target/ppc/gdbstub.c

   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_float64(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_float64(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