| 1 | /* Target-dependent code for Motorola 68000 BSD's. |
| 2 | |
| 3 | Copyright (C) 2004-2016 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "arch-utils.h" |
| 22 | #include "frame.h" |
| 23 | #include "osabi.h" |
| 24 | #include "regcache.h" |
| 25 | #include "regset.h" |
| 26 | #include "trad-frame.h" |
| 27 | #include "tramp-frame.h" |
| 28 | #include "gdbtypes.h" |
| 29 | |
| 30 | #include "m68k-tdep.h" |
| 31 | #include "solib-svr4.h" |
| 32 | |
| 33 | /* Core file support. */ |
| 34 | |
| 35 | /* Sizeof `struct reg' in <machine/reg.h>. */ |
| 36 | #define M68KBSD_SIZEOF_GREGS (18 * 4) |
| 37 | |
| 38 | /* Sizeof `struct fpreg' in <machine/reg.h. */ |
| 39 | #define M68KBSD_SIZEOF_FPREGS (((8 * 3) + 3) * 4) |
| 40 | |
| 41 | int |
| 42 | m68kbsd_fpreg_offset (struct gdbarch *gdbarch, int regnum) |
| 43 | { |
| 44 | int fp_len = TYPE_LENGTH (gdbarch_register_type (gdbarch, regnum)); |
| 45 | |
| 46 | if (regnum >= M68K_FPC_REGNUM) |
| 47 | return 8 * fp_len + (regnum - M68K_FPC_REGNUM) * 4; |
| 48 | |
| 49 | return (regnum - M68K_FP0_REGNUM) * fp_len; |
| 50 | } |
| 51 | |
| 52 | /* Supply register REGNUM from the buffer specified by FPREGS and LEN |
| 53 | in the floating-point register set REGSET to register cache |
| 54 | REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ |
| 55 | |
| 56 | static void |
| 57 | m68kbsd_supply_fpregset (const struct regset *regset, |
| 58 | struct regcache *regcache, |
| 59 | int regnum, const void *fpregs, size_t len) |
| 60 | { |
| 61 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 62 | const gdb_byte *regs = (const gdb_byte *) fpregs; |
| 63 | int i; |
| 64 | |
| 65 | gdb_assert (len >= M68KBSD_SIZEOF_FPREGS); |
| 66 | |
| 67 | for (i = M68K_FP0_REGNUM; i <= M68K_PC_REGNUM; i++) |
| 68 | { |
| 69 | if (regnum == i || regnum == -1) |
| 70 | regcache_raw_supply (regcache, i, |
| 71 | regs + m68kbsd_fpreg_offset (gdbarch, i)); |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | /* Supply register REGNUM from the buffer specified by GREGS and LEN |
| 76 | in the general-purpose register set REGSET to register cache |
| 77 | REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ |
| 78 | |
| 79 | static void |
| 80 | m68kbsd_supply_gregset (const struct regset *regset, |
| 81 | struct regcache *regcache, |
| 82 | int regnum, const void *gregs, size_t len) |
| 83 | { |
| 84 | const gdb_byte *regs = (const gdb_byte *) gregs; |
| 85 | int i; |
| 86 | |
| 87 | gdb_assert (len >= M68KBSD_SIZEOF_GREGS); |
| 88 | |
| 89 | for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++) |
| 90 | { |
| 91 | if (regnum == i || regnum == -1) |
| 92 | regcache_raw_supply (regcache, i, regs + i * 4); |
| 93 | } |
| 94 | |
| 95 | if (len >= M68KBSD_SIZEOF_GREGS + M68KBSD_SIZEOF_FPREGS) |
| 96 | { |
| 97 | regs += M68KBSD_SIZEOF_GREGS; |
| 98 | len -= M68KBSD_SIZEOF_GREGS; |
| 99 | m68kbsd_supply_fpregset (regset, regcache, regnum, regs, len); |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | /* Motorola 68000 register sets. */ |
