xref: /openbmc/qemu/target/ppc/gdbstub.c (revision 9940412ae4ae2d4971959c13311ba8d822974452)
1 /*
2  * PowerPC gdb server stub
3  *
4  * Copyright (c) 2003-2005 Fabrice Bellard
5  * Copyright (c) 2013 SUSE LINUX Products GmbH
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * This library 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 GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  */
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "exec/gdbstub.h"
23 #include "gdbstub/helpers.h"
24 #include "internal.h"
25 
26 static int ppc_gdb_register_len_apple(int n)
27 {
28     switch (n) {
29     case 0 ... 31:
30         /* gprs */
31         return 8;
32     case 32 ... 63:
33         /* fprs */
34         return 8;
35     case 64 ... 95:
36         return 16;
37     case 64 + 32: /* nip */
38     case 65 + 32: /* msr */
39     case 67 + 32: /* lr */
40     case 68 + 32: /* ctr */
41     case 70 + 32: /* fpscr */
42         return 8;
43     case 66 + 32: /* cr */
44     case 69 + 32: /* xer */
45         return 4;
46     default:
47         return 0;
48     }
49 }
50 
51 static int ppc_gdb_register_len(int n)
52 {
53     switch (n) {
54     case 0 ... 31:
55         /* gprs */
56         return sizeof(target_ulong);
57     case 66:
58         /* cr */
59     case 69:
60         /* xer */
61         return 4;
62     case 64:
63         /* nip */
64     case 65:
65         /* msr */
66     case 67:
67         /* lr */
68     case 68:
69         /* ctr */
70         return sizeof(target_ulong);
71     default:
72         return 0;
73     }
74 }
75 
76 /*
77  * We need to present the registers to gdb in the "current" memory
78  * ordering.  For user-only mode we get this for free;
79  * TARGET_BIG_ENDIAN is set to the proper ordering for the
80  * binary, and cannot be changed.  For system mode,
81  * TARGET_BIG_ENDIAN is always set, and we must check the current
82  * mode of the chip to see if we're running in little-endian.
83  */
84 void ppc_maybe_bswap_register(CPUPPCState *env, uint8_t *mem_buf, int len)
85 {
86 #ifndef CONFIG_USER_ONLY
87     if (!FIELD_EX64(env->msr, MSR, LE)) {
88         /* do nothing */
89     } else if (len == 4) {
90         bswap32s((uint32_t *)mem_buf);
91     } else if (len == 8) {
92         bswap64s((uint64_t *)mem_buf);
93     } else if (len == 16) {
94         bswap128s((Int128 *)mem_buf);
95     } else {
96         g_assert_not_reached();
97     }
98 #endif
99 }
100 
101 /*
102  * Old gdb always expects FP registers.  Newer (xml-aware) gdb only
103  * expects whatever the target description contains.  Due to a
104  * historical mishap the FP registers appear in between core integer
105  * regs and PC, MSR, CR, and so forth.  We hack round this by giving
106  * the FP regs zero size when talking to a newer gdb.
107  */
108 
109 int ppc_cpu_gdb_read_register(CPUState *cs, GByteArray *buf, int n)
110 {
111     PowerPCCPU *cpu = POWERPC_CPU(cs);
112     CPUPPCState *env = &cpu->env;
113     uint8_t *mem_buf;
114     int r = ppc_gdb_register_len(n);
115 
116     if (!r) {
117         return r;
118     }
119 
120     if (n < 32) {
121         /* gprs */
122         gdb_get_regl(buf, env->gpr[n]);
123     } else {
124         switch (n) {
125         case 64:
126             gdb_get_regl(buf, env->nip);
127             break;
128         case 65:
129             gdb_get_regl(buf, env->msr);
130             break;
131         case 66:
132             {
133                 uint32_t cr = ppc_get_cr(env);
134                 gdb_get_reg32(buf, cr);
135                 break;
136             }
137         case 67:
138             gdb_get_regl(buf, env->lr);
139             break;
140         case 68:
