src/arch/x86/exception.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 #include <arch/cpu.h>
   3 #include <arch/breakpoint.h>
   4 #include <arch/null_breakpoint.h>
   5 #include <arch/stack_canary_breakpoint.h>
   6 #include <arch/exception.h>
   7 #include <arch/registers.h>
   8 #include <commonlib/helpers.h>
   9 #include <console/console.h>
  10 #include <console/streams.h>
  11 #include <cpu/x86/cr.h>
  12 #include <cpu/x86/lapic.h>
  13 #include <stdint.h>
  14 #include <string.h>
  15
  16 #if CONFIG(GDB_STUB)
  17
  18 /* BUFMAX defines the maximum number of characters in inbound/outbound buffers.
  19  * At least NUM_REGBYTES*2 are needed for register packets
  20  */
  21 #define BUFMAX 400
  22 enum regnames {
  23         EAX = 0, ECX, EDX, EBX, ESP, EBP, ESI, EDI,
  24         PC /* also known as eip */,
  25         PS /* also known as eflags */,
  26         CS, SS, DS, ES, FS, GS,
  27         NUM_REGS /* Number of registers. */
  28 };
  29
  30 static uint32_t gdb_stub_registers[NUM_REGS];
  31
  32 #define GDB_SIG0         0     /* Signal 0 */
  33 #define GDB_SIGHUP       1     /* Hangup */
  34 #define GDB_SIGINT       2     /* Interrupt */
  35 #define GDB_SIGQUIT      3     /* Quit */
  36 #define GDB_SIGILL       4     /* Illegal instruction */
  37 #define GDB_SIGTRAP      5     /* Trace/breakpoint trap */
  38 #define GDB_SIGABRT      6     /* Aborted */
  39 #define GDB_SIGEMT       7     /* Emulation trap */
  40 #define GDB_SIGFPE       8     /* Arithmetic exception */
  41 #define GDB_SIGKILL      9     /* Killed */
  42 #define GDB_SIGBUS       10    /* Bus error */
  43 #define GDB_SIGSEGV      11    /* Segmentation fault */
  44 #define GDB_SIGSYS       12    /* Bad system call */
  45 #define GDB_SIGPIPE      13    /* Broken pipe */
  46 #define GDB_SIGALRM      14    /* Alarm clock */
  47 #define GDB_SIGTERM      15    /* Terminated */
  48 #define GDB_SIGURG       16    /* Urgent I/O condition */
  49 #define GDB_SIGSTOP      17    /* Stopped (signal) */
  50 #define GDB_SIGTSTP      18    /* Stopped (user) */
  51 #define GDB_SIGCONT      19    /* Continued */
  52 #define GDB_SIGCHLD      20    /* Child status changed */
  53 #define GDB_SIGTTIN      21    /* Stopped (tty input) */
  54 #define GDB_SIGTTOU      22    /* Stopped (tty output) */
  55 #define GDB_SIGIO        23    /* I/O possible */
  56 #define GDB_SIGXCPU      24    /* CPU time limit exceeded */
  57 #define GDB_SIGXFSZ      25    /* File size limit exceeded */
  58 #define GDB_SIGVTALRM    26    /* Virtual timer expired */
  59 #define GDB_SIGPROF      27    /* Profiling timer expired */
  60 #define GDB_SIGWINCH     28    /* Window size changed */
  61 #define GDB_SIGLOST      29    /* Resource lost */
  62 #define GDB_SIGUSR1      30    /* User defined signal 1 */
  63 #define GDB_SUGUSR2      31    /* User defined signal 2 */
  64 #define GDB_SIGPWR       32    /* Power fail/restart */
  65 #define GDB_SIGPOLL      33    /* Pollable event occurred */
  66 #define GDB_SIGWIND      34    /* SIGWIND */
  67 #define GDB_SIGPHONE     35    /* SIGPHONE */
  68 #define GDB_SIGWAITING   36    /* Process's LWPs are blocked */