| 104 | |
| 105 | static const struct regset m68kbsd_gregset = |
| 106 | { |
| 107 | NULL, |
| 108 | m68kbsd_supply_gregset, |
| 109 | NULL, |
| 110 | REGSET_VARIABLE_SIZE |
| 111 | }; |
| 112 | |
| 113 | static const struct regset m68kbsd_fpregset = |
| 114 | { |
| 115 | NULL, |
| 116 | m68kbsd_supply_fpregset |
| 117 | }; |
| 118 | |
| 119 | /* Iterate over core file register note sections. */ |
| 120 | |
| 121 | static void |
| 122 | m68kbsd_iterate_over_regset_sections (struct gdbarch *gdbarch, |
| 123 | iterate_over_regset_sections_cb *cb, |
| 124 | void *cb_data, |
| 125 | const struct regcache *regcache) |
| 126 | { |
| 127 | cb (".reg", M68KBSD_SIZEOF_GREGS, &m68kbsd_gregset, NULL, cb_data); |
| 128 | cb (".reg2", M68KBSD_SIZEOF_FPREGS, &m68kbsd_fpregset, NULL, cb_data); |
| 129 | } |
| 130 | \f |
| 131 | |
| 132 | /* Signal trampolines. */ |
| 133 | |
| 134 | static void |
| 135 | m68kobsd_sigtramp_cache_init (const struct tramp_frame *self, |
| 136 | struct frame_info *this_frame, |
| 137 | struct trad_frame_cache *this_cache, |
| 138 | CORE_ADDR func) |
| 139 | { |
| 140 | CORE_ADDR addr, base, pc; |
| 141 | int regnum; |
| 142 | |
| 143 | base = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM); |
| 144 | |
| 145 | /* The 'addql #4,%sp' instruction at offset 8 adjusts the stack |
| 146 | pointer. Adjust the frame base accordingly. */ |
| 147 | pc = get_frame_register_unsigned (this_frame, M68K_PC_REGNUM); |
| 148 | if ((pc - func) > 8) |
| 149 | base -= 4; |
| 150 | |
| 151 | /* Get frame pointer, stack pointer, program counter and processor |
| 152 | state from `struct sigcontext'. */ |
| 153 | addr = get_frame_memory_unsigned (this_frame, base + 8, 4); |
| 154 | trad_frame_set_reg_addr (this_cache, M68K_FP_REGNUM, addr + 8); |
| 155 | trad_frame_set_reg_addr (this_cache, M68K_SP_REGNUM, addr + 12); |
| 156 | trad_frame_set_reg_addr (this_cache, M68K_PC_REGNUM, addr + 20); |
| 157 | trad_frame_set_reg_addr (this_cache, M68K_PS_REGNUM, addr + 24); |
| 158 | |
| 159 | /* The sc_ap member of `struct sigcontext' points to additional |
| 160 | hardware state. Here we find the missing registers. */ |
| 161 | addr = get_frame_memory_unsigned (this_frame, addr + 16, 4) + 4; |
| 162 | for (regnum = M68K_D0_REGNUM; regnum < M68K_FP_REGNUM; regnum++, addr += 4) |
| 163 | trad_frame_set_reg_addr (this_cache, regnum, addr); |
| 164 | |
| 165 | /* Construct the frame ID using the function start. */ |
| 166 | trad_frame_set_id (this_cache, frame_id_build (base, func)); |
| 167 | } |
| 168 | |
| 169 | static const struct tramp_frame m68kobsd_sigtramp = { |
| 170 | SIGTRAMP_FRAME, |
| 171 | 2, |
| 172 | { |
| 173 | { 0x206f, -1 }, { 0x000c, -1}, /* moveal %sp@(12),%a0 */ |
| 174 | { 0x4e90, -1 }, /* jsr %a0@ */ |
| 175 | { 0x588f, -1 }, /* addql #4,%sp */ |
| 176 | { 0x4e41, -1 }, /* trap #1 */ |
| 177 | { 0x2f40, -1 }, { 0x0004, -1 }, /* moveal %d0,%sp@(4) */ |
| 178 | { 0x7001, -1 }, /* moveq #SYS_exit,%d0 */ |
