target/arm/gdbstub.c

   1 /*
   2  * ARM 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 "internals.h"
  23 #include "exec/gdbstub.h"
  24
  25 typedef struct RegisterSysregXmlParam {
  26     CPUState *cs;
  27     GString *s;
  28     int n;
  29 } RegisterSysregXmlParam;
  30
  31 /* Old gdb always expect FPA registers.  Newer (xml-aware) gdb only expect
  32    whatever the target description contains.  Due to a historical mishap
  33    the FPA registers appear in between core integer regs and the CPSR.
  34    We hack round this by giving the FPA regs zero size when talking to a
  35    newer gdb.  */
  36
  37 int arm_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
  38 {
  39     ARMCPU *cpu = ARM_CPU(cs);
  40     CPUARMState *env = &cpu->env;
  41
  42     if (n < 16) {
  43         /* Core integer register.  */
  44         return gdb_get_reg32(mem_buf, env->regs[n]);
  45     }
  46     if (n < 24) {
  47         /* FPA registers.  */
  48         if (gdb_has_xml) {
  49             return 0;
  50         }
  51         return gdb_get_zeroes(mem_buf, 12);
  52     }
  53     switch (n) {
  54     case 24:
  55         /* FPA status register.  */
  56         if (gdb_has_xml) {
  57             return 0;
  58         }
  59         return gdb_get_reg32(mem_buf, 0);
  60     case 25:
  61         /* CPSR, or XPSR for M-profile */
  62         if (arm_feature(env, ARM_FEATURE_M)) {
  63             return gdb_get_reg32(mem_buf, xpsr_read(env));
  64         } else {
  65             return gdb_get_reg32(mem_buf, cpsr_read(env));
  66         }
  67     }
  68     /* Unknown register.  */
  69     return 0;
  70 }
  71
  72 int arm_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
  73 {
  74     ARMCPU *cpu = ARM_CPU(cs);
  75     CPUARMState *env = &cpu->env;
  76     uint32_t tmp;
  77
  78     tmp = ldl_p(mem_buf);
  79
  80     /* Mask out low bit of PC to workaround gdb bugs.  This will probably
  81        cause problems if we ever implement the Jazelle DBX extensions.  */
  82     if (n == 15) {
  83         tmp &= ~1;
  84     }
  85
  86     if (n < 16) {
  87         /* Core integer register.  */
  88         if (n == 13 && arm_feature(env, ARM_FEATURE_M)) {
  89             /* M profile SP low bits are always 0 */
  90             tmp &= ~3;
  91         }
  92         env->regs[n] = tmp;
  93         return 4;
  94     }
  95     if (n < 24) { /* 16-23 */
  96         /* FPA registers (ignored).  */
  97         if (gdb_has_xml) {
  98             return 0;
  99         }
 100         return 12;
 101     }
 102     switch (n) {
 103     case 24:
 104         /* FPA status register (ignored).  */
 105         if (gdb_has_xml) {
 106             return 0;
 107         }
 108         return 4;
 109     case 25:
 110         /* CPSR, or XPSR for M-profile */
 111         if (arm_feature(env, ARM_FEATURE_M)) {
 112             /*
 113              * Don't allow writing to XPSR.Exception as it can cause
 114              * a transition into or out of handler mode (it's not
 115              * writeable via the MSR insn so this is a reasonable
 116              * restriction). Other fields are safe to update.