141             gdb_get_regl(buf, env->ctr);
142             break;
143         case 69:
144             gdb_get_reg32(buf, cpu_read_xer(env));
145             break;
146         }
147     }
148     mem_buf = buf->data + buf->len - r;
149     ppc_maybe_bswap_register(env, mem_buf, r);
150     return r;
151 }
152 
153 int ppc_cpu_gdb_read_register_apple(CPUState *cs, GByteArray *buf, int n)
154 {
155     PowerPCCPU *cpu = POWERPC_CPU(cs);
156     CPUPPCState *env = &cpu->env;
157     uint8_t *mem_buf;
158     int r = ppc_gdb_register_len_apple(n);
159 
160     if (!r) {
161         return r;
162     }
163 
164     if (n < 32) {
165         /* gprs */
166         gdb_get_reg64(buf, env->gpr[n]);
167     } else if (n < 64) {
168         /* fprs */
169         gdb_get_reg64(buf, *cpu_fpr_ptr(env, n - 32));
170     } else if (n < 96) {
171         /* Altivec */
172         gdb_get_reg64(buf, n - 64);
173         gdb_get_reg64(buf, 0);
174     } else {
175         switch (n) {
176         case 64 + 32:
177             gdb_get_reg64(buf, env->nip);
178             break;
179         case 65 + 32:
180             gdb_get_reg64(buf, env->msr);
181             break;
182         case 66 + 32:
183             {
184                 uint32_t cr = ppc_get_cr(env);
185                 gdb_get_reg32(buf, cr);
186                 break;
187             }
188         case 67 + 32:
189             gdb_get_reg64(buf, env->lr);
190             break;
191         case 68 + 32:
192             gdb_get_reg64(buf, env->ctr);
193             break;
194         case 69 + 32:
195             gdb_get_reg32(buf, cpu_read_xer(env));
196             break;
197         case 70 + 32:
198             gdb_get_reg64(buf, env->fpscr);
199             break;
200         }
201     }
202     mem_buf = buf->data + buf->len - r;
203     ppc_maybe_bswap_register(env, mem_buf, r);
204     return r;
205 }
206 
207 int ppc_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
208 {
209     PowerPCCPU *cpu = POWERPC_CPU(cs);
210     CPUPPCState *env = &cpu->env;
211     int r = ppc_gdb_register_len(n);
212 
213     if (!r) {
214         return r;
215     }
216     ppc_maybe_bswap_register(env, mem_buf, r);
217     if (n < 32) {
218         /* gprs */
219         env->gpr[n] = ldtul_p(mem_buf);
220     } else if (n < 64) {
221         /* fprs */
222         *cpu_fpr_ptr(env, n - 32) = ldq_p(mem_buf);
223     } else {
224         switch (n) {
225         case 64:
226             env->nip = ldtul_p(mem_buf);
227             break;
228         case 65:
229             ppc_store_msr(env, ldtul_p(mem_buf));
230             break;
231         case 66:
232             {
233                 uint32_t cr = ldl_p(mem_buf);
234                 ppc_set_cr(env, cr);
235                 break;
236             }
237         case 67:
238             env->lr = ldtul_p(mem_buf);
239             break;
240         case 68:
241             env->ctr = ldtul_p(mem_buf);
242             break;
243         case 69:
244             cpu_write_xer(env, ldl_p(mem_buf));
245             break;
246         case 70:
247             /* fpscr */
248             ppc_store_fpscr(env, ldtul_p(mem_buf));
249             break;
250         }
251     }
252     return r;
253 }
254 int ppc_cpu_gdb_write_register_apple(CPUState *cs, uint8_t *mem_buf, int n)
255 {
256     PowerPCCPU *cpu = POWERPC_CPU(cs);
257     CPUPPCState *env = &cpu->env;
258     int r = ppc_gdb_register_len_apple(n);
259 
260     if (!r) {
261         return r;
262     }
263     ppc_maybe_bswap_register(env, mem_buf, r);
264     if (n < 32) {
265         /* gprs */
266         env->gpr[n] = ldq_p(mem_buf);
267     } else if (n < 64) {
268         /* fprs */
269         *cpu_fpr_ptr(env, n - 32) = ldq_p(mem_buf);