  69 #define GDB_SIGLWP       37    /* Signal LWP */
  70 #define GDB_SIGDANGER    38    /* Swap space dangerously low */
  71 #define GDB_SIGGRANT     39    /* Monitor mode granted */
  72 #define GDB_SIGRETRACT   40    /* Need to relinquish monitor mode */
  73 #define GDB_SIGMSG       41    /* Monitor mode data available */
  74 #define GDB_SIGSOUND     42    /* Sound completed */
  75 #define GDB_SIGSAK       43    /* Secure attention */
  76 #define GDB_SIGPRIO      44    /* SIGPRIO */
  77
  78 #define GDB_SIG33        45    /* Real-time event 33 */
  79 #define GDB_SIG34        46    /* Real-time event 34 */
  80 #define GDB_SIG35        47    /* Real-time event 35 */
  81 #define GDB_SIG36        48    /* Real-time event 36 */
  82 #define GDB_SIG37        49    /* Real-time event 37 */
  83 #define GDB_SIG38        50    /* Real-time event 38 */
  84 #define GDB_SIG39        51    /* Real-time event 39 */
  85 #define GDB_SIG40        52    /* Real-time event 40 */
  86 #define GDB_SIG41        53    /* Real-time event 41 */
  87 #define GDB_SIG42        54    /* Real-time event 42 */
  88 #define GDB_SIG43        55    /* Real-time event 43 */
  89 #define GDB_SIG44        56    /* Real-time event 44 */
  90 #define GDB_SIG45        57    /* Real-time event 45 */
  91 #define GDB_SIG46        58    /* Real-time event 46 */
  92 #define GDB_SIG47        59    /* Real-time event 47 */
  93 #define GDB_SIG48        60    /* Real-time event 48 */
  94 #define GDB_SIG49        61    /* Real-time event 49 */
  95 #define GDB_SIG50        62    /* Real-time event 50 */
  96 #define GDB_SIG51        63    /* Real-time event 51 */
  97 #define GDB_SIG52        64    /* Real-time event 52 */
  98 #define GDB_SIG53        65    /* Real-time event 53 */
  99 #define GDB_SIG54        66    /* Real-time event 54 */
 100 #define GDB_SIG55        67    /* Real-time event 55 */
 101 #define GDB_SIG56        68    /* Real-time event 56 */
 102 #define GDB_SIG57        69    /* Real-time event 57 */
 103 #define GDB_SIG58        70    /* Real-time event 58 */
 104 #define GDB_SIG59        71    /* Real-time event 59 */
 105 #define GDB_SIG60        72    /* Real-time event 60 */
 106 #define GDB_SIG61        73    /* Real-time event 61 */
 107 #define GDB_SIG62        74    /* Real-time event 62 */
 108 #define GDB_SIG63        75    /* Real-time event 63 */
 109 #define GDB_SIGCANCEL    76    /* LWP internal signal */
 110 #define GDB_SIG32        77    /* Real-time event 32 */
 111 #define GDB_SIG64        78    /* Real-time event 64 */
 112 #define GDB_SIG65        79    /* Real-time event 65 */
 113 #define GDB_SIG66        80    /* Real-time event 66 */
 114 #define GDB_SIG67        81    /* Real-time event 67 */
 115 #define GDB_SIG68        82    /* Real-time event 68 */
 116 #define GDB_SIG69        83    /* Real-time event 69 */
 117 #define GDB_SIG70        84    /* Real-time event 70 */
 118 #define GDB_SIG71        85    /* Real-time event 71 */
 119 #define GDB_SIG72        86    /* Real-time event 72 */
 120 #define GDB_SIG73        87    /* Real-time event 73 */
 121 #define GDB_SIG74        88    /* Real-time event 74 */
