1 /* GNU/Linux on TI C6x target support. 2 Copyright (C) 2011-2016 Free Software Foundation, Inc. 3 Contributed by Yao Qi <yao@codesourcery.com> 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 "defs.h" 21 #include "solib.h" 22 #include "osabi.h" 23 #include "linux-tdep.h" 24 #include "tic6x-tdep.h" 25 #include "trad-frame.h" 26 #include "tramp-frame.h" 27 #include "elf-bfd.h" 28 #include "elf/tic6x.h" 29 30 #include "features/tic6x-c64xp-linux.c" 31 #include "features/tic6x-c64x-linux.c" 32 #include "features/tic6x-c62x-linux.c" 33 34 /* The offset from rt_sigframe pointer to SP register. */ 35 #define TIC6X_SP_RT_SIGFRAME 8 36 /* Size of struct siginfo info. */ 37 #define TIC6X_SIGINFO_SIZE 128 38 /* Size of type stack_t, which contains three fields of type void*, int, and 39 size_t respectively. */ 40 #define TIC6X_STACK_T_SIZE (3 * 4) 41 42 static const gdb_byte tic6x_bkpt_bnop_be[] = { 0x00, 0x00, 0xa1, 0x22 }; 43 static const gdb_byte tic6x_bkpt_bnop_le[] = { 0x22, 0xa1, 0x00, 0x00 }; 44 45 /* Return the offset of register REGNUM in struct sigcontext. Return 0 if no 46 such register in sigcontext. */ 47 48 static unsigned int 49 tic6x_register_sigcontext_offset (unsigned int regnum, struct gdbarch *gdbarch) 50 { 51 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 52 53 if (regnum == TIC6X_A4_REGNUM || regnum == TIC6X_A4_REGNUM + 2 54 || regnum == TIC6X_A4_REGNUM + 4) 55 return 4 * (regnum - TIC6X_A4_REGNUM + 2); /* A4, A6, A8 */ 56 else if (regnum == TIC6X_A5_REGNUM || regnum == TIC6X_A5_REGNUM + 2 57 || regnum == TIC6X_A5_REGNUM + 4) 58 return 4 * (regnum - TIC6X_A5_REGNUM + 12); /* A5, A7, A9 */ 59 else if (regnum == TIC6X_B4_REGNUM || regnum == TIC6X_B4_REGNUM + 2 60 || regnum == TIC6X_B4_REGNUM + 4) 61 return 4 * (regnum - TIC6X_B4_REGNUM + 3); /* B4, B6, B8 */ 62 else if (regnum == TIC6X_B5_REGNUM || regnum == TIC6X_B5_REGNUM + 2 63 || regnum == TIC6X_B5_REGNUM + 4) 64 return 4 * (regnum - TIC6X_B5_REGNUM + 19); /* B5, B7, B9 */ 65 else if (regnum < TIC6X_A4_REGNUM) 66 return 4 * (regnum - 0 + 8); /* A0 - A3 */ 67 else if (regnum >= TIC6X_B0_REGNUM && regnum < TIC6X_B4_REGNUM) 68 return 4 * (regnum - TIC6X_B0_REGNUM + 15); /* B0 - B3 */ 69 else if (regnum >= 34 && regnum < 34 + 32) 70 return 4 * (regnum - 34 + 23); /* A16 - A31, B16 - B31 */ 71 else if (regnum == TIC6X_PC_REGNUM) 72 return 4 * (tdep->has_gp ? 55 : 23); 73 else if (regnum == TIC6X_SP_REGNUM) 74 return 4; 75 76 return 0; 77 } 78 79 /* Support unwinding frame in signal trampoline. We don't check sigreturn, 80 since it is not used in kernel. */ 81 82 static void 83 tic6x_linux_rt_sigreturn_init (const struct tramp_frame *self, 84 struct frame_info *this_frame, 85 struct trad_frame_cache *this_cache, 86 CORE_ADDR func) 87 { 88 struct gdbarch *gdbarch = get_frame_arch (this_frame); 89 CORE_ADDR sp = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM); 90 /* The base of struct sigcontext is computed by examining the definition of 91 struct rt_sigframe in linux kernel source arch/c6x/kernel/signal.c. */ 92 CORE_ADDR base = (sp + TIC6X_SP_RT_SIGFRAME 93 /* Pointer type *pinfo and *puc in struct rt_sigframe. */ 94 + 4 + 4 95 + TIC6X_SIGINFO_SIZE 96 + 4 + 4 /* uc_flags and *uc_link in struct ucontext. */ 97 + TIC6X_STACK_T_SIZE); 98 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 99 unsigned int reg_offset; 100 unsigned int i; 101 102 for (i = 0; i < 10; i++) /* A0 - A9 */ 103 { 104 reg_offset = tic6x_register_sigcontext_offset (i, gdbarch); 105 gdb_assert (reg_offset != 0); 106 107 trad_frame_set_reg_addr (this_cache, i, base + reg_offset); 108 } 109 110 for (i = TIC6X_B0_REGNUM; i < TIC6X_B0_REGNUM + 10; i++) /* B0 - B9 */ 111 { 112 reg_offset = tic6x_register_sigcontext_offset (i, gdbarch); 113 gdb_assert (reg_offset != 0); 114 115 trad_frame_set_reg_addr (this_cache, i, base + reg_offset); 116 } 117 118 if (tdep->has_gp) 119 for (i = 34; i < 34 + 32; i++) /* A16 - A31, B16 - B31 */ 120 { 121 reg_offset = tic6x_register_sigcontext_offset (i, gdbarch); 122 gdb_assert (reg_offset != 0); 123 124 trad_frame_set_reg_addr (this_cache, i, base + reg_offset); 125 } 126 127 trad_frame_set_reg_addr (this_cache, TIC6X_PC_REGNUM, 128 base + tic6x_register_sigcontext_offset (TIC6X_PC_REGNUM, 129 gdbarch)); 130 trad_frame_set_reg_addr (this_cache, TIC6X_SP_REGNUM, 131 base + tic6x_register_sigcontext_offset (TIC6X_SP_REGNUM, 132 gdbarch)); 133 134 /* Save a frame ID. */ 135 trad_frame_set_id (this_cache, frame_id_build (sp, func)); 136 } 137 138 static struct tramp_frame tic6x_linux_rt_sigreturn_tramp_frame = 139 { 140 SIGTRAMP_FRAME, 141 4, 142 { 143 {0x000045aa, 0x0fffffff}, /* mvk .S2 139,b0 */ 144 {0x10000000, -1}, /* swe */ 145 {TRAMP_SENTINEL_INSN} 146 }, 147 tic6x_linux_rt_sigreturn_init 148 }; 149 150 /* When FRAME is at a syscall instruction, return the PC of the next 151 instruction to be executed. */ 152 153 static CORE_ADDR 154 tic6x_linux_syscall_next_pc (struct frame_info *frame) 155 { 156 ULONGEST syscall_number = get_frame_register_unsigned (frame, 157 TIC6X_B0_REGNUM); 158 CORE_ADDR pc = get_frame_pc (frame); 159 160 if (syscall_number == 139 /* rt_sigreturn */) 161 return frame_unwind_caller_pc (frame); 162 163 return pc + 4; 164 } 165 166 167 extern struct target_so_ops dsbt_so_ops; 168 static void 169 tic6x_uclinux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 170 { 171 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 172 173 linux_init_abi (info, gdbarch); 174 175 /* Shared library handling. */ 176 set_solib_ops (gdbarch, &dsbt_so_ops); 177 178 tdep->syscall_next_pc = tic6x_linux_syscall_next_pc; 179 180 #ifdef HAVE_ELF 181 /* In tic6x Linux kernel, breakpoint instructions varies on different archs. 182 On C64x+ and C67x+, breakpoint instruction is 0x56454314, which is an 183 illegal opcode. On other arch, breakpoint instruction is 0x0000a122 184 (BNOP .S2 0,5). */ 185 if (info.abfd) 186 switch (bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_ISA)) 187 { 188 case C6XABI_Tag_ISA_C64XP: 189 case C6XABI_Tag_ISA_C67XP: 190 if (info.byte_order == BFD_ENDIAN_BIG) 191 tdep->breakpoint = tic6x_bkpt_illegal_opcode_be; 192 else 193 tdep->breakpoint = tic6x_bkpt_illegal_opcode_le; 194 break; 195 default: 196 { 197 if (info.byte_order == BFD_ENDIAN_BIG) 198 tdep->breakpoint = tic6x_bkpt_bnop_be; 199 else 200 tdep->breakpoint = tic6x_bkpt_bnop_le; 201 } 202 } 203 #endif 204 205 /* Signal trampoline support. */ 206 tramp_frame_prepend_unwinder (gdbarch, 207 &tic6x_linux_rt_sigreturn_tramp_frame); 208 } 209 210 /* Provide a prototype to silence -Wmissing-prototypes. */ 211 extern initialize_file_ftype _initialize_tic6x_linux_tdep; 212 213 void 214 _initialize_tic6x_linux_tdep (void) 215 { 216 gdbarch_register_osabi (bfd_arch_tic6x, 0, GDB_OSABI_LINUX, 217 tic6x_uclinux_init_abi); 218 219 initialize_tdesc_tic6x_c64xp_linux (); 220 initialize_tdesc_tic6x_c64x_linux (); 221 initialize_tdesc_tic6x_c62x_linux (); 222 } 223