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a332e593 SC |
1 | /* Target-machine dependent code for Zilog Z8000, for GDB. |
2 | Copyright (C) 1992 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 | ||
26 | #include "defs.h" | |
27 | #include "frame.h" | |
28 | #include "obstack.h" | |
29 | #include "symtab.h" | |
30 | #include "gdbtypes.h" | |
31 | ||
32 | ||
33 | /* Return the saved PC from this frame. | |
34 | ||
35 | If the frame has a memory copy of SRP_REGNUM, use that. If not, | |
36 | just use the register SRP_REGNUM itself. */ | |
37 | ||
38 | CORE_ADDR | |
39 | frame_saved_pc (frame) | |
40 | FRAME frame; | |
41 | { | |
42 | return ( read_memory_pointer(frame->frame+(BIG ? 4 : 2))); | |
43 | } | |
44 | ||
45 | #define IS_PUSHL(x) (BIG ? ((x & 0xfff0) == 0x91e0):((x & 0xfff0) == 0x91F0)) | |
46 | #define IS_PUSHW(x) (BIG ? ((x & 0xfff0) == 0x93e0):((x & 0xfff0)==0x93f0)) | |
47 | #define IS_MOVE_FP(x) (BIG ? x == 0xa1ea : x == 0xa1fa) | |
48 | #define IS_MOV_SP_FP(x) (BIG ? x == 0x94ea : x == 0x0d76) | |
49 | #define IS_SUB2_SP(x) (x==0x1b87) | |
50 | #define IS_MOVK_R5(x) (x==0x7905) | |
51 | #define IS_SUB_SP(x) ((x & 0xffff) == 0x020f) | |
52 | #define IS_PUSH_FP(x) (BIG ? (x == 0x93ea) : (x == 0x93fa)) | |
53 | ||
54 | ||
55 | /* work out how much local space is on the stack and | |
56 | return the pc pointing to the first push */ | |
57 | ||
58 | static | |
59 | CORE_ADDR | |
60 | skip_adjust(pc, size) | |
61 | CORE_ADDR pc; | |
62 | int *size; | |
63 | { | |
64 | *size = 0; | |
65 | ||
66 | if (IS_PUSH_FP(read_memory_short(pc)) | |
67 | && IS_MOV_SP_FP(read_memory_short(pc+2))) | |
68 | { | |
69 | /* This is a function with an explict frame pointer */ | |
70 | pc += 4; | |
71 | *size += 2; /* remember the frame pointer */ | |
72 | } | |
73 | ||
74 | /* remember any stack adjustment */ | |
75 | if (IS_SUB_SP(read_memory_short(pc))) | |
76 | { | |
77 | *size += read_memory_short(pc+2); | |
78 | pc += 4; | |
79 | } | |
80 | return pc; | |
81 | } | |
82 | ||
83 | ||
84 | int | |
85 | examine_frame(pc, regs, sp) | |
86 | CORE_ADDR pc; | |
87 | struct frame_saved_regs *regs; | |
88 | CORE_ADDR sp; | |
89 | { | |
90 | int w = read_memory_short(pc); | |
91 | int offset = 0; | |
92 | int regno; | |
93 | ||
94 | ||
95 | ||
96 | for (regno = 0; regno < NUM_REGS; regno++) | |
97 | regs->regs[regno] = 0; | |
98 | ||
99 | while (IS_PUSHW(w) || IS_PUSHL(w)) | |
100 | { | |
101 | /* work out which register is being pushed to where */ | |
102 | if (IS_PUSHL(w)) | |
103 | { | |
104 | regs->regs[w & 0xf] = offset; | |
105 | regs->regs[(w & 0xf) + 1] = offset +2; | |
106 | offset += 4; | |
107 | } | |
108 | else { | |
109 | regs->regs[w & 0xf] = offset; | |
110 | offset += 2; | |
111 | } | |
112 | pc += 2; | |
113 | w = read_memory_short(pc); | |
114 | } | |
115 | ||
116 | if (IS_MOVE_FP(w)) | |
117 | { | |
118 | /* We know the fp */ | |
119 | ||
120 | } | |
121 | else if (IS_SUB_SP(w)) | |
122 | { | |
123 | /* Subtracting a value from the sp, so were in a function | |
124 | which needs stack space for locals, but has no fp. We fake up | |
125 | the values as if we had an fp */ | |
126 | regs->regs[FP_REGNUM] = sp; | |
127 | } | |
128 | else | |
129 | { | |
130 | /* This one didn't have an fp, we'll fake it up */ | |
131 | regs->regs[SP_REGNUM] = sp; | |
132 | } | |
133 | /* stack pointer contains address of next frame */ | |
134 | /* regs->regs[fp_regnum()] = fp;*/ | |
