target. Naturally, when listing shared libraries, Symbian stubs report the DLL filenames. Setting this makes it so that GDB automatically looks for the corresponding ELF files on the host's filesystem. */ set_gdbarch_solib_symbols_extension (gdbarch, "sym"); /* Canonical paths on this target look like `c:\sys\bin\bar.dll', for example. */ set_gdbarch_has_dos_based_file_system (gdbarch, 1); set_solib_ops (gdbarch, &solib_target_so_ops); } /* Recognize Symbian object files. */ static enum gdb_osabi arm_symbian_osabi_sniffer (bfd *abfd) { Elf_Internal_Phdr *phdrs; long phdrs_size; int num_phdrs, i; /* Symbian executables are always shared objects (ET_DYN). */ if (elf_elfheader (abfd)->e_type == ET_EXEC) return GDB_OSABI_UNKNOWN; if (elf_elfheader (abfd)->e_ident[EI_OSABI] != ELFOSABI_NONE) return GDB_OSABI_UNKNOWN; /* Check for the ELF headers not being part of any PT_LOAD segment. Symbian is the only GDB supported (or GNU binutils supported) ARM target which uses a postlinker to flatten ELF files, dropping the ELF dynamic info in the process. */ phdrs_size = bfd_get_elf_phdr_upper_bound (abfd); if (phdrs_size == -1) return GDB_OSABI_UNKNOWN; phdrs = (Elf_Internal_Phdr *) alloca (phdrs_size); num_phdrs = bfd_get_elf_phdrs (abfd, phdrs); if (num_phdrs == -1) return GDB_OSABI_UNKNOWN; for (i = 0; i < num_phdrs; i++) if (phdrs[i].p_type == PT_LOAD && phdrs[i].p_offset == 0) return GDB_OSABI_UNKNOWN; /* Looks like a Symbian binary. */ return GDB_OSABI_SYMBIAN; } void _initialize_arm_symbian_tdep (void) { gdbarch_register_osabi_sniffer (bfd_arch_arm, bfd_target_elf_flavour, arm_symbian_osabi_sniffer); gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_SYMBIAN, arm_symbian_init_abi); }