| /* Target-dependent code for NetBSD/Alpha. |
| Copyright 2002 Free Software Foundation, Inc. |
| Contributed by Wasabi Systems, 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 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. */ |
| |
| #include "defs.h" |
| #include "gdbcore.h" |
| #include "frame.h" |
| #include "regcache.h" |
| #include "value.h" |
| |
| #include "solib-svr4.h" |
| |
| #include "alpha-tdep.h" |
| #include "alphabsd-tdep.h" |
| #include "nbsd-tdep.h" |
| |
| static void |
| fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which, |
| CORE_ADDR ignore) |
| { |
| char *regs, *fpregs; |
| int regno; |
| |
| /* Table to map a gdb register number to a trapframe register index. */ |
| static const int regmap[] = |
| { |
| 0, 1, 2, 3, |
| 4, 5, 6, 7, |
| 8, 9, 10, 11, |
| 12, 13, 14, 15, |
| 30, 31, 32, 16, |
| 17, 18, 19, 20, |
| 21, 22, 23, 24, |
| 25, 29, 26 |
| }; |
| #define SIZEOF_TRAPFRAME (33 * 8) |
| |
| /* We get everything from one section. */ |
| if (which != 0) |
| return; |
| |
| regs = core_reg_sect; |
| fpregs = core_reg_sect + SIZEOF_TRAPFRAME; |
| |
| if (core_reg_size < (SIZEOF_TRAPFRAME + SIZEOF_STRUCT_FPREG)) |
| { |
| warning ("Wrong size register set in core file."); |
| return; |
| } |
| |
| /* Integer registers. */ |
| for (regno = 0; regno < ALPHA_ZERO_REGNUM; regno++) |
| supply_register (regno, regs + (regmap[regno] * 8)); |
| supply_register (ALPHA_ZERO_REGNUM, NULL); |
| supply_register (FP_REGNUM, NULL); |
| supply_register (PC_REGNUM, regs + (28 * 8)); |
| |
| /* Floating point registers. */ |
| alphabsd_supply_fpreg (fpregs, -1); |
| } |
| |
| static void |
| fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size, int which, |
| CORE_ADDR ignore) |
| { |
| switch (which) |
| { |
| case 0: /* Integer registers. */ |
| if (core_reg_size != SIZEOF_STRUCT_REG) |
| warning ("Wrong size register set in core file."); |
| else |
| alphabsd_supply_reg (core_reg_sect, -1); |
| break; |
| |
| case 2: /* Floating point registers. */ |
| if (core_reg_size != SIZEOF_STRUCT_FPREG) |
| warning ("Wrong size FP register set in core file."); |
| else |
| alphabsd_supply_fpreg (core_reg_sect, -1); |
| break; |
| |
| default: |
| /* Don't know what kind of register request this is; just ignore it. */ |
| break; |
| } |
| } |
| |
| static struct core_fns alphanbsd_core_fns = |
| { |
| bfd_target_unknown_flavour, /* core_flavour */ |
| default_check_format, /* check_format */ |
| default_core_sniffer, /* core_sniffer */ |
| fetch_core_registers, /* core_read_registers */ |
| NULL /* next */ |
| }; |
| |
| static struct core_fns alphanbsd_elfcore_fns = |
| { |
| bfd_target_elf_flavour, /* core_flavour */ |
| default_check_format, /* check_format */ |
| default_core_sniffer, /* core_sniffer */ |
| fetch_elfcore_registers, /* core_read_registers */ |
| NULL /* next */ |
| }; |
| |
| /* Under NetBSD/alpha, signal handler invocations can be identified by the |
| designated code sequence that is used to return from a signal handler. |
| In particular, the return address of a signal handler points to the |
| following code sequence: |
| |
| ldq a0, 0(sp) |
| lda sp, 16(sp) |
| lda v0, 295(zero) # __sigreturn14 |
| call_pal callsys |
| |
| Each instruction has a unique encoding, so we simply attempt to match |
