| 1 | /* i386-nto-tdep.c - i386 specific functionality for QNX Neutrino. |
| 2 | |
| 3 | Copyright 2003 Free Software Foundation, Inc. |
| 4 | |
| 5 | Contributed by QNX Software Systems Ltd. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 2 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program; if not, write to the Free Software |
| 21 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 22 | Boston, MA 02111-1307, USA. */ |
| 23 | |
| 24 | #include "gdb_string.h" |
| 25 | #include "gdb_assert.h" |
| 26 | #include "defs.h" |
| 27 | #include "frame.h" |
| 28 | #include "target.h" |
| 29 | #include "regcache.h" |
| 30 | #include "solib-svr4.h" |
| 31 | #include "i386-tdep.h" |
| 32 | #include "nto-tdep.h" |
| 33 | #include "osabi.h" |
| 34 | #include "i387-tdep.h" |
| 35 | |
| 36 | #ifndef X86_CPU_FXSR |
| 37 | #define X86_CPU_FXSR (1L << 12) |
| 38 | #endif |
| 39 | |
| 40 | /* Why 13? Look in our /usr/include/x86/context.h header at the |
| 41 | x86_cpu_registers structure and you'll see an 'exx' junk register |
| 42 | that is just filler. Don't ask me, ask the kernel guys. */ |
| 43 | #define NUM_GPREGS 13 |
| 44 | |
| 45 | /* Map a GDB register number to an offset in the reg structure. */ |
| 46 | static int regmap[] = { |
| 47 | (7 * 4), /* eax */ |
| 48 | (6 * 4), /* ecx */ |
| 49 | (5 * 4), /* edx */ |
| 50 | (4 * 4), /* ebx */ |
| 51 | (11 * 4), /* esp */ |
| 52 | (2 * 4), /* epb */ |
| 53 | (1 * 4), /* esi */ |
| 54 | (0 * 4), /* edi */ |
| 55 | (8 * 4), /* eip */ |
| 56 | (10 * 4), /* eflags */ |
| 57 | (9 * 4), /* cs */ |
| 58 | (12 * 4), /* ss */ |
| 59 | (-1 * 4) /* filler */ |
| 60 | }; |
| 61 | |
| 62 | /* Given a gdb regno, return the offset into Neutrino's register structure |
| 63 | or -1 if register is unknown. */ |
| 64 | static int |
| 65 | nto_reg_offset (int regno) |
| 66 | { |
| 67 | return (regno >= 0 && regno < NUM_GPREGS) ? regmap[regno] : -1; |
| 68 | } |
| 69 | |
| 70 | static void |
| 71 | i386nto_supply_gregset (char *gpregs) |
| 72 | { |
| 73 | unsigned regno; |
| 74 | int empty = 0; |
| 75 | |
| 76 | for (regno = 0; regno < FP0_REGNUM; regno++) |
| 77 | { |
| 78 | int offset = nto_reg_offset (regno); |
| 79 | if (offset == -1) |
| 80 | supply_register (regno, (char *) &empty); |
| 81 | else |
| 82 | supply_register (regno, gpregs + offset); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | static void |
| 87 | i386nto_supply_fpregset (char *fpregs) |
| 88 | { |
| 89 | if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR) |
| 90 | i387_supply_fxsave (current_regcache, -1, fpregs); |
| 91 | else |
| 92 | i387_supply_fsave (current_regcache, -1, fpregs); |
| 93 | } |
| 94 | |
| 95 | static void |
| 96 | i386nto_supply_regset (int regset, char *data) |
| 97 | { |
| 98 | switch (regset) |
| 99 | { |
| 100 | case NTO_REG_GENERAL: /* QNX has different ordering of GP regs than GDB. */ |
| 101 | i386nto_supply_gregset (data); |
| 102 | break; |
| 103 | case NTO_REG_FLOAT: |
| 104 | i386nto_supply_fpregset (data); |
| 105 | break; |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | static int |
| 110 | i386nto_regset_id (int regno) |