135 | regs->regs[SP_REGNUM] = sp; | |
136 | return pc; | |
137 | } | |
138 | ||
139 | CORE_ADDR z8k_skip_prologue(start_pc) | |
140 | CORE_ADDR start_pc; | |
141 | { | |
142 | struct frame_saved_regs dummy; | |
143 | return examine_frame(start_pc, &dummy, 0); | |
144 | } | |
145 | ||
146 | CORE_ADDR addr_bits_remove(x) | |
147 | CORE_ADDR x; | |
148 | { | |
149 | return x & PTR_MASK; | |
150 | } | |
151 | ||
152 | read_memory_pointer(x) | |
153 | CORE_ADDR x; | |
154 | { | |
155 | ||
156 | return read_memory_integer(ADDR_BITS_REMOVE(x), BIG ? 4 : 2); | |
157 | } | |
158 | ||
159 | FRAME_ADDR | |
160 | frame_chain (thisframe) | |
161 | FRAME thisframe; | |
162 | { | |
163 | if (thisframe->prev == 0) | |
164 | { | |
165 | /* This is the top of the stack, let's get the sp for real */ | |
166 | } | |
167 | if (!inside_entry_file ((thisframe)->pc)) | |
168 | { | |
169 | return read_memory_pointer ((thisframe)->frame); | |
170 | } | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | init_frame_pc() { abort(); } | |
176 | ||
177 | /* Put here the code to store, into a struct frame_saved_regs, | |
178 | the addresses of the saved registers of frame described by FRAME_INFO. | |
179 | This includes special registers such as pc and fp saved in special | |
180 | ways in the stack frame. sp is even more special: | |
181 | the address we return for it IS the sp for the next frame. */ | |
182 | ||
183 | void get_frame_saved_regs(frame_info, frame_saved_regs) | |
184 | struct frame_info *frame_info; | |
185 | struct frame_saved_regs *frame_saved_regs; | |
186 | ||
187 | { | |
188 | CORE_ADDR pc; | |
189 | int w; | |
190 | bzero(frame_saved_regs, sizeof(*frame_saved_regs)); | |
191 | pc = get_pc_function_start(frame_info->pc); | |
192 | ||
193 | /* wander down the instruction stream */ | |
194 | examine_frame(pc, frame_saved_regs, frame_info->frame); | |
195 | ||
196 | } | |
197 | ||
198 | ||
199 | extract_return_value(valtype, regbuf, valbuf) | |
200 | struct type *valtype; | |
201 | char regbuf[REGISTER_BYTES]; | |
202 | char *valbuf; | |
203 | { | |
204 | bcopy(regbuf + REGISTER_BYTE(2), valbuf, TYPE_LENGTH(valtype)); | |
205 | } | |
206 | void z8k_push_dummy_frame() { abort(); } | |
207 | ||
208 | int print_insn(memaddr, stream) | |
209 | CORE_ADDR memaddr; | |
210 | FILE *stream; | |
211 | { | |
212 | char temp[20]; | |
213 | read_memory (memaddr, temp, 20); | |
214 | if (BIG) { | |
215 | return print_insn_z8001(memaddr, temp, stream); | |
216 | } | |
217 | else { | |
218 | return print_insn_z8002(memaddr, temp, stream); | |
219 | } | |
220 | } | |
221 | ||
222 | void | |
223 | store_return_value() | |
224 | { | |
225 | abort(); | |
226 | } | |
227 | void | |
228 | store_struct_return() { abort(); } | |
229 | ||
230 | ||
231 | ||
232 | /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or | |
233 | is not the address of a valid instruction, the address of the next | |
234 | instruction beyond ADDR otherwise. *PWORD1 receives the first word | |
235 | of the instruction.*/ | |
236 | ||
237 | ||
238 | CORE_ADDR | |
239 | NEXT_PROLOGUE_INSN(addr, lim, pword1) | |
240 | CORE_ADDR addr; | |
241 | CORE_ADDR lim; | |
242 | short *pword1; | |
243 | { | |
244 | if (addr < lim+8) | |
245 | { | |
246 | read_memory (addr, pword1, sizeof(*pword1)); | |
247 | SWAP_TARGET_AND_HOST (pword1, sizeof (short)); | |
248 | return addr + 2; | |
249 | } | |
250 | ||
251 | return 0; | |
252 | ||
253 | } | |
254 | ||
255 | ||
