| 1 | /* OBSOLETE /* Target-dependent code for the TI TMS320C80 (MVP) for GDB, the GNU debugger. */ |
| 2 | /* OBSOLETE Copyright 1996, 1997, 1999, 2000, 2001 Free Software Foundation, Inc. */ |
| 3 | /* OBSOLETE */ |
| 4 | /* OBSOLETE This file is part of GDB. */ |
| 5 | /* OBSOLETE */ |
| 6 | /* OBSOLETE This program is free software; you can redistribute it and/or modify */ |
| 7 | /* OBSOLETE it under the terms of the GNU General Public License as published by */ |
| 8 | /* OBSOLETE the Free Software Foundation; either version 2 of the License, or */ |
| 9 | /* OBSOLETE (at your option) any later version. */ |
| 10 | /* OBSOLETE */ |
| 11 | /* OBSOLETE This program is distributed in the hope that it will be useful, */ |
| 12 | /* OBSOLETE but WITHOUT ANY WARRANTY; without even the implied warranty of */ |
| 13 | /* OBSOLETE MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */ |
| 14 | /* OBSOLETE GNU General Public License for more details. */ |
| 15 | /* OBSOLETE */ |
| 16 | /* OBSOLETE You should have received a copy of the GNU General Public License */ |
| 17 | /* OBSOLETE along with this program; if not, write to the Free Software */ |
| 18 | /* OBSOLETE Foundation, Inc., 59 Temple Place - Suite 330, */ |
| 19 | /* OBSOLETE Boston, MA 02111-1307, USA. */ */ |
| 20 | /* OBSOLETE */ |
| 21 | /* OBSOLETE #include "defs.h" */ |
| 22 | /* OBSOLETE #include "value.h" */ |
| 23 | /* OBSOLETE #include "frame.h" */ |
| 24 | /* OBSOLETE #include "inferior.h" */ |
| 25 | /* OBSOLETE #include "obstack.h" */ |
| 26 | /* OBSOLETE #include "target.h" */ |
| 27 | /* OBSOLETE #include "bfd.h" */ |
| 28 | /* OBSOLETE #include "gdb_string.h" */ |
| 29 | /* OBSOLETE #include "gdbcore.h" */ |
| 30 | /* OBSOLETE #include "symfile.h" */ |
| 31 | /* OBSOLETE #include "regcache.h" */ |
| 32 | /* OBSOLETE */ |
| 33 | /* OBSOLETE /* Function: frame_find_saved_regs */ |
| 34 | /* OBSOLETE Return the frame_saved_regs structure for the frame. */ |
| 35 | /* OBSOLETE Doesn't really work for dummy frames, but it does pass back */ |
| 36 | /* OBSOLETE an empty frame_saved_regs, so I guess that's better than total failure */ */ |
| 37 | /* OBSOLETE */ |
| 38 | /* OBSOLETE void */ |
| 39 | /* OBSOLETE tic80_frame_find_saved_regs (struct frame_info *fi, */ |
| 40 | /* OBSOLETE struct frame_saved_regs *regaddr) */ |
| 41 | /* OBSOLETE { */ |
| 42 | /* OBSOLETE memcpy (regaddr, &fi->fsr, sizeof (struct frame_saved_regs)); */ |
| 43 | /* OBSOLETE } */ |
| 44 | /* OBSOLETE */ |
| 45 | /* OBSOLETE /* Function: skip_prologue */ |
| 46 | /* OBSOLETE Find end of function prologue. */ */ |
| 47 | /* OBSOLETE */ |
| 48 | /* OBSOLETE CORE_ADDR */ |
| 49 | /* OBSOLETE tic80_skip_prologue (CORE_ADDR pc) */ |
| 50 | /* OBSOLETE { */ |
| 51 | /* OBSOLETE CORE_ADDR func_addr, func_end; */ |
| 52 | /* OBSOLETE struct symtab_and_line sal; */ |
| 53 | /* OBSOLETE */ |
| 54 | /* OBSOLETE /* See what the symbol table says */ */ |
| 55 | /* OBSOLETE */ |
| 56 | /* OBSOLETE if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) */ |
| 57 | /* OBSOLETE { */ |
| 58 | /* OBSOLETE sal = find_pc_line (func_addr, 0); */ |
| 59 | /* OBSOLETE */ |
| 60 | /* OBSOLETE if (sal.line != 0 && sal.end < func_end) */ |
