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. */
4 /* OBSOLETE This file is part of GDB. */
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. */
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. */
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. */ */
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" */
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 */ */
39 /* OBSOLETE tic80_frame_find_saved_regs (struct frame_info *fi, */
40 /* OBSOLETE struct frame_saved_regs *regaddr) */
42 /* OBSOLETE memcpy (regaddr, &fi->fsr, sizeof (struct frame_saved_regs)); */
45 /* OBSOLETE /* Function: skip_prologue */
46 /* OBSOLETE Find end of function prologue. */ */
48 /* OBSOLETE CORE_ADDR */
49 /* OBSOLETE tic80_skip_prologue (CORE_ADDR pc) */
51 /* OBSOLETE CORE_ADDR func_addr, func_end; */
52 /* OBSOLETE struct symtab_and_line sal; */
54 /* OBSOLETE /* See what the symbol table says */ */
56 /* OBSOLETE if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) */
58 /* OBSOLETE sal = find_pc_line (func_addr, 0); */
60 /* OBSOLETE if (sal.line != 0 && sal.end < func_end) */
61 /* OBSOLETE return sal.end; */
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; */
69 /* OBSOLETE /* We can't find the start of this function, so there's nothing we can do. */ */
70 /* OBSOLETE return pc; */
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. */ */
81 /* OBSOLETE static void */
82 /* OBSOLETE tic80_scan_prologue (struct frame_info *fi) */
84 /* OBSOLETE struct symtab_and_line sal; */
85 /* OBSOLETE CORE_ADDR prologue_start, prologue_end, current_pc; */
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; */
92 /* OBSOLETE /* this code essentially duplicates skip_prologue, */
93 /* OBSOLETE but we need the start address below. */ */
95 /* OBSOLETE if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) */
97 /* OBSOLETE sal = find_pc_line (prologue_start, 0); */
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; */
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) */ */
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" */ */
112 /* OBSOLETE prologue_end = min (prologue_end, fi->pc); */
114 /* OBSOLETE /* Now search the prologue looking for instructions that set up the */
115 /* OBSOLETE frame pointer, adjust the stack pointer, and save registers. */ */
117 /* OBSOLETE for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 4) */
119 /* OBSOLETE unsigned int insn; */
120 /* OBSOLETE int regno; */
121 /* OBSOLETE int offset = 0; */
123 /* OBSOLETE insn = read_memory_unsigned_integer (current_pc, 4); */
125 /* OBSOLETE if ((insn & 0x301000) == 0x301000) /* Long immediate? */ */
126 /* OBSOLETE /* FIXME - set offset for long immediate instructions */ */
127 /* OBSOLETE current_pc += 4; */
130 /* OBSOLETE offset = insn & 0x7fff; /* extract 15-bit offset */ */
131 /* OBSOLETE if (offset & 0x4000) /* if negative, sign-extend */ */
132 /* OBSOLETE offset = -(0x8000 - offset); */
135 /* OBSOLETE if ((insn & 0x7fd0000) == 0x590000) /* st.{w,d} reg, xx(r1) */ */
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; */
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 */ */
146 /* OBSOLETE fi->framereg = FP_REGNUM; /* fp is now valid */ */
147 /* OBSOLETE fi->frameoffset = offset; */
148 /* OBSOLETE break; /* end of stack adjustments */ */
150 /* OBSOLETE else if (insn == 0xf03b2001) /* addu r1, r0, r30 */ */
152 /* OBSOLETE fi->framereg = FP_REGNUM; /* fp is now valid */ */
153 /* OBSOLETE fi->frameoffset = 0; */
154 /* OBSOLETE break; /* end of stack adjustments */ */
157 /* OBSOLETE /* FIXME - handle long immediate instructions */ */
158 /* OBSOLETE break; /* anything else isn't prologue */ */
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. */ */
170 /* OBSOLETE tic80_init_extra_frame_info (struct frame_info *fi) */
172 /* OBSOLETE int reg; */
174 /* OBSOLETE if (fi->next) */
175 /* OBSOLETE fi->pc = FRAME_SAVED_PC (fi->next); */
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; */
182 /* OBSOLETE if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) */
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; */
193 /* OBSOLETE tic80_scan_prologue (fi); */
195 /* OBSOLETE if (!fi->next) /* this is the innermost frame? */ */
196 /* OBSOLETE fi->frame = read_register (fi->framereg); */
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); */
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 */ */
209 /* OBSOLETE fi->fsr.regs[reg] += fi->frame - fi->frameoffset; */
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. */ */
220 /* OBSOLETE CORE_ADDR */
