| 1 | /* Motorola m68k target-dependent support for GNU/Linux. |
| 2 | |
| 3 | Copyright 1996, 1998, 2000, 2001, 2002, 2003 Free Software Foundation, |
| 4 | Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 21 | Boston, MA 02111-1307, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "gdbcore.h" |
| 25 | #include "doublest.h" |
| 26 | #include "floatformat.h" |
| 27 | #include "frame.h" |
| 28 | #include "target.h" |
| 29 | #include "gdb_string.h" |
| 30 | #include "gdbtypes.h" |
| 31 | #include "osabi.h" |
| 32 | #include "regcache.h" |
| 33 | #include "objfiles.h" |
| 34 | #include "symtab.h" |
| 35 | #include "m68k-tdep.h" |
| 36 | \f |
| 37 | /* Offsets (in target ints) into jmp_buf. */ |
| 38 | |
| 39 | #define M68K_LINUX_JB_ELEMENT_SIZE 4 |
| 40 | #define M68K_LINUX_JB_PC 7 |
| 41 | |
| 42 | /* Check whether insn1 and insn2 are parts of a signal trampoline. */ |
| 43 | |
| 44 | #define IS_SIGTRAMP(insn1, insn2) \ |
| 45 | (/* addaw #20,sp; moveq #119,d0; trap #0 */ \ |
| 46 | (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \ |
| 47 | /* moveq #119,d0; trap #0 */ \ |
| 48 | || insn1 == 0x70774e40) |
| 49 | |
| 50 | #define IS_RT_SIGTRAMP(insn1, insn2) \ |
| 51 | (/* movel #173,d0; trap #0 */ \ |
| 52 | (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \ |
| 53 | /* moveq #82,d0; notb d0; trap #0 */ \ |
| 54 | || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40)) |
| 55 | |
| 56 | /* Return non-zero if PC points into the signal trampoline. For the |
| 57 | sake of m68k_linux_get_sigtramp_info we also distinguish between |
| 58 | non-RT and RT signal trampolines. */ |
| 59 | |
| 60 | static int |
| 61 | m68k_linux_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| 62 | { |
| 63 | CORE_ADDR sp; |
| 64 | char buf[12]; |
| 65 | unsigned long insn0, insn1, insn2; |
| 66 | |
| 67 | if (read_memory_nobpt (pc - 4, buf, sizeof (buf))) |
| 68 | return 0; |
| 69 | insn1 = extract_unsigned_integer (buf + 4, 4); |
| 70 | insn2 = extract_unsigned_integer (buf + 8, 4); |
| 71 | if (IS_SIGTRAMP (insn1, insn2)) |
| 72 | return 1; |
| 73 | if (IS_RT_SIGTRAMP (insn1, insn2)) |
| 74 | return 2; |
| 75 | |
| 76 | insn0 = extract_unsigned_integer (buf, 4); |
| 77 | if (IS_SIGTRAMP (insn0, insn1)) |
| 78 | return 1; |
| 79 | if (IS_RT_SIGTRAMP (insn0, insn1)) |
| 80 | return 2; |
| 81 | |
| 82 | insn0 = ((insn0 << 16) & 0xffffffff) | (insn1 >> 16); |
| 83 | insn1 = ((insn1 << 16) & 0xffffffff) | (insn2 >> 16); |
| 84 | if (IS_SIGTRAMP (insn0, insn1)) |
| 85 | return 1; |
| 86 | if (IS_RT_SIGTRAMP (insn0, insn1)) |
| 87 | return 2; |
| 88 | |
| 89 | return 0; |
| 90 | } |
| 91 | |
| 92 | /* From <asm/sigcontext.h>. */ |
| 93 | static int m68k_linux_sigcontext_reg_offset[M68K_NUM_REGS] = |
| 94 | { |
| 95 | 2 * 4, /* %d0 */ |
| 96 | 3 * 4, /* %d1 */ |
| 97 | -1, /* %d2 */ |
| 98 | -1, /* %d3 */ |
| 99 | -1, /* %d4 */ |
| 100 | -1, /* %d5 */ |
| 101 | -1, /* %d6 */ |
| 102 | -1, /* %d7 */ |
| 103 | 4 * 4, /* %a0 */ |
| 104 | 5 * 4, /* %a1 */ |
| 105 | -1, /* %a2 */ |
| 106 | -1, /* %a3 */ |
| 107 | -1, /* %a4 */ |
| 108 | -1, /* %a5 */ |
| 109 | -1, /* %fp */ |
| 110 | 1 * 4, /* %sp */ |
| 111 | 5 * 4 + 2, /* %sr */ |
| 112 | 6 * 4 + 2, /* %pc */ |
| 113 | 8 * 4, /* %fp0 */ |
| 114 | 11 * 4, /* %fp1 */ |
| 115 | -1, /* %fp2 */ |
| 116 | -1, /* %fp3 */ |
| 117 | -1, /* %fp4 */ |
| 118 | -1, /* %fp5 */ |
| 119 | -1, /* %fp6 */ |
