linux-user/main.c

   1 /*
   2  *  qemu main
   3  *
   4  *  Copyright (c) 2003 Fabrice Bellard
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <stdarg.h>
  23 #include <string.h>
  24 #include <errno.h>
  25 #include <unistd.h>
  26
  27 #include "qemu.h"
  28
  29 #define DEBUG_LOGFILE "/tmp/qemu.log"
  30
  31 FILE *logfile = NULL;
  32 int loglevel;
  33 static const char *interp_prefix = CONFIG_QEMU_PREFIX;
  34
  35 #ifdef __i386__
  36 /* Force usage of an ELF interpreter even if it is an ELF shared
  37    object ! */
  38 const char interp[] __attribute__((section(".interp"))) = "/lib/ld-linux.so.2";
  39 #endif
  40
  41 /* for recent libc, we add these dummies symbol which are not declared
  42    when generating a linked object (bug in ld ?) */
  43 #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)
  44 long __init_array_start[0];
  45 long __init_array_end[0];
  46 long __fini_array_start[0];
  47 long __fini_array_end[0];
  48 #endif
  49
  50 /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
  51    we allocate a bigger stack. Need a better solution, for example
  52    by remapping the process stack directly at the right place */
  53 unsigned long x86_stack_size = 512 * 1024;
  54
  55 void gemu_log(const char *fmt, ...)
  56 {
  57     va_list ap;
  58
  59     va_start(ap, fmt);
  60     vfprintf(stderr, fmt, ap);
  61     va_end(ap);
  62 }
  63
  64 #ifdef TARGET_I386
  65 /***********************************************************/
  66 /* CPUX86 core interface */
  67
  68 void cpu_x86_outb(CPUX86State *env, int addr, int val)
  69 {
  70     fprintf(stderr, "outb: port=0x%04x, data=%02x\n", addr, val);
  71 }
  72
  73 void cpu_x86_outw(CPUX86State *env, int addr, int val)
  74 {
  75     fprintf(stderr, "outw: port=0x%04x, data=%04x\n", addr, val);
  76 }
  77
  78 void cpu_x86_outl(CPUX86State *env, int addr, int val)
  79 {
  80     fprintf(stderr, "outl: port=0x%04x, data=%08x\n", addr, val);
  81 }
  82
  83 int cpu_x86_inb(CPUX86State *env, int addr)
  84 {
  85     fprintf(stderr, "inb: port=0x%04x\n", addr);
  86     return 0;
  87 }
  88
  89 int cpu_x86_inw(CPUX86State *env, int addr)
  90 {
  91     fprintf(stderr, "inw: port=0x%04x\n", addr);
  92     return 0;
  93 }
  94
  95 int cpu_x86_inl(CPUX86State *env, int addr)
  96 {
  97     fprintf(stderr, "inl: port=0x%04x\n", addr);
  98     return 0;
  99 }
 100
 101 int cpu_x86_get_pic_interrupt(CPUX86State *env)
 102 {
 103     return -1;
 104 }
 105
 106 static void write_dt(void *ptr, unsigned long addr, unsigned long limit,
 107                      int flags)
 108 {
 109     unsigned int e1, e2;
 110     e1 = (addr << 16) | (limit & 0xffff);
 111     e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
 112     e2 |= flags;
 113     stl((uint8_t *)ptr, e1);
 114     stl((uint8_t *)ptr + 4, e2);
 115 }
 116
 117 static void set_gate(void *ptr, unsigned int type, unsigned int dpl,
 118                      unsigned long addr, unsigned int sel)
 119 {
 120     unsigned int e1, e2;
 121     e1 = (addr & 0xffff) | (sel << 16);
 122     e2 = (addr & 0xffff0000) | 0x8000 | (dpl << 13) | (type << 8);
 123     stl((uint8_t *)ptr, e1);
 124     stl((uint8_t *)ptr + 4, e2);
 125 }
 126
 127 uint64_t gdt_table[6];
 128 uint64_t idt_table[256];
 129
 130 /* only dpl matters as we do only user space emulation */
 131 static void set_idt(int n, unsigned int dpl)
 132 {
 133     set_gate(idt_table + n, 0, dpl, 0, 0);
 134 }
 135
 136 void cpu_loop(CPUX86State *env)
 137 {
 138     int trapnr;
 139     uint8_t *pc;
 140     target_siginfo_t info;
 141
 142     for(;;) {
 143         trapnr = cpu_x86_exec(env);
 144         switch(trapnr) {
 145         case 0x80:
 146             /* linux syscall */
 147             env->regs[R_EAX] = do_syscall(env,
 148                                           env->regs[R_EAX],
 149                                           env->regs[R_EBX],
 150                                           env->regs[R_ECX],
 151                                           env->regs[R_EDX],
 152                                           env->regs[R_ESI],
 153                                           env->regs[R_EDI],
