xref: /openbmc/qemu/target/ppc/gdbstub.c (revision 707ded20)
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         /*
328          * GDB identifies registers based on the order they are
329          * presented in the XML. These ids will not match QEMU's
330          * representation (which follows the PowerISA).
331          *
332          * Store the position of the current register description so
333          * we can make the correspondence later.
334          */
335         spr->gdb_id = num_regs;
336         num_regs++;
337 
338         gdb_feature_builder_append_reg(&builder, g_ascii_strdown(spr->name, -1),
339                                        TARGET_LONG_BITS, num_regs,
340                                        "int", "spr");
341     }
342 
343     gdb_feature_builder_end(&builder);
344 }
345 #endif
346 
347 #if !defined(CONFIG_USER_ONLY)
348 static int gdb_find_spr_idx(CPUPPCState *env, int n)
349 {
350     int i;
351 
352     for (i = 0; i < ARRAY_SIZE(env->spr_cb); i++) {
353         ppc_spr_t *spr = &env->spr_cb[i];
354 
355         if (spr->name && spr->gdb_id == n) {
356             return i;
357         }
358     }
359     return -1;
360 }
361 
362 static int gdb_get_spr_reg(CPUState *cs, GByteArray *buf, int n)
363 {
364     PowerPCCPU *cpu = POWERPC_CPU(cs);
365     CPUPPCState *env = &cpu->env;
366     int reg;
367     int len;
368 
369     reg = gdb_find_spr_idx(env, n);
370     if (reg < 0) {
371         return 0;
372     }
373 
374     len = TARGET_LONG_SIZE;
375 
376     /* Handle those SPRs that are not part of the env->spr[] array */
377     target_ulong val;
378     switch (reg) {
379 #if defined(TARGET_PPC64)
380     case SPR_CFAR:
381         val = env->cfar;
382         break;
383 #endif
384     case SPR_HDEC:
385         val = cpu_ppc_load_hdecr(env);
386         break;
387     case SPR_TBL:
388         val = cpu_ppc_load_tbl(env);
389         break;
390     case SPR_TBU:
391         val = cpu_ppc_load_tbu(env);
392         break;
393     case SPR_DECR:
394         val = cpu_ppc_load_decr(env);
395         break;
396     default:
397         val = env->spr[reg];
398     }
399     gdb_get_regl(buf, val);
400 
401     ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, len), len);
402     return len;
403 }
404 
405 static int gdb_set_spr_reg(CPUState *cs, uint8_t *mem_buf, int n)
406 {
407     PowerPCCPU *cpu = POWERPC_CPU(cs);
408     CPUPPCState *env = &cpu->env;
409     int reg;
410     int len;
411 
412     reg = gdb_find_spr_idx(env, n);
413     if (reg < 0) {
414         return 0;
415     }
416 
417     len = TARGET_LONG_SIZE;
418     ppc_maybe_bswap_register(env, mem_buf, len);
419 
420     /* Handle those SPRs that are not part of the env->spr[] array */
421     target_ulong val = ldn_p(mem_buf, len);
422     switch (reg) {
423 #if defined(TARGET_PPC64)
424     case SPR_CFAR:
425         env->cfar = val;
426         break;
427 #endif
428     default:
429         env->spr[reg] = val;
430     }
431 
432     return len;
433 }
434 #endif
435 
436 static int gdb_get_float_reg(CPUState *cs, GByteArray *buf, int n)
437 {
438     PowerPCCPU *cpu = POWERPC_CPU(cs);
439     CPUPPCState *env = &cpu->env;
