xref: /openbmc/qemu/target/ppc/gdbstub.c (revision a010bdbe)
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 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 
24 static int ppc_gdb_register_len_apple(int n)
25 {
26     switch (n) {
27     case 0 ... 31:
28         /* gprs */
29         return 8;
30     case 32 ... 63:
31         /* fprs */
32         return 8;
33     case 64 ... 95:
34         return 16;
35     case 64 + 32: /* nip */
36     case 65 + 32: /* msr */
37     case 67 + 32: /* lr */
38     case 68 + 32: /* ctr */
39     case 70 + 32: /* fpscr */
40         return 8;
41     case 66 + 32: /* cr */
42     case 69 + 32: /* xer */
43         return 4;
44     default:
45         return 0;
46     }
47 }
48 
49 static int ppc_gdb_register_len(int n)
50 {
51     switch (n) {
52     case 0 ... 31:
53         /* gprs */
54         return sizeof(target_ulong);
55     case 32 ... 63:
56         /* fprs */
57         if (gdb_has_xml) {
58             return 0;
59         }
60         return 8;
61     case 66:
62         /* cr */
63     case 69:
64         /* xer */
65         return 4;
66     case 64:
67         /* nip */
68     case 65:
69         /* msr */
70     case 67:
71         /* lr */
72     case 68:
73         /* ctr */
74         return sizeof(target_ulong);
75     case 70:
76         /* fpscr */
77         if (gdb_has_xml) {
78             return 0;
79         }
80         return sizeof(target_ulong);
81     default:
82         return 0;
83     }
84 }
85 
86 /*
87  * We need to present the registers to gdb in the "current" memory
88  * ordering.  For user-only mode we get this for free;
89  * TARGET_WORDS_BIGENDIAN is set to the proper ordering for the
90  * binary, and cannot be changed.  For system mode,
91  * TARGET_WORDS_BIGENDIAN is always set, and we must check the current
92  * mode of the chip to see if we're running in little-endian.
93  */
94 void ppc_maybe_bswap_register(CPUPPCState *env, uint8_t *mem_buf, int len)
95 {
96 #ifndef CONFIG_USER_ONLY
97     if (!msr_le) {
98         /* do nothing */
99     } else if (len == 4) {
100         bswap32s((uint32_t *)mem_buf);
101     } else if (len == 8) {
102         bswap64s((uint64_t *)mem_buf);
103     } else {
104         g_assert_not_reached();
105     }
106 #endif
107 }
108 
109 /*
110  * Old gdb always expects FP registers.  Newer (xml-aware) gdb only
111  * expects whatever the target description contains.  Due to a
112  * historical mishap the FP registers appear in between core integer
113  * regs and PC, MSR, CR, and so forth.  We hack round this by giving
114  * the FP regs zero size when talking to a newer gdb.
