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 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 typedef struct RegisterSysregXmlParam {
  25     CPUState *cs;
  26     GString *s;
  27     int n;
  28 } RegisterSysregXmlParam;
  29
  30 /* Old gdb always expect FPA registers.  Newer (xml-aware) gdb only expect
  31    whatever the target description contains.  Due to a historical mishap
  32    the FPA registers appear in between core integer regs and the CPSR.
  33    We hack round this by giving the FPA regs zero size when talking to a
  34    newer gdb.  */
  35
  36 int arm_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
  37 {
  38     ARMCPU *cpu = ARM_CPU(cs);
  39     CPUARMState *env = &cpu->env;
  40
  41     if (n < 16) {
  42         /* Core integer register.  */
  43         return gdb_get_reg32(mem_buf, env->regs[n]);
  44     }
  45     if (n < 24) {
  46         /* FPA registers.  */
  47         if (gdb_has_xml) {
  48             return 0;
  49         }
  50         memset(mem_buf, 0, 12);
  51         return 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 */
  62         return gdb_get_reg32(mem_buf, cpsr_read(env));
  63     }
  64     /* Unknown register.  */
  65     return 0;
  66 }
  67
  68 int arm_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
  69 {
  70     ARMCPU *cpu = ARM_CPU(cs);
  71     CPUARMState *env = &cpu->env;
  72     uint32_t tmp;
  73
  74     tmp = ldl_p(mem_buf);
  75
  76     /* Mask out low bit of PC to workaround gdb bugs.  This will probably
  77        cause problems if we ever implement the Jazelle DBX extensions.  */
  78     if (n == 15) {
  79         tmp &= ~1;
  80     }
  81
  82     if (n < 16) {
  83         /* Core integer register.  */
  84         env->regs[n] = tmp;
  85         return 4;
  86     }
  87     if (n < 24) { /* 16-23 */
  88         /* FPA registers (ignored).  */
  89         if (gdb_has_xml) {
  90             return 0;
  91         }
  92         return 12;
  93     }
  94     switch (n) {
  95     case 24:
  96         /* FPA status register (ignored).  */
  97         if (gdb_has_xml) {
  98             return 0;
  99         }
 100         return 4;
 101     case 25:
 102         /* CPSR */
 103         cpsr_write(env, tmp, 0xffffffff, CPSRWriteByGDBStub);
 104         return 4;
 105     }
 106     /* Unknown register.  */
 107     return 0;
 108 }
 109
 110 static void arm_gen_one_xml_sysreg_tag(GString *s, DynamicGDBXMLInfo *dyn_xml,
 111                                        ARMCPRegInfo *ri, uint32_t ri_key,
 112                                        int bitsize, int regnum)
 113 {
 114     g_string_append_printf(s, "<reg name=\"%s\"", ri->name);
 115     g_string_append_printf(s, " bitsize=\"%d\"", bitsize);
 116     g_string_append_printf(s, " regnum=\"%d\"", regnum);
 117     g_string_append_printf(s, " group=\"cp_regs\"/>");
 118     dyn_xml->data.cpregs.keys[dyn_xml->num] = ri_key;
 119     dyn_xml->num++;
 120 }
 121
 122 static void arm_register_sysreg_for_xml(gpointer key, gpointer value,
 123                                         gpointer p)
 124 {
 125     uint32_t ri_key = *(uint32_t *)key;
 126     ARMCPRegInfo *ri = value;
 127     RegisterSysregXmlParam *param = (RegisterSysregXmlParam *)p;
 128     GString *s = param->s;
 129     ARMCPU *cpu = ARM_CPU(param->cs);
 130     CPUARMState *env = &cpu->env;
 131     DynamicGDBXMLInfo *dyn_xml = &cpu->dyn_sysreg_xml;
 132
 133     if (!(ri->type & (ARM_CP_NO_RAW | ARM_CP_NO_GDB))) {
 134         if (arm_feature(env, ARM_FEATURE_AARCH64)) {
 135             if (ri->state == ARM_CP_STATE_AA64) {
 136                 arm_gen_one_xml_sysreg_tag(s , dyn_xml, ri, ri_key, 64,
