Add a comment for the ARM_F{0..7}_REGNUM registers
[binutils-gdb.git] / gdb / ft32-tdep.c
blob99ef69de770f4c585eb2d22bfdbc59c42151f242
1 /* Target-dependent code for FT32.
3 Copyright (C) 2009-2020 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
20 #include "defs.h"
21 #include "frame.h"
22 #include "frame-unwind.h"
23 #include "frame-base.h"
24 #include "symtab.h"
25 #include "gdbtypes.h"
26 #include "gdbcmd.h"
27 #include "gdbcore.h"
28 #include "value.h"
29 #include "inferior.h"
30 #include "symfile.h"
31 #include "objfiles.h"
32 #include "osabi.h"
33 #include "language.h"
34 #include "arch-utils.h"
35 #include "regcache.h"
36 #include "trad-frame.h"
37 #include "dis-asm.h"
38 #include "record.h"
40 #include "opcode/ft32.h"
42 #include "ft32-tdep.h"
43 #include "gdb/sim-ft32.h"
44 #include <algorithm>
46 #define RAM_BIAS 0x800000 /* Bias added to RAM addresses. */
48 /* Use an invalid address -1 as 'not available' marker. */
49 enum { REG_UNAVAIL = (CORE_ADDR) (-1) };
51 struct ft32_frame_cache
53 /* Base address of the frame */
54 CORE_ADDR base;
55 /* Function this frame belongs to */
56 CORE_ADDR pc;
57 /* Total size of this frame */
58 LONGEST framesize;
59 /* Saved registers in this frame */
60 CORE_ADDR saved_regs[FT32_NUM_REGS];
61 /* Saved SP in this frame */
62 CORE_ADDR saved_sp;
63 /* Has the new frame been LINKed. */
64 bfd_boolean established;
67 /* Implement the "frame_align" gdbarch method. */
69 static CORE_ADDR
70 ft32_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
72 /* Align to the size of an instruction (so that they can safely be
73 pushed onto the stack. */
74 return sp & ~1;
78 constexpr gdb_byte ft32_break_insn[] = { 0x02, 0x00, 0x34, 0x00 };
80 typedef BP_MANIPULATION (ft32_break_insn) ft32_breakpoint;
82 /* FT32 register names. */
84 static const char *const ft32_register_names[] =
86 "fp", "sp",
87 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
88 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
89 "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
90 "r24", "r25", "r26", "r27", "r28", "cc",
91 "pc"
94 /* Implement the "register_name" gdbarch method. */
96 static const char *
97 ft32_register_name (struct gdbarch *gdbarch, int reg_nr)
99 if (reg_nr < 0)
100 return NULL;
101 if (reg_nr >= FT32_NUM_REGS)
102 return NULL;
103 return ft32_register_names[reg_nr];
106 /* Implement the "register_type" gdbarch method. */
108 static struct type *
109 ft32_register_type (struct gdbarch *gdbarch, int reg_nr)
111 if (reg_nr == FT32_PC_REGNUM)
112 return gdbarch_tdep (gdbarch)->pc_type;
113 else if (reg_nr == FT32_SP_REGNUM || reg_nr == FT32_FP_REGNUM)
114 return builtin_type (gdbarch)->builtin_data_ptr;
115 else
116 return builtin_type (gdbarch)->builtin_int32;
119 /* Write into appropriate registers a function return value
120 of type TYPE, given in virtual format. */
122 static void
123 ft32_store_return_value (struct type *type, struct regcache *regcache,
124 const gdb_byte *valbuf)
126 struct gdbarch *gdbarch = regcache->arch ();
127 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
128 CORE_ADDR regval;
129 int len = TYPE_LENGTH (type);
131 /* Things always get returned in RET1_REGNUM, RET2_REGNUM. */
132 regval = extract_unsigned_integer (valbuf, len > 4 ? 4 : len, byte_order);
133 regcache_cooked_write_unsigned (regcache, FT32_R0_REGNUM, regval);
134 if (len > 4)
136 regval = extract_unsigned_integer (valbuf + 4,
137 len - 4, byte_order);
138 regcache_cooked_write_unsigned (regcache, FT32_R1_REGNUM, regval);
142 /* Fetch a single 32-bit instruction from address a. If memory contains
143 a compressed instruction pair, return the expanded instruction. */
145 static ULONGEST
146 ft32_fetch_instruction (CORE_ADDR a, int *isize,
147 enum bfd_endian byte_order)
149 unsigned int sc[2];
150 ULONGEST inst;
152 CORE_ADDR a4 = a & ~3;
153 inst = read_code_unsigned_integer (a4, 4, byte_order);
154 *isize = ft32_decode_shortcode (a4, inst, sc) ? 2 : 4;
155 if (*isize == 2)
156 return sc[1 & (a >> 1)];
157 else
158 return inst;
161 /* Decode the instructions within the given address range. Decide
162 when we must have reached the end of the function prologue. If a
163 frame_info pointer is provided, fill in its saved_regs etc.
