| 1 | /* Target-dependent code for Hitachi Super-H, for GDB. |
| 2 | Copyright (C) 1993, 1994, 1995 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 2 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, write to the Free Software |
| 18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | /* |
| 21 | Contributed by Steve Chamberlain |
| 22 | sac@cygnus.com |
| 23 | */ |
| 24 | |
| 25 | #include "defs.h" |
| 26 | #include "frame.h" |
| 27 | #include "obstack.h" |
| 28 | #include "symtab.h" |
| 29 | #include "gdbtypes.h" |
| 30 | #include "gdbcmd.h" |
| 31 | #include "gdbcore.h" |
| 32 | #include "value.h" |
| 33 | #include "dis-asm.h" |
| 34 | |
| 35 | /* Prologue looks like |
| 36 | [mov.l <regs>,@-r15]... |
| 37 | [sts.l pr,@-r15] |
| 38 | [mov.l r14,@-r15] |
| 39 | [mov r15,r14] |
| 40 | */ |
| 41 | |
| 42 | #define IS_STS(x) ((x) == 0x4f22) |
| 43 | #define IS_PUSH(x) (((x) & 0xff0f) == 0x2f06) |
| 44 | #define GET_PUSHED_REG(x) (((x) >> 4) & 0xf) |
| 45 | #define IS_MOV_SP_FP(x) ((x) == 0x6ef3) |
| 46 | #define IS_ADD_SP(x) (((x) & 0xff00) == 0x7f00) |
| 47 | #define IS_MOV_R3(x) (((x) & 0xff00) == 0x1a00) |
| 48 | #define IS_SHLL_R3(x) ((x) == 0x4300) |
| 49 | #define IS_ADD_R3SP(x) ((x) == 0x3f3c) |
| 50 | |
| 51 | /* Skip any prologue before the guts of a function */ |
| 52 | |
| 53 | CORE_ADDR |
| 54 | sh_skip_prologue (start_pc) |
| 55 | CORE_ADDR start_pc; |
| 56 | { |
| 57 | int w; |
| 58 | |
| 59 | w = read_memory_integer (start_pc, 2); |
| 60 | while (IS_STS (w) |
| 61 | || IS_PUSH (w) |
| 62 | || IS_MOV_SP_FP (w) |
| 63 | || IS_MOV_R3 (w) |
| 64 | || IS_ADD_R3SP (w) |
| 65 | || IS_ADD_SP (w) |
| 66 | || IS_SHLL_R3 (w)) |
| 67 | { |
| 68 | start_pc += 2; |
| 69 | w = read_memory_integer (start_pc, 2); |
| 70 | } |
| 71 | |
| 72 | return start_pc; |
| 73 | } |
| 74 | |
| 75 | /* Disassemble an instruction. */ |
| 76 | |
| 77 | int |
| 78 | gdb_print_insn_sh (memaddr, info) |
| 79 | bfd_vma memaddr; |
| 80 | disassemble_info *info; |
| 81 | { |
| 82 | if (TARGET_BYTE_ORDER == BIG_ENDIAN) |
| 83 | return print_insn_sh (memaddr, info); |
| 84 | else |
| 85 | return print_insn_shl (memaddr, info); |
| 86 | } |
| 87 | |
| 88 | /* Given a GDB frame, determine the address of the calling function's frame. |
| 89 | This will be used to create a new GDB frame struct, and then |
| 90 | INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. |
| 91 | |
| 92 | For us, the frame address is its stack pointer value, so we look up |
| 93 | the function prologue to determine the caller's sp value, and return it. */ |
| 94 | |
| 95 | CORE_ADDR |
| 96 | sh_frame_chain (frame) |
| 97 | struct frame_info *frame; |
| 98 | { |
| 99 | if (!inside_entry_file (frame->pc)) |
| 100 | return read_memory_integer (FRAME_FP (frame) + frame->f_offset, 4); |
| 101 | else |
| 102 | return 0; |
| 103 | } |
| 104 | |
| 105 | /* Put here the code to store, into a struct frame_saved_regs, the |
| 106 | addresses of the saved registers of frame described by FRAME_INFO. |
