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 24class m68k_target : public linux_process_target 25{ 26public: 27 28 const regs_info *get_regs_info () override; 29 30 const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override; 31 32protected: 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 53static m68k_target the_m68k_target; 54 55bool 56m68k_target::low_supports_breakpoints () 57{ 58 return true; 59} 60 61CORE_ADDR 62m68k_target::low_get_pc (regcache *regcache) 63{ 64 return linux_get_pc_32bit (regcache); 65} 66 67void 68m68k_target::low_set_pc (regcache *regcache, CORE_ADDR pc) 69{ 70 linux_set_pc_32bit (regcache, pc); 71} 72 73int 74m68k_target::low_decr_pc_after_break () 75{ 76 return 2; 77} 78 79/* Defined in auto-generated file reg-m68k.c. */ 80void init_registers_m68k (void); 81extern 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 */ 91static 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 114bool 115m68k_target::low_cannot_store_register (int regno) 116{ 117 return (regno >= m68k_num_regs); 118} 119 120bool 121m68k_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 130static void 131m68k_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 139static void 140m68k_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 148static void 149m68k_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 158static void 159m68k_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 170static 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 182static 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 187const gdb_byte * 188m68k_target::sw_breakpoint_from_kind (int kind, int *size) 189{ 190 *size = m68k_breakpoint_len; 191 return m68k_breakpoint; 192} 193 194bool 195m68k_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 211ps_err_e 212ps_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 227static struct regsets_info m68k_regsets_info = 228 { 229 m68k_regsets, /* regsets */ 230 0, /* num_regsets */ 231 NULL, /* disabled_regsets */ 232 }; 233 234static struct usrregs_info m68k_usrregs_info = 235 { 236 m68k_num_regs, 237 m68k_regmap, 238 }; 239 240static struct regs_info myregs_info = 241 { 242 NULL, /* regset_bitmap */ 243 &m68k_usrregs_info, 244 &m68k_regsets_info 245 }; 246 247const regs_info * 248m68k_target::get_regs_info () 249{ 250 return &myregs_info; 251} 252 253void 254m68k_target::low_arch_setup () 255{ 256 current_process ()->tdesc = tdesc_m68k; 257} 258 259/* The linux target ops object. */ 260 261linux_process_target *the_linux_target = &the_m68k_target; 262 263void 264initialize_low_arch (void) 265{ 266 /* Initialize the Linux target descriptions. */ 267 init_registers_m68k (); 268 269 initialize_regsets_info (&m68k_regsets_info); 270} 271