165 Returns the address of the first instruction after the prologue. */
167 static CORE_ADDR
168 ft32_analyze_prologue (CORE_ADDR start_addr, CORE_ADDR end_addr,
169 struct ft32_frame_cache *cache,
170 struct gdbarch *gdbarch)
172 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
173 CORE_ADDR next_addr;
174 ULONGEST inst;
175 int isize = 0;
176 int regnum, pushreg;
177 struct bound_minimal_symbol msymbol;
178 const int first_saved_reg = 13; /* The first saved register. */
179 /* PROLOGS are addresses of the subroutine prologs, PROLOGS[n]
180 is the address of __prolog_$rN.
181 __prolog_$rN pushes registers from 13 through n inclusive.
182 So for example CALL __prolog_$r15 is equivalent to:
183 PUSH $r13
184 PUSH $r14
185 PUSH $r15
186 Note that PROLOGS[0] through PROLOGS[12] are unused. */
187 CORE_ADDR prologs[32];
189 cache->saved_regs[FT32_PC_REGNUM] = 0;
190 cache->framesize = 0;
192 for (regnum = first_saved_reg; regnum < 32; regnum++)
194 char prolog_symbol[32];
196 snprintf (prolog_symbol, sizeof (prolog_symbol), "__prolog_$r%02d",
197 regnum);
198 msymbol = lookup_minimal_symbol (prolog_symbol, NULL, NULL);
199 if (msymbol.minsym)
200 prologs[regnum] = BMSYMBOL_VALUE_ADDRESS (msymbol);
201 else
202 prologs[regnum] = 0;
205 if (start_addr >= end_addr)
206 return end_addr;
208 cache->established = 0;
209 for (next_addr = start_addr; next_addr < end_addr; next_addr += isize)
211 inst = ft32_fetch_instruction (next_addr, &isize, byte_order);
213 if (FT32_IS_PUSH (inst))
215 pushreg = FT32_PUSH_REG (inst);
216 cache->framesize += 4;
217 cache->saved_regs[FT32_R0_REGNUM + pushreg] = cache->framesize;
219 else if (FT32_IS_CALL (inst))
221 for (regnum = first_saved_reg; regnum < 32; regnum++)
223 if ((4 * (inst & 0x3ffff)) == prologs[regnum])
225 for (pushreg = first_saved_reg; pushreg <= regnum;
226 pushreg++)
228 cache->framesize += 4;
229 cache->saved_regs[FT32_R0_REGNUM + pushreg] =
230 cache->framesize;
234 break;
236 else
237 break;
239 for (regnum = FT32_R0_REGNUM; regnum < FT32_PC_REGNUM; regnum++)
241 if (cache->saved_regs[regnum] != REG_UNAVAIL)
242 cache->saved_regs[regnum] =
243 cache->framesize - cache->saved_regs[regnum];
245 cache->saved_regs[FT32_PC_REGNUM] = cache->framesize;
247 /* It is a LINK? */
248 if (next_addr < end_addr)
250 inst = ft32_fetch_instruction (next_addr, &isize, byte_order);
251 if (FT32_IS_LINK (inst))
253 cache->established = 1;
254 for (regnum = FT32_R0_REGNUM; regnum < FT32_PC_REGNUM; regnum++)
256 if (cache->saved_regs[regnum] != REG_UNAVAIL)
257 cache->saved_regs[regnum] += 4;
259 cache->saved_regs[FT32_PC_REGNUM] = cache->framesize + 4;
260 cache->saved_regs[FT32_FP_REGNUM] = 0;
261 cache->framesize += FT32_LINK_SIZE (inst);
262 next_addr += isize;
266 return next_addr;
269 /* Find the end of function prologue. */
271 static CORE_ADDR
272 ft32_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
274 CORE_ADDR func_addr = 0, func_end = 0;
275 const char *func_name;
277 /* See if we can determine the end of the prologue via the symbol table.