 154                                           env->regs[R_EBP]);
 155             break;
 156         case EXCP0B_NOSEG:
 157         case EXCP0C_STACK:
 158             info.si_signo = SIGBUS;
 159             info.si_errno = 0;
 160             info.si_code = TARGET_SI_KERNEL;
 161             info._sifields._sigfault._addr = 0;
 162             queue_signal(info.si_signo, &info);
 163             break;
 164         case EXCP0D_GPF:
 165             if (env->eflags & VM_MASK) {
 166                 handle_vm86_fault(env);
 167             } else {
 168                 info.si_signo = SIGSEGV;
 169                 info.si_errno = 0;
 170                 info.si_code = TARGET_SI_KERNEL;
 171                 info._sifields._sigfault._addr = 0;
 172                 queue_signal(info.si_signo, &info);
 173             }
 174             break;
 175         case EXCP0E_PAGE:
 176             info.si_signo = SIGSEGV;
 177             info.si_errno = 0;
 178             if (!(env->error_code & 1))
 179                 info.si_code = TARGET_SEGV_MAPERR;
 180             else
 181                 info.si_code = TARGET_SEGV_ACCERR;
 182             info._sifields._sigfault._addr = env->cr[2];
 183             queue_signal(info.si_signo, &info);
 184             break;
 185         case EXCP00_DIVZ:
 186             if (env->eflags & VM_MASK) {
 187                 handle_vm86_trap(env, trapnr);
 188             } else {
 189                 /* division by zero */
 190                 info.si_signo = SIGFPE;
 191                 info.si_errno = 0;
 192                 info.si_code = TARGET_FPE_INTDIV;
 193                 info._sifields._sigfault._addr = env->eip;
 194                 queue_signal(info.si_signo, &info);
 195             }
 196             break;
 197         case EXCP01_SSTP:
 198         case EXCP03_INT3:
 199             if (env->eflags & VM_MASK) {
 200                 handle_vm86_trap(env, trapnr);
 201             } else {
 202                 info.si_signo = SIGTRAP;
 203                 info.si_errno = 0;
 204                 if (trapnr == EXCP01_SSTP) {
 205                     info.si_code = TARGET_TRAP_BRKPT;
 206                     info._sifields._sigfault._addr = env->eip;
 207                 } else {
 208                     info.si_code = TARGET_SI_KERNEL;
 209                     info._sifields._sigfault._addr = 0;
 210                 }
 211                 queue_signal(info.si_signo, &info);
 212             }
 213             break;
 214         case EXCP04_INTO:
 215         case EXCP05_BOUND:
 216             if (env->eflags & VM_MASK) {
 217                 handle_vm86_trap(env, trapnr);
 218             } else {
 219                 info.si_signo = SIGSEGV;
 220                 info.si_errno = 0;
 221                 info.si_code = TARGET_SI_KERNEL;
 222                 info._sifields._sigfault._addr = 0;
 223                 queue_signal(info.si_signo, &info);
 224             }
 225             break;
 226         case EXCP06_ILLOP:
 227             info.si_signo = SIGILL;
 228             info.si_errno = 0;
 229             info.si_code = TARGET_ILL_ILLOPN;
 230             info._sifields._sigfault._addr = env->eip;
 231             queue_signal(info.si_signo, &info);
 232             break;
 233         case EXCP_INTERRUPT:
 234             /* just indicate that signals should be handled asap */
 235             break;
 236         default:
 237             pc = env->segs[R_CS].base + env->eip;
 238             fprintf(stderr, "qemu: 0x%08lx: unhandled CPU exception 0x%x - aborting\n",
 239                     (long)pc, trapnr);
 240             abort();
 241         }
 242         process_pending_signals(env);
 243     }
 244 }
 245 #endif
 246
 247 #ifdef TARGET_ARM
 248
 249 void cpu_loop(CPUARMState *env)
 250 {
 251     int trapnr;
 252     unsigned int n, insn;
 253     target_siginfo_t info;
 254
 255     for(;;) {
 256         trapnr = cpu_arm_exec(env);
 257         switch(trapnr) {
 258         case EXCP_UDEF:
 259             info.si_signo = SIGILL;
 260             info.si_errno = 0;
 261             info.si_code = TARGET_ILL_ILLOPN;