 122 #define GDB_SIG75        89    /* Real-time event 75 */
 123 #define GDB_SIG76        90    /* Real-time event 76 */
 124 #define GDB_SIG77        91    /* Real-time event 77 */
 125 #define GDB_SIG78        92    /* Real-time event 78 */
 126 #define GDB_SIG79        93    /* Real-time event 79 */
 127 #define GDB_SIG80        94    /* Real-time event 80 */
 128 #define GDB_SIG81        95    /* Real-time event 81 */
 129 #define GDB_SIG82        96    /* Real-time event 82 */
 130 #define GDB_SIG83        97    /* Real-time event 83 */
 131 #define GDB_SIG84        98    /* Real-time event 84 */
 132 #define GDB_SIG85        99    /* Real-time event 85 */
 133 #define GDB_SIG86       100    /* Real-time event 86 */
 134 #define GDB_SIG87       101    /* Real-time event 87 */
 135 #define GDB_SIG88       102    /* Real-time event 88 */
 136 #define GDB_SIG89       103    /* Real-time event 89 */
 137 #define GDB_SIG90       104    /* Real-time event 90 */
 138 #define GDB_SIG91       105    /* Real-time event 91 */
 139 #define GDB_SIG92       106    /* Real-time event 92 */
 140 #define GDB_SIG93       107    /* Real-time event 93 */
 141 #define GDB_SIG94       108    /* Real-time event 94 */
 142 #define GDB_SIG95       109    /* Real-time event 95 */
 143 #define GDB_SIG96       110    /* Real-time event 96 */
 144 #define GDB_SIG97       111    /* Real-time event 97 */
 145 #define GDB_SIG98       112    /* Real-time event 98 */
 146 #define GDB_SIG99       113    /* Real-time event 99 */
 147 #define GDB_SIG100      114    /* Real-time event 100 */
 148 #define GDB_SIG101      115    /* Real-time event 101 */
 149 #define GDB_SIG102      116    /* Real-time event 102 */
 150 #define GDB_SIG103      117    /* Real-time event 103 */
 151 #define GDB_SIG104      118    /* Real-time event 104 */
 152 #define GDB_SIG105      119    /* Real-time event 105 */
 153 #define GDB_SIG106      120    /* Real-time event 106 */
 154 #define GDB_SIG107      121    /* Real-time event 107 */
 155 #define GDB_SIG108      122    /* Real-time event 108 */
 156 #define GDB_SIG109      123    /* Real-time event 109 */
 157 #define GDB_SIG110      124    /* Real-time event 110 */
 158 #define GDB_SIG111      125    /* Real-time event 111 */
 159 #define GDB_SIG112      126    /* Real-time event 112 */
 160 #define GDB_SIG113      127    /* Real-time event 113 */
 161 #define GDB_SIG114      128    /* Real-time event 114 */
 162 #define GDB_SIG115      129    /* Real-time event 115 */
 163 #define GDB_SIG116      130    /* Real-time event 116 */
 164 #define GDB_SIG117      131    /* Real-time event 117 */
 165 #define GDB_SIG118      132    /* Real-time event 118 */
 166 #define GDB_SIG119      133    /* Real-time event 119 */
 167 #define GDB_SIG120      134    /* Real-time event 120 */
 168 #define GDB_SIG121      135    /* Real-time event 121 */
 169 #define GDB_SIG122      136    /* Real-time event 122 */
 170 #define GDB_SIG123      137    /* Real-time event 123 */
 171 #define GDB_SIG124      138    /* Real-time event 124 */
 172 #define GDB_SIG125      139    /* Real-time event 125 */
 173 #define GDB_SIG126      140    /* Real-time event 126 */
