| 1 | /* GNU/Linux/ARM specific low level interface, for the remote server for GDB. |
| 2 | Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, |
| 3 | 2006, 2007, 2008, 2009 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "server.h" |
| 21 | #include "linux-low.h" |
| 22 | |
| 23 | #include <sys/ptrace.h> |
| 24 | |
| 25 | #include "gdb_proc_service.h" |
| 26 | |
| 27 | /* Defined in auto-generated file reg-arm.c. */ |
| 28 | void init_registers_arm (void); |
| 29 | /* Defined in auto-generated file arm-with-iwmmxt.c. */ |
| 30 | void init_registers_arm_with_iwmmxt (void); |
| 31 | |
| 32 | #ifndef PTRACE_GET_THREAD_AREA |
| 33 | #define PTRACE_GET_THREAD_AREA 22 |
| 34 | #endif |
| 35 | |
| 36 | #ifndef PTRACE_GETWMMXREGS |
| 37 | # define PTRACE_GETWMMXREGS 18 |
| 38 | # define PTRACE_SETWMMXREGS 19 |
| 39 | #endif |
| 40 | |
| 41 | #ifdef HAVE_SYS_REG_H |
| 42 | #include <sys/reg.h> |
| 43 | #endif |
| 44 | |
| 45 | #define arm_num_regs 26 |
| 46 | |
| 47 | static int arm_regmap[] = { |
| 48 | 0, 4, 8, 12, 16, 20, 24, 28, |
| 49 | 32, 36, 40, 44, 48, 52, 56, 60, |
| 50 | -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 51 | 64 |
| 52 | }; |
| 53 | |
| 54 | static int |
| 55 | arm_cannot_store_register (int regno) |
| 56 | { |
| 57 | return (regno >= arm_num_regs); |
| 58 | } |
| 59 | |
| 60 | static int |
| 61 | arm_cannot_fetch_register (int regno) |
| 62 | { |
| 63 | return (regno >= arm_num_regs); |
| 64 | } |
| 65 | |
| 66 | static void |
| 67 | arm_fill_gregset (void *buf) |
| 68 | { |
| 69 | int i; |
| 70 | |
| 71 | for (i = 0; i < arm_num_regs; i++) |
| 72 | if (arm_regmap[i] != -1) |
| 73 | collect_register (i, ((char *) buf) + arm_regmap[i]); |
| 74 | } |
| 75 | |
| 76 | static void |
| 77 | arm_store_gregset (const void *buf) |
| 78 | { |
| 79 | int i; |
| 80 | char zerobuf[8]; |
| 81 | |
| 82 | memset (zerobuf, 0, 8); |
| 83 | for (i = 0; i < arm_num_regs; i++) |
| 84 | if (arm_regmap[i] != -1) |
| 85 | supply_register (i, ((char *) buf) + arm_regmap[i]); |
| 86 | else |
| 87 | supply_register (i, zerobuf); |
| 88 | } |
| 89 | |
| 90 | #ifdef __IWMMXT__ |
| 91 | |
| 92 | static void |
| 93 | arm_fill_wmmxregset (void *buf) |
| 94 | { |
| 95 | int i; |
| 96 | |
| 97 | for (i = 0; i < 16; i++) |
| 98 | collect_register (arm_num_regs + i, (char *) buf + i * 8); |
| 99 | |
| 100 | /* We only have access to wcssf, wcasf, and wcgr0-wcgr3. */ |
| 101 | for (i = 0; i < 6; i++) |
| 102 | collect_register (arm_num_regs + i + 16, (char *) buf + 16 * 8 + i * 4); |
| 103 | } |
| 104 | |
| 105 | static void |
| 106 | arm_store_wmmxregset (const void *buf) |
| 107 | { |
| 108 | int i; |
| 109 | |
| 110 | for (i = 0; i < 16; i++) |
| 111 | supply_register (arm_num_regs + i, (char *) buf + i * 8); |
| 112 | |
| 113 | /* We only have access to wcssf, wcasf, and wcgr0-wcgr3. */ |
| 114 | for (i = 0; i < 6; i++) |
| 115 | supply_register (arm_num_regs + i + 16, (char *) buf + 16 * 8 + i * 4); |
| 116 | } |
| 117 | |
| 118 | #endif /* __IWMMXT__ */ |
| 119 | |
| 120 | extern int debug_threads; |
| 121 | |
| 122 | static CORE_ADDR |
| 123 | arm_get_pc () |
| 124 | { |
| 125 | unsigned long pc; |
| 126 | collect_register_by_name ("pc", &pc); |
| 127 | if (debug_threads) |
| 128 | fprintf (stderr, "stop pc is %08lx\n", pc); |
| 129 | return pc; |
| 130 | } |
| 131 | |
| 132 | static void |
| 133 | arm_set_pc (CORE_ADDR pc) |
| 134 | { |
| 135 | unsigned long newpc = pc; |
| 136 | supply_register_by_name ("pc", &newpc); |
| 137 | } |
| 138 | |
| 139 | /* Correct in either endianness. */ |
| 140 | static const unsigned long arm_breakpoint = 0xef9f0001; |
| 141 | #define arm_breakpoint_len 4 |