440     uint8_t *mem_buf;
441     if (n < 32) {
442         gdb_get_reg64(buf, *cpu_fpr_ptr(env, n));
443         mem_buf = gdb_get_reg_ptr(buf, 8);
444         ppc_maybe_bswap_register(env, mem_buf, 8);
445         return 8;
446     }
447     if (n == 32) {
448         gdb_get_reg32(buf, env->fpscr);
449         mem_buf = gdb_get_reg_ptr(buf, 4);
450         ppc_maybe_bswap_register(env, mem_buf, 4);
451         return 4;
452     }
453     return 0;
454 }
455 
456 static int gdb_set_float_reg(CPUState *cs, uint8_t *mem_buf, int n)
457 {
458     PowerPCCPU *cpu = POWERPC_CPU(cs);
459     CPUPPCState *env = &cpu->env;
460 
461     if (n < 32) {
462         ppc_maybe_bswap_register(env, mem_buf, 8);
463         *cpu_fpr_ptr(env, n) = ldq_p(mem_buf);
464         return 8;
465     }
466     if (n == 32) {
467         ppc_maybe_bswap_register(env, mem_buf, 4);
468         ppc_store_fpscr(env, ldl_p(mem_buf));
469         return 4;
470     }
471     return 0;
472 }
473 
474 static int gdb_get_avr_reg(CPUState *cs, GByteArray *buf, int n)
475 {
476     PowerPCCPU *cpu = POWERPC_CPU(cs);
477     CPUPPCState *env = &cpu->env;
478     uint8_t *mem_buf;
479 
480     if (n < 32) {
481         ppc_avr_t *avr = cpu_avr_ptr(env, n);
482         gdb_get_reg128(buf, avr->VsrD(0), avr->VsrD(1));
483         mem_buf = gdb_get_reg_ptr(buf, 16);
484         ppc_maybe_bswap_register(env, mem_buf, 16);
485         return 16;
486     }
487     if (n == 32) {
488         gdb_get_reg32(buf, ppc_get_vscr(env));
489         mem_buf = gdb_get_reg_ptr(buf, 4);
490         ppc_maybe_bswap_register(env, mem_buf, 4);
491         return 4;
492     }
493     if (n == 33) {
494         gdb_get_reg32(buf, (uint32_t)env->spr[SPR_VRSAVE]);
495         mem_buf = gdb_get_reg_ptr(buf, 4);
496         ppc_maybe_bswap_register(env, mem_buf, 4);
497         return 4;
498     }
499     return 0;
500 }
501 
502 static int gdb_set_avr_reg(CPUState *cs, uint8_t *mem_buf, int n)
503 {
504     PowerPCCPU *cpu = POWERPC_CPU(cs);
505     CPUPPCState *env = &cpu->env;
506 
507     if (n < 32) {
508         ppc_avr_t *avr = cpu_avr_ptr(env, n);
509         ppc_maybe_bswap_register(env, mem_buf, 16);
510         avr->VsrD(0) = ldq_p(mem_buf);
511         avr->VsrD(1) = ldq_p(mem_buf + 8);
512         return 16;
513     }
514     if (n == 32) {
515         ppc_maybe_bswap_register(env, mem_buf, 4);
516         ppc_store_vscr(env, ldl_p(mem_buf));
517         return 4;
518     }
519     if (n == 33) {
520         ppc_maybe_bswap_register(env, mem_buf, 4);
521         env->spr[SPR_VRSAVE] = (target_ulong)ldl_p(mem_buf);
522         return 4;
523     }
524     return 0;
525 }
526 
527 static int gdb_get_spe_reg(CPUState *cs, GByteArray *buf, int n)
528 {
529     PowerPCCPU *cpu = POWERPC_CPU(cs);
530     CPUPPCState *env = &cpu->env;
531 
532     if (n < 32) {
533 #if defined(TARGET_PPC64)
534         gdb_get_reg32(buf, env->gpr[n] >> 32);
535         ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, 4), 4);
536 #else
537         gdb_get_reg32(buf, env->gprh[n]);
538 #endif
539         return 4;
540     }
541     if (n == 32) {
542         gdb_get_reg64(buf, env->spe_acc);
543         ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, 8), 8);