 174 #define GDB_SIG127      141    /* Real-time event 127 */
 175 #define GDB_SIGINFO     142    /* Information request */
 176 #define GDB_UNKNOWN     143    /* Unknown signal */
 177 #define GDB_DEFAULT     144    /* error: default signal */
 178 /* Mach exceptions */
 179 #define GDB_EXC_BAD_ACCESS     145 /* Could not access memory */
 180 #define GDB_EXC_BAD_INSTRCTION 146 /* Illegal instruction/operand */
 181 #define GDB_EXC_ARITHMETIC     147 /* Arithmetic exception */
 182 #define GDB_EXC_EMULATION      148 /* Emulation instruction */
 183 #define GDB_EXC_SOFTWARE       149 /* Software generated exception */
 184 #define GDB_EXC_BREAKPOINT     150 /* Breakpoint */
 185
 186 static unsigned char exception_to_signal[] = {
 187         [0]  = GDB_SIGFPE,  /* divide by zero */
 188         [1]  = GDB_SIGTRAP, /* debug exception */
 189         [2]  = GDB_SIGSEGV, /* NMI Interrupt */
 190         [3]  = GDB_SIGTRAP, /* Breakpoint */
 191         [4]  = GDB_SIGSEGV, /* into instruction (overflow) */
 192         [5]  = GDB_SIGSEGV, /* bound instruction */
 193         [6]  = GDB_SIGILL,  /* Invalid opcode */
 194         [7]  = GDB_SIGSEGV, /* coprocessor not available */
 195         [8]  = GDB_SIGSEGV, /* double fault */
 196         [9]  = GDB_SIGFPE,  /* coprocessor segment overrun */
 197         [10] = GDB_SIGSEGV, /* Invalid TSS */
 198         [11] = GDB_SIGBUS,  /* Segment not present */
 199         [12] = GDB_SIGBUS,  /* stack exception */
 200         [13] = GDB_SIGSEGV, /* general protection */
 201         [14] = GDB_SIGSEGV, /* page fault */
 202         [15] = GDB_UNKNOWN, /* reserved */
 203         [16] = GDB_SIGEMT,  /* coprocessor error */
 204         [17] = GDB_SIGBUS,  /* alignment check */
 205         [18] = GDB_SIGSEGV, /* machine check */
 206         [19] = GDB_SIGFPE,  /* simd floating point exception */
 207         [20] = GDB_UNKNOWN,
 208         [21] = GDB_UNKNOWN,
 209         [22] = GDB_UNKNOWN,
 210         [23] = GDB_UNKNOWN,
 211         [24] = GDB_UNKNOWN,
 212         [25] = GDB_UNKNOWN,
 213         [26] = GDB_UNKNOWN,
 214         [27] = GDB_UNKNOWN,
 215         [28] = GDB_UNKNOWN,
 216         [29] = GDB_UNKNOWN,
 217         [30] = GDB_UNKNOWN,
 218         [31] = GDB_UNKNOWN,
 219         [32] = GDB_SIGINT,  /* User interrupt */
 220 };
 221
 222 static const char hexchars[] = "0123456789abcdef";
 223 static char in_buffer[BUFMAX];
 224 static char out_buffer[BUFMAX];
 225
 226 static inline void stub_putc(int ch)
 227 {
 228         gdb_tx_byte(ch);
 229 }
 230
 231 static inline void stub_flush(void)
 232 {
 233         gdb_tx_flush();
 234 }
 235
 236 static inline int stub_getc(void)
 237 {
 238         return gdb_rx_byte();
 239 }
 240
 241 static int hex(char ch)
 242 {
 243         if ((ch >= 'a') && (ch <= 'f'))
 244                 return (ch - 'a' + 10);
 245         if ((ch >= '0') && (ch <= '9'))
 246                 return (ch - '0');
 247         if ((ch >= 'A') && (ch <= 'F'))
 248                 return (ch - 'A' + 10);
 249         return (-1);
 250 }
 251
 252 /*
 253  * While we find hexadecimal digits, build an int.
 254  * Fals is returned if nothing is parsed true otherwise.