| 120 | -1, /* %fp7 */ |
| 121 | 14 * 4, /* %fpcr */ |
| 122 | 15 * 4, /* %fpsr */ |
| 123 | 16 * 4 /* %fpiaddr */ |
| 124 | }; |
| 125 | |
| 126 | /* From <asm/ucontext.h>. */ |
| 127 | static int m68k_linux_ucontext_reg_offset[M68K_NUM_REGS] = |
| 128 | { |
| 129 | 6 * 4, /* %d0 */ |
| 130 | 7 * 4, /* %d1 */ |
| 131 | 8 * 4, /* %d2 */ |
| 132 | 9 * 4, /* %d3 */ |
| 133 | 10 * 4, /* %d4 */ |
| 134 | 11 * 4, /* %d5 */ |
| 135 | 12 * 4, /* %d6 */ |
| 136 | 13 * 4, /* %d7 */ |
| 137 | 14 * 4, /* %a0 */ |
| 138 | 15 * 4, /* %a1 */ |
| 139 | 16 * 4, /* %a2 */ |
| 140 | 17 * 4, /* %a3 */ |
| 141 | 18 * 4, /* %a4 */ |
| 142 | 19 * 4, /* %a5 */ |
| 143 | 20 * 4, /* %fp */ |
| 144 | 21 * 4, /* %sp */ |
| 145 | 23 * 4, /* %sr */ |
| 146 | 22 * 4, /* %pc */ |
| 147 | 27 * 4, /* %fp0 */ |
| 148 | 30 * 4, /* %fp1 */ |
| 149 | 33 * 4, /* %fp2 */ |
| 150 | 36 * 4, /* %fp3 */ |
| 151 | 39 * 4, /* %fp4 */ |
| 152 | 42 * 4, /* %fp5 */ |
| 153 | 45 * 4, /* %fp6 */ |
| 154 | 48 * 4, /* %fp7 */ |
| 155 | 24 * 4, /* %fpcr */ |
| 156 | 25 * 4, /* %fpsr */ |
| 157 | 26 * 4 /* %fpiaddr */ |
| 158 | }; |
| 159 | |
| 160 | |
| 161 | /* Get info about saved registers in sigtramp. */ |
| 162 | |
| 163 | static struct m68k_sigtramp_info |
| 164 | m68k_linux_get_sigtramp_info (struct frame_info *next_frame) |
| 165 | { |
| 166 | CORE_ADDR sp; |
| 167 | char buf[4]; |
| 168 | struct m68k_sigtramp_info info; |
| 169 | |
| 170 | frame_unwind_register (next_frame, M68K_SP_REGNUM, buf); |
| 171 | sp = extract_unsigned_integer (buf, 4); |
| 172 | |
| 173 | /* Get sigcontext address, it is the third parameter on the stack. */ |
| 174 | info.sigcontext_addr = read_memory_unsigned_integer (sp + 8, 4); |
| 175 | |
| 176 | if (m68k_linux_pc_in_sigtramp (frame_pc_unwind (next_frame), 0) == 2) |
| 177 | info.sc_reg_offset = m68k_linux_ucontext_reg_offset; |
| 178 | else |
| 179 | info.sc_reg_offset = m68k_linux_sigcontext_reg_offset; |
| 180 | return info; |
| 181 | } |
| 182 | |
| 183 | /* Extract from an array REGBUF containing the (raw) register state, a |
| 184 | function return value of TYPE, and copy that, in virtual format, |
| 185 | into VALBUF. */ |
| 186 | |
| 187 | static void |
| 188 | m68k_linux_extract_return_value (struct type *type, struct regcache *regcache, |
| 189 | void *valbuf) |
| 190 | { |
| 191 | int len = TYPE_LENGTH (type); |
| 192 | char buf[M68K_MAX_REGISTER_SIZE]; |
| 193 | |
| 194 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT |
| 195 | && TYPE_NFIELDS (type) == 1) |
| 196 | { |
| 197 | m68k_linux_extract_return_value (TYPE_FIELD_TYPE (type, 0), regcache, |
| 198 | valbuf); |
| 199 | return; |
| 200 | } |
| 201 | |
| 202 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 203 | { |
| 204 | regcache_raw_read (regcache, M68K_FP0_REGNUM, buf); |
| 205 | convert_typed_floating (buf, builtin_type_m68881_ext, valbuf, type); |
| 206 | } |
| 207 | else if (TYPE_CODE (type) == TYPE_CODE_PTR) |
| 208 | regcache_raw_read (regcache, M68K_A0_REGNUM, valbuf); |
| 209 | else |
| 210 | { |
| 211 | if (len <= 4) |
| 212 | { |
| 213 | regcache_raw_read (regcache, M68K_D0_REGNUM, buf); |
| 214 | memcpy (valbuf, buf + (4 - len), len); |
| 215 | } |
| 216 | else if (len <= 8) |
| 217 | { |
| 218 | regcache_raw_read (regcache, M68K_D0_REGNUM, buf); |
| 219 | memcpy (valbuf, buf + (8 - len), len - 4); |
| 220 | regcache_raw_read (regcache, M68K_D1_REGNUM, |