256 | /* Put here the code to store, into a struct frame_saved_regs, | |
257 | the addresses of the saved registers of frame described by FRAME_INFO. | |
258 | This includes special registers such as pc and fp saved in special | |
259 | ways in the stack frame. sp is even more special: | |
260 | the address we return for it IS the sp for the next frame. | |
261 | ||
262 | We cache the result of doing this in the frame_cache_obstack, since | |
263 | it is fairly expensive. */ | |
264 | ||
265 | void | |
266 | frame_find_saved_regs (fip, fsrp) | |
267 | struct frame_info *fip; | |
268 | struct frame_saved_regs *fsrp; | |
269 | { | |
270 | int locals; | |
271 | CORE_ADDR pc; | |
272 | CORE_ADDR adr; | |
273 | int i; | |
274 | ||
275 | memset (fsrp, 0, sizeof *fsrp); | |
276 | ||
277 | pc = skip_adjust(get_pc_function_start (fip->pc), &locals); | |
278 | ||
279 | { | |
280 | adr = fip->frame - locals; | |
281 | for (i = 0; i < 8; i++) | |
282 | { | |
283 | int word = read_memory_short(pc); | |
284 | pc += 2 ; | |
285 | if (IS_PUSHL(word)) { | |
286 | fsrp->regs[word & 0xf] = adr; | |
287 | fsrp->regs[(word & 0xf) + 1] = adr - 2; | |
288 | adr -= 4; | |
289 | } | |
290 | else if (IS_PUSHW(word)) { | |
291 | fsrp->regs[word & 0xf] = adr; | |
292 | adr -= 2; | |
293 | } | |
294 | else | |
295 | break; | |
296 | } | |
297 | ||
298 | } | |
299 | ||
300 | fsrp->regs[PC_REGNUM] = fip->frame + 4; | |
301 | fsrp->regs[FP_REGNUM] = fip->frame; | |
302 | ||
303 | } | |
304 | ||
305 | void | |
306 | addr_bits_set() { abort(); } | |
307 | ||
308 | int | |
309 | saved_pc_after_call() | |
310 | { | |
311 | return addr_bits_remove(read_memory_integer(read_register(SP_REGNUM), PTR_SIZE)); | |
312 | } | |
313 | ||
314 | void | |
315 | print_register_hook(regno) | |
316 | int regno; | |
317 | { | |
318 | ||
319 | if ((regno & 1)==0 && regno < 16) | |
320 | { | |
321 | unsigned short l[2]; | |
322 | read_relative_register_raw_bytes(regno, (char *)(l+0)); | |
323 | read_relative_register_raw_bytes(regno+1, (char *)(l+1)); | |
324 | printf("\t"); | |
325 | printf("%04x%04x", l[0],l[1]); | |
326 | } | |
327 | ||
328 | if ((regno & 3)== 0 && regno < 16) | |
329 | { | |
330 | unsigned short l[4]; | |
331 | read_relative_register_raw_bytes(regno, l+0); | |
332 | read_relative_register_raw_bytes(regno+1, l+1); | |
333 | read_relative_register_raw_bytes(regno+2, l+2); | |
334 | read_relative_register_raw_bytes(regno+3, l+3); | |
335 | ||
336 | printf("\t"); | |
337 | printf("%04x%04x%04x%04x", l[0],l[1],l[2],l[3]); | |
338 | } | |
339 | if (regno == 15) | |
340 | { | |
341 | unsigned short rval; | |
342 | int i; | |
343 | read_relative_register_raw_bytes(regno, (char *)(&rval)); | |
344 | ||
345 | printf("\n"); | |
346 | for (i = 0; i < 10; i+=2) { | |
347 | printf("(sp+%d=%04x)",i, read_memory_short(rval+i)); | |
348 | } | |
349 | } | |
350 | ||
351 | } | |
352 | ||
353 | ||
354 | void | |
355 | register_convert_to_virtual(regnum, from, to) | |
356 | unsigned char *from; | |
357 | unsigned char *to; | |
358 | { | |
359 | to[0] = from[0]; | |
360 | to[1] = from[1]; | |
361 | to[2] = from[2]; | |
362 | to[3] = from[3]; | |
363 | } | |
364 | ||
365 | void | |
366 | register_convert_to_raw(regnum, to, from) | |
367 | char *to; | |
368 | char *from; | |
369 | { | |
370 | to[0] = from[0]; | |
371 | to[1] = from[1]; | |
372 | to[2] = from[2]; | |
373 | to[3] = from[3]; | |
374 | } | |
375 | ||
376 | ||
377 | ||
378 | void z8k_pop_frame() { } |