270     } else {
271         switch (n) {
272         case 64 + 32:
273             env->nip = ldq_p(mem_buf);
274             break;
275         case 65 + 32:
276             ppc_store_msr(env, ldq_p(mem_buf));
277             break;
278         case 66 + 32:
279             {
280                 uint32_t cr = ldl_p(mem_buf);
281                 ppc_set_cr(env, cr);
282                 break;
283             }
284         case 67 + 32:
285             env->lr = ldq_p(mem_buf);
286             break;
287         case 68 + 32:
288             env->ctr = ldq_p(mem_buf);
289             break;
290         case 69 + 32:
291             cpu_write_xer(env, ldl_p(mem_buf));
292             break;
293         case 70 + 32:
294             /* fpscr */
295             ppc_store_fpscr(env, ldq_p(mem_buf));
296             break;
297         }
298     }
299     return r;
300 }
301 
302 #ifndef CONFIG_USER_ONLY
303 static void gdb_gen_spr_feature(CPUState *cs)
304 {
305     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cs);
306     PowerPCCPU *cpu = POWERPC_CPU(cs);
307     CPUPPCState *env = &cpu->env;
308     GDBFeatureBuilder builder;
309     unsigned int num_regs = 0;
310     int i;
311 
312     if (pcc->gdb_spr.xml) {
313         return;
314     }
315 
316     gdb_feature_builder_init(&builder, &pcc->gdb_spr,
317                              "org.qemu.power.spr", "power-spr.xml",
318                              cs->gdb_num_regs);
319 
320     for (i = 0; i < ARRAY_SIZE(env->spr_cb); i++) {
321         ppc_spr_t *spr = &env->spr_cb[i];
322 
323         if (!spr->name) {
324             continue;
325         }
326 
327         gdb_feature_builder_append_reg(&builder, g_ascii_strdown(spr->name, -1),
328                                        TARGET_LONG_BITS, num_regs,
329                                        "int", "spr");
330         /*
331          * GDB identifies registers based on the order they are
332          * presented in the XML. These ids will not match QEMU's
333          * representation (which follows the PowerISA).
334          *
335          * Store the position of the current register description so
336          * we can make the correspondence later.
337          */
338         spr->gdb_id = num_regs;
339         num_regs++;
340     }
341 
342     gdb_feature_builder_end(&builder);
343 }
344 #endif
345 
346 #if !defined(CONFIG_USER_ONLY)
347 static int gdb_find_spr_idx(CPUPPCState *env, int n)
348 {
349     int i;
350 
351     for (i = 0; i < ARRAY_SIZE(env->spr_cb); i++) {
352         ppc_spr_t *spr = &env->spr_cb[i];
353 
354         if (spr->name && spr->gdb_id == n) {
355             return i;
356         }
357     }
358     return -1;
359 }
360 
361 static int gdb_get_spr_reg(CPUState *cs, GByteArray *buf, int n)
362 {
363     PowerPCCPU *cpu = POWERPC_CPU(cs);
364     CPUPPCState *env = &cpu->env;
365     int reg;
366     int len;
367 
368     reg = gdb_find_spr_idx(env, n);
369     if (reg < 0) {
370         return 0;
371     }
372 
373     len = TARGET_LONG_SIZE;
374 
375     /* Handle those SPRs that are not part of the env->spr[] array */
376     target_ulong val;
377     switch (reg) {
378 #if defined(TARGET_PPC64)
379     case SPR_CFAR:
380         val = env->cfar;
381         break;
382 #endif
383     case SPR_HDEC:
384         val = cpu_ppc_load_hdecr(env);
385         break;
386     case SPR_TBL:
387         val = cpu_ppc_load_tbl(env);
388         break;
389     case SPR_TBU:
390         val = cpu_ppc_load_tbu(env);
391         break;
392     case SPR_DECR:
393         val = cpu_ppc_load_decr(env);
394         break;
395     default:
396         val = env->spr[reg];
397     }
398     gdb_get_regl(buf, val);
399 