278 If so, then return either PC, or the PC after the prologue, whichever
279 is greater. */
280 if (find_pc_partial_function (pc, &func_name, &func_addr, &func_end))
282 CORE_ADDR post_prologue_pc
283 = skip_prologue_using_sal (gdbarch, func_addr);
284 if (post_prologue_pc != 0)
285 return std::max (pc, post_prologue_pc);
286 else
288 /* Can't determine prologue from the symbol table, need to examine
289 instructions. */
290 struct symtab_and_line sal;
291 struct symbol *sym;
292 struct ft32_frame_cache cache;
293 CORE_ADDR plg_end;
295 memset (&cache, 0, sizeof cache);
297 plg_end = ft32_analyze_prologue (func_addr,
298 func_end, &cache, gdbarch);
299 /* Found a function. */
300 sym = lookup_symbol (func_name, NULL, VAR_DOMAIN, NULL).symbol;
301 /* Don't use line number debug info for assembly source files. */
302 if ((sym != NULL) && sym->language () != language_asm)
304 sal = find_pc_line (func_addr, 0);
305 if (sal.end && sal.end < func_end)
307 /* Found a line number, use it as end of prologue. */
308 return sal.end;
311 /* No useable line symbol. Use result of prologue parsing method. */
312 return plg_end;
316 /* No function symbol -- just return the PC. */
317 return pc;
320 /* Implementation of `pointer_to_address' gdbarch method.
322 On FT32 address space zero is RAM, address space 1 is flash.
323 RAM appears at address RAM_BIAS, flash at address 0. */
325 static CORE_ADDR
326 ft32_pointer_to_address (struct gdbarch *gdbarch,
327 struct type *type, const gdb_byte *buf)
329 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
330 CORE_ADDR addr
331 = extract_unsigned_integer (buf, TYPE_LENGTH (type), byte_order);
333 if (TYPE_ADDRESS_CLASS_1 (type))
334 return addr;
335 else
336 return addr | RAM_BIAS;
339 /* Implementation of `address_class_type_flags' gdbarch method.
341 This method maps DW_AT_address_class attributes to a
342 type_instance_flag_value. */
344 static int
345 ft32_address_class_type_flags (int byte_size, int dwarf2_addr_class)
347 /* The value 1 of the DW_AT_address_class attribute corresponds to the
348 __flash__ qualifier, meaning pointer to data in FT32 program memory.
350 if (dwarf2_addr_class == 1)
351 return TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1;
352 return 0;
355 /* Implementation of `address_class_type_flags_to_name' gdbarch method.
357 Convert a type_instance_flag_value to an address space qualifier. */
359 static const char*
360 ft32_address_class_type_flags_to_name (struct gdbarch *gdbarch, int type_flags)
362 if (type_flags & TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1)
363 return "flash";
364 else
365 return NULL;
368 /* Implementation of `address_class_name_to_type_flags' gdbarch method.