| 111 | { |
| 112 | if (regno == -1) |
| 113 | return NTO_REG_END; |
| 114 | else if (regno < FP0_REGNUM) |
| 115 | return NTO_REG_GENERAL; |
| 116 | else if (regno < FPC_REGNUM) |
| 117 | return NTO_REG_FLOAT; |
| 118 | |
| 119 | return -1; /* Error. */ |
| 120 | } |
| 121 | |
| 122 | static int |
| 123 | i386nto_register_area (int regno, int regset, unsigned *off) |
| 124 | { |
| 125 | int len; |
| 126 | |
| 127 | *off = 0; |
| 128 | if (regset == NTO_REG_GENERAL) |
| 129 | { |
| 130 | if (regno == -1) |
| 131 | return NUM_GPREGS * 4; |
| 132 | |
| 133 | *off = nto_reg_offset (regno); |
| 134 | if (*off == -1) |
| 135 | return 0; |
| 136 | return 4; |
| 137 | } |
| 138 | else if (regset == NTO_REG_FLOAT) |
| 139 | { |
| 140 | unsigned off_adjust, regsize, regset_size; |
| 141 | |
| 142 | if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR) |
| 143 | { |
| 144 | off_adjust = 32; |
| 145 | regsize = 16; |
| 146 | regset_size = 512; |
| 147 | } |
| 148 | else |
| 149 | { |
| 150 | off_adjust = 28; |
| 151 | regsize = 10; |
| 152 | regset_size = 128; |
| 153 | } |
| 154 | |
| 155 | if (regno == -1) |
| 156 | return regset_size; |
| 157 | |
| 158 | *off = (regno - FP0_REGNUM) * regsize + off_adjust; |
| 159 | return 10; |
| 160 | /* Why 10 instead of regsize? GDB only stores 10 bytes per FP |
| 161 | register so if we're sending a register back to the target, |
| 162 | we only want pdebug to write 10 bytes so as not to clobber |
| 163 | the reserved 6 bytes in the fxsave structure. */ |
| 164 | } |
| 165 | return -1; |
| 166 | } |
| 167 | |
| 168 | static int |
| 169 | i386nto_regset_fill (int regset, char *data) |
| 170 | { |
| 171 | if (regset == NTO_REG_GENERAL) |
| 172 | { |
| 173 | int regno; |
| 174 | |
| 175 | for (regno = 0; regno < NUM_GPREGS; regno++) |
| 176 | { |
| 177 | int offset = nto_reg_offset (regno); |
| 178 | if (offset != -1) |
| 179 | regcache_collect (regno, data + offset); |
| 180 | } |
| 181 | } |
| 182 | else if (regset == NTO_REG_FLOAT) |
| 183 | { |
| 184 | if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR) |
| 185 | i387_fill_fxsave (data, -1); |
| 186 | else |
| 187 | i387_fill_fsave (data, -1); |
| 188 | } |
| 189 | else |
| 190 | return -1; |
| 191 | |
| 192 | return 0; |
| 193 | } |
| 194 | |
| 195 | static struct link_map_offsets * |
| 196 | i386nto_svr4_fetch_link_map_offsets (void) |
| 197 | { |
| 198 | static struct link_map_offsets lmo; |
| 199 | static struct link_map_offsets *lmp = NULL; |
| 200 | |
| 201 | if (lmp == NULL) |
| 202 | { |
| 203 | lmp = &lmo; |
| 204 | |
| 205 | lmo.r_debug_size = 8; /* The actual size is 20 bytes, but |
| 206 | only 8 bytes are used. */ |
| 207 | lmo.r_map_offset = 4; |
| 208 | lmo.r_map_size = 4; |
| 209 | |
| 210 | lmo.link_map_size = 20; /* The actual size is 552 bytes, but |
| 211 | only 20 bytes are used. */ |
| 212 | lmo.l_addr_offset = 0; |
| 213 | lmo.l_addr_size = 4; |
| 214 | |
| 215 | lmo.l_name_offset = 4; |
| 216 | lmo.l_name_size = 4; |
| 217 | |
| 218 | lmo.l_next_offset = 12; |
| 219 | lmo.l_next_size = 4; |
| 220 | |
| 221 | lmo.l_prev_offset = 16; |