400     ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, len), len);
401     return len;
402 }
403 
404 static int gdb_set_spr_reg(CPUState *cs, uint8_t *mem_buf, int n)
405 {
406     PowerPCCPU *cpu = POWERPC_CPU(cs);
407     CPUPPCState *env = &cpu->env;
408     int reg;
409     int len;
410 
411     reg = gdb_find_spr_idx(env, n);
412     if (reg < 0) {
413         return 0;
414     }
415 
416     len = TARGET_LONG_SIZE;
417     ppc_maybe_bswap_register(env, mem_buf, len);
418 
419     /* Handle those SPRs that are not part of the env->spr[] array */
420     target_ulong val = ldn_p(mem_buf, len);
421     switch (reg) {
422 #if defined(TARGET_PPC64)
423     case SPR_CFAR:
424         env->cfar = val;
425         break;
426 #endif
427     default:
428         env->spr[reg] = val;
429     }
430 
431     return len;
432 }
433 #endif
434 
435 static int gdb_get_float_reg(CPUState *cs, GByteArray *buf, int n)
436 {
437     PowerPCCPU *cpu = POWERPC_CPU(cs);
438     CPUPPCState *env = &cpu->env;
439     uint8_t *mem_buf;
440     if (n < 32) {
441         gdb_get_reg64(buf, *cpu_fpr_ptr(env, n));
442         mem_buf = gdb_get_reg_ptr(buf, 8);
443         ppc_maybe_bswap_register(env, mem_buf, 8);
444         return 8;
445     }
446     if (n == 32) {
447         gdb_get_reg32(buf, env->fpscr);
448         mem_buf = gdb_get_reg_ptr(buf, 4);
449         ppc_maybe_bswap_register(env, mem_buf, 4);
450         return 4;
451     }
452     return 0;
453 }
454 
455 static int gdb_set_float_reg(CPUState *cs, uint8_t *mem_buf, int n)
456 {
457     PowerPCCPU *cpu = POWERPC_CPU(cs);
458     CPUPPCState *env = &cpu->env;
459 
460     if (n < 32) {
461         ppc_maybe_bswap_register(env, mem_buf, 8);
462         *cpu_fpr_ptr(env, n) = ldq_p(mem_buf);
463         return 8;
464     }
465     if (n == 32) {
466         ppc_maybe_bswap_register(env, mem_buf, 4);
467         ppc_store_fpscr(env, ldl_p(mem_buf));
468         return 4;
469     }
470     return 0;
471 }
472 
473 static int gdb_get_avr_reg(CPUState *cs, GByteArray *buf, int n)
474 {
475     PowerPCCPU *cpu = POWERPC_CPU(cs);
476     CPUPPCState *env = &cpu->env;
477     uint8_t *mem_buf;
478 
479     if (n < 32) {
480         ppc_avr_t *avr = cpu_avr_ptr(env, n);
481         gdb_get_reg128(buf, avr->VsrD(0), avr->VsrD(1));
482         mem_buf = gdb_get_reg_ptr(buf, 16);
483         ppc_maybe_bswap_register(env, mem_buf, 16);
484         return 16;
485     }
486     if (n == 32) {
487         gdb_get_reg32(buf, ppc_get_vscr(env));
488         mem_buf = gdb_get_reg_ptr(buf, 4);
489         ppc_maybe_bswap_register(env, mem_buf, 4);
490         return 4;
491     }
492     if (n == 33) {
493         gdb_get_reg32(buf, (uint32_t)env->spr[SPR_VRSAVE]);
494         mem_buf = gdb_get_reg_ptr(buf, 4);
495         ppc_maybe_bswap_register(env, mem_buf, 4);
496         return 4;
497     }
498     return 0;
499 }
500 
501 static int gdb_set_avr_reg(CPUState *cs, uint8_t *mem_buf, int n)
502 {
503     PowerPCCPU *cpu = POWERPC_CPU(cs);
504     CPUPPCState *env = &cpu->env;
505 
506     if (n < 32) {
507         ppc_avr_t *avr = cpu_avr_ptr(env, n);
508         ppc_maybe_bswap_register(env, mem_buf, 16);
509         avr->VsrD(0) = ldq_p(mem_buf);
510         avr->VsrD(1) = ldq_p(mem_buf + 8);
511         return 16;
512     }
513     if (n == 32) {
514         ppc_maybe_bswap_register(env, mem_buf, 4);
515         ppc_store_vscr(env, ldl_p(mem_buf));
516         return 4;
517     }
518     if (n == 33) {
519         ppc_maybe_bswap_register(env, mem_buf, 4);
520         env->spr[SPR_VRSAVE] = (target_ulong)ldl_p(mem_buf);
521         return 4;
522     }
523     return 0;
524 }
525 
526 static int gdb_get_spe_reg(CPUState *cs, GByteArray *buf, int n)
