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 #include "cpu-i386.h"
  30
  31 #define DEBUG_LOGFILE "/tmp/qemu.log"
  32
  33 FILE *logfile = NULL;
  34 int loglevel;
  35 const char *interp_prefix = CONFIG_QEMU_PREFIX "/qemu-i386";
  36
  37 /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
  38    we allocate a bigger stack. Need a better solution, for example
  39    by remapping the process stack directly at the right place */
  40 unsigned long x86_stack_size = 512 * 1024;
  41 unsigned long stktop;
  42
  43 void gemu_log(const char *fmt, ...)
  44 {
  45     va_list ap;
  46
  47     va_start(ap, fmt);
  48     vfprintf(stderr, fmt, ap);
  49     va_end(ap);
  50 }
  51
  52 /***********************************************************/
  53 /* CPUX86 core interface */
  54
  55 void cpu_x86_outb(int addr, int val)
  56 {
  57     fprintf(stderr, "outb: port=0x%04x, data=%02x\n", addr, val);
  58 }
  59
  60 void cpu_x86_outw(int addr, int val)
  61 {
  62     fprintf(stderr, "outw: port=0x%04x, data=%04x\n", addr, val);
  63 }
  64
  65 void cpu_x86_outl(int addr, int val)
  66 {
  67     fprintf(stderr, "outl: port=0x%04x, data=%08x\n", addr, val);
  68 }
  69
  70 int cpu_x86_inb(int addr)
  71 {
  72     fprintf(stderr, "inb: port=0x%04x\n", addr);
  73     return 0;
  74 }
  75
  76 int cpu_x86_inw(int addr)
  77 {
  78     fprintf(stderr, "inw: port=0x%04x\n", addr);
  79     return 0;
  80 }
  81
  82 int cpu_x86_inl(int addr)
  83 {
  84     fprintf(stderr, "inl: port=0x%04x\n", addr);
  85     return 0;
  86 }
  87
  88 void write_dt(void *ptr, unsigned long addr, unsigned long limit,
  89               int seg32_bit)
  90 {
  91     unsigned int e1, e2, limit_in_pages;
  92     limit_in_pages = 0;
  93     if (limit > 0xffff) {
  94         limit = limit >> 12;
  95         limit_in_pages = 1;
  96     }
  97     e1 = (addr << 16) | (limit & 0xffff);
  98     e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
  99     e2 |= limit_in_pages << 23; /* byte granularity */
 100     e2 |= seg32_bit << 22; /* 32 bit segment */
 101     stl((uint8_t *)ptr, e1);
 102     stl((uint8_t *)ptr + 4, e2);
 103 }
 104
 105 uint64_t gdt_table[6];
 106
 107 void cpu_loop(struct CPUX86State *env)
 108 {
 109     int err;
 110     uint8_t *pc;
 111     target_siginfo_t info;
 112
 113     for(;;) {
 114         err = cpu_x86_exec(env);
 115         pc = env->seg_cache[R_CS].base + env->eip;
 116         switch(err) {
 117         case EXCP0D_GPF:
 118             if (pc[0] == 0xcd && pc[1] == 0x80) {
 119                 /* syscall */
 120                 env->eip += 2;
 121                 env->regs[R_EAX] = do_syscall(env,
 122                                               env->regs[R_EAX],
 123                                               env->regs[R_EBX],
 124                                               env->regs[R_ECX],
 125                                               env->regs[R_EDX],
 126                                               env->regs[R_ESI],
 127                                               env->regs[R_EDI],
 128                                               env->regs[R_EBP]);
 129             } else {
 130                 /* XXX: more precise info */
 131                 info.si_signo = SIGSEGV;
 132                 info.si_errno = 0;
 133                 info.si_code = 0;
 134                 info._sifields._sigfault._addr = 0;
 135                 queue_signal(info.si_signo, &info);
 136             }
 137             break;
 138         case EXCP00_DIVZ:
 139             /* division by zero */
 140             info.si_signo = SIGFPE;
 141             info.si_errno = 0;
 142             info.si_code = TARGET_FPE_INTDIV;
 143             info._sifields._sigfault._addr = env->eip;
 144             queue_signal(info.si_signo, &info);
 145             break;
 146         case EXCP04_INTO:
 147         case EXCP05_BOUND:
 148             info.si_signo = SIGSEGV;