 262             info._sifields._sigfault._addr = env->regs[15];
 263             queue_signal(info.si_signo, &info);
 264             break;
 265         case EXCP_SWI:
 266             {
 267                 /* system call */
 268                 insn = ldl((void *)(env->regs[15] - 4));
 269                 n = insn & 0xffffff;
 270                 if (n >= ARM_SYSCALL_BASE) {
 271                     /* linux syscall */
 272                     n -= ARM_SYSCALL_BASE;
 273                     env->regs[0] = do_syscall(env,
 274                                               n,
 275                                               env->regs[0],
 276                                               env->regs[1],
 277                                               env->regs[2],
 278                                               env->regs[3],
 279                                               env->regs[4],
 280                                               0);
 281                 } else {
 282                     goto error;
 283                 }
 284             }
 285             break;
 286         case EXCP_INTERRUPT:
 287             /* just indicate that signals should be handled asap */
 288             break;
 289         default:
 290         error:
 291             fprintf(stderr, "qemu: unhandled CPU exception 0x%x - aborting\n",
 292                     trapnr);
 293             cpu_arm_dump_state(env, stderr, 0);
 294             abort();
 295         }
 296         process_pending_signals(env);
 297     }
 298 }
 299
 300 #endif
 301
 302 void usage(void)
 303 {
 304     printf("qemu version " QEMU_VERSION ", Copyright (c) 2003 Fabrice Bellard\n"
 305            "usage: qemu [-h] [-d] [-L path] [-s size] program [arguments...]\n"
 306            "Linux CPU emulator (compiled for %s emulation)\n"
 307            "\n"
 308            "-h           print this help\n"
 309            "-L path      set the elf interpreter prefix (default=%s)\n"
 310            "-s size      set the stack size in bytes (default=%ld)\n"
 311            "\n"
 312            "debug options:\n"
 313            "-d           activate log (logfile=%s)\n"
 314            "-p pagesize  set the host page size to 'pagesize'\n",
 315            TARGET_ARCH,
 316            interp_prefix,
 317            x86_stack_size,
 318            DEBUG_LOGFILE);
 319     _exit(1);
 320 }
 321
 322 /* XXX: currently only used for async signals (see signal.c) */
 323 CPUState *global_env;
 324 /* used only if single thread */
 325 CPUState *cpu_single_env = NULL;
 326
 327 /* used to free thread contexts */
 328 TaskState *first_task_state;
 329
 330 int main(int argc, char **argv)
 331 {
 332     const char *filename;
 333     struct target_pt_regs regs1, *regs = &regs1;
 334     struct image_info info1, *info = &info1;
 335     TaskState ts1, *ts = &ts1;
 336     CPUState *env;
 337     int optind;
 338     const char *r;
 339
 340     if (argc <= 1)
 341         usage();
 342
 343     loglevel = 0;
 344     optind = 1;
 345     for(;;) {
 346         if (optind >= argc)
 347             break;
 348         r = argv[optind];
 349         if (r[0] != '-')
 350             break;
 351         optind++;
 352         r++;
 353         if (!strcmp(r, "-")) {
 354             break;
 355         } else if (!strcmp(r, "d")) {
 356             loglevel = 1;
 357         } else if (!strcmp(r, "s")) {
 358             r = argv[optind++];
 359             x86_stack_size = strtol(r, (char **)&r, 0);
 360             if (x86_stack_size <= 0)
 361                 usage();
 362             if (*r == 'M')
 363                 x86_stack_size *= 1024 * 1024;
 364             else if (*r == 'k' || *r == 'K')
 365                 x86_stack_size *= 1024;
 366         } else if (!strcmp(r, "L")) {
 367             interp_prefix = argv[optind++];
 368         } else if (!strcmp(r, "p")) {
 369             host_page_size = atoi(argv[optind++]);
 370             if (host_page_size == 0 ||
 371                 (host_page_size & (host_page_size - 1)) != 0) {
 372                 fprintf(stderr, "page size must be a power of two\n");
 373                 exit(1);
 374             }
 375         } else {
 376             usage();