 137                                            param->n++);
 138             }
 139         } else {
 140             if (ri->state == ARM_CP_STATE_AA32) {
 141                 if (!arm_feature(env, ARM_FEATURE_EL3) &&
 142                     (ri->secure & ARM_CP_SECSTATE_S)) {
 143                     return;
 144                 }
 145                 if (ri->type & ARM_CP_64BIT) {
 146                     arm_gen_one_xml_sysreg_tag(s , dyn_xml, ri, ri_key, 64,
 147                                                param->n++);
 148                 } else {
 149                     arm_gen_one_xml_sysreg_tag(s , dyn_xml, ri, ri_key, 32,
 150                                                param->n++);
 151                 }
 152             }
 153         }
 154     }
 155 }
 156
 157 int arm_gen_dynamic_sysreg_xml(CPUState *cs, int base_reg)
 158 {
 159     ARMCPU *cpu = ARM_CPU(cs);
 160     GString *s = g_string_new(NULL);
 161     RegisterSysregXmlParam param = {cs, s, base_reg};
 162
 163     cpu->dyn_sysreg_xml.num = 0;
 164     cpu->dyn_sysreg_xml.data.cpregs.keys = g_new(uint32_t, g_hash_table_size(cpu->cp_regs));
 165     g_string_printf(s, "<?xml version=\"1.0\"?>");
 166     g_string_append_printf(s, "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">");
 167     g_string_append_printf(s, "<feature name=\"org.qemu.gdb.arm.sys.regs\">");
 168     g_hash_table_foreach(cpu->cp_regs, arm_register_sysreg_for_xml, &param);
 169     g_string_append_printf(s, "</feature>");
 170     cpu->dyn_sysreg_xml.desc = g_string_free(s, false);
 171     return cpu->dyn_sysreg_xml.num;
 172 }
 173
 174 struct TypeSize {
 175     const char *gdb_type;
 176     int  size;
 177     const char sz, suffix;
 178 };
 179
 180 static const struct TypeSize vec_lanes[] = {
 181     /* quads */
 182     { "uint128", 128, 'q', 'u' },
 183     { "int128", 128, 'q', 's' },
 184     /* 64 bit */
 185     { "uint64", 64, 'd', 'u' },
 186     { "int64", 64, 'd', 's' },
 187     { "ieee_double", 64, 'd', 'f' },
 188     /* 32 bit */
 189     { "uint32", 32, 's', 'u' },
 190     { "int32", 32, 's', 's' },
 191     { "ieee_single", 32, 's', 'f' },
 192     /* 16 bit */
 193     { "uint16", 16, 'h', 'u' },
 194     { "int16", 16, 'h', 's' },
 195     { "ieee_half", 16, 'h', 'f' },
 196     /* bytes */
 197     { "uint8", 8, 'b', 'u' },
 198     { "int8", 8, 'b', 's' },
 199 };
 200
 201
 202 int arm_gen_dynamic_svereg_xml(CPUState *cs, int base_reg)
 203 {
 204     ARMCPU *cpu = ARM_CPU(cs);
 205     GString *s = g_string_new(NULL);
 206     DynamicGDBXMLInfo *info = &cpu->dyn_svereg_xml;
 207     g_autoptr(GString) ts = g_string_new("");
 208     int i, bits, reg_width = (cpu->sve_max_vq * 128);
 209     info->num = 0;
 210     g_string_printf(s, "<?xml version=\"1.0\"?>");
 211     g_string_append_printf(s, "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">");
 212     g_string_append_printf(s, "<feature name=\"org.qemu.gdb.aarch64.sve\">");
 213
 214     /* First define types and totals in a whole VL */
 215     for (i = 0; i < ARRAY_SIZE(vec_lanes); i++) {
 216         int count = reg_width / vec_lanes[i].size;
 217         g_string_printf(ts, "vq%d%c%c", count,
 218                         vec_lanes[i].sz, vec_lanes[i].suffix);
 219         g_string_append_printf(s,
 220                                "<vector id=\"%s\" type=\"%s\" count=\"%d\"/>",
 221                                ts->str, vec_lanes[i].gdb_type, count);
 222     }
 223     /*
 224      * Now define a union for each size group containing unsigned and
 225      * signed and potentially float versions of each size from 128 to
 226      * 8 bits.
