| 1 | /* GNU/Linux/m68k specific low level interface, for the remote server for GDB. |
| 2 | Copyright (C) 1995-2020 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include "server.h" |
| 20 | #include "linux-low.h" |
| 21 | |
| 22 | /* Linux target op definitions for the m68k architecture. */ |
| 23 | |
| 24 | class m68k_target : public linux_process_target |
| 25 | { |
| 26 | public: |
| 27 | |
| 28 | const regs_info *get_regs_info () override; |
| 29 | |
| 30 | const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override; |
| 31 | |
| 32 | protected: |
| 33 | |
| 34 | void low_arch_setup () override; |
| 35 | |
| 36 | bool low_cannot_fetch_register (int regno) override; |
| 37 | |
| 38 | bool low_cannot_store_register (int regno) override; |
| 39 | |
| 40 | bool low_supports_breakpoints () override; |
| 41 | |
| 42 | CORE_ADDR low_get_pc (regcache *regcache) override; |
| 43 | |
| 44 | void low_set_pc (regcache *regcache, CORE_ADDR newpc) override; |
| 45 | |
| 46 | int low_decr_pc_after_break () override; |
| 47 | |
| 48 | bool low_breakpoint_at (CORE_ADDR pc) override; |
| 49 | }; |
| 50 | |
| 51 | /* The singleton target ops object. */ |
| 52 | |
| 53 | static m68k_target the_m68k_target; |
| 54 | |
| 55 | bool |
| 56 | m68k_target::low_supports_breakpoints () |
| 57 | { |
| 58 | return true; |
| 59 | } |
| 60 | |
| 61 | CORE_ADDR |
| 62 | m68k_target::low_get_pc (regcache *regcache) |
| 63 | { |
| 64 | return linux_get_pc_32bit (regcache); |
| 65 | } |
| 66 | |
| 67 | void |
| 68 | m68k_target::low_set_pc (regcache *regcache, CORE_ADDR pc) |
| 69 | { |
| 70 | linux_set_pc_32bit (regcache, pc); |
| 71 | } |
| 72 | |
| 73 | int |
| 74 | m68k_target::low_decr_pc_after_break () |
| 75 | { |
| 76 | return 2; |
| 77 | } |
| 78 | |
| 79 | /* Defined in auto-generated file reg-m68k.c. */ |
| 80 | void init_registers_m68k (void); |
| 81 | extern const struct target_desc *tdesc_m68k; |
| 82 | |
| 83 | #ifdef HAVE_SYS_REG_H |
| 84 | #include <sys/reg.h> |
| 85 | #endif |
| 86 | |
| 87 | #define m68k_num_regs 29 |
| 88 | #define m68k_num_gregs 18 |
| 89 | |
| 90 | /* This table must line up with REGISTER_NAMES in tm-m68k.h */ |
| 91 | static int m68k_regmap[] = |
| 92 | { |
| 93 | #ifdef PT_D0 |
| 94 | PT_D0 * 4, PT_D1 * 4, PT_D2 * 4, PT_D3 * 4, |
| 95 | PT_D4 * 4, PT_D5 * 4, PT_D6 * 4, PT_D7 * 4, |
| 96 | PT_A0 * 4, PT_A1 * 4, PT_A2 * 4, PT_A3 * 4, |
| 97 | PT_A4 * 4, PT_A5 * 4, PT_A6 * 4, PT_USP * 4, |
| 98 | PT_SR * 4, PT_PC * 4, |
| 99 | #else |
| 100 | 14 * 4, 0 * 4, 1 * 4, 2 * 4, 3 * 4, 4 * 4, 5 * 4, 6 * 4, |
| 101 | 7 * 4, 8 * 4, 9 * 4, 10 * 4, 11 * 4, 12 * 4, 13 * 4, 15 * 4, |
| 102 | 17 * 4, 18 * 4, |
| 103 | #endif |
| 104 | #ifdef PT_FP0 |
| 105 | PT_FP0 * 4, PT_FP1 * 4, PT_FP2 * 4, PT_FP3 * 4, |
| 106 | PT_FP4 * 4, PT_FP5 * 4, PT_FP6 * 4, PT_FP7 * 4, |
| 107 | PT_FPCR * 4, PT_FPSR * 4, PT_FPIAR * 4 |
| 108 | #else |
| 109 | 21 * 4, 24 * 4, 27 * 4, 30 * 4, 33 * 4, 36 * 4, |
| 110 | 39 * 4, 42 * 4, 45 * 4, 46 * 4, 47 * 4 |
| 111 | #endif |
| 112 | }; |
| 113 | |
| 114 | bool |
| 115 | m68k_target::low_cannot_store_register (int regno) |
| 116 | { |
| 117 | return (regno >= m68k_num_regs); |
| 118 | } |
| 119 | |
| 120 | bool |
| 121 | m68k_target::low_cannot_fetch_register (int regno) |
| 122 | { |
| 123 | return (regno >= m68k_num_regs); |
| 124 | } |
| 125 | |
| 126 | #ifdef HAVE_PTRACE_GETREGS |
| 127 | #include <sys/procfs.h> |
| 128 | #include "nat/gdb_ptrace.h" |
| 129 | |
| 130 | static void |
| 131 | m68k_fill_gregset (struct regcache *regcache, void *buf) |
| 132 | { |
| 133 | int i; |
| 134 | |
| 135 | for (i = 0; i < m68k_num_gregs; i++) |
| 136 | collect_register (regcache, i, (char *) buf + m68k_regmap[i]); |
| 137 | } |
| 138 | |
| 139 | static void |
| 140 | m68k_store_gregset (struct regcache *regcache, const void *buf) |
| 141 | { |
| 142 | int i; |
| 143 | |
| 144 | for (i = 0; i < m68k_num_gregs; i++) |
| 145 | supply_register (regcache, i, (const char *) buf + m68k_regmap[i]); |
| 146 | } |
| 147 | |
| 148 | static void |
| 149 | m68k_fill_fpregset (struct regcache *regcache, void *buf) |