 255  */
 256 static int parse_ulong(char **ptr, unsigned long *value)
 257 {
 258         int digit;
 259         char *start;
 260
 261         start = *ptr;
 262         *value = 0;
 263
 264         while ((digit = hex(**ptr)) >= 0) {
 265                 *value = ((*value) << 4) | digit;
 266                 (*ptr)++;
 267         }
 268         return start != *ptr;
 269 }
 270
 271 /* convert the memory pointed to by mem into hex, placing result in buf */
 272 /* return a pointer to the last char put in buf (null) */
 273 static void copy_to_hex(char *buf, void *addr, unsigned long count)
 274 {
 275         unsigned char ch;
 276         char *mem = addr;
 277
 278         while (count--) {
 279                 ch = *mem++;
 280                 *buf++ = hexchars[ch >> 4];
 281                 *buf++ = hexchars[ch & 0x0f];
 282         }
 283         *buf = 0;
 284 }
 285
 286 /* convert the hex array pointed to by buf into binary to be placed in mem */
 287 /* return a pointer to the character AFTER the last byte written */
 288 static void copy_from_hex(void *addr, char *buf, unsigned long count)
 289 {
 290         unsigned char ch;
 291         char *mem = addr;
 292
 293         while (count--) {
 294                 ch = hex(*buf++) << 4;
 295                 ch = ch + hex(*buf++);
 296                 *mem++ = ch;
 297         }
 298 }
 299
 300 /* scan for the sequence $<data>#<checksum>     */
 301
 302 static int get_packet(char *buffer)
 303 {
 304         unsigned char checksum;
 305         unsigned char xmitcsum;
 306         int count;
 307         char ch;
 308
 309         /* TODO: implement a timeout in get_packet */
 310         do {
 311                 /* wait around for the start character, ignore all other
 312                  * characters
 313                  */
 314                 while ((ch = (stub_getc() & 0x7f)) != '$')
 315                         ;
 316                 checksum = 0;
 317                 xmitcsum = -1;
 318
 319                 count = 0;
 320
 321                 /* now, read until a # or end of buffer is found */
 322                 while (count < BUFMAX) {
 323                         ch = stub_getc() & 0x7f;
 324                         if (ch == '#')
 325                                 break;
 326                         checksum = checksum + ch;
 327                         buffer[count] = ch;
 328                         count = count + 1;
 329                 }
 330                 buffer[count] = 0;
 331
 332                 if (ch == '#') {
 333                         xmitcsum = hex(stub_getc() & 0x7f) << 4;
 334                         xmitcsum += hex(stub_getc() & 0x7f);
 335
 336                         if (checksum != xmitcsum) {
 337                                 stub_putc('-'); /* failed checksum */
 338                                 stub_flush();
 339                         } else {
 340                                 stub_putc('+'); /* successful transfer */
 341                                 stub_flush();
 342                         }
 343                 }
 344         } while (checksum != xmitcsum);
 345         return 1;
 346 }
 347
 348 /* send the packet in buffer.*/
 349 static void put_packet(char *buffer)
 350 {
 351         unsigned char checksum;
 352         int count;
 353         char ch;
 354
 355         /*  $<packet info>#<checksum>. */
 356         do {
 357                 stub_putc('$');
 358                 checksum = 0;
 359                 count = 0;
 360
 361                 while ((ch = buffer[count])) {
 362                         stub_putc(ch);
 363                         checksum += ch;
 364                         count += 1;
 365                 }
 366
 367                 stub_putc('#');
 368                 stub_putc(hexchars[checksum >> 4]);
 369                 stub_putc(hexchars[checksum % 16]);
 370                 stub_flush();
 371
 372         } while ((stub_getc() & 0x7f) != '+');
 373 }
 374 #endif /* CONFIG_GDB_STUB */
 375
 376 #define DEBUG_VECTOR 1
 377
 378 void x86_exception(struct eregs *info);
 379
 380 void x86_exception(struct eregs *info)
 381 {
 382 #if CONFIG(GDB_STUB)