370 Convert an address space qualifier to a type_instance_flag_value. */
372 static int
373 ft32_address_class_name_to_type_flags (struct gdbarch *gdbarch,
374 const char* name,
375 int *type_flags_ptr)
377 if (strcmp (name, "flash") == 0)
379 *type_flags_ptr = TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1;
380 return 1;
382 else
383 return 0;
386 /* Given a return value in `regbuf' with a type `valtype',
387 extract and copy its value into `valbuf'. */
389 static void
390 ft32_extract_return_value (struct type *type, struct regcache *regcache,
391 gdb_byte *dst)
393 struct gdbarch *gdbarch = regcache->arch ();
394 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
395 bfd_byte *valbuf = dst;
396 int len = TYPE_LENGTH (type);
397 ULONGEST tmp;
399 /* By using store_unsigned_integer we avoid having to do
400 anything special for small big-endian values. */
401 regcache_cooked_read_unsigned (regcache, FT32_R0_REGNUM, &tmp);
402 store_unsigned_integer (valbuf, (len > 4 ? len - 4 : len), byte_order, tmp);
404 /* Ignore return values more than 8 bytes in size because the ft32
405 returns anything more than 8 bytes in the stack. */
406 if (len > 4)
408 regcache_cooked_read_unsigned (regcache, FT32_R1_REGNUM, &tmp);
409 store_unsigned_integer (valbuf + len - 4, 4, byte_order, tmp);
413 /* Implement the "return_value" gdbarch method. */
415 static enum return_value_convention
416 ft32_return_value (struct gdbarch *gdbarch, struct value *function,
417 struct type *valtype, struct regcache *regcache,
418 gdb_byte *readbuf, const gdb_byte *writebuf)
420 if (TYPE_LENGTH (valtype) > 8)
421 return RETURN_VALUE_STRUCT_CONVENTION;
422 else
424 if (readbuf != NULL)
425 ft32_extract_return_value (valtype, regcache, readbuf);
426 if (writebuf != NULL)
427 ft32_store_return_value (valtype, regcache, writebuf);
428 return RETURN_VALUE_REGISTER_CONVENTION;
432 /* Allocate and initialize a ft32_frame_cache object. */
434 static struct ft32_frame_cache *
435 ft32_alloc_frame_cache (void)
437 struct ft32_frame_cache *cache;
438 int i;
440 cache = FRAME_OBSTACK_ZALLOC (struct ft32_frame_cache);
442 for (i = 0; i < FT32_NUM_REGS; ++i)
443 cache->saved_regs[i] = REG_UNAVAIL;
445 return cache;
448 /* Populate a ft32_frame_cache object for this_frame. */
450 static struct ft32_frame_cache *
451 ft32_frame_cache (struct frame_info *this_frame, void **this_cache)
453 struct ft32_frame_cache *cache;
454 CORE_ADDR current_pc;
455 int i;
457 if (*this_cache)
458 return (struct ft32_frame_cache *) *this_cache;
460 cache = ft32_alloc_frame_cache ();
461 *this_cache = cache;
463 cache->base = get_frame_register_unsigned (this_frame, FT32_FP_REGNUM);
464 if (cache->base == 0)
465 return cache;
467 cache->pc = get_frame_func (this_frame);
468 current_pc = get_frame_pc (this_frame);
469 if (cache->pc)
471 struct gdbarch *gdbarch = get_frame_arch (this_frame);
473 ft32_analyze_prologue (cache->pc, current_pc, cache, gdbarch);
474 if (!cache->established)
475 cache->base = get_frame_register_unsigned (this_frame, FT32_SP_REGNUM);
478 cache->saved_sp = cache->base - 4;
480 for (i = 0; i < FT32_NUM_REGS; ++i)
481 if (cache->saved_regs[i] != REG_UNAVAIL)
482 cache->saved_regs[i] = cache->base + cache->saved_regs[i];
484 return cache;
487 /* Given a GDB frame, determine the address of the calling function's
488 frame. This will be used to create a new GDB frame struct. */
490 static void
491 ft32_frame_this_id (struct frame_info *this_frame,
492 void **this_prologue_cache, struct frame_id *this_id)
494 struct ft32_frame_cache *cache = ft32_frame_cache (this_frame,
495 this_prologue_cache);
497 /* This marks the outermost frame. */
498 if (cache->base == 0)
499 return;
501 *this_id = frame_id_build (cache->saved_sp, cache->pc);
504 /* Get the value of register regnum in the previous stack frame. */