115  */
116 
117 int ppc_cpu_gdb_read_register(CPUState *cs, GByteArray *buf, int n)
118 {
119     PowerPCCPU *cpu = POWERPC_CPU(cs);
120     CPUPPCState *env = &cpu->env;
121     uint8_t *mem_buf;
122     int r = ppc_gdb_register_len(n);
123 
124     if (!r) {
125         return r;
126     }
127 
128     if (n < 32) {
129         /* gprs */
130         gdb_get_regl(buf, env->gpr[n]);
131     } else if (n < 64) {
132         /* fprs */
133         gdb_get_reg64(buf, *cpu_fpr_ptr(env, n - 32));
134     } else {
135         switch (n) {
136         case 64:
137             gdb_get_regl(buf, env->nip);
138             break;
139         case 65:
140             gdb_get_regl(buf, env->msr);
141             break;
142         case 66:
143             {
144                 uint32_t cr = 0;
145                 int i;
146                 for (i = 0; i < 8; i++) {
147                     cr |= env->crf[i] << (32 - ((i + 1) * 4));
148                 }
149                 gdb_get_reg32(buf, cr);
150                 break;
151             }
152         case 67:
153             gdb_get_regl(buf, env->lr);
154             break;
155         case 68:
156             gdb_get_regl(buf, env->ctr);
157             break;
158         case 69:
159             gdb_get_reg32(buf, env->xer);
160             break;
161         case 70:
162             gdb_get_reg32(buf, env->fpscr);
163             break;
164         }
165     }
166     mem_buf = buf->data + buf->len - r;
167     ppc_maybe_bswap_register(env, mem_buf, r);
168     return r;
169 }
170 
171 int ppc_cpu_gdb_read_register_apple(CPUState *cs, GByteArray *buf, int n)
172 {
173     PowerPCCPU *cpu = POWERPC_CPU(cs);
174     CPUPPCState *env = &cpu->env;
175     uint8_t *mem_buf;
176     int r = ppc_gdb_register_len_apple(n);
177 
178     if (!r) {
179         return r;
180     }
181 
182     if (n < 32) {
183         /* gprs */
184         gdb_get_reg64(buf, env->gpr[n]);
185     } else if (n < 64) {
186         /* fprs */
187         gdb_get_reg64(buf, *cpu_fpr_ptr(env, n - 32));
188     } else if (n < 96) {
189         /* Altivec */
190         gdb_get_reg64(buf, n - 64);
191         gdb_get_reg64(buf, 0);
192     } else {
193         switch (n) {
194         case 64 + 32:
195             gdb_get_reg64(buf, env->nip);
196             break;
197         case 65 + 32:
198             gdb_get_reg64(buf, env->msr);
199             break;
200         case 66 + 32:
201             {
202                 uint32_t cr = 0;
203                 int i;
204                 for (i = 0; i < 8; i++) {
205                     cr |= env->crf[i] << (32 - ((i + 1) * 4));
206                 }
207                 gdb_get_reg32(buf, cr);
208                 break;
209             }
210         case 67 + 32:
211             gdb_get_reg64(buf, env->lr);
212             break;
213         case 68 + 32:
214             gdb_get_reg64(buf, env->ctr);
215             break;
216         case 69 + 32:
217             gdb_get_reg32(buf, env->xer);
218             break;
219         case 70 + 32:
220             gdb_get_reg64(buf, env->fpscr);
221             break;
222         }
223     }
224     mem_buf = buf->data + buf->len - r;
225     ppc_maybe_bswap_register(env, mem_buf, r);
226     return r;
227 }
228 
229 int ppc_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
230 {
231     PowerPCCPU *cpu = POWERPC_CPU(cs);
232     CPUPPCState *env = &cpu->env;
233     int r = ppc_gdb_register_len(n);
234 
235     if (!r) {
236         return r;
237     }
238     ppc_maybe_bswap_register(env, mem_buf, r);
239     if (n < 32) {
240         /* gprs */
241         env->gpr[n] = ldtul_p(mem_buf);
242     } else if (n < 64) {
243         /* fprs */
244         *cpu_fpr_ptr(env, n - 32) = ldfq_p(mem_buf);
245     } else {
246         switch (n) {
247         case 64:
248             env->nip = ldtul_p(mem_buf);
249             break;
250         case 65:
251             ppc_store_msr(env, ldtul_p(mem_buf));
252             break;
253         case 66:
254             {
255                 uint32_t cr = ldl_p(mem_buf);
256                 int i;