 383         /* TODO implement 64bit mode */
 384         int signo;
 385         memcpy(gdb_stub_registers, info, 8*sizeof(uint32_t));
 386         gdb_stub_registers[PC] = info->eip;
 387         gdb_stub_registers[CS] = info->cs;
 388         gdb_stub_registers[PS] = info->eflags;
 389         signo = GDB_UNKNOWN;
 390         if (info->vector < ARRAY_SIZE(exception_to_signal))
 391                 signo = exception_to_signal[info->vector];
 392
 393         /* reply to the host that an exception has occurred */
 394         out_buffer[0] = 'S';
 395         out_buffer[1] = hexchars[(signo>>4) & 0xf];
 396         out_buffer[2] = hexchars[signo & 0xf];
 397         out_buffer[3] = '\0';
 398         put_packet(out_buffer);
 399
 400         while (1) {
 401                 unsigned long addr, length;
 402                 char *ptr;
 403                 out_buffer[0] = '\0';
 404                 out_buffer[1] = '\0';
 405                 if (!get_packet(in_buffer))
 406                         break;
 407                 switch (in_buffer[0]) {
 408                 case '?': /* last signal */
 409                         out_buffer[0] = 'S';
 410                         out_buffer[1] = hexchars[(signo >> 4) & 0xf];
 411                         out_buffer[2] = hexchars[signo & 0xf];
 412                         out_buffer[3] = '\0';
 413                         break;
 414                 case 'g': /* return the value of the CPU registers */
 415                         copy_to_hex(out_buffer, &gdb_stub_registers,
 416                                 sizeof(gdb_stub_registers));
 417                         break;
 418                 case 'G': /* set the value of the CPU registers - return OK */
 419                         copy_from_hex(&gdb_stub_registers, in_buffer + 1,
 420                                 sizeof(gdb_stub_registers));
 421                         memcpy(info, gdb_stub_registers, 8*sizeof(uint32_t));
 422                         info->eip    = gdb_stub_registers[PC];
 423                         info->cs     = gdb_stub_registers[CS];
 424                         info->eflags = gdb_stub_registers[PS];
 425                         memcpy(out_buffer, "OK", 3);
 426                         break;
 427                 case 'm':
 428                         /* mAA..AA,LLLL  Read LLLL bytes at address AA..AA */
 429                         ptr = &in_buffer[1];
 430                         if (parse_ulong(&ptr, &addr) &&
 431                                 (*ptr++ == ',') &&
 432                                 parse_ulong(&ptr, &length)) {
 433                                 copy_to_hex(out_buffer, (void *)addr, length);
 434                         } else
 435                                 memcpy(out_buffer, "E01", 4);
 436                         break;
 437                 case 'M':
 438                         /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA
 439                          * return OK
 440                          */
 441                         ptr = &in_buffer[1];
 442                         if (parse_ulong(&ptr, &addr) &&
 443                                 (*(ptr++) == ',') &&
 444                                 parse_ulong(&ptr, &length) &&
 445                                 (*(ptr++) == ':')) {
 446                                 copy_from_hex((void *)addr, ptr, length);
 447                                 memcpy(out_buffer, "OK", 3);
 448                         } else
 449                                 memcpy(out_buffer, "E02", 4);
 450                         break;
 451                 case 's':
 452                 case 'c':
 453                         /* cAA..AA    Continue at address AA..AA(optional)
 454                          * sAA..AA    Step one instruction from AA..AA(optional)
 455                          */
 456                         ptr = &in_buffer[1];
 457                         if (parse_ulong(&ptr, &addr))
 458                                 info->eip = addr;
 459
 460                         /* Clear the trace bit */
 461                         info->eflags &= ~(1 << 8);
 462                         /* Set the trace bit if we are single stepping */