544         return 8;
545     }
546     if (n == 33) {
547         gdb_get_reg32(buf, env->spe_fscr);
548         ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, 4), 4);
549         return 4;
550     }
551     return 0;
552 }
553 
554 static int gdb_set_spe_reg(CPUState *cs, uint8_t *mem_buf, int n)
555 {
556     PowerPCCPU *cpu = POWERPC_CPU(cs);
557     CPUPPCState *env = &cpu->env;
558 
559     if (n < 32) {
560 #if defined(TARGET_PPC64)
561         target_ulong lo = (uint32_t)env->gpr[n];
562         target_ulong hi;
563 
564         ppc_maybe_bswap_register(env, mem_buf, 4);
565 
566         hi = (target_ulong)ldl_p(mem_buf) << 32;
567         env->gpr[n] = lo | hi;
568 #else
569         env->gprh[n] = ldl_p(mem_buf);
570 #endif
571         return 4;
572     }
573     if (n == 32) {
574         ppc_maybe_bswap_register(env, mem_buf, 8);
575         env->spe_acc = ldq_p(mem_buf);
576         return 8;
577     }
578     if (n == 33) {
579         ppc_maybe_bswap_register(env, mem_buf, 4);
580         env->spe_fscr = ldl_p(mem_buf);
581         return 4;
582     }
583     return 0;
584 }
585 
586 static int gdb_get_vsx_reg(CPUState *cs, GByteArray *buf, int n)
587 {
588     PowerPCCPU *cpu = POWERPC_CPU(cs);
589     CPUPPCState *env = &cpu->env;
590 
591     if (n < 32) {
592         gdb_get_reg64(buf, *cpu_vsrl_ptr(env, n));
593         ppc_maybe_bswap_register(env, gdb_get_reg_ptr(buf, 8), 8);
594         return 8;
595     }
596     return 0;
597 }
598 
599 static int gdb_set_vsx_reg(CPUState *cs, uint8_t *mem_buf, int n)
600 {
601     PowerPCCPU *cpu = POWERPC_CPU(cs);
602     CPUPPCState *env = &cpu->env;
603 
604     if (n < 32) {
605         ppc_maybe_bswap_register(env, mem_buf, 8);
606         *cpu_vsrl_ptr(env, n) = ldq_p(mem_buf);
607         return 8;
608     }
609     return 0;
610 }
611 
612 const gchar *ppc_gdb_arch_name(CPUState *cs)
613 {
614 #if defined(TARGET_PPC64)
615     return "powerpc:common64";
616 #else
617     return "powerpc:common";
618 #endif
619 }
620 
621 void ppc_gdb_init(CPUState *cs, PowerPCCPUClass *pcc)
622 {
623     if (pcc->insns_flags & PPC_FLOAT) {
624         gdb_register_coprocessor(cs, gdb_get_float_reg, gdb_set_float_reg,
625                                  gdb_find_static_feature("power-fpu.xml"), 0);
626     }
627     if (pcc->insns_flags & PPC_ALTIVEC) {
628         gdb_register_coprocessor(cs, gdb_get_avr_reg, gdb_set_avr_reg,
629                                  gdb_find_static_feature("power-altivec.xml"),
630                                  0);
631     }
632     if (pcc->insns_flags & PPC_SPE) {
633         gdb_register_coprocessor(cs, gdb_get_spe_reg, gdb_set_spe_reg,
634                                  gdb_find_static_feature("power-spe.xml"), 0);
635     }
636     if (pcc->insns_flags2 & PPC2_VSX) {
637         gdb_register_coprocessor(cs, gdb_get_vsx_reg, gdb_set_vsx_reg,
638                                  gdb_find_static_feature("power-vsx.xml"), 0);
639     }
640 #ifndef CONFIG_USER_ONLY
641     gdb_gen_spr_feature(cs);
642     gdb_register_coprocessor(cs, gdb_get_spr_reg, gdb_set_spr_reg,
643                              &pcc->gdb_spr, 0);
644 #endif
645 }
646