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 /* The linux target ops object. */ 260 261 linux_process_target *the_linux_target = &the_m68k_target; 262 263 void 264 initialize_low_arch (void) 265 { 266 /* Initialize the Linux target descriptions. */ 267 init_registers_m68k (); 268 269 initialize_regsets_info (&m68k_regsets_info); 270 } 271