| the instruction the PC is pointing to with any of the above instructions. |
| If there is a hit, we know the offset to the start of the designated |
| sequence and can then check whether we really are executing in the |
| signal trampoline. If not, -1 is returned, otherwise the offset from the |
| start of the return sequence is returned. */ |
| static const unsigned char sigtramp_retcode[] = |
| { |
| 0x00, 0x00, 0x1e, 0xa6, /* ldq a0, 0(sp) */ |
| 0x10, 0x00, 0xde, 0x23, /* lda sp, 16(sp) */ |
| 0x27, 0x01, 0x1f, 0x20, /* lda v0, 295(zero) */ |
| 0x83, 0x00, 0x00, 0x00, /* call_pal callsys */ |
| }; |
| #define RETCODE_NWORDS 4 |
| #define RETCODE_SIZE (RETCODE_NWORDS * 4) |
| |
| LONGEST |
| alphanbsd_sigtramp_offset (CORE_ADDR pc) |
| { |
| unsigned char ret[RETCODE_SIZE], w[4]; |
| LONGEST off; |
| int i; |
| |
| if (read_memory_nobpt (pc, (char *) w, 4) != 0) |
| return -1; |
| |
| for (i = 0; i < RETCODE_NWORDS; i++) |
| { |
| if (memcmp (w, sigtramp_retcode + (i * 4), 4) == 0) |
| break; |
| } |
| if (i == RETCODE_NWORDS) |
| return (-1); |
| |
| off = i * 4; |
| pc -= off; |
| |
| if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0) |
| return -1; |
| |
| if (memcmp (ret, sigtramp_retcode, RETCODE_SIZE) == 0) |
| return off; |
| |
| return -1; |
| } |
| |
| static int |
| alphanbsd_pc_in_sigtramp (CORE_ADDR pc, char *func_name) |
| { |
| return (nbsd_pc_in_sigtramp (pc, func_name) |
| || alphanbsd_sigtramp_offset (pc) >= 0); |
| } |
| |
| static CORE_ADDR |
| alphanbsd_sigcontext_addr (struct frame_info *frame) |
| { |
| /* FIXME: This is not correct for all versions of NetBSD/alpha. |
| We will probably need to disassemble the trampoline to figure |
| out which trampoline frame type we have. */ |
| return frame->frame; |
| } |
| |
| static CORE_ADDR |
| alphanbsd_skip_sigtramp_frame (struct frame_info *frame, CORE_ADDR pc) |
| { |
| char *name; |
| |
| /* FIXME: This is not correct for all versions of NetBSD/alpha. |
| We will probably need to disassemble the trampoline to figure |
| out which trampoline frame type we have. */ |
| find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL); |
| if (PC_IN_SIGTRAMP (pc, name)) |
| return frame->frame; |
| return 0; |
| } |
| |
| static void |
| alphanbsd_init_abi (struct gdbarch_info info, |
| struct gdbarch *gdbarch) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| |
| set_gdbarch_pc_in_sigtramp (gdbarch, alphanbsd_pc_in_sigtramp); |
| |
| /* NetBSD/alpha does not provide single step support via ptrace(2); we |
| must use software single-stepping. */ |
| set_gdbarch_software_single_step (gdbarch, alpha_software_single_step); |
| |
| set_solib_svr4_fetch_link_map_offsets (gdbarch, |
| nbsd_lp64_solib_svr4_fetch_link_map_offsets); |
| |
| tdep->skip_sigtramp_frame = alphanbsd_skip_sigtramp_frame; |
| tdep->dynamic_sigtramp_offset = alphanbsd_sigtramp_offset; |
| tdep->sigcontext_addr = alphanbsd_sigcontext_addr; |
| |
| tdep->jb_pc = 2; |
| tdep->jb_elt_size = 8; |
| } |
| |
| void |
| _initialize_alphanbsd_tdep (void) |
| { |
| gdbarch_register_osabi (bfd_arch_alpha, GDB_OSABI_NETBSD_ELF, |
| alphanbsd_init_abi); |
| |
| add_core_fns (&alphanbsd_core_fns); |
| add_core_fns (&alphanbsd_elfcore_fns); |
| } |