 463                         if (in_buffer[0] == 's')
 464                                 info->eflags |= (1 << 8);
 465                         return;
 466                 case 'D':
 467                         memcpy(out_buffer, "OK", 3);
 468                         break;
 469                 case 'k':  /* kill request? */
 470                         break;
 471                 case 'q':  /* query */
 472                         break;
 473                 case 'z':  /* z0AAAA,LLLL remove memory breakpoint */
 474                            /* z1AAAA,LLLL remove hardware breakpoint */
 475                            /* z2AAAA,LLLL remove write watchpoint */
 476                            /* z3AAAA,LLLL remove read watchpoint */
 477                            /* z4AAAA,LLLL remove access watchpoint */
 478                 case 'Z':  /* Z0AAAA,LLLL insert memory breakpoint */
 479                            /* Z1AAAA,LLLL insert hardware breakpoint */
 480                            /* Z2AAAA,LLLL insert write watchpoint */
 481                            /* Z3AAAA,LLLL insert read watchpoint */
 482                            /* Z4AAAA,LLLL insert access watchpoint */
 483                         break;
 484                 default:
 485                         break;
 486                 }
 487                 put_packet(out_buffer);
 488         }
 489 #else /* !CONFIG_GDB_STUB */
 490
 491         int logical_processor = 0;
 492
 493         if (info->vector == DEBUG_VECTOR) {
 494                 if (breakpoint_dispatch_handler(info) == 0)
 495                         return;
 496         }
 497
 498 #if ENV_RAMSTAGE
 499         logical_processor = cpu_index();
 500 #endif
 501         u8 *code;
 502 #if ENV_X86_64
 503 #define MDUMP_SIZE 0x100
 504         printk(BIOS_EMERG,
 505                 "CPU Index %d - APIC %d Unexpected Exception:\n"
 506                 "%lld @ %02llx:%016llx - Halting\n"
 507                 "Code: %lld rflags: %016llx cr2: %016llx\n"
 508                 "rax: %016llx rbx: %016llx\n"
 509                 "rcx: %016llx rdx: %016llx\n"
 510                 "rdi: %016llx rsi: %016llx\n"
 511                 "rbp: %016llx rsp: %016llx\n"
 512                 "r08: %016llx r09: %016llx\n"
 513                 "r10: %016llx r11: %016llx\n"
 514                 "r12: %016llx r13: %016llx\n"
 515                 "r14: %016llx r15: %016llx\n",
 516                 logical_processor, early_lapicid(),
 517                 info->vector, info->cs, info->rip,
 518                 info->error_code, info->rflags, read_cr2(),
 519                 info->rax, info->rbx, info->rcx, info->rdx,
 520                 info->rdi, info->rsi, info->rbp, info->rsp,
 521                 info->r8, info->r9, info->r10, info->r11,
 522                 info->r12, info->r13, info->r14, info->r15);
 523         code = (u8 *)((uintptr_t)info->rip - (MDUMP_SIZE >> 2));
 524 #else
 525 #define MDUMP_SIZE 0x80
 526
 527         printk(BIOS_EMERG,
 528                 "CPU Index %d - APIC %d Unexpected Exception:"
 529                 "%d @ %02x:%08x - Halting\n"
 530                 "Code: %d eflags: %08x cr2: %08x\n"
 531                 "eax: %08x ebx: %08x ecx: %08x edx: %08x\n"
 532                 "edi: %08x esi: %08x ebp: %08x esp: %08x\n",
 533                 logical_processor, early_lapicid(),
 534                 info->vector, info->cs, info->eip,
 535                 info->error_code, info->eflags, read_cr2(),
 536                 info->eax, info->ebx, info->ecx, info->edx,
 537                 info->edi, info->esi, info->ebp, info->esp);
 538         code = (u8 *)((uintptr_t)info->eip - (MDUMP_SIZE >> 1));
 539 #endif
 540         /* Align to 8-byte boundary please, and print eight bytes per row.
 541          * This is done to make DRAM burst timing/reordering errors more
 542          * evident from the looking at the dump */
 543         code = (u8 *)((uintptr_t)code & ~0x7);
 544         int i;
 545         for (i = 0; i < MDUMP_SIZE; i++) {
 546                 if ((i & 0x07) == 0)
 547                         printk(BIOS_EMERG, "\n%p:\t", code + i);