| 61 | /* OBSOLETE return sal.end; */ |
| 62 | /* OBSOLETE else */ |
| 63 | /* OBSOLETE /* Either there's no line info, or the line after the prologue is after */ |
| 64 | /* OBSOLETE the end of the function. In this case, there probably isn't a */ |
| 65 | /* OBSOLETE prologue. */ */ |
| 66 | /* OBSOLETE return pc; */ |
| 67 | /* OBSOLETE } */ |
| 68 | /* OBSOLETE */ |
| 69 | /* OBSOLETE /* We can't find the start of this function, so there's nothing we can do. */ */ |
| 70 | /* OBSOLETE return pc; */ |
| 71 | /* OBSOLETE } */ |
| 72 | /* OBSOLETE */ |
| 73 | /* OBSOLETE /* Function: tic80_scan_prologue */ |
| 74 | /* OBSOLETE This function decodes the target function prologue to determine: */ |
| 75 | /* OBSOLETE 1) the size of the stack frame */ |
| 76 | /* OBSOLETE 2) which registers are saved on it */ |
| 77 | /* OBSOLETE 3) the offsets of saved regs */ |
| 78 | /* OBSOLETE 4) the frame size */ |
| 79 | /* OBSOLETE This information is stored in the "extra" fields of the frame_info. */ */ |
| 80 | /* OBSOLETE */ |
| 81 | /* OBSOLETE static void */ |
| 82 | /* OBSOLETE tic80_scan_prologue (struct frame_info *fi) */ |
| 83 | /* OBSOLETE { */ |
| 84 | /* OBSOLETE struct symtab_and_line sal; */ |
| 85 | /* OBSOLETE CORE_ADDR prologue_start, prologue_end, current_pc; */ |
| 86 | /* OBSOLETE */ |
| 87 | /* OBSOLETE /* Assume there is no frame until proven otherwise. */ */ |
| 88 | /* OBSOLETE fi->framereg = SP_REGNUM; */ |
| 89 | /* OBSOLETE fi->framesize = 0; */ |
| 90 | /* OBSOLETE fi->frameoffset = 0; */ |
| 91 | /* OBSOLETE */ |
| 92 | /* OBSOLETE /* this code essentially duplicates skip_prologue, */ |
| 93 | /* OBSOLETE but we need the start address below. */ */ |
| 94 | /* OBSOLETE */ |
| 95 | /* OBSOLETE if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) */ |
| 96 | /* OBSOLETE { */ |
| 97 | /* OBSOLETE sal = find_pc_line (prologue_start, 0); */ |
| 98 | /* OBSOLETE */ |
| 99 | /* OBSOLETE if (sal.line == 0) /* no line info, use current PC */ */ |
| 100 | /* OBSOLETE if (prologue_start != entry_point_address ()) */ |
| 101 | /* OBSOLETE prologue_end = fi->pc; */ |
| 102 | /* OBSOLETE else */ |
| 103 | /* OBSOLETE return; /* _start has no frame or prologue */ */ |
| 104 | /* OBSOLETE else if (sal.end < prologue_end) /* next line begins after fn end */ */ |
| 105 | /* OBSOLETE prologue_end = sal.end; /* (probably means no prologue) */ */ |
| 106 | /* OBSOLETE } */ |
| 107 | /* OBSOLETE else */ |
| 108 | /* OBSOLETE /* FIXME */ */ |
| 109 | /* OBSOLETE prologue_end = prologue_start + 40; /* We're in the boondocks: allow for */ */ |
| 110 | /* OBSOLETE /* 16 pushes, an add, and "mv fp,sp" */ */ |
| 111 | /* OBSOLETE */ |
| 112 | /* OBSOLETE prologue_end = min (prologue_end, fi->pc); */ |
| 113 | /* OBSOLETE */ |
| 114 | /* OBSOLETE /* Now search the prologue looking for instructions that set up the */ |
| 115 | /* OBSOLETE frame pointer, adjust the stack pointer, and save registers. */ */ |
| 116 | /* OBSOLETE */ |
| 117 | /* OBSOLETE for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 4) */ |
| 118 | /* OBSOLETE { */ |
| 119 | /* OBSOLETE unsigned int insn; */ |
| 120 | /* OBSOLETE int regno; */ |