| 221 | (char *) valbuf + (len - 4)); |
| 222 | } |
| 223 | else |
| 224 | internal_error (__FILE__, __LINE__, |
| 225 | "Cannot extract return value of %d bytes long.", len); |
| 226 | } |
| 227 | } |
| 228 | |
| 229 | /* Write into the appropriate registers a function return value stored |
| 230 | in VALBUF of type TYPE, given in virtual format. */ |
| 231 | |
| 232 | static void |
| 233 | m68k_linux_store_return_value (struct type *type, struct regcache *regcache, |
| 234 | const void *valbuf) |
| 235 | { |
| 236 | int len = TYPE_LENGTH (type); |
| 237 | |
| 238 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT |
| 239 | && TYPE_NFIELDS (type) == 1) |
| 240 | { |
| 241 | m68k_linux_store_return_value (TYPE_FIELD_TYPE (type, 0), regcache, |
| 242 | valbuf); |
| 243 | return; |
| 244 | } |
| 245 | |
| 246 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 247 | { |
| 248 | char buf[M68K_MAX_REGISTER_SIZE]; |
| 249 | convert_typed_floating (valbuf, type, buf, builtin_type_m68881_ext); |
| 250 | regcache_raw_write (regcache, M68K_FP0_REGNUM, buf); |
| 251 | } |
| 252 | else if (TYPE_CODE (type) == TYPE_CODE_PTR) |
| 253 | regcache_raw_write (regcache, M68K_A0_REGNUM, valbuf); |
| 254 | else |
| 255 | { |
| 256 | if (len <= 4) |
| 257 | regcache_raw_write_part (regcache, M68K_D0_REGNUM, |
| 258 | 4 - len, len, valbuf); |
| 259 | else if (len <= 8) |
| 260 | { |
| 261 | regcache_raw_write_part (regcache, M68K_D1_REGNUM, 8 - len, |
| 262 | len - 4, valbuf); |
| 263 | regcache_raw_write (regcache, M68K_D0_REGNUM, |
| 264 | (char *) valbuf + (len - 4)); |
| 265 | } |
| 266 | else |
| 267 | internal_error (__FILE__, __LINE__, |
| 268 | "Cannot store return value of %d bytes long.", len); |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | /* Extract from an array REGBUF containing the (raw) register state |
| 273 | the address in which a function should return its structure value, |
| 274 | as a CORE_ADDR. */ |
| 275 | |
| 276 | static CORE_ADDR |
| 277 | m68k_linux_extract_struct_value_address (struct regcache *regcache) |
| 278 | { |
| 279 | char buf[4]; |
| 280 | |
| 281 | regcache_cooked_read (regcache, M68K_A0_REGNUM, buf); |
| 282 | return extract_unsigned_integer (buf, 4); |
| 283 | } |
| 284 | |
| 285 | static void |
| 286 | m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 287 | { |
| 288 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 289 | |
| 290 | tdep->jb_pc = M68K_LINUX_JB_PC; |
| 291 | tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE; |
| 292 | tdep->get_sigtramp_info = m68k_linux_get_sigtramp_info; |
| 293 | tdep->struct_return = reg_struct_return; |
| 294 | |
| 295 | set_gdbarch_extract_return_value (gdbarch, m68k_linux_extract_return_value); |
| 296 | set_gdbarch_store_return_value (gdbarch, m68k_linux_store_return_value); |
| 297 | set_gdbarch_deprecated_extract_struct_value_address (gdbarch, m68k_linux_extract_struct_value_address); |
| 298 | |
| 299 | set_gdbarch_deprecated_pc_in_sigtramp (gdbarch, m68k_linux_pc_in_sigtramp); |
| 300 | |
| 301 | /* Shared library handling. */ |
| 302 | set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section); |
| 303 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
| 304 | } |
| 305 | |
| 306 | void |
| 307 | _initialize_m68k_linux_tdep (void) |
| 308 | { |
| 309 | gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX, |
| 310 | m68k_linux_init_abi); |
| 311 | } |