| 142 | static const unsigned short thumb_breakpoint = 0xde01; |
| 143 | #define thumb_breakpoint_len 2 |
| 144 | |
| 145 | /* For new EABI binaries. We recognize it regardless of which ABI |
| 146 | is used for gdbserver, so single threaded debugging should work |
| 147 | OK, but for multi-threaded debugging we only insert the current |
| 148 | ABI's breakpoint instruction. For now at least. */ |
| 149 | static const unsigned long arm_eabi_breakpoint = 0xe7f001f0; |
| 150 | |
| 151 | static int |
| 152 | arm_breakpoint_at (CORE_ADDR where) |
| 153 | { |
| 154 | unsigned long cpsr; |
| 155 | |
| 156 | collect_register_by_name ("cpsr", &cpsr); |
| 157 | |
| 158 | if (cpsr & 0x20) |
| 159 | { |
| 160 | /* Thumb mode. */ |
| 161 | unsigned short insn; |
| 162 | |
| 163 | (*the_target->read_memory) (where, (unsigned char *) &insn, 2); |
| 164 | if (insn == thumb_breakpoint) |
| 165 | return 1; |
| 166 | } |
| 167 | else |
| 168 | { |
| 169 | /* ARM mode. */ |
| 170 | unsigned long insn; |
| 171 | |
| 172 | (*the_target->read_memory) (where, (unsigned char *) &insn, 4); |
| 173 | if (insn == arm_breakpoint) |
| 174 | return 1; |
| 175 | |
| 176 | if (insn == arm_eabi_breakpoint) |
| 177 | return 1; |
| 178 | } |
| 179 | |
| 180 | return 0; |
| 181 | } |
| 182 | |
| 183 | /* We only place breakpoints in empty marker functions, and thread locking |
| 184 | is outside of the function. So rather than importing software single-step, |
| 185 | we can just run until exit. */ |
| 186 | static CORE_ADDR |
| 187 | arm_reinsert_addr () |
| 188 | { |
| 189 | unsigned long pc; |
| 190 | collect_register_by_name ("lr", &pc); |
| 191 | return pc; |
| 192 | } |
| 193 | |
| 194 | /* Fetch the thread-local storage pointer for libthread_db. */ |
| 195 | |
| 196 | ps_err_e |
| 197 | ps_get_thread_area (const struct ps_prochandle *ph, |
| 198 | lwpid_t lwpid, int idx, void **base) |
| 199 | { |
| 200 | if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0) |
| 201 | return PS_ERR; |
| 202 | |
| 203 | /* IDX is the bias from the thread pointer to the beginning of the |
| 204 | thread descriptor. It has to be subtracted due to implementation |
| 205 | quirks in libthread_db. */ |
| 206 | *base = (void *) ((char *)*base - idx); |
| 207 | |
| 208 | return PS_OK; |
| 209 | } |
| 210 | |
| 211 | struct regset_info target_regsets[] = { |
| 212 | { PTRACE_GETREGS, PTRACE_SETREGS, 18 * 4, |
| 213 | GENERAL_REGS, |
| 214 | arm_fill_gregset, arm_store_gregset }, |
| 215 | #ifdef __IWMMXT__ |
| 216 | { PTRACE_GETWMMXREGS, PTRACE_SETWMMXREGS, 16 * 8 + 6 * 4, |
| 217 | EXTENDED_REGS, |
| 218 | arm_fill_wmmxregset, arm_store_wmmxregset }, |
| 219 | #endif |
| 220 | { 0, 0, -1, -1, NULL, NULL } |
| 221 | }; |
| 222 | |
| 223 | struct linux_target_ops the_low_target = { |
| 224 | #ifdef __IWMMXT__ |
| 225 | init_registers_arm_with_iwmmxt, |
| 226 | #else |
| 227 | init_registers_arm, |
| 228 | #endif |
| 229 | arm_num_regs, |
| 230 | arm_regmap, |
| 231 | arm_cannot_fetch_register, |
| 232 | arm_cannot_store_register, |
| 233 | arm_get_pc, |
| 234 | arm_set_pc, |
| 235 | |
| 236 | /* Define an ARM-mode breakpoint; we only set breakpoints in the C |
| 237 | library, which is most likely to be ARM. If the kernel supports |
| 238 | clone events, we will never insert a breakpoint, so even a Thumb |
| 239 | C library will work; so will mixing EABI/non-EABI gdbserver and |
| 240 | application. */ |
| 241 | #ifndef __ARM_EABI__ |
| 242 | (const unsigned char *) &arm_breakpoint, |
| 243 | #else |
| 244 | (const unsigned char *) &arm_eabi_breakpoint, |
| 245 | #endif |
| 246 | arm_breakpoint_len, |
| 247 | arm_reinsert_addr, |
| 248 | 0, |
| 249 | arm_breakpoint_at, |
| 250 | }; |