| 121 | /* OBSOLETE int offset = 0; */ |
| 122 | /* OBSOLETE */ |
| 123 | /* OBSOLETE insn = read_memory_unsigned_integer (current_pc, 4); */ |
| 124 | /* OBSOLETE */ |
| 125 | /* OBSOLETE if ((insn & 0x301000) == 0x301000) /* Long immediate? */ */ |
| 126 | /* OBSOLETE /* FIXME - set offset for long immediate instructions */ */ |
| 127 | /* OBSOLETE current_pc += 4; */ |
| 128 | /* OBSOLETE else */ |
| 129 | /* OBSOLETE { */ |
| 130 | /* OBSOLETE offset = insn & 0x7fff; /* extract 15-bit offset */ */ |
| 131 | /* OBSOLETE if (offset & 0x4000) /* if negative, sign-extend */ */ |
| 132 | /* OBSOLETE offset = -(0x8000 - offset); */ |
| 133 | /* OBSOLETE } */ |
| 134 | /* OBSOLETE */ |
| 135 | /* OBSOLETE if ((insn & 0x7fd0000) == 0x590000) /* st.{w,d} reg, xx(r1) */ */ |
| 136 | /* OBSOLETE { */ |
| 137 | /* OBSOLETE regno = ((insn >> 27) & 0x1f); */ |
| 138 | /* OBSOLETE fi->fsr.regs[regno] = offset; */ |
| 139 | /* OBSOLETE if (insn & 0x8000) /* 64-bit store (st.d)? */ */ |
| 140 | /* OBSOLETE fi->fsr.regs[regno + 1] = offset + 4; */ |
| 141 | /* OBSOLETE } */ |
| 142 | /* OBSOLETE else if ((insn & 0xffff8000) == 0x086c8000) /* addu xx, r1, r1 */ */ |
| 143 | /* OBSOLETE fi->framesize = -offset; */ |
| 144 | /* OBSOLETE else if ((insn & 0xffff8000) == 0xf06c8000) /* addu xx, r1, r30 */ */ |
| 145 | /* OBSOLETE { */ |
| 146 | /* OBSOLETE fi->framereg = FP_REGNUM; /* fp is now valid */ */ |
| 147 | /* OBSOLETE fi->frameoffset = offset; */ |
| 148 | /* OBSOLETE break; /* end of stack adjustments */ */ |
| 149 | /* OBSOLETE } */ |
| 150 | /* OBSOLETE else if (insn == 0xf03b2001) /* addu r1, r0, r30 */ */ |
| 151 | /* OBSOLETE { */ |
| 152 | /* OBSOLETE fi->framereg = FP_REGNUM; /* fp is now valid */ */ |
| 153 | /* OBSOLETE fi->frameoffset = 0; */ |
| 154 | /* OBSOLETE break; /* end of stack adjustments */ */ |
| 155 | /* OBSOLETE } */ |
| 156 | /* OBSOLETE else */ |
| 157 | /* OBSOLETE /* FIXME - handle long immediate instructions */ */ |
| 158 | /* OBSOLETE break; /* anything else isn't prologue */ */ |
| 159 | /* OBSOLETE } */ |
| 160 | /* OBSOLETE } */ |
| 161 | /* OBSOLETE */ |
| 162 | /* OBSOLETE /* Function: init_extra_frame_info */ |
| 163 | /* OBSOLETE This function actually figures out the frame address for a given pc and */ |
| 164 | /* OBSOLETE sp. This is tricky on the c80 because we sometimes don't use an explicit */ |
| 165 | /* OBSOLETE frame pointer, and the previous stack pointer isn't necessarily recorded */ |
| 166 | /* OBSOLETE on the stack. The only reliable way to get this info is to */ |
| 167 | /* OBSOLETE examine the prologue. */ */ |
| 168 | /* OBSOLETE */ |
| 169 | /* OBSOLETE void */ |
| 170 | /* OBSOLETE tic80_init_extra_frame_info (struct frame_info *fi) */ |
| 171 | /* OBSOLETE { */ |
| 172 | /* OBSOLETE int reg; */ |
| 173 | /* OBSOLETE */ |
| 174 | /* OBSOLETE if (fi->next) */ |
| 175 | /* OBSOLETE fi->pc = FRAME_SAVED_PC (fi->next); */ |
| 176 | /* OBSOLETE */ |
| 177 | /* OBSOLETE /* Because zero is a valid register offset relative to SP, we initialize */ |
| 178 | /* OBSOLETE the offsets to -1 to indicate unused entries. */ */ |
| 179 | /* OBSOLETE for (reg = 0; reg < NUM_REGS; reg++) */ |
| 180 | /* OBSOLETE fi->fsr.regs[reg] = -1; */ |