| 150 | { |
| 151 | int i; |
| 152 | |
| 153 | for (i = m68k_num_gregs; i < m68k_num_regs; i++) |
| 154 | collect_register (regcache, i, ((char *) buf |
| 155 | + (m68k_regmap[i] - m68k_regmap[m68k_num_gregs]))); |
| 156 | } |
| 157 | |
| 158 | static void |
| 159 | m68k_store_fpregset (struct regcache *regcache, const void *buf) |
| 160 | { |
| 161 | int i; |
| 162 | |
| 163 | for (i = m68k_num_gregs; i < m68k_num_regs; i++) |
| 164 | supply_register (regcache, i, ((const char *) buf |
| 165 | + (m68k_regmap[i] - m68k_regmap[m68k_num_gregs]))); |
| 166 | } |
| 167 | |
| 168 | #endif /* HAVE_PTRACE_GETREGS */ |
| 169 | |
| 170 | static struct regset_info m68k_regsets[] = { |
| 171 | #ifdef HAVE_PTRACE_GETREGS |
| 172 | { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t), |
| 173 | GENERAL_REGS, |
| 174 | m68k_fill_gregset, m68k_store_gregset }, |
| 175 | { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (elf_fpregset_t), |
| 176 | FP_REGS, |
| 177 | m68k_fill_fpregset, m68k_store_fpregset }, |
| 178 | #endif /* HAVE_PTRACE_GETREGS */ |
| 179 | NULL_REGSET |
| 180 | }; |
| 181 | |
| 182 | static const gdb_byte m68k_breakpoint[] = { 0x4E, 0x4F }; |
| 183 | #define m68k_breakpoint_len 2 |
| 184 | |
| 185 | /* Implementation of target ops method "sw_breakpoint_from_kind". */ |
| 186 | |
| 187 | const gdb_byte * |
| 188 | m68k_target::sw_breakpoint_from_kind (int kind, int *size) |
| 189 | { |
| 190 | *size = m68k_breakpoint_len; |
| 191 | return m68k_breakpoint; |
| 192 | } |
| 193 | |
| 194 | bool |
| 195 | m68k_target::low_breakpoint_at (CORE_ADDR pc) |
| 196 | { |
| 197 | unsigned char c[2]; |
| 198 | |
| 199 | read_inferior_memory (pc, c, 2); |
| 200 | if (c[0] == 0x4E && c[1] == 0x4F) |
| 201 | return true; |
| 202 | |
| 203 | return false; |
| 204 | } |
| 205 | |
| 206 | #include <asm/ptrace.h> |
| 207 | |
| 208 | #ifdef PTRACE_GET_THREAD_AREA |
| 209 | /* Fetch the thread-local storage pointer for libthread_db. */ |
| 210 | |
| 211 | ps_err_e |
| 212 | ps_get_thread_area (struct ps_prochandle *ph, |
| 213 | lwpid_t lwpid, int idx, void **base) |
| 214 | { |
| 215 | if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0) |
| 216 | return PS_ERR; |
| 217 | |
| 218 | /* IDX is the bias from the thread pointer to the beginning of the |
| 219 | thread descriptor. It has to be subtracted due to implementation |
| 220 | quirks in libthread_db. */ |
| 221 | *base = (void *) ((char *)*base - idx); |
| 222 | |
| 223 | return PS_OK; |
| 224 | } |
| 225 | #endif /* PTRACE_GET_THREAD_AREA */ |
| 226 | |
| 227 | static struct regsets_info m68k_regsets_info = |
| 228 | { |
| 229 | m68k_regsets, /* regsets */ |
| 230 | 0, /* num_regsets */ |
| 231 | NULL, /* disabled_regsets */ |
| 232 | }; |
| 233 | |
| 234 | static struct usrregs_info m68k_usrregs_info = |
| 235 | { |
| 236 | m68k_num_regs, |
| 237 | m68k_regmap, |
| 238 | }; |
| 239 | |
| 240 | static struct regs_info myregs_info = |
| 241 | { |
| 242 | NULL, /* regset_bitmap */ |
| 243 | &m68k_usrregs_info, |
| 244 | &m68k_regsets_info |
| 245 | }; |
| 246 | |
| 247 | const regs_info * |
| 248 | m68k_target::get_regs_info () |
| 249 | { |
| 250 | return &myregs_info; |
| 251 | } |
| 252 | |
| 253 | void |
| 254 | m68k_target::low_arch_setup () |
| 255 | { |
| 256 | current_process ()->tdesc = tdesc_m68k; |
| 257 | } |
| 258 | |
| 259 | /* Support for hardware single step. */ |
| 260 | |
| 261 | static int |
| 262 | m68k_supports_hardware_single_step (void) |
| 263 | { |
| 264 | return 1; |
| 265 | } |
| 266 | |
| 267 | struct linux_target_ops the_low_target = { |
| 268 | NULL, /* supports_range_stepping */ |
| 269 | m68k_supports_hardware_single_step, |
| 270 | }; |
| 271 | |
| 272 | /* The linux target ops object. */ |
| 273 | |
| 274 | linux_process_target *the_linux_target = &the_m68k_target; |
| 275 | |
| 276 | void |
| 277 | initialize_low_arch (void) |
| 278 | { |
| 279 | /* Initialize the Linux target descriptions. */ |
| 280 | init_registers_m68k (); |
| 281 | |
| 282 | initialize_regsets_info (&m68k_regsets_info); |
| 283 | } |