221 /* OBSOLETE tic80_find_callers_reg (struct frame_info *fi, int regnum) */
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); */
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. */ */
238 /* OBSOLETE CORE_ADDR */
239 /* OBSOLETE tic80_frame_chain (struct frame_info *fi) */
241 /* OBSOLETE CORE_ADDR fn_start, callers_pc, fp; */
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 */ */
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 */ */
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 */ */
257 /* OBSOLETE if (fi->framereg == FP_REGNUM) */
258 /* OBSOLETE return tic80_find_callers_reg (fi, FP_REGNUM); */
260 /* OBSOLETE return fi->frame + fi->framesize; */
263 /* OBSOLETE /* Function: pop_frame */
264 /* OBSOLETE Discard from the stack the innermost frame, */
265 /* OBSOLETE restoring all saved registers. */ */
267 /* OBSOLETE struct frame_info * */
268 /* OBSOLETE tic80_pop_frame (struct frame_info *frame) */
270 /* OBSOLETE int regnum; */
272 /* OBSOLETE if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) */
273 /* OBSOLETE generic_pop_dummy_frame (); */
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)); */
281 /* OBSOLETE write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); */
282 /* OBSOLETE write_register (SP_REGNUM, read_register (FP_REGNUM)); */
284 /* OBSOLETE if (read_register (PSW_REGNUM) & 0x80) */
285 /* OBSOLETE write_register (SPU_REGNUM, read_register (SP_REGNUM)); */
287 /* OBSOLETE write_register (SPI_REGNUM, read_register (SP_REGNUM)); */
288 /* OBSOLETE #endif */
290 /* OBSOLETE flush_cached_frames (); */
291 /* OBSOLETE return NULL; */
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. */ */
298 /* OBSOLETE CORE_ADDR */
299 /* OBSOLETE tic80_frame_saved_pc (struct frame_info *fi) */
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); */
304 /* OBSOLETE return tic80_find_callers_reg (fi, LR_REGNUM); */
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) */ */
312 /* OBSOLETE CORE_ADDR */
313 /* OBSOLETE tic80_push_return_address (CORE_ADDR pc, CORE_ADDR sp) */
315 /* OBSOLETE write_register (LR_REGNUM, CALL_DUMMY_ADDRESS ()); */
316 /* OBSOLETE return sp; */
320 /* OBSOLETE /* Function: push_arguments */
321 /* OBSOLETE Setup the function arguments for calling a function in the inferior. */
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. */
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. */
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. */
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. */
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). */
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). */
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. */ */
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) */
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; */
372 /* OBSOLETE /* first force sp to a 4-byte alignment */ */
373 /* OBSOLETE sp = sp & ~3; */
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); */
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 */ */
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. */ */
391 /* OBSOLETE argreg = ARG0_REGNUM; */
392 /* OBSOLETE for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++) */
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]); */
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; */
403 /* OBSOLETE if (!is_struct) */
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; */
410 /* OBSOLETE if (len > 4 && (len & 3) != 0) */
411 /* OBSOLETE odd_sized_struct = 1; /* such structs go entirely on stack */ */
415 /* OBSOLETE /* Structs are always passed by reference. */ */
416 /* OBSOLETE write_register (argreg, sp + stack_offset); */
417 /* OBSOLETE argreg++; */
420 /* OBSOLETE while (len > 0) */
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; */
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? */ */
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); */
443 /* OBSOLETE return sp; */
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. */ */
451 /* OBSOLETE tic80_write_sp (CORE_ADDR val) */
454 /* OBSOLETE unsigned long psw = read_register (PSW_REGNUM); */
456 /* OBSOLETE if (psw & 0x80) /* stack mode: user or interrupt */ */
457 /* OBSOLETE write_register (SPU_REGNUM, val); */
459 /* OBSOLETE write_register (SPI_REGNUM, val); */
460 /* OBSOLETE #endif */
461 /* OBSOLETE write_register (SP_REGNUM, val); */
465 /* OBSOLETE _initialize_tic80_tdep (void) */
467 /* OBSOLETE tm_print_insn = print_insn_tic80; */
This page took 0.04016 seconds and 4 git commands to generate.