| 181 | /* OBSOLETE */ |
| 182 | /* OBSOLETE if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) */ |
| 183 | /* OBSOLETE { */ |
| 184 | /* OBSOLETE /* We need to setup fi->frame here because run_stack_dummy gets it wrong */ |
| 185 | /* OBSOLETE by assuming it's always FP. */ */ |
| 186 | /* OBSOLETE fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM); */ |
| 187 | /* OBSOLETE fi->framesize = 0; */ |
| 188 | /* OBSOLETE fi->frameoffset = 0; */ |
| 189 | /* OBSOLETE return; */ |
| 190 | /* OBSOLETE } */ |
| 191 | /* OBSOLETE else */ |
| 192 | /* OBSOLETE { */ |
| 193 | /* OBSOLETE tic80_scan_prologue (fi); */ |
| 194 | /* OBSOLETE */ |
| 195 | /* OBSOLETE if (!fi->next) /* this is the innermost frame? */ */ |
| 196 | /* OBSOLETE fi->frame = read_register (fi->framereg); */ |
| 197 | /* OBSOLETE else */ |
| 198 | /* OBSOLETE /* not the innermost frame */ */ |
| 199 | /* OBSOLETE /* If this function uses FP as the frame register, and the function */ |
| 200 | /* OBSOLETE it called saved the FP, get the saved FP. */ if (fi->framereg == FP_REGNUM && */ |
| 201 | /* OBSOLETE fi->next->fsr.regs[FP_REGNUM] != (unsigned) -1) */ |
| 202 | /* OBSOLETE fi->frame = read_memory_integer (fi->next->fsr.regs[FP_REGNUM], 4); */ |
| 203 | /* OBSOLETE */ |
| 204 | /* OBSOLETE /* Convert SP-relative offsets of saved registers to real addresses. */ */ |
| 205 | /* OBSOLETE for (reg = 0; reg < NUM_REGS; reg++) */ |
| 206 | /* OBSOLETE if (fi->fsr.regs[reg] == (unsigned) -1) */ |
| 207 | /* OBSOLETE fi->fsr.regs[reg] = 0; /* unused entry */ */ |
| 208 | /* OBSOLETE else */ |
| 209 | /* OBSOLETE fi->fsr.regs[reg] += fi->frame - fi->frameoffset; */ |
| 210 | /* OBSOLETE } */ |
| 211 | /* OBSOLETE } */ |
| 212 | /* OBSOLETE */ |
| 213 | /* OBSOLETE /* Function: find_callers_reg */ |
| 214 | /* OBSOLETE Find REGNUM on the stack. Otherwise, it's in an active register. One thing */ |
| 215 | /* OBSOLETE we might want to do here is to check REGNUM against the clobber mask, and */ |
| 216 | /* OBSOLETE somehow flag it as invalid if it isn't saved on the stack somewhere. This */ |
| 217 | /* OBSOLETE would provide a graceful failure mode when trying to get the value of */ |
| 218 | /* OBSOLETE caller-saves registers for an inner frame. */ */ |
| 219 | /* OBSOLETE */ |
| 220 | /* OBSOLETE CORE_ADDR */ |
| 221 | /* OBSOLETE tic80_find_callers_reg (struct frame_info *fi, int regnum) */ |
| 222 | /* OBSOLETE { */ |
| 223 | /* OBSOLETE for (; fi; fi = fi->next) */ |
| 224 | /* OBSOLETE if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) */ |
| 225 | /* OBSOLETE return generic_read_register_dummy (fi->pc, fi->frame, regnum); */ |
| 226 | /* OBSOLETE else if (fi->fsr.regs[regnum] != 0) */ |
| 227 | /* OBSOLETE return read_memory_integer (fi->fsr.regs[regnum], */ |
| 228 | /* OBSOLETE REGISTER_RAW_SIZE (regnum)); */ |
| 229 | /* OBSOLETE return read_register (regnum); */ |
| 230 | /* OBSOLETE } */ |
| 231 | /* OBSOLETE */ |
| 232 | /* OBSOLETE /* Function: frame_chain */ |
| 233 | /* OBSOLETE Given a GDB frame, determine the address of the calling function's frame. */ |
| 234 | /* OBSOLETE This will be used to create a new GDB frame struct, and then */ |