| 222 | lmo.l_prev_size = 4; |
| 223 | } |
| 224 | |
| 225 | return lmp; |
| 226 | } |
| 227 | |
| 228 | static int |
| 229 | i386nto_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| 230 | { |
| 231 | return name && strcmp ("__signalstub", name) == 0; |
| 232 | } |
| 233 | |
| 234 | #define I386_NTO_SIGCONTEXT_OFFSET 136 |
| 235 | |
| 236 | /* Assuming NEXT_FRAME is a frame following a QNX Neutrino sigtramp |
| 237 | routine, return the address of the associated sigcontext structure. */ |
| 238 | |
| 239 | static CORE_ADDR |
| 240 | i386nto_sigcontext_addr (struct frame_info *next_frame) |
| 241 | { |
| 242 | char buf[4]; |
| 243 | CORE_ADDR sp; |
| 244 | |
| 245 | frame_unwind_register (next_frame, SP_REGNUM, buf); |
| 246 | sp = extract_unsigned_integer (buf, 4); |
| 247 | |
| 248 | return sp + I386_NTO_SIGCONTEXT_OFFSET; |
| 249 | } |
| 250 | |
| 251 | static void |
| 252 | init_i386nto_ops (void) |
| 253 | { |
| 254 | current_nto_target.nto_regset_id = i386nto_regset_id; |
| 255 | current_nto_target.nto_supply_gregset = i386nto_supply_gregset; |
| 256 | current_nto_target.nto_supply_fpregset = i386nto_supply_fpregset; |
| 257 | current_nto_target.nto_supply_altregset = nto_dummy_supply_regset; |
| 258 | current_nto_target.nto_supply_regset = i386nto_supply_regset; |
| 259 | current_nto_target.nto_register_area = i386nto_register_area; |
| 260 | current_nto_target.nto_regset_fill = i386nto_regset_fill; |
| 261 | current_nto_target.nto_fetch_link_map_offsets = |
| 262 | i386nto_svr4_fetch_link_map_offsets; |
| 263 | } |
| 264 | |
| 265 | static void |
| 266 | i386nto_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 267 | { |
| 268 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 269 | |
| 270 | /* NTO uses ELF. */ |
| 271 | i386_elf_init_abi (info, gdbarch); |
| 272 | |
| 273 | /* Neutrino rewinds to look more normal. */ |
| 274 | set_gdbarch_decr_pc_after_break (gdbarch, 0); |
| 275 | |
| 276 | /* NTO has shared libraries. */ |
| 277 | set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section); |
| 278 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
| 279 | |
| 280 | set_gdbarch_pc_in_sigtramp (gdbarch, i386nto_pc_in_sigtramp); |
| 281 | tdep->sigcontext_addr = i386nto_sigcontext_addr; |
| 282 | tdep->sc_pc_offset = 56; |
| 283 | tdep->sc_sp_offset = 68; |
| 284 | |
| 285 | /* Setjmp()'s return PC saved in EDX (5). */ |
| 286 | tdep->jb_pc_offset = 20; /* 5x32 bit ints in. */ |
| 287 | |
| 288 | set_solib_svr4_fetch_link_map_offsets (gdbarch, |
| 289 | i386nto_svr4_fetch_link_map_offsets); |
| 290 | |
| 291 | /* Our loader handles solib relocations slightly differently than svr4. */ |
| 292 | TARGET_SO_RELOCATE_SECTION_ADDRESSES = nto_relocate_section_addresses; |
| 293 | |
| 294 | /* Supply a nice function to find our solibs. */ |
| 295 | TARGET_SO_FIND_AND_OPEN_SOLIB = nto_find_and_open_solib; |
| 296 | |
| 297 | init_i386nto_ops (); |
| 298 | } |
| 299 | |
| 300 | void |
| 301 | _initialize_i386nto_tdep (void) |
| 302 | { |
| 303 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_QNXNTO, |
| 304 | i386nto_init_abi); |
| 305 | } |