xref: /openbmc/qemu/target/ppc/gdbstub.c (revision 3d9569b8)
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, uint8_t *mem_buf, int n)
118 {
119     PowerPCCPU *cpu = POWERPC_CPU(cs);
120     CPUPPCState *env = &cpu->env;
121     int r = ppc_gdb_register_len(n);
122 
123     if (!r) {
124         return r;
125     }
126 
127     if (n < 32) {
128         /* gprs */
129         gdb_get_regl(mem_buf, env->gpr[n]);
130     } else if (n < 64) {
131         /* fprs */
132         stfq_p(mem_buf, *cpu_fpr_ptr(env, n - 32));
133     } else {
134         switch (n) {
135         case 64:
136             gdb_get_regl(mem_buf, env->nip);
137             break;
138         case 65:
139             gdb_get_regl(mem_buf, env->msr);
140             break;
141         case 66:
142             {
143                 uint32_t cr = 0;
144                 int i;
145                 for (i = 0; i < 8; i++) {
146                     cr |= env->crf[i] << (32 - ((i + 1) * 4));
147                 }
148                 gdb_get_reg32(mem_buf, cr);
149                 break;
150             }
151         case 67:
152             gdb_get_regl(mem_buf, env->lr);
153             break;
154         case 68:
155             gdb_get_regl(mem_buf, env->ctr);
156             break;
157         case 69:
158             gdb_get_reg32(mem_buf, env->xer);
159             break;
160         case 70:
161             gdb_get_reg32(mem_buf, env->fpscr);
162             break;
163         }
164     }
165     ppc_maybe_bswap_register(env, mem_buf, r);
166     return r;
167 }
168 
169 int ppc_cpu_gdb_read_register_apple(CPUState *cs, uint8_t *mem_buf, int n)
170 {
171     PowerPCCPU *cpu = POWERPC_CPU(cs);
172     CPUPPCState *env = &cpu->env;
173     int r = ppc_gdb_register_len_apple(n);
174 
175     if (!r) {
176         return r;
177     }
178 
179     if (n < 32) {
180         /* gprs */
181         gdb_get_reg64(mem_buf, env->gpr[n]);
182     } else if (n < 64) {
183         /* fprs */
184         stfq_p(mem_buf, *cpu_fpr_ptr(env, n - 32));
185     } else if (n < 96) {
186         /* Altivec */
187         stq_p(mem_buf, n - 64);
188         stq_p(mem_buf + 8, 0);
189     } else {
190         switch (n) {
191         case 64 + 32:
192             gdb_get_reg64(mem_buf, env->nip);
193             break;
194         case 65 + 32:
195             gdb_get_reg64(mem_buf, env->msr);
196             break;
197         case 66 + 32:
198             {
199                 uint32_t cr = 0;
200                 int i;
201                 for (i = 0; i < 8; i++) {
202                     cr |= env->crf[i] << (32 - ((i + 1) * 4));
203                 }
204                 gdb_get_reg32(mem_buf, cr);
205                 break;
206             }
207         case 67 + 32:
208             gdb_get_reg64(mem_buf, env->lr);
209             break;
210         case 68 + 32:
211             gdb_get_reg64(mem_buf, env->ctr);
212             break;
213         case 69 + 32:
214             gdb_get_reg32(mem_buf, env->xer);
215             break;
216         case 70 + 32:
217             gdb_get_reg64(mem_buf, env->fpscr);
218             break;
219         }
220     }
221     ppc_maybe_bswap_register(env, mem_buf, r);
222     return r;
223 }
224 
225 int ppc_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
226 {
227     PowerPCCPU *cpu = POWERPC_CPU(cs);
228     CPUPPCState *env = &cpu->env;
229     int r = ppc_gdb_register_len(n);
230 
231     if (!r) {
232         return r;
233     }
234     ppc_maybe_bswap_register(env, mem_buf, r);
235     if (n < 32) {
236         /* gprs */
237         env->gpr[n] = ldtul_p(mem_buf);
238     } else if (n < 64) {
239         /* fprs */
240         *cpu_fpr_ptr(env, n - 32) = ldfq_p(mem_buf);
241     } else {
242         switch (n) {
243         case 64:
244             env->nip = ldtul_p(mem_buf);
245             break;
246         case 65:
247             ppc_store_msr(env, ldtul_p(mem_buf));
248             break;
249         case 66:
250             {
251                 uint32_t cr = ldl_p(mem_buf);
252                 int i;