 117              */
 118             xpsr_write(env, tmp, ~XPSR_EXCP);
 119         } else {
 120             cpsr_write(env, tmp, 0xffffffff, CPSRWriteByGDBStub);
 121         }
 122         return 4;
 123     }
 124     /* Unknown register.  */
 125     return 0;
 126 }
 127
 128 static int vfp_gdb_get_reg(CPUARMState *env, GByteArray *buf, int reg)
 129 {
 130     ARMCPU *cpu = env_archcpu(env);
 131     int nregs = cpu_isar_feature(aa32_simd_r32, cpu) ? 32 : 16;
 132
 133     /* VFP data registers are always little-endian.  */
 134     if (reg < nregs) {
 135         return gdb_get_reg64(buf, *aa32_vfp_dreg(env, reg));
 136     }
 137     if (arm_feature(env, ARM_FEATURE_NEON)) {
 138         /* Aliases for Q regs.  */
 139         nregs += 16;
 140         if (reg < nregs) {
 141             uint64_t *q = aa32_vfp_qreg(env, reg - 32);
 142             return gdb_get_reg128(buf, q[0], q[1]);
 143         }
 144     }
 145     switch (reg - nregs) {
 146     case 0:
 147         return gdb_get_reg32(buf, vfp_get_fpscr(env));
 148     }
 149     return 0;
 150 }
 151
 152 static int vfp_gdb_set_reg(CPUARMState *env, uint8_t *buf, int reg)
 153 {
 154     ARMCPU *cpu = env_archcpu(env);
 155     int nregs = cpu_isar_feature(aa32_simd_r32, cpu) ? 32 : 16;
 156
 157     if (reg < nregs) {
 158         *aa32_vfp_dreg(env, reg) = ldq_le_p(buf);
 159         return 8;
 160     }
 161     if (arm_feature(env, ARM_FEATURE_NEON)) {
 162         nregs += 16;
 163         if (reg < nregs) {
 164             uint64_t *q = aa32_vfp_qreg(env, reg - 32);
 165             q[0] = ldq_le_p(buf);
 166             q[1] = ldq_le_p(buf + 8);
 167             return 16;
 168         }
 169     }
 170     switch (reg - nregs) {
 171     case 0:
 172         vfp_set_fpscr(env, ldl_p(buf));
 173         return 4;
 174     }
 175     return 0;
 176 }
 177
 178 static int vfp_gdb_get_sysreg(CPUARMState *env, GByteArray *buf, int reg)
 179 {
 180     switch (reg) {
 181     case 0:
 182         return gdb_get_reg32(buf, env->vfp.xregs[ARM_VFP_FPSID]);
 183     case 1:
 184         return gdb_get_reg32(buf, env->vfp.xregs[ARM_VFP_FPEXC]);
 185     }
 186     return 0;
 187 }
 188
 189 static int vfp_gdb_set_sysreg(CPUARMState *env, uint8_t *buf, int reg)
 190 {
 191     switch (reg) {
 192     case 0:
 193         env->vfp.xregs[ARM_VFP_FPSID] = ldl_p(buf);
 194         return 4;
 195     case 1:
 196         env->vfp.xregs[ARM_VFP_FPEXC] = ldl_p(buf) & (1 << 30);
 197         return 4;
 198     }
 199     return 0;
 200 }
 201
 202 /**
 203  * arm_get/set_gdb_*: get/set a gdb register
 204  * @env: the CPU state
 205  * @buf: a buffer to copy to/from
 206  * @reg: register number (offset from start of group)
 207  *
 208  * We return the number of bytes copied
 209  */
 210
 211 static int arm_gdb_get_sysreg(CPUARMState *env, GByteArray *buf, int reg)
 212 {
 213     ARMCPU *cpu = env_archcpu(env);
 214     const ARMCPRegInfo *ri;
 215     uint32_t key;
 216
 217     key = cpu->dyn_sysreg_xml.data.cpregs.keys[reg];
 218     ri = get_arm_cp_reginfo(cpu->cp_regs, key);
 219     if (ri) {
 220         if (cpreg_field_is_64bit(ri)) {
 221             return gdb_get_reg64(buf, (uint64_t)read_raw_cp_reg(env, ri));
 222         } else {
 223             return gdb_get_reg32(buf, (uint32_t)read_raw_cp_reg(env, ri));
 224         }
 225     }
 226     return 0;
 227 }
 228
 229 static int arm_gdb_set_sysreg(CPUARMState *env, uint8_t *buf, int reg)
 230 {
 231     return 0;
 232 }
 233
