| 1 | /* Target-dependent code for FreeBSD/arm. |
| 2 | |
| 3 | Copyright (C) 2017-2018 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 "defs.h" |
| 21 | |
| 22 | #include "elf/common.h" |
| 23 | #include "arm-tdep.h" |
| 24 | #include "arm-fbsd-tdep.h" |
| 25 | #include "auxv.h" |
| 26 | #include "fbsd-tdep.h" |
| 27 | #include "gdbcore.h" |
| 28 | #include "osabi.h" |
| 29 | #include "solib-svr4.h" |
| 30 | #include "trad-frame.h" |
| 31 | #include "tramp-frame.h" |
| 32 | |
| 33 | /* In a signal frame, sp points to a 'struct sigframe' which is |
| 34 | defined as: |
| 35 | |
| 36 | struct sigframe { |
| 37 | siginfo_t sf_si; |
| 38 | ucontext_t sf_uc; |
| 39 | mcontext_vfp_t sf_vfp; |
| 40 | }; |
| 41 | |
| 42 | ucontext_t is defined as: |
| 43 | |
| 44 | struct __ucontext { |
| 45 | sigset_t uc_sigmask; |
| 46 | mcontext_t uc_mcontext; |
| 47 | ... |
| 48 | }; |
| 49 | |
| 50 | mcontext_t is defined as: |
| 51 | |
| 52 | struct { |
| 53 | unsigned int __gregs[17]; |
| 54 | size_t mc_vfp_size; |
| 55 | void *mc_vfp_ptr; |
| 56 | ... |
| 57 | }; |
| 58 | |
| 59 | mcontext_vfp_t is defined as: |
| 60 | |
| 61 | struct { |
| 62 | uint64_t mcv_reg[32]; |
| 63 | uint32_t mcv_fpscr; |
| 64 | }; |
| 65 | |
| 66 | If the VFP state is valid, then mc_vfp_ptr will point to sf_vfp in |
| 67 | the sigframe, otherwise it is NULL. There is no non-VFP floating |
| 68 | point register state saved in the signal frame. */ |
| 69 | |
| 70 | #define ARM_MCONTEXT_REG_SIZE 4 |
| 71 | #define ARM_MCONTEXT_VFP_REG_SIZE 8 |
| 72 | #define ARM_SIGFRAME_UCONTEXT_OFFSET 64 |
| 73 | #define ARM_UCONTEXT_MCONTEXT_OFFSET 16 |
| 74 | #define ARM_MCONTEXT_VFP_PTR_OFFSET 72 |
| 75 | |
| 76 | /* Implement the "init" method of struct tramp_frame. */ |
| 77 | |
| 78 | static void |
| 79 | arm_fbsd_sigframe_init (const struct tramp_frame *self, |
| 80 | struct frame_info *this_frame, |
| 81 | struct trad_frame_cache *this_cache, |
| 82 | CORE_ADDR func) |
| 83 | { |
| 84 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| 85 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 86 | CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); |
| 87 | CORE_ADDR mcontext_addr = (sp |
| 88 | + ARM_SIGFRAME_UCONTEXT_OFFSET |
| 89 | + ARM_UCONTEXT_MCONTEXT_OFFSET); |
| 90 | ULONGEST mcontext_vfp_addr; |
| 91 | |
| 92 | for (int i = 0; i < 16; i++) |
| 93 | { |
| 94 | trad_frame_set_reg_addr (this_cache, |
| 95 | ARM_A1_REGNUM + i, |
| 96 | mcontext_addr + i * ARM_MCONTEXT_REG_SIZE); |
| 97 | } |
| 98 | trad_frame_set_reg_addr (this_cache, ARM_PS_REGNUM, |
| 99 | mcontext_addr + 16 * ARM_MCONTEXT_REG_SIZE); |
| 100 | |
| 101 | if (safe_read_memory_unsigned_integer (mcontext_addr |
| 102 | + ARM_MCONTEXT_VFP_PTR_OFFSET, 4, |
| 103 | byte_order, |
| 104 | &mcontext_vfp_addr) |
| 105 | && mcontext_vfp_addr != 0) |
| 106 | { |
| 107 | for (int i = 0; i < 32; i++) |
| 108 | { |
| 109 | trad_frame_set_reg_addr (this_cache, ARM_D0_REGNUM + i, |
| 110 | mcontext_vfp_addr |
| 111 | + i * ARM_MCONTEXT_VFP_REG_SIZE); |
| 112 | } |
| 113 | trad_frame_set_reg_addr (this_cache, ARM_FPSCR_REGNUM, |
| 114 | mcontext_vfp_addr |
| 115 | + 32 * ARM_MCONTEXT_VFP_REG_SIZE); |
| 116 | } |
| 117 | |
| 118 | trad_frame_set_id (this_cache, frame_id_build (sp, func)); |
| 119 | } |
| 120 | |
| 121 | static const struct tramp_frame arm_fbsd_sigframe = |
| 122 | { |
| 123 | SIGTRAMP_FRAME, |
| 124 | 4, |
| 125 | { |
| 126 | {0xe1a0000d, -1}, /* mov r0, sp */ |
| 127 | {0xe2800040, -1}, /* add r0, r0, #SIGF_UC */ |
| 128 | {0xe59f700c, -1}, /* ldr r7, [pc, #12] */ |
| 129 | {0xef0001a1, -1}, /* swi SYS_sigreturn */ |
| 130 | {TRAMP_SENTINEL_INSN, -1} |
| 131 | }, |
| 132 | arm_fbsd_sigframe_init |
| 133 | }; |
| 134 | |
| 135 | /* Register maps. */ |
| 136 | |
| 137 | static const struct regcache_map_entry arm_fbsd_gregmap[] = |
| 138 | { |
| 139 | { 13, ARM_A1_REGNUM, 4 }, /* r0 ... r12 */ |
| 140 | { 1, ARM_SP_REGNUM, 4 }, |