 227      */
 228     for (bits = 128; bits >= 8; bits /= 2) {
 229         int count = reg_width / bits;
 230         g_string_append_printf(s, "<union id=\"vq%dn\">", count);
 231         for (i = 0; i < ARRAY_SIZE(vec_lanes); i++) {
 232             if (vec_lanes[i].size == bits) {
 233                 g_string_append_printf(s, "<field name=\"%c\" type=\"vq%d%c%c\"/>",
 234                                        vec_lanes[i].suffix,
 235                                        count,
 236                                        vec_lanes[i].sz, vec_lanes[i].suffix);
 237             }
 238         }
 239         g_string_append(s, "</union>");
 240     }
 241     /* And now the final union of unions */
 242     g_string_append(s, "<union id=\"vq\">");
 243     for (bits = 128; bits >= 8; bits /= 2) {
 244         int count = reg_width / bits;
 245         for (i = 0; i < ARRAY_SIZE(vec_lanes); i++) {
 246             if (vec_lanes[i].size == bits) {
 247                 g_string_append_printf(s, "<field name=\"%c\" type=\"vq%dn\"/>",
 248                                        vec_lanes[i].sz, count);
 249                 break;
 250             }
 251         }
 252     }
 253     g_string_append(s, "</union>");
 254
 255     /* Then define each register in parts for each vq */
 256     for (i = 0; i < 32; i++) {
 257         g_string_append_printf(s,
 258                                "<reg name=\"z%d\" bitsize=\"%d\""
 259                                " regnum=\"%d\" group=\"vector\""
 260                                " type=\"vq\"/>",
 261                                i, reg_width, base_reg++);
 262         info->num++;
 263     }
 264     /* fpscr & status registers */
 265     g_string_append_printf(s, "<reg name=\"fpsr\" bitsize=\"32\""
 266                            " regnum=\"%d\" group=\"float\""
 267                            " type=\"int\"/>", base_reg++);
 268     g_string_append_printf(s, "<reg name=\"fpcr\" bitsize=\"32\""
 269                            " regnum=\"%d\" group=\"float\""
 270                            " type=\"int\"/>", base_reg++);
 271     info->num += 2;
 272     /*
 273      * Predicate registers aren't so big they are worth splitting up
 274      * but we do need to define a type to hold the array of quad
 275      * references.
 276      */
 277     g_string_append_printf(s,
 278                            "<vector id=\"vqp\" type=\"uint16\" count=\"%d\"/>",
 279                            cpu->sve_max_vq);
 280     for (i = 0; i < 16; i++) {
 281         g_string_append_printf(s,
 282                                "<reg name=\"p%d\" bitsize=\"%d\""
 283                                " regnum=\"%d\" group=\"vector\""
 284                                " type=\"vqp\"/>",
 285                                i, cpu->sve_max_vq * 16, base_reg++);
 286         info->num++;
 287     }
 288     g_string_append_printf(s,
 289                            "<reg name=\"ffr\" bitsize=\"%d\""
 290                            " regnum=\"%d\" group=\"vector\""
 291                            " type=\"vqp\"/>",
 292                            cpu->sve_max_vq * 16, base_reg++);
 293     g_string_append_printf(s,
 294                            "<reg name=\"vg\" bitsize=\"64\""
 295                            " regnum=\"%d\" group=\"vector\""
 296                            " type=\"uint32\"/>",
 297                            base_reg++);
 298     info->num += 2;
 299     g_string_append_printf(s, "</feature>");
 300     cpu->dyn_svereg_xml.desc = g_string_free(s, false);
 301
 302     return cpu->dyn_svereg_xml.num;
 303 }
 304
 305
 306 const char *arm_gdb_get_dynamic_xml(CPUState *cs, const char *xmlname)
 307 {
 308     ARMCPU *cpu = ARM_CPU(cs);
 309
 310     if (strcmp(xmlname, "system-registers.xml") == 0) {
 311         return cpu->dyn_sysreg_xml.desc;
 312     } else if (strcmp(xmlname, "sve-registers.xml") == 0) {
 313         return cpu->dyn_svereg_xml.desc;
 314     }
 315     return NULL;
 316 }