 377         }
 378     }
 379     if (optind >= argc)
 380         usage();
 381     filename = argv[optind];
 382
 383     /* init debug */
 384     if (loglevel) {
 385         logfile = fopen(DEBUG_LOGFILE, "w");
 386         if (!logfile) {
 387             perror(DEBUG_LOGFILE);
 388             _exit(1);
 389         }
 390         setvbuf(logfile, NULL, _IOLBF, 0);
 391     }
 392
 393     /* Zero out regs */
 394     memset(regs, 0, sizeof(struct target_pt_regs));
 395
 396     /* Zero out image_info */
 397     memset(info, 0, sizeof(struct image_info));
 398
 399     /* Scan interp_prefix dir for replacement files. */
 400     init_paths(interp_prefix);
 401
 402     /* NOTE: we need to init the CPU at this stage to get the
 403        host_page_size */
 404     env = cpu_init();
 405
 406     if (elf_exec(filename, argv+optind, environ, regs, info) != 0) {
 407         printf("Error loading %s\n", filename);
 408         _exit(1);
 409     }
 410
 411     if (loglevel) {
 412         page_dump(logfile);
 413
 414         fprintf(logfile, "start_brk   0x%08lx\n" , info->start_brk);
 415         fprintf(logfile, "end_code    0x%08lx\n" , info->end_code);
 416         fprintf(logfile, "start_code  0x%08lx\n" , info->start_code);
 417         fprintf(logfile, "end_data    0x%08lx\n" , info->end_data);
 418         fprintf(logfile, "start_stack 0x%08lx\n" , info->start_stack);
 419         fprintf(logfile, "brk         0x%08lx\n" , info->brk);
 420         fprintf(logfile, "entry       0x%08lx\n" , info->entry);
 421     }
 422
 423     target_set_brk((char *)info->brk);
 424     syscall_init();
 425     signal_init();
 426
 427     global_env = env;
 428
 429     /* build Task State */
 430     memset(ts, 0, sizeof(TaskState));
 431     env->opaque = ts;
 432     ts->used = 1;
 433     env->user_mode_only = 1;
 434
 435 #if defined(TARGET_I386)
 436     env->cr[0] = CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK;
 437
 438     /* linux register setup */
 439     env->regs[R_EAX] = regs->eax;
 440     env->regs[R_EBX] = regs->ebx;
 441     env->regs[R_ECX] = regs->ecx;
 442     env->regs[R_EDX] = regs->edx;
 443     env->regs[R_ESI] = regs->esi;
 444     env->regs[R_EDI] = regs->edi;
 445     env->regs[R_EBP] = regs->ebp;
 446     env->regs[R_ESP] = regs->esp;
 447     env->eip = regs->eip;
 448
 449     /* linux interrupt setup */
 450     env->idt.base = (void *)idt_table;
 451     env->idt.limit = sizeof(idt_table) - 1;
 452     set_idt(0, 0);
 453     set_idt(1, 0);
 454     set_idt(2, 0);
 455     set_idt(3, 3);
 456     set_idt(4, 3);
 457     set_idt(5, 3);
 458     set_idt(6, 0);
 459     set_idt(7, 0);
 460     set_idt(8, 0);
 461     set_idt(9, 0);
 462     set_idt(10, 0);
 463     set_idt(11, 0);
 464     set_idt(12, 0);
 465     set_idt(13, 0);
 466     set_idt(14, 0);
 467     set_idt(15, 0);
 468     set_idt(16, 0);
 469     set_idt(17, 0);
 470     set_idt(18, 0);
 471     set_idt(19, 0);
 472     set_idt(0x80, 3);
 473
 474     /* linux segment setup */
 475     env->gdt.base = (void *)gdt_table;
 476     env->gdt.limit = sizeof(gdt_table) - 1;
 477     write_dt(&gdt_table[__USER_CS >> 3], 0, 0xfffff,
 478              DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
 479              (3 << DESC_DPL_SHIFT) | (0xa << DESC_TYPE_SHIFT));
 480     write_dt(&gdt_table[__USER_DS >> 3], 0, 0xfffff,
 481              DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
 482              (3 << DESC_DPL_SHIFT) | (0x2 << DESC_TYPE_SHIFT));
 483     cpu_x86_load_seg(env, R_CS, __USER_CS);
 484     cpu_x86_load_seg(env, R_DS, __USER_DS);
 485     cpu_x86_load_seg(env, R_ES, __USER_DS);
 486     cpu_x86_load_seg(env, R_SS, __USER_DS);
 487     cpu_x86_load_seg(env, R_FS, __USER_DS);
 488     cpu_x86_load_seg(env, R_GS, __USER_DS);
 489
 490 #elif defined(TARGET_ARM)
 491     {
 492         int i;
 493         for(i = 0; i < 16; i++) {
 494             env->regs[i] = regs->uregs[i];
 495         }
 496         env->cpsr = regs->uregs[16];
 497     }
 498 #else
 499 #error unsupported target CPU
 500 #endif
 501
 502     cpu_loop(env);
 503     /* never exits */
 504     return 0;
 505 }