| 107 | This includes special registers such as pc and fp saved in special |
| 108 | ways in the stack frame. sp is even more special: the address we |
| 109 | return for it IS the sp for the next frame. */ |
| 110 | |
| 111 | void |
| 112 | frame_find_saved_regs (fi, fsr) |
| 113 | struct frame_info *fi; |
| 114 | struct frame_saved_regs *fsr; |
| 115 | { |
| 116 | int where[NUM_REGS]; |
| 117 | int rn; |
| 118 | int have_fp = 0; |
| 119 | int depth; |
| 120 | int pc; |
| 121 | int opc; |
| 122 | int insn; |
| 123 | int r3_val = 0; |
| 124 | |
| 125 | opc = pc = get_pc_function_start (fi->pc); |
| 126 | |
| 127 | insn = read_memory_integer (pc, 2); |
| 128 | |
| 129 | fi->leaf_function = 1; |
| 130 | fi->f_offset = 0; |
| 131 | |
| 132 | for (rn = 0; rn < NUM_REGS; rn++) |
| 133 | where[rn] = -1; |
| 134 | |
| 135 | depth = 0; |
| 136 | |
| 137 | /* Loop around examining the prologue insns, but give up |
| 138 | after 15 of them, since we're getting silly then */ |
| 139 | while (pc < opc + 15 * 2) |
| 140 | { |
| 141 | /* See where the registers will be saved to */ |
| 142 | if (IS_PUSH (insn)) |
| 143 | { |
| 144 | pc += 2; |
| 145 | rn = GET_PUSHED_REG (insn); |
| 146 | where[rn] = depth; |
| 147 | insn = read_memory_integer (pc, 2); |
| 148 | depth += 4; |
| 149 | } |
| 150 | else if (IS_STS (insn)) |
| 151 | { |
| 152 | pc += 2; |
| 153 | where[PR_REGNUM] = depth; |
| 154 | insn = read_memory_integer (pc, 2); |
| 155 | /* If we're storing the pr then this isn't a leaf */ |
| 156 | fi->leaf_function = 0; |
| 157 | depth += 4; |
| 158 | } |
| 159 | else if (IS_MOV_R3 (insn)) |
| 160 | { |
| 161 | r3_val = (char) (insn & 0xff); |
| 162 | pc += 2; |
| 163 | insn = read_memory_integer (pc, 2); |
| 164 | } |
| 165 | else if (IS_SHLL_R3 (insn)) |
| 166 | { |
| 167 | r3_val <<= 1; |
| 168 | pc += 2; |
| 169 | insn = read_memory_integer (pc, 2); |
| 170 | } |
| 171 | else if (IS_ADD_R3SP (insn)) |
| 172 | { |
| 173 | depth += -r3_val; |
| 174 | pc += 2; |
| 175 | insn = read_memory_integer (pc, 2); |
| 176 | } |
| 177 | else if (IS_ADD_SP (insn)) |
| 178 | { |
| 179 | pc += 2; |
| 180 | depth += -((char) (insn & 0xff)); |
| 181 | insn = read_memory_integer (pc, 2); |
| 182 | } |
| 183 | else |
| 184 | break; |
| 185 | } |
| 186 | |
| 187 | /* Now we know how deep things are, we can work out their addresses */ |
| 188 | |
| 189 | for (rn = 0; rn < NUM_REGS; rn++) |
| 190 | { |
| 191 | if (where[rn] >= 0) |
| 192 | { |
| 193 | if (rn == FP_REGNUM) |
| 194 | have_fp = 1; |
| 195 | |
| 196 | fsr->regs[rn] = fi->frame - where[rn] + depth - 4; |
| 197 | } |
| 198 | else |
| 199 | { |
| 200 | fsr->regs[rn] = 0; |
| 201 | } |
| 202 | } |
| 203 | |
| 204 | if (have_fp) |
| 205 | { |
| 206 | fsr->regs[SP_REGNUM] = read_memory_integer (fsr->regs[FP_REGNUM], 4); |
| 207 | } |
| 208 | else |
| 209 | { |
| 210 | fsr->regs[SP_REGNUM] = fi->frame - 4; |
| 211 | } |
| 212 | |
| 213 | fi->f_offset = depth - where[FP_REGNUM] - 4; |
| 214 | /* Work out the return pc - either from the saved pr or the pr |