 548                 printk(BIOS_EMERG, "%.2x ", code[i]);
 549         }
 550
 551         /* Align to 4-byte boundary and up the stack. */
 552         u32 *ptr = (u32 *)(ALIGN_DOWN((uintptr_t)info->esp, sizeof(u32)) + MDUMP_SIZE - 4);
 553         for (i = 0; i < MDUMP_SIZE / sizeof(u32); ++i, --ptr) {
 554                 printk(BIOS_EMERG, "\n%p:\t0x%08x", ptr, *ptr);
 555                 if ((uintptr_t)ptr == info->ebp)
 556                         printk(BIOS_EMERG, " <-ebp");
 557                 else if ((uintptr_t)ptr == info->esp)
 558                         printk(BIOS_EMERG, " <-esp");
 559         }
 560
 561         die("\n");
 562 #endif
 563 }
 564
 565 #define GATE_P          (1 << 15)
 566 #define GATE_DPL(x)     (((x) & 0x3) << 13)
 567 #define GATE_SIZE_16    (0 << 11)
 568 #define GATE_SIZE_32    (1 << 11)
 569
 570 #define IGATE_FLAGS (GATE_P | GATE_DPL(0) | GATE_SIZE_32 | (0x6 << 8))
 571
 572 struct intr_gate {
 573         uint16_t offset_0;
 574         uint16_t segsel;
 575         uint16_t flags;
 576         uint16_t offset_1;
 577 #if ENV_X86_64
 578         uint32_t offset_2;
 579         uint32_t reserved;
 580 #endif
 581 } __packed;
 582
 583 /* Even though the vecX symbols are interrupt entry points just treat them
 584    like data to more easily get the pointer values in C. Because IDT entries
 585    format splits the offset field up, one can't use the linker to resolve
 586    parts of a relocation on x86 ABI. An array of pointers is used to gather
 587    the symbols. The IDT is initialized at runtime when exception_init() is
 588    called. */
 589 extern u8 vec0[], vec1[], vec2[], vec3[], vec4[], vec5[], vec6[], vec7[];
 590 extern u8 vec8[], vec9[], vec10[], vec11[], vec12[], vec13[], vec14[], vec15[];
 591 extern u8 vec16[], vec17[], vec18[], vec19[];
 592
 593 static const uintptr_t intr_entries[] = {
 594         (uintptr_t)vec0, (uintptr_t)vec1, (uintptr_t)vec2, (uintptr_t)vec3,
 595         (uintptr_t)vec4, (uintptr_t)vec5, (uintptr_t)vec6, (uintptr_t)vec7,
 596         (uintptr_t)vec8, (uintptr_t)vec9, (uintptr_t)vec10, (uintptr_t)vec11,
 597         (uintptr_t)vec12, (uintptr_t)vec13, (uintptr_t)vec14, (uintptr_t)vec15,
 598         (uintptr_t)vec16, (uintptr_t)vec17, (uintptr_t)vec18, (uintptr_t)vec19,
 599 };
 600
 601 static struct intr_gate idt[ARRAY_SIZE(intr_entries)] __aligned(8);
 602
 603 static inline uint16_t get_cs(void)
 604 {
 605         uint16_t segment;
 606
 607         asm volatile (
 608                 "mov    %%cs, %0\n"
 609                 : "=r" (segment)
 610                 :
 611                 : "memory"
 612         );
 613
 614         return segment;
 615 }
 616
 617 struct lidtarg {
 618         uint16_t limit;
 619 #if ENV_X86_32
 620         uint32_t base;
 621 #else
 622         uint64_t base;
 623 #endif
 624 } __packed;
 625
 626 /* This global is for src/cpu/x86/lapic/secondary.S usage which is only
 627    used during ramstage. */
 628 struct lidtarg idtarg;
 629
 630 static void load_idt(void *table, size_t sz)
 631 {
 632         struct lidtarg lidtarg = {
 633                 .limit = sz - 1,
 634                 .base = (uintptr_t)table,
 635         };
 636
 637         asm volatile (
 638                 "lidt   %0"
 639                 :
 640                 : "m" (lidtarg)
 641                 : "memory"
 642         );
 643
 644         if (ENV_RAMSTAGE)
 645                 memcpy(&idtarg, &lidtarg, sizeof(idtarg));
 646 }
 647
 648 asmlinkage void exception_init(void)
 649 {
 650         int i;
 651         uint16_t segment;
 652
 653         segment = get_cs();
 654
 655         /* Initialize IDT. */
 656         for (i = 0; i < ARRAY_SIZE(idt); i++) {
 657                 idt[i].offset_0 = intr_entries[i];
 658                 idt[i].segsel = segment;
 659                 idt[i].flags = IGATE_FLAGS;
 660                 idt[i].offset_1 = intr_entries[i] >> 16;
 661 #if ENV_X86_64
 662                 idt[i].offset_2 = intr_entries[i] >> 32;
 663 #endif
 664         }
 665
 666         load_idt(idt, sizeof(idt));
 667
 668         null_breakpoint_init();
 669         stack_canary_breakpoint_init();
 670 }