| 235 | /* OBSOLETE INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. */ |
| 236 | /* OBSOLETE For c80, we save the frame size when we initialize the frame_info. */ */ |
| 237 | /* OBSOLETE */ |
| 238 | /* OBSOLETE CORE_ADDR */ |
| 239 | /* OBSOLETE tic80_frame_chain (struct frame_info *fi) */ |
| 240 | /* OBSOLETE { */ |
| 241 | /* OBSOLETE CORE_ADDR fn_start, callers_pc, fp; */ |
| 242 | /* OBSOLETE */ |
| 243 | /* OBSOLETE /* is this a dummy frame? */ */ |
| 244 | /* OBSOLETE if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) */ |
| 245 | /* OBSOLETE return fi->frame; /* dummy frame same as caller's frame */ */ |
| 246 | /* OBSOLETE */ |
| 247 | /* OBSOLETE /* is caller-of-this a dummy frame? */ */ |
| 248 | /* OBSOLETE callers_pc = FRAME_SAVED_PC (fi); /* find out who called us: */ */ |
| 249 | /* OBSOLETE fp = tic80_find_callers_reg (fi, FP_REGNUM); */ |
| 250 | /* OBSOLETE if (PC_IN_CALL_DUMMY (callers_pc, fp, fp)) */ |
| 251 | /* OBSOLETE return fp; /* dummy frame's frame may bear no relation to ours */ */ |
| 252 | /* OBSOLETE */ |
| 253 | /* OBSOLETE if (find_pc_partial_function (fi->pc, 0, &fn_start, 0)) */ |
| 254 | /* OBSOLETE if (fn_start == entry_point_address ()) */ |
| 255 | /* OBSOLETE return 0; /* in _start fn, don't chain further */ */ |
| 256 | /* OBSOLETE */ |
| 257 | /* OBSOLETE if (fi->framereg == FP_REGNUM) */ |
| 258 | /* OBSOLETE return tic80_find_callers_reg (fi, FP_REGNUM); */ |
| 259 | /* OBSOLETE else */ |
| 260 | /* OBSOLETE return fi->frame + fi->framesize; */ |
| 261 | /* OBSOLETE } */ |
| 262 | /* OBSOLETE */ |
| 263 | /* OBSOLETE /* Function: pop_frame */ |
| 264 | /* OBSOLETE Discard from the stack the innermost frame, */ |
| 265 | /* OBSOLETE restoring all saved registers. */ */ |
| 266 | /* OBSOLETE */ |
| 267 | /* OBSOLETE struct frame_info * */ |
| 268 | /* OBSOLETE tic80_pop_frame (struct frame_info *frame) */ |
| 269 | /* OBSOLETE { */ |
| 270 | /* OBSOLETE int regnum; */ |
| 271 | /* OBSOLETE */ |
| 272 | /* OBSOLETE if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) */ |
| 273 | /* OBSOLETE generic_pop_dummy_frame (); */ |
| 274 | /* OBSOLETE else */ |
| 275 | /* OBSOLETE { */ |
| 276 | /* OBSOLETE for (regnum = 0; regnum < NUM_REGS; regnum++) */ |
| 277 | /* OBSOLETE if (frame->fsr.regs[regnum] != 0) */ |
| 278 | /* OBSOLETE write_register (regnum, */ |
| 279 | /* OBSOLETE read_memory_integer (frame->fsr.regs[regnum], 4)); */ |
| 280 | /* OBSOLETE */ |
| 281 | /* OBSOLETE write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); */ |
| 282 | /* OBSOLETE write_register (SP_REGNUM, read_register (FP_REGNUM)); */ |
| 283 | /* OBSOLETE #if 0 */ |
| 284 | /* OBSOLETE if (read_register (PSW_REGNUM) & 0x80) */ |
| 285 | /* OBSOLETE write_register (SPU_REGNUM, read_register (SP_REGNUM)); */ |
| 286 | /* OBSOLETE else */ |
| 287 | /* OBSOLETE write_register (SPI_REGNUM, read_register (SP_REGNUM)); */ |
| 288 | /* OBSOLETE #endif */ |
| 289 | /* OBSOLETE } */ |
| 290 | /* OBSOLETE flush_cached_frames (); */ |
| 291 | /* OBSOLETE return NULL; */ |
| 292 | /* OBSOLETE } */ |
| 293 | /* OBSOLETE */ |
| 294 | /* OBSOLETE /* Function: frame_saved_pc */ |