 234 static void arm_gen_one_xml_sysreg_tag(GString *s, DynamicGDBXMLInfo *dyn_xml,
 235                                        ARMCPRegInfo *ri, uint32_t ri_key,
 236                                        int bitsize, int regnum)
 237 {
 238     g_string_append_printf(s, "<reg name=\"%s\"", ri->name);
 239     g_string_append_printf(s, " bitsize=\"%d\"", bitsize);
 240     g_string_append_printf(s, " regnum=\"%d\"", regnum);
 241     g_string_append_printf(s, " group=\"cp_regs\"/>");
 242     dyn_xml->data.cpregs.keys[dyn_xml->num] = ri_key;
 243     dyn_xml->num++;
 244 }
 245
 246 static void arm_register_sysreg_for_xml(gpointer key, gpointer value,
 247                                         gpointer p)
 248 {
 249     uint32_t ri_key = *(uint32_t *)key;
 250     ARMCPRegInfo *ri = value;
 251     RegisterSysregXmlParam *param = (RegisterSysregXmlParam *)p;
 252     GString *s = param->s;
 253     ARMCPU *cpu = ARM_CPU(param->cs);
 254     CPUARMState *env = &cpu->env;
 255     DynamicGDBXMLInfo *dyn_xml = &cpu->dyn_sysreg_xml;
 256
 257     if (!(ri->type & (ARM_CP_NO_RAW | ARM_CP_NO_GDB))) {
 258         if (arm_feature(env, ARM_FEATURE_AARCH64)) {
 259             if (ri->state == ARM_CP_STATE_AA64) {
 260                 arm_gen_one_xml_sysreg_tag(s , dyn_xml, ri, ri_key, 64,
 261                                            param->n++);
 262             }
 263         } else {
 264             if (ri->state == ARM_CP_STATE_AA32) {
 265                 if (!arm_feature(env, ARM_FEATURE_EL3) &&
 266                     (ri->secure & ARM_CP_SECSTATE_S)) {
 267                     return;
 268                 }
 269                 if (ri->type & ARM_CP_64BIT) {
 270                     arm_gen_one_xml_sysreg_tag(s , dyn_xml, ri, ri_key, 64,
 271                                                param->n++);
 272                 } else {
 273                     arm_gen_one_xml_sysreg_tag(s , dyn_xml, ri, ri_key, 32,
 274                                                param->n++);
 275                 }
 276             }
 277         }
 278     }
 279 }
 280
 281 int arm_gen_dynamic_sysreg_xml(CPUState *cs, int base_reg)
 282 {
 283     ARMCPU *cpu = ARM_CPU(cs);
 284     GString *s = g_string_new(NULL);
 285     RegisterSysregXmlParam param = {cs, s, base_reg};
 286
 287     cpu->dyn_sysreg_xml.num = 0;
 288     cpu->dyn_sysreg_xml.data.cpregs.keys = g_new(uint32_t, g_hash_table_size(cpu->cp_regs));
 289     g_string_printf(s, "<?xml version=\"1.0\"?>");
 290     g_string_append_printf(s, "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">");
 291     g_string_append_printf(s, "<feature name=\"org.qemu.gdb.arm.sys.regs\">");
 292     g_hash_table_foreach(cpu->cp_regs, arm_register_sysreg_for_xml, &param);
 293     g_string_append_printf(s, "</feature>");
 294     cpu->dyn_sysreg_xml.desc = g_string_free(s, false);
 295     return cpu->dyn_sysreg_xml.num;
 296 }
 297
 298 struct TypeSize {
 299     const char *gdb_type;
 300     int  size;
 301     const char sz, suffix;
 302 };
 303
 304 static const struct TypeSize vec_lanes[] = {
 305     /* quads */
 306     { "uint128", 128, 'q', 'u' },
 307     { "int128", 128, 'q', 's' },
 308     /* 64 bit */
 309     { "ieee_double", 64, 'd', 'f' },
 310     { "uint64", 64, 'd', 'u' },
 311     { "int64", 64, 'd', 's' },
 312     /* 32 bit */
 313     { "ieee_single", 32, 's', 'f' },
 314     { "uint32", 32, 's', 'u' },
 315     { "int32", 32, 's', 's' },
 316     /* 16 bit */
 317     { "ieee_half", 16, 'h', 'f' },
 318     { "uint16", 16, 'h', 'u' },