| 141 | { 1, ARM_LR_REGNUM, 4 }, |
| 142 | { 1, ARM_PC_REGNUM, 4 }, |
| 143 | { 1, ARM_PS_REGNUM, 4 }, |
| 144 | { 0 } |
| 145 | }; |
| 146 | |
| 147 | static const struct regcache_map_entry arm_fbsd_vfpregmap[] = |
| 148 | { |
| 149 | { 32, ARM_D0_REGNUM, 8 }, /* d0 ... d31 */ |
| 150 | { 1, ARM_FPSCR_REGNUM, 4 }, |
| 151 | { 0 } |
| 152 | }; |
| 153 | |
| 154 | /* Register set definitions. */ |
| 155 | |
| 156 | const struct regset arm_fbsd_gregset = |
| 157 | { |
| 158 | arm_fbsd_gregmap, |
| 159 | regcache_supply_regset, regcache_collect_regset |
| 160 | }; |
| 161 | |
| 162 | const struct regset arm_fbsd_vfpregset = |
| 163 | { |
| 164 | arm_fbsd_vfpregmap, |
| 165 | regcache_supply_regset, regcache_collect_regset |
| 166 | }; |
| 167 | |
| 168 | /* Implement the "regset_from_core_section" gdbarch method. */ |
| 169 | |
| 170 | static void |
| 171 | arm_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch, |
| 172 | iterate_over_regset_sections_cb *cb, |
| 173 | void *cb_data, |
| 174 | const struct regcache *regcache) |
| 175 | { |
| 176 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 177 | |
| 178 | cb (".reg", ARM_FBSD_SIZEOF_GREGSET, &arm_fbsd_gregset, NULL, cb_data); |
| 179 | |
| 180 | /* While FreeBSD/arm cores do contain a NT_FPREGSET / ".reg2" |
| 181 | register set, it is not populated with register values by the |
| 182 | kernel but just contains all zeroes. */ |
| 183 | if (tdep->vfp_register_count > 0) |
| 184 | cb (".reg-arm-vfp", ARM_FBSD_SIZEOF_VFPREGSET, &arm_fbsd_vfpregset, |
| 185 | "VFP floating-point", cb_data); |
| 186 | } |
| 187 | |
| 188 | /* Lookup a target description from a target's AT_HWCAP auxiliary |
| 189 | vector. */ |
| 190 | |
| 191 | const struct target_desc * |
| 192 | arm_fbsd_read_description_auxv (struct target_ops *target) |
| 193 | { |
| 194 | CORE_ADDR arm_hwcap = 0; |
| 195 | |
| 196 | if (target_auxv_search (target, AT_FREEBSD_HWCAP, &arm_hwcap) != 1) |
| 197 | return NULL; |
| 198 | |
| 199 | if (arm_hwcap & HWCAP_VFP) |
| 200 | { |
| 201 | if (arm_hwcap & HWCAP_NEON) |
| 202 | return tdesc_arm_with_neon; |
| 203 | else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPD32)) |
| 204 | == (HWCAP_VFPv3 | HWCAP_VFPD32)) |
| 205 | return tdesc_arm_with_vfpv3; |
| 206 | else |
| 207 | return tdesc_arm_with_vfpv2; |
| 208 | } |
| 209 | |
| 210 | return NULL; |
| 211 | } |
| 212 | |
| 213 | /* Implement the "core_read_description" gdbarch method. */ |
| 214 | |
| 215 | static const struct target_desc * |
| 216 | arm_fbsd_core_read_description (struct gdbarch *gdbarch, |
| 217 | struct target_ops *target, |
| 218 | bfd *abfd) |
| 219 | { |
| 220 | return arm_fbsd_read_description_auxv (target); |
| 221 | } |
| 222 | |
| 223 | /* Implement the 'init_osabi' method of struct gdb_osabi_handler. */ |
| 224 | |
| 225 | static void |
| 226 | arm_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 227 | { |
| 228 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 229 | |
| 230 | /* Generic FreeBSD support. */ |
| 231 | fbsd_init_abi (info, gdbarch); |
| 232 | |
| 233 | if (tdep->fp_model == ARM_FLOAT_AUTO) |
| 234 | tdep->fp_model = ARM_FLOAT_SOFT_VFP; |
| 235 | |
| 236 | tramp_frame_prepend_unwinder (gdbarch, &arm_fbsd_sigframe); |
| 237 | |
| 238 | set_solib_svr4_fetch_link_map_offsets |
| 239 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
| 240 | |
| 241 | tdep->jb_pc = 24; |
| 242 | tdep->jb_elt_size = 4; |
| 243 | |
| 244 | set_gdbarch_iterate_over_regset_sections |
| 245 | (gdbarch, arm_fbsd_iterate_over_regset_sections); |
| 246 | set_gdbarch_core_read_description (gdbarch, arm_fbsd_core_read_description); |
| 247 | |
| 248 | /* Single stepping. */ |
| 249 | set_gdbarch_software_single_step (gdbarch, arm_software_single_step); |
| 250 | } |
| 251 | |
| 252 | void |
| 253 | _initialize_arm_fbsd_tdep (void) |
| 254 | { |
| 255 | gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_FREEBSD, |
| 256 | arm_fbsd_init_abi); |
| 257 | } |