| 295 | /* OBSOLETE Find the caller of this frame. We do this by seeing if LR_REGNUM is saved */ |
| 296 | /* OBSOLETE in the stack anywhere, otherwise we get it from the registers. */ */ |
| 297 | /* OBSOLETE */ |
| 298 | /* OBSOLETE CORE_ADDR */ |
| 299 | /* OBSOLETE tic80_frame_saved_pc (struct frame_info *fi) */ |
| 300 | /* OBSOLETE { */ |
| 301 | /* OBSOLETE if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) */ |
| 302 | /* OBSOLETE return generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM); */ |
| 303 | /* OBSOLETE else */ |
| 304 | /* OBSOLETE return tic80_find_callers_reg (fi, LR_REGNUM); */ |
| 305 | /* OBSOLETE } */ |
| 306 | /* OBSOLETE */ |
| 307 | /* OBSOLETE /* Function: tic80_push_return_address (pc, sp) */ |
| 308 | /* OBSOLETE Set up the return address for the inferior function call. */ |
| 309 | /* OBSOLETE Necessary for targets that don't actually execute a JSR/BSR instruction */ |
| 310 | /* OBSOLETE (ie. when using an empty CALL_DUMMY) */ */ |
| 311 | /* OBSOLETE */ |
| 312 | /* OBSOLETE CORE_ADDR */ |
| 313 | /* OBSOLETE tic80_push_return_address (CORE_ADDR pc, CORE_ADDR sp) */ |
| 314 | /* OBSOLETE { */ |
| 315 | /* OBSOLETE write_register (LR_REGNUM, CALL_DUMMY_ADDRESS ()); */ |
| 316 | /* OBSOLETE return sp; */ |
| 317 | /* OBSOLETE } */ |
| 318 | /* OBSOLETE */ |
| 319 | /* OBSOLETE */ |
| 320 | /* OBSOLETE /* Function: push_arguments */ |
| 321 | /* OBSOLETE Setup the function arguments for calling a function in the inferior. */ |
| 322 | /* OBSOLETE */ |
| 323 | /* OBSOLETE On the TI C80 architecture, there are six register pairs (R2/R3 to R12/13) */ |
| 324 | /* OBSOLETE which are dedicated for passing function arguments. Up to the first six */ |
| 325 | /* OBSOLETE arguments (depending on size) may go into these registers. */ |
| 326 | /* OBSOLETE The rest go on the stack. */ |
| 327 | /* OBSOLETE */ |
| 328 | /* OBSOLETE Arguments that are smaller than 4 bytes will still take up a whole */ |
| 329 | /* OBSOLETE register or a whole 32-bit word on the stack, and will be */ |
| 330 | /* OBSOLETE right-justified in the register or the stack word. This includes */ |
| 331 | /* OBSOLETE chars, shorts, and small aggregate types. */ |
| 332 | /* OBSOLETE */ |
| 333 | /* OBSOLETE Arguments that are four bytes or less in size are placed in the */ |
| 334 | /* OBSOLETE even-numbered register of a register pair, and the odd-numbered */ |
| 335 | /* OBSOLETE register is not used. */ |
| 336 | /* OBSOLETE */ |
| 337 | /* OBSOLETE Arguments of 8 bytes size (such as floating point doubles) are placed */ |
| 338 | /* OBSOLETE in a register pair. The least significant 32-bit word is placed in */ |
| 339 | /* OBSOLETE the even-numbered register, and the most significant word in the */ |
| 340 | /* OBSOLETE odd-numbered register. */ |
| 341 | /* OBSOLETE */ |
| 342 | /* OBSOLETE Aggregate types with sizes between 4 and 8 bytes are passed */ |
| 343 | /* OBSOLETE entirely on the stack, and are left-justified within the */ |
| 344 | /* OBSOLETE double-word (as opposed to aggregates smaller than 4 bytes */ |
| 345 | /* OBSOLETE which are right-justified). */ |
| 346 | /* OBSOLETE */ |
| 347 | /* OBSOLETE Aggregates of greater than 8 bytes are first copied onto the stack, */ |