 149             info.si_errno = 0;
 150             info.si_code = 0;
 151             info._sifields._sigfault._addr = 0;
 152             queue_signal(info.si_signo, &info);
 153             break;
 154         case EXCP06_ILLOP:
 155             info.si_signo = SIGILL;
 156             info.si_errno = 0;
 157             info.si_code = TARGET_ILL_ILLOPN;
 158             info._sifields._sigfault._addr = env->eip;
 159             queue_signal(info.si_signo, &info);
 160             break;
 161         case EXCP_INTERRUPT:
 162             /* just indicate that signals should be handled asap */
 163             break;
 164         default:
 165             fprintf(stderr, "0x%08lx: Unknown exception CPU %d, aborting\n",
 166                     (long)pc, err);
 167             abort();
 168         }
 169         process_pending_signals(env);
 170     }
 171 }
 172
 173 void usage(void)
 174 {
 175     printf("qemu version " QEMU_VERSION ", Copyright (c) 2003 Fabrice Bellard\n"
 176            "usage: qemu [-h] [-d] [-L path] [-s size] program [arguments...]\n"
 177            "Linux x86 emulator\n"
 178            "\n"
 179            "-h        print this help\n"
 180            "-d        activate log (logfile=%s)\n"
 181            "-L path   set the x86 elf interpreter prefix (default=%s)\n"
 182            "-s size   set the x86 stack size in bytes (default=%ld)\n",
 183            DEBUG_LOGFILE,
 184            interp_prefix,
 185            x86_stack_size);
 186     exit(1);
 187 }
 188
 189 /* XXX: currently only used for async signals (see signal.c) */
 190 CPUX86State *global_env;
 191
 192 int main(int argc, char **argv)
 193 {
 194     const char *filename;
 195     struct target_pt_regs regs1, *regs = &regs1;
 196     struct image_info info1, *info = &info1;
 197     CPUX86State *env;
 198     int optind;
 199     const char *r;
 200
 201     if (argc <= 1)
 202         usage();
 203     loglevel = 0;
 204     optind = 1;
 205     for(;;) {
 206         if (optind >= argc)
 207             break;
 208         r = argv[optind];
 209         if (r[0] != '-')
 210             break;
 211         optind++;
 212         r++;
 213         if (!strcmp(r, "-")) {
 214             break;
 215         } else if (!strcmp(r, "d")) {
 216             loglevel = 1;
 217         } else if (!strcmp(r, "s")) {
 218             r = argv[optind++];
 219             x86_stack_size = strtol(r, (char **)&r, 0);
 220             if (x86_stack_size <= 0)
 221                 usage();
 222             if (*r == 'M')
 223                 x86_stack_size *= 1024 * 1024;
 224             else if (*r == 'k' || *r == 'K')
 225                 x86_stack_size *= 1024;
 226         } else if (!strcmp(r, "L")) {
 227             interp_prefix = argv[optind++];
 228         } else {
 229             usage();
 230         }
 231     }
 232     if (optind >= argc)
 233         usage();
 234     filename = argv[optind];
 235
 236     /* init debug */
 237     if (loglevel) {
 238         logfile = fopen(DEBUG_LOGFILE, "w");
 239         if (!logfile) {
 240             perror(DEBUG_LOGFILE);
 241             exit(1);
 242         }
 243         setvbuf(logfile, NULL, _IOLBF, 0);
 244     }
 245
 246     /* Zero out regs */
 247     memset(regs, 0, sizeof(struct target_pt_regs));
 248
 249     /* Zero out image_info */
 250     memset(info, 0, sizeof(struct image_info));
 251
 252     if(elf_exec(interp_prefix, filename, argv+optind, environ, regs, info) != 0) {
 253         printf("Error loading %s\n", filename);
 254         exit(1);
 255     }
 256
 257     if (loglevel) {
 258         fprintf(logfile, "start_brk   0x%08lx\n" , info->start_brk);
 259         fprintf(logfile, "end_code    0x%08lx\n" , info->end_code);
 260         fprintf(logfile, "start_code  0x%08lx\n" , info->start_code);
 261         fprintf(logfile, "end_data    0x%08lx\n" , info->end_data);
 262         fprintf(logfile, "start_stack 0x%08lx\n" , info->