257                 for (i = 0; i < 8; i++) {
258                     env->crf[i] = (cr >> (32 - ((i + 1) * 4))) & 0xF;
259                 }
260                 break;
261             }
262         case 67:
263             env->lr = ldtul_p(mem_buf);
264             break;
265         case 68:
266             env->ctr = ldtul_p(mem_buf);
267             break;
268         case 69:
269             env->xer = ldl_p(mem_buf);
270             break;
271         case 70:
272             /* fpscr */
273             store_fpscr(env, ldtul_p(mem_buf), 0xffffffff);
274             break;
275         }
276     }
277     return r;
278 }
279 int ppc_cpu_gdb_write_register_apple(CPUState *cs, uint8_t *mem_buf, int n)
280 {
281     PowerPCCPU *cpu = POWERPC_CPU(cs);
282     CPUPPCState *env = &cpu->env;
283     int r = ppc_gdb_register_len_apple(n);
284 
285     if (!r) {
286         return r;
287     }
288     ppc_maybe_bswap_register(env, mem_buf, r);
289     if (n < 32) {
290         /* gprs */
291         env->gpr[n] = ldq_p(mem_buf);
292     } else if (n < 64) {
293         /* fprs */
294         *cpu_fpr_ptr(env, n - 32) = ldfq_p(mem_buf);
295     } else {
296         switch (n) {
297         case 64 + 32:
298             env->nip = ldq_p(mem_buf);
299             break;
300         case 65 + 32:
301             ppc_store_msr(env, ldq_p(mem_buf));
302             break;
303         case 66 + 32:
304             {
305                 uint32_t cr = ldl_p(mem_buf);
306                 int i;
307                 for (i = 0; i < 8; i++) {
308                     env->crf[i] = (cr >> (32 - ((i + 1) * 4))) & 0xF;
309                 }
310                 break;
311             }
312         case 67 + 32:
313             env->lr = ldq_p(mem_buf);
314             break;
315         case 68 + 32:
316             env->ctr = ldq_p(mem_buf);
317             break;
318         case 69 + 32:
319             env->xer = ldl_p(mem_buf);
320             break;
321         case 70 + 32:
322             /* fpscr */
323             store_fpscr(env, ldq_p(mem_buf), 0xffffffff);
324             break;
325         }
326     }
327     return r;
328 }
329 
330 #ifndef CONFIG_USER_ONLY
331 void ppc_gdb_gen_spr_xml(PowerPCCPU *cpu)
332 {
333     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
334     CPUPPCState *env = &cpu->env;
335     GString *xml;
336     char *spr_name;
337     unsigned int num_regs = 0;
338     int i;
339 
340     if (pcc->gdb_spr_xml) {
341         return;
342     }
343 
344     xml = g_string_new("<?xml version=\"1.0\"?>");
345     g_string_append(xml, "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">");
346     g_string_append(xml, "<feature name=\"org.qemu.power.spr\">");
347 
348     for (i = 0; i < ARRAY_SIZE(env->spr_cb); i++) {
349         ppc_spr_t *spr = &env->spr_cb[i];
350 
351         if (!spr->name) {
352             continue;
353         }
354 
355         spr_name = g_ascii_strdown(spr->name, -1);
356         g_string_append_printf(xml, "<reg name=\"%s\"", spr_name);
357         g_free(spr_name);
358 
359         g_string_append_printf(xml, " bitsize=\"%d\"", TARGET_LONG_BITS);
360         g_string_append(xml, " group=\"spr\"/>");
361 
362         /*
363          * GDB identifies registers based on the order they are
364          * presented in the XML. These ids will not match QEMU's
365          * representation (which follows the PowerISA).
366          *
367          * Store the position of the current register description so
368          * we can make the correspondence later.
369          */
370         spr->gdb_id = num_regs;
371         num_regs++;
372     }
373 
374     g_string_append(xml, "</feature>");
375 
376     pcc->gdb_num_sprs = num_regs;
377     pcc->gdb_spr_xml = g_string_free(xml, false);
378 }
379 
380 const char *ppc_gdb_get_dynamic_xml(CPUState *cs, const char *xml_name)
381 {
382     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cs);
383 
384     if (strcmp(xml_name, "power-spr.xml") == 0) {
385         return pcc->gdb_spr_xml;
386     }
387     return NULL;
388 }
389 #endif
390