| 348 | /* OBSOLETE and then a pointer to the copy is passed in the place of the normal */ |
| 349 | /* OBSOLETE argument (either in a register if available, or on the stack). */ |
| 350 | /* OBSOLETE */ |
| 351 | /* OBSOLETE Functions that must return an aggregate type can return it in the */ |
| 352 | /* OBSOLETE normal return value registers (R2 and R3) if its size is 8 bytes or */ |
| 353 | /* OBSOLETE less. For larger return values, the caller must allocate space for */ |
| 354 | /* OBSOLETE the callee to copy the return value to. A pointer to this space is */ |
| 355 | /* OBSOLETE passed as an implicit first argument, always in R0. */ */ |
| 356 | /* OBSOLETE */ |
| 357 | /* OBSOLETE CORE_ADDR */ |
| 358 | /* OBSOLETE tic80_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp, */ |
| 359 | /* OBSOLETE unsigned char struct_return, CORE_ADDR struct_addr) */ |
| 360 | /* OBSOLETE { */ |
| 361 | /* OBSOLETE int stack_offset, stack_alloc; */ |
| 362 | /* OBSOLETE int argreg; */ |
| 363 | /* OBSOLETE int argnum; */ |
| 364 | /* OBSOLETE struct type *type; */ |
| 365 | /* OBSOLETE CORE_ADDR regval; */ |
| 366 | /* OBSOLETE char *val; */ |
| 367 | /* OBSOLETE char valbuf[4]; */ |
| 368 | /* OBSOLETE int len; */ |
| 369 | /* OBSOLETE int odd_sized_struct; */ |
| 370 | /* OBSOLETE int is_struct; */ |
| 371 | /* OBSOLETE */ |
| 372 | /* OBSOLETE /* first force sp to a 4-byte alignment */ */ |
| 373 | /* OBSOLETE sp = sp & ~3; */ |
| 374 | /* OBSOLETE */ |
| 375 | /* OBSOLETE argreg = ARG0_REGNUM; */ |
| 376 | /* OBSOLETE /* The "struct return pointer" pseudo-argument goes in R0 */ */ |
| 377 | /* OBSOLETE if (struct_return) */ |
| 378 | /* OBSOLETE write_register (argreg++, struct_addr); */ |
| 379 | /* OBSOLETE */ |
| 380 | /* OBSOLETE /* Now make sure there's space on the stack */ */ |
| 381 | /* OBSOLETE for (argnum = 0, stack_alloc = 0; */ |
| 382 | /* OBSOLETE argnum < nargs; argnum++) */ |
| 383 | /* OBSOLETE stack_alloc += ((TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 3) & ~3); */ |
| 384 | /* OBSOLETE sp -= stack_alloc; /* make room on stack for args */ */ |
| 385 | /* OBSOLETE */ |
| 386 | /* OBSOLETE */ |
| 387 | /* OBSOLETE /* Now load as many as possible of the first arguments into */ |
| 388 | /* OBSOLETE registers, and push the rest onto the stack. There are 16 bytes */ |
| 389 | /* OBSOLETE in four registers available. Loop thru args from first to last. */ */ |
| 390 | /* OBSOLETE */ |
| 391 | /* OBSOLETE argreg = ARG0_REGNUM; */ |
| 392 | /* OBSOLETE for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++) */ |
| 393 | /* OBSOLETE { */ |
| 394 | /* OBSOLETE type = VALUE_TYPE (args[argnum]); */ |
| 395 | /* OBSOLETE len = TYPE_LENGTH (type); */ |
| 396 | /* OBSOLETE memset (valbuf, 0, sizeof (valbuf)); */ |
| 397 | /* OBSOLETE val = (char *) VALUE_CONTENTS (args[argnum]); */ |
| 398 | /* OBSOLETE */ |
| 399 | /* OBSOLETE /* FIXME -- tic80 can take doubleword arguments in register pairs */ */ |
| 400 | /* OBSOLETE is_struct = (type->code == TYPE_CODE_STRUCT); */ |
| 401 | /* OBSOLETE odd_sized_struct = 0; */ |
| 402 | /* OBSOLETE */ |
| 403 | /* OBSOLETE if (!is_struct) */ |
| 404 | /* OBSOLETE { */ |