253                 for (i = 0; i < 8; i++) {
254                     env->crf[i] = (cr >> (32 - ((i + 1) * 4))) & 0xF;
255                 }
256                 break;
257             }
258         case 67:
259             env->lr = ldtul_p(mem_buf);
260             break;
261         case 68:
262             env->ctr = ldtul_p(mem_buf);
263             break;
264         case 69:
265             env->xer = ldl_p(mem_buf);
266             break;
267         case 70:
268             /* fpscr */
269             store_fpscr(env, ldtul_p(mem_buf), 0xffffffff);
270             break;
271         }
272     }
273     return r;
274 }
275 int ppc_cpu_gdb_write_register_apple(CPUState *cs, uint8_t *mem_buf, int n)
276 {
277     PowerPCCPU *cpu = POWERPC_CPU(cs);
278     CPUPPCState *env = &cpu->env;
279     int r = ppc_gdb_register_len_apple(n);
280 
281     if (!r) {
282         return r;
283     }
284     ppc_maybe_bswap_register(env, mem_buf, r);
285     if (n < 32) {
286         /* gprs */
287         env->gpr[n] = ldq_p(mem_buf);
288     } else if (n < 64) {
289         /* fprs */
290         *cpu_fpr_ptr(env, n - 32) = ldfq_p(mem_buf);
291     } else {
292         switch (n) {
293         case 64 + 32:
294             env->nip = ldq_p(mem_buf);
295             break;
296         case 65 + 32:
297             ppc_store_msr(env, ldq_p(mem_buf));
298             break;
299         case 66 + 32:
300             {
301                 uint32_t cr = ldl_p(mem_buf);
302                 int i;
303                 for (i = 0; i < 8; i++) {
304                     env->crf[i] = (cr >> (32 - ((i + 1) * 4))) & 0xF;
305                 }
306                 break;
307             }
308         case 67 + 32:
309             env->lr = ldq_p(mem_buf);
310             break;
311         case 68 + 32:
312             env->ctr = ldq_p(mem_buf);
313             break;
314         case 69 + 32:
315             env->xer = ldl_p(mem_buf);
316             break;
317         case 70 + 32:
318             /* fpscr */
319             store_fpscr(env, ldq_p(mem_buf), 0xffffffff);
320             break;
321         }
322     }
323     return r;
324 }
325 
326 #ifndef CONFIG_USER_ONLY
327 void ppc_gdb_gen_spr_xml(PowerPCCPU *cpu)
328 {
329     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
330     CPUPPCState *env = &cpu->env;
331     GString *xml;
332     char *spr_name;
333     unsigned int num_regs = 0;
334     int i;
335 
336     if (pcc->gdb_spr_xml) {
337         return;
338     }
339 
340     xml = g_string_new("<?xml version=\"1.0\"?>");
341     g_string_append(xml, "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">");
342     g_string_append(xml, "<feature name=\"org.qemu.power.spr\">");
343 
344     for (i = 0; i < ARRAY_SIZE(env->spr_cb); i++) {
345         ppc_spr_t *spr = &env->spr_cb[i];
346 
347         if (!spr->name) {
348             continue;
349         }
350 
351         spr_name = g_ascii_strdown(spr->name, -1);
352         g_string_append_printf(xml, "<reg name=\"%s\"", spr_name);
353         g_free(spr_name);
354 
355         g_string_append_printf(xml, " bitsize=\"%d\"", TARGET_LONG_BITS);
356         g_string_append(xml, " group=\"spr\"/>");
357 
358         /*
359          * GDB identifies registers based on the order they are
360          * presented in the XML. These ids will not match QEMU's
361          * representation (which follows the PowerISA).
362          *
363          * Store the position of the current register description so
364          * we can make the correspondence later.
365          */
366         spr->gdb_id = num_regs;
367         num_regs++;
368     }
369 
370     g_string_append(xml, "</feature>");
371 
372     pcc->gdb_num_sprs = num_regs;
373     pcc->gdb_spr_xml = g_string_free(xml, false);
374 }
375 
376 const char *ppc_gdb_get_dynamic_xml(CPUState *cs, const char *xml_name)
377 {
378     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cs);
379 
380     if (strcmp(xml_name, "power-spr.xml") == 0) {
381         return pcc->gdb_spr_xml;
382     }
383     return NULL;
384 }
385 #endif
386