| 179 | { 0x4e40, -1 }, /* trap #0 */ |
| 180 | { TRAMP_SENTINEL_INSN, -1 } |
| 181 | }, |
| 182 | m68kobsd_sigtramp_cache_init |
| 183 | }; |
| 184 | \f |
| 185 | |
| 186 | static void |
| 187 | m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 188 | { |
| 189 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 190 | |
| 191 | tdep->jb_pc = 5; |
| 192 | tdep->jb_elt_size = 4; |
| 193 | |
| 194 | set_gdbarch_decr_pc_after_break (gdbarch, 2); |
| 195 | |
| 196 | set_gdbarch_iterate_over_regset_sections |
| 197 | (gdbarch, m68kbsd_iterate_over_regset_sections); |
| 198 | } |
| 199 | |
| 200 | /* OpenBSD and NetBSD a.out. */ |
| 201 | |
| 202 | static void |
| 203 | m68kbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 204 | { |
| 205 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 206 | |
| 207 | m68kbsd_init_abi (info, gdbarch); |
| 208 | |
| 209 | tdep->struct_return = reg_struct_return; |
| 210 | |
| 211 | tramp_frame_prepend_unwinder (gdbarch, &m68kobsd_sigtramp); |
| 212 | } |
| 213 | |
| 214 | /* NetBSD ELF. */ |
| 215 | |
| 216 | static void |
| 217 | m68kbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 218 | { |
| 219 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 220 | |
| 221 | m68kbsd_init_abi (info, gdbarch); |
| 222 | |
| 223 | /* NetBSD ELF uses the SVR4 ABI. */ |
| 224 | m68k_svr4_init_abi (info, gdbarch); |
| 225 | tdep->struct_return = pcc_struct_return; |
| 226 | |
| 227 | /* NetBSD ELF uses SVR4-style shared libraries. */ |
| 228 | set_solib_svr4_fetch_link_map_offsets |
| 229 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
| 230 | } |
| 231 | \f |
| 232 | |
| 233 | static enum gdb_osabi |
| 234 | m68kbsd_aout_osabi_sniffer (bfd *abfd) |
| 235 | { |
| 236 | if (strcmp (bfd_get_target (abfd), "a.out-m68k-netbsd") == 0 |
| 237 | || strcmp (bfd_get_target (abfd), "a.out-m68k4k-netbsd") == 0) |
| 238 | return GDB_OSABI_NETBSD_AOUT; |
| 239 | |
| 240 | return GDB_OSABI_UNKNOWN; |
| 241 | } |
| 242 | |
| 243 | static enum gdb_osabi |
| 244 | m68kbsd_core_osabi_sniffer (bfd *abfd) |
| 245 | { |
| 246 | if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0) |
| 247 | return GDB_OSABI_NETBSD_AOUT; |
| 248 | |
| 249 | return GDB_OSABI_UNKNOWN; |
| 250 | } |
| 251 | \f |
| 252 | |
| 253 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 254 | void _initialize_m68kbsd_tdep (void); |
| 255 | |
| 256 | void |
| 257 | _initialize_m68kbsd_tdep (void) |
| 258 | { |
| 259 | gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_aout_flavour, |
| 260 | m68kbsd_aout_osabi_sniffer); |
| 261 | |
| 262 | /* BFD doesn't set a flavour for NetBSD style a.out core files. */ |
| 263 | gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_unknown_flavour, |
| 264 | m68kbsd_core_osabi_sniffer); |
| 265 | |
| 266 | gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_AOUT, |
| 267 | m68kbsd_aout_init_abi); |
| 268 | gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_ELF, |
| 269 | m68kbsd_elf_init_abi); |
| 270 | } |