| 405 | /* OBSOLETE if (len < 4) */ |
| 406 | /* OBSOLETE { /* value gets right-justified in the register or stack word */ */ |
| 407 | /* OBSOLETE memcpy (valbuf + (4 - len), val, len); */ |
| 408 | /* OBSOLETE val = valbuf; */ |
| 409 | /* OBSOLETE } */ |
| 410 | /* OBSOLETE if (len > 4 && (len & 3) != 0) */ |
| 411 | /* OBSOLETE odd_sized_struct = 1; /* such structs go entirely on stack */ */ |
| 412 | /* OBSOLETE } */ |
| 413 | /* OBSOLETE else */ |
| 414 | /* OBSOLETE { */ |
| 415 | /* OBSOLETE /* Structs are always passed by reference. */ */ |
| 416 | /* OBSOLETE write_register (argreg, sp + stack_offset); */ |
| 417 | /* OBSOLETE argreg++; */ |
| 418 | /* OBSOLETE } */ |
| 419 | /* OBSOLETE */ |
| 420 | /* OBSOLETE while (len > 0) */ |
| 421 | /* OBSOLETE { */ |
| 422 | /* OBSOLETE if (is_struct || argreg > ARGLAST_REGNUM || odd_sized_struct) */ |
| 423 | /* OBSOLETE { /* must go on the stack */ */ |
| 424 | /* OBSOLETE write_memory (sp + stack_offset, val, 4); */ |
| 425 | /* OBSOLETE stack_offset += 4; */ |
| 426 | /* OBSOLETE } */ |
| 427 | /* OBSOLETE /* NOTE WELL!!!!! This is not an "else if" clause!!! */ |
| 428 | /* OBSOLETE That's because some things get passed on the stack */ |
| 429 | /* OBSOLETE AND in the registers! */ */ |
| 430 | /* OBSOLETE if (!is_struct && argreg <= ARGLAST_REGNUM) */ |
| 431 | /* OBSOLETE { /* there's room in a register */ */ |
| 432 | /* OBSOLETE regval = extract_address (val, REGISTER_RAW_SIZE (argreg)); */ |
| 433 | /* OBSOLETE write_register (argreg, regval); */ |
| 434 | /* OBSOLETE argreg += 2; /* FIXME -- what about doubleword args? */ */ |
| 435 | /* OBSOLETE } */ |
| 436 | /* OBSOLETE /* Store the value 4 bytes at a time. This means that things */ |
| 437 | /* OBSOLETE larger than 4 bytes may go partly in registers and partly */ |
| 438 | /* OBSOLETE on the stack. */ */ |
| 439 | /* OBSOLETE len -= REGISTER_RAW_SIZE (argreg); */ |
| 440 | /* OBSOLETE val += REGISTER_RAW_SIZE (argreg); */ |
| 441 | /* OBSOLETE } */ |
| 442 | /* OBSOLETE } */ |
| 443 | /* OBSOLETE return sp; */ |
| 444 | /* OBSOLETE } */ |
| 445 | /* OBSOLETE */ |
| 446 | /* OBSOLETE /* Function: tic80_write_sp */ |
| 447 | /* OBSOLETE Because SP is really a read-only register that mirrors either SPU or SPI, */ |
| 448 | /* OBSOLETE we must actually write one of those two as well, depending on PSW. */ */ |
| 449 | /* OBSOLETE */ |
| 450 | /* OBSOLETE void */ |
| 451 | /* OBSOLETE tic80_write_sp (CORE_ADDR val) */ |
| 452 | /* OBSOLETE { */ |
| 453 | /* OBSOLETE #if 0 */ |
| 454 | /* OBSOLETE unsigned long psw = read_register (PSW_REGNUM); */ |
| 455 | /* OBSOLETE */ |
| 456 | /* OBSOLETE if (psw & 0x80) /* stack mode: user or interrupt */ */ |
| 457 | /* OBSOLETE write_register (SPU_REGNUM, val); */ |
| 458 | /* OBSOLETE else */ |
| 459 | /* OBSOLETE write_register (SPI_REGNUM, val); */ |
| 460 | /* OBSOLETE #endif */ |
| 461 | /* OBSOLETE write_register (SP_REGNUM, val); */ |
| 462 | /* OBSOLETE } */ |
| 463 | /* OBSOLETE */ |
| 464 | /* OBSOLETE void */ |
| 465 | /* OBSOLETE _initialize_tic80_tdep (void) */ |
| 466 | /* OBSOLETE { */ |
| 467 | /* OBSOLETE tm_print_insn = print_insn_tic80; */ |
| 468 | /* OBSOLETE } */ |