| 215 | value */ |
| 216 | /* Just called, so dig out the real return */ |
| 217 | if (fi->return_pc == 0) |
| 218 | { |
| 219 | fi->return_pc = read_register (PR_REGNUM) + 4; |
| 220 | } |
| 221 | else |
| 222 | { |
| 223 | |
| 224 | if (fsr->regs[PR_REGNUM]) |
| 225 | { |
| 226 | fi->return_pc = read_memory_integer (fsr->regs[PR_REGNUM], 4) + 4; |
| 227 | } |
| 228 | else |
| 229 | { |
| 230 | fi->return_pc = read_register (PR_REGNUM) + 4; |
| 231 | } |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | /* initialize the extra info saved in a FRAME */ |
| 236 | |
| 237 | void |
| 238 | init_extra_frame_info (fromleaf, fi) |
| 239 | int fromleaf; |
| 240 | struct frame_info *fi; |
| 241 | { |
| 242 | struct frame_saved_regs dummy; |
| 243 | |
| 244 | frame_find_saved_regs (fi, &dummy); |
| 245 | } |
| 246 | |
| 247 | |
| 248 | /* Discard from the stack the innermost frame, |
| 249 | restoring all saved registers. */ |
| 250 | |
| 251 | void |
| 252 | pop_frame () |
| 253 | { |
| 254 | register struct frame_info *frame = get_current_frame (); |
| 255 | register CORE_ADDR fp; |
| 256 | register int regnum; |
| 257 | struct frame_saved_regs fsr; |
| 258 | |
| 259 | fp = FRAME_FP (frame); |
| 260 | get_frame_saved_regs (frame, &fsr); |
| 261 | |
| 262 | /* Copy regs from where they were saved in the frame */ |
| 263 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 264 | { |
| 265 | if (fsr.regs[regnum]) |
| 266 | { |
| 267 | write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); |
| 268 | } |
| 269 | } |
| 270 | |
| 271 | write_register (PC_REGNUM, frame->return_pc); |
| 272 | write_register (SP_REGNUM, fp + 4); |
| 273 | flush_cached_frames (); |
| 274 | } |
| 275 | |
| 276 | /* Print the registers in a form similar to the E7000 */ |
| 277 | |
| 278 | static void |
| 279 | show_regs (args, from_tty) |
| 280 | char *args; |
| 281 | int from_tty; |
| 282 | { |
| 283 | printf_filtered ("PC=%08x SR=%08x PR=%08x MACH=%08x MACHL=%08x\n", |
| 284 | read_register (PC_REGNUM), |
| 285 | read_register (SR_REGNUM), |
| 286 | read_register (PR_REGNUM), |
| 287 | read_register (MACH_REGNUM), |
| 288 | read_register (MACL_REGNUM)); |
| 289 | |
| 290 | printf_filtered ("R0-R7 %08x %08x %08x %08x %08x %08x %08x %08x\n", |
| 291 | read_register (0), |
| 292 | read_register (1), |
| 293 | read_register (2), |
| 294 | read_register (3), |
| 295 | read_register (4), |
| 296 | read_register (5), |
| 297 | read_register (6), |
| 298 | read_register (7)); |
| 299 | printf_filtered ("R8-R15 %08x %08x %08x %08x %08x %08x %08x %08x\n", |
| 300 | read_register (8), |
| 301 | read_register (9), |
| 302 | read_register (10), |
| 303 | read_register (11), |
| 304 | read_register (12), |
| 305 | read_register (13), |
| 306 | read_register (14), |
| 307 | read_register (15)); |
| 308 | } |
| 309 | \f |
| 310 | void |
| 311 | _initialize_sh_tdep () |
| 312 | { |
| 313 | tm_print_insn = gdb_print_insn_sh; |
| 314 | |
| 315 | add_com ("regs", class_vars, show_regs, "Print all registers"); |
| 316 | } |