 319     { "int16", 16, 'h', 's' },
 320     /* bytes */
 321     { "uint8", 8, 'b', 'u' },
 322     { "int8", 8, 'b', 's' },
 323 };
 324
 325
 326 int arm_gen_dynamic_svereg_xml(CPUState *cs, int base_reg)
 327 {
 328     ARMCPU *cpu = ARM_CPU(cs);
 329     GString *s = g_string_new(NULL);
 330     DynamicGDBXMLInfo *info = &cpu->dyn_svereg_xml;
 331     g_autoptr(GString) ts = g_string_new("");
 332     int i, j, bits, reg_width = (cpu->sve_max_vq * 128);
 333     info->num = 0;
 334     g_string_printf(s, "<?xml version=\"1.0\"?>");
 335     g_string_append_printf(s, "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">");
 336     g_string_append_printf(s, "<feature name=\"org.gnu.gdb.aarch64.sve\">");
 337
 338     /* First define types and totals in a whole VL */
 339     for (i = 0; i < ARRAY_SIZE(vec_lanes); i++) {
 340         int count = reg_width / vec_lanes[i].size;
 341         g_string_printf(ts, "svev%c%c", vec_lanes[i].sz, vec_lanes[i].suffix);
 342         g_string_append_printf(s,
 343                                "<vector id=\"%s\" type=\"%s\" count=\"%d\"/>",
 344                                ts->str, vec_lanes[i].gdb_type, count);
 345     }
 346     /*
 347      * Now define a union for each size group containing unsigned and
 348      * signed and potentially float versions of each size from 128 to
 349      * 8 bits.
 350      */
 351     for (bits = 128, i = 0; bits >= 8; bits /= 2, i++) {
 352         const char suf[] = { 'q', 'd', 's', 'h', 'b' };
 353         g_string_append_printf(s, "<union id=\"svevn%c\">", suf[i]);
 354         for (j = 0; j < ARRAY_SIZE(vec_lanes); j++) {
 355             if (vec_lanes[j].size == bits) {
 356                 g_string_append_printf(s, "<field name=\"%c\" type=\"svev%c%c\"/>",
 357                                        vec_lanes[j].suffix,
 358                                        vec_lanes[j].sz, vec_lanes[j].suffix);
 359             }
 360         }
 361         g_string_append(s, "</union>");
 362     }
 363     /* And now the final union of unions */
 364     g_string_append(s, "<union id=\"svev\">");
 365     for (bits = 128, i = 0; bits >= 8; bits /= 2, i++) {
 366         const char suf[] = { 'q', 'd', 's', 'h', 'b' };
 367         g_string_append_printf(s, "<field name=\"%c\" type=\"svevn%c\"/>",
 368                                suf[i], suf[i]);
 369     }
 370     g_string_append(s, "</union>");
 371
 372     /* Finally the sve prefix type */
 373     g_string_append_printf(s,
 374                            "<vector id=\"svep\" type=\"uint8\" count=\"%d\"/>",
 375                            reg_width / 8);
 376
 377     /* Then define each register in parts for each vq */
 378     for (i = 0; i < 32; i++) {
 379         g_string_append_printf(s,
 380                                "<reg name=\"z%d\" bitsize=\"%d\""
 381                                " regnum=\"%d\" type=\"svev\"/>",
 382                                i, reg_width, base_reg++);
 383         info->num++;
 384     }
 385     /* fpscr & status registers */
 386     g_string_append_printf(s, "<reg name=\"fpsr\" bitsize=\"32\""
 387                            " regnum=\"%d\" group=\"float\""
 388                            " type=\"int\"/>", base_reg++);
 389     g_string_append_printf(s, "<reg name=\"fpcr\" bitsize=\"32\""
 390                            " regnum=\"%d\" group=\"float\""
 391                            " type=\"int\"/>", base_reg++);
 392     info->num += 2;
 393
 394     for (i = 0; i < 16; i++) {
 395         g_string_append_printf(s,