527 {
528     PowerPCCPU *cpu = POWERPC_CPU(cs);
529     CPUPPCState *env = &cpu->env;
530 
531     if (n < 32) {
532 #if defined(TARGET_PPC64)
533         gdb_get_reg32(buf, env->gpr[n] >> 32);
534         ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, 4), 4);
535 #else
536         gdb_get_reg32(buf, env->gprh[n]);
537 #endif
538         return 4;
539     }
540     if (n == 32) {
541         gdb_get_reg64(buf, env->spe_acc);
542         ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, 8), 8);
543         return 8;
544     }
545     if (n == 33) {
546         gdb_get_reg32(buf, env->spe_fscr);
547         ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, 4), 4);
548         return 4;
549     }
550     return 0;
551 }
552 
553 static int gdb_set_spe_reg(CPUState *cs, uint8_t *mem_buf, int n)
554 {
555     PowerPCCPU *cpu = POWERPC_CPU(cs);
556     CPUPPCState *env = &cpu->env;
557 
558     if (n < 32) {
559 #if defined(TARGET_PPC64)
560         target_ulong lo = (uint32_t)env->gpr[n];
561         target_ulong hi;
562 
563         ppc_maybe_bswap_register(env, mem_buf, 4);
564 
565         hi = (target_ulong)ldl_p(mem_buf) << 32;
566         env->gpr[n] = lo | hi;
567 #else
568         env->gprh[n] = ldl_p(mem_buf);
569 #endif
570         return 4;
571     }
572     if (n == 32) {
573         ppc_maybe_bswap_register(env, mem_buf, 8);
574         env->spe_acc = ldq_p(mem_buf);
575         return 8;
576     }
577     if (n == 33) {
578         ppc_maybe_bswap_register(env, mem_buf, 4);
579         env->spe_fscr = ldl_p(mem_buf);
580         return 4;
581     }
582     return 0;
583 }
584 
585 static int gdb_get_vsx_reg(CPUState *cs, GByteArray *buf, int n)
586 {
587     PowerPCCPU *cpu = POWERPC_CPU(cs);
588     CPUPPCState *env = &cpu->env;
589 
590     if (n < 32) {
591         gdb_get_reg64(buf, *cpu_vsrl_ptr(env, n));
592         ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, 8), 8);
593         return 8;
594     }
595     return 0;
596 }
597 
598 static int gdb_set_vsx_reg(CPUState *cs, uint8_t *mem_buf, int n)
599 {
600     PowerPCCPU *cpu = POWERPC_CPU(cs);
601     CPUPPCState *env = &cpu->env;
602 
603     if (n < 32) {
604         ppc_maybe_bswap_register(env, mem_buf, 8);
605         *cpu_vsrl_ptr(env, n) = ldq_p(mem_buf);
606         return 8;
607     }
608     return 0;
609 }
610 
611 const gchar *ppc_gdb_arch_name(CPUState *cs)
612 {
613 #if defined(TARGET_PPC64)
614     return "powerpc:common64";
615 #else
616     return "powerpc:common";
617 #endif
618 }
619 
620 void ppc_gdb_init(CPUState *cs, PowerPCCPUClass *pcc)
621 {
622     if (pcc->insns_flags & PPC_FLOAT) {
623         gdb_register_coprocessor(cs, gdb_get_float_reg, gdb_set_float_reg,
624                                  gdb_find_static_feature("power-fpu.xml"), 0);
625     }
626     if (pcc->insns_flags & PPC_ALTIVEC) {
627         gdb_register_coprocessor(cs, gdb_get_avr_reg, gdb_set_avr_reg,
628                                  gdb_find_static_feature("power-altivec.xml"),
629                                  0);
630     }
631     if (pcc->insns_flags & PPC_SPE) {
632         gdb_register_coprocessor(cs, gdb_get_spe_reg, gdb_set_spe_reg,
633                                  gdb_find_static_feature("power-spe.xml"), 0);
634     }
635     if (pcc->insns_flags2 & PPC2_VSX) {
636         gdb_register_coprocessor(cs, gdb_get_vsx_reg, gdb_set_vsx_reg,
637                                  gdb_find_static_feature("power-vsx.xml"), 0);
638     }
639 #ifndef CONFIG_USER_ONLY
640     gdb_gen_spr_feature(cs);
641     gdb_register_coprocessor(cs, gdb_get_spr_reg, gdb_set_spr_reg,
642                              &pcc->gdb_spr, 0);
643 #endif
644 }
645