506 static struct value *
507 ft32_frame_prev_register (struct frame_info *this_frame,
508 void **this_prologue_cache, int regnum)
510 struct ft32_frame_cache *cache = ft32_frame_cache (this_frame,
511 this_prologue_cache);
513 gdb_assert (regnum >= 0);
515 if (regnum == FT32_SP_REGNUM && cache->saved_sp)
516 return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp);
518 if (regnum < FT32_NUM_REGS && cache->saved_regs[regnum] != REG_UNAVAIL)
519 return frame_unwind_got_memory (this_frame, regnum,
520 RAM_BIAS | cache->saved_regs[regnum]);
522 return frame_unwind_got_register (this_frame, regnum, regnum);
525 static const struct frame_unwind ft32_frame_unwind =
527 NORMAL_FRAME,
528 default_frame_unwind_stop_reason,
529 ft32_frame_this_id,
530 ft32_frame_prev_register,
531 NULL,
532 default_frame_sniffer
535 /* Return the base address of this_frame. */
537 static CORE_ADDR
538 ft32_frame_base_address (struct frame_info *this_frame, void **this_cache)
540 struct ft32_frame_cache *cache = ft32_frame_cache (this_frame,
541 this_cache);
543 return cache->base;
546 static const struct frame_base ft32_frame_base =
548 &ft32_frame_unwind,
549 ft32_frame_base_address,
550 ft32_frame_base_address,
551 ft32_frame_base_address
554 /* Allocate and initialize the ft32 gdbarch object. */
556 static struct gdbarch *
557 ft32_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
559 struct gdbarch *gdbarch;
560 struct gdbarch_tdep *tdep;
561 struct type *void_type;
562 struct type *func_void_type;
564 /* If there is already a candidate, use it. */
565 arches = gdbarch_list_lookup_by_info (arches, &info);
566 if (arches != NULL)
567 return arches->gdbarch;
569 /* Allocate space for the new architecture. */
570 tdep = XCNEW (struct gdbarch_tdep);
571 gdbarch = gdbarch_alloc (&info, tdep);
573 /* Create a type for PC. We can't use builtin types here, as they may not
574 be defined. */
575 void_type = arch_type (gdbarch, TYPE_CODE_VOID, TARGET_CHAR_BIT, "void");
576 func_void_type = make_function_type (void_type, NULL);
577 tdep->pc_type = arch_pointer_type (gdbarch, 4 * TARGET_CHAR_BIT, NULL,
578 func_void_type);
579 TYPE_INSTANCE_FLAGS (tdep->pc_type) |= TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1;
581 set_gdbarch_num_regs (gdbarch, FT32_NUM_REGS);
582 set_gdbarch_sp_regnum (gdbarch, FT32_SP_REGNUM);
583 set_gdbarch_pc_regnum (gdbarch, FT32_PC_REGNUM);
584 set_gdbarch_register_name (gdbarch, ft32_register_name);
585 set_gdbarch_register_type (gdbarch, ft32_register_type);
587 set_gdbarch_return_value (gdbarch, ft32_return_value);
589 set_gdbarch_pointer_to_address (gdbarch, ft32_pointer_to_address);
591 set_gdbarch_skip_prologue (gdbarch, ft32_skip_prologue);
592 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
593 set_gdbarch_breakpoint_kind_from_pc (gdbarch, ft32_breakpoint::kind_from_pc);
594 set_gdbarch_sw_breakpoint_from_kind (gdbarch, ft32_breakpoint::bp_from_kind);
595 set_gdbarch_frame_align (gdbarch, ft32_frame_align);
597 frame_base_set_default (gdbarch, &ft32_frame_base);
599 /* Hook in ABI-specific overrides, if they have been registered. */
600 gdbarch_init_osabi (info, gdbarch);
602 /* Hook in the default unwinders. */
603 frame_unwind_append_unwinder (gdbarch, &ft32_frame_unwind);
605 /* Support simple overlay manager. */
606 set_gdbarch_overlay_update (gdbarch, simple_overlay_update);
608 set_gdbarch_address_class_type_flags (gdbarch, ft32_address_class_type_flags);
609 set_gdbarch_address_class_name_to_type_flags
610 (gdbarch, ft32_address_class_name_to_type_flags);
611 set_gdbarch_address_class_type_flags_to_name
612 (gdbarch, ft32_address_class_type_flags_to_name);
614 return gdbarch;
617 /* Register this machine's init routine. */
619 void _initialize_ft32_tdep ();
620 void
621 _initialize_ft32_tdep ()
623 register_gdbarch_init (bfd_arch_ft32, ft32_gdbarch_init);