 396                                "<reg name=\"p%d\" bitsize=\"%d\""
 397                                " regnum=\"%d\" type=\"svep\"/>",
 398                                i, cpu->sve_max_vq * 16, base_reg++);
 399         info->num++;
 400     }
 401     g_string_append_printf(s,
 402                            "<reg name=\"ffr\" bitsize=\"%d\""
 403                            " regnum=\"%d\" group=\"vector\""
 404                            " type=\"svep\"/>",
 405                            cpu->sve_max_vq * 16, base_reg++);
 406     g_string_append_printf(s,
 407                            "<reg name=\"vg\" bitsize=\"64\""
 408                            " regnum=\"%d\" type=\"int\"/>",
 409                            base_reg++);
 410     info->num += 2;
 411     g_string_append_printf(s, "</feature>");
 412     cpu->dyn_svereg_xml.desc = g_string_free(s, false);
 413
 414     return cpu->dyn_svereg_xml.num;
 415 }
 416
 417
 418 const char *arm_gdb_get_dynamic_xml(CPUState *cs, const char *xmlname)
 419 {
 420     ARMCPU *cpu = ARM_CPU(cs);
 421
 422     if (strcmp(xmlname, "system-registers.xml") == 0) {
 423         return cpu->dyn_sysreg_xml.desc;
 424     } else if (strcmp(xmlname, "sve-registers.xml") == 0) {
 425         return cpu->dyn_svereg_xml.desc;
 426     }
 427     return NULL;
 428 }
 429
 430 void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
 431 {
 432     CPUState *cs = CPU(cpu);
 433     CPUARMState *env = &cpu->env;
 434
 435     if (arm_feature(env, ARM_FEATURE_AARCH64)) {
 436         /*
 437          * The lower part of each SVE register aliases to the FPU
 438          * registers so we don't need to include both.
 439          */
 440 #ifdef TARGET_AARCH64
 441         if (isar_feature_aa64_sve(&cpu->isar)) {
 442             gdb_register_coprocessor(cs, arm_gdb_get_svereg, arm_gdb_set_svereg,
 443                                      arm_gen_dynamic_svereg_xml(cs, cs->gdb_num_regs),
 444                                      "sve-registers.xml", 0);
 445         } else {
 446             gdb_register_coprocessor(cs, aarch64_fpu_gdb_get_reg,
 447                                      aarch64_fpu_gdb_set_reg,
 448                                      34, "aarch64-fpu.xml", 0);
 449         }
 450 #endif
 451     } else {
 452         if (arm_feature(env, ARM_FEATURE_NEON)) {
 453             gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
 454                                      49, "arm-neon.xml", 0);
 455         } else if (cpu_isar_feature(aa32_simd_r32, cpu)) {
 456             gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
 457                                      33, "arm-vfp3.xml", 0);
 458         } else if (cpu_isar_feature(aa32_vfp_simd, cpu)) {
 459             gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
 460                                      17, "arm-vfp.xml", 0);
 461         }
 462         if (!arm_feature(env, ARM_FEATURE_M)) {
 463             /*
 464              * A and R profile have FP sysregs FPEXC and FPSID that we
 465              * expose to gdb.
 466              */
 467             gdb_register_coprocessor(cs, vfp_gdb_get_sysreg, vfp_gdb_set_sysreg,
 468                                      2, "arm-vfp-sysregs.xml", 0);
 469         }
 470     }
 471     gdb_register_coprocessor(cs, arm_gdb_get_sysreg, arm_gdb_set_sysreg,
 472                              arm_gen_dynamic_sysreg_xml(cs, cs->gdb_num_regs),
 473                              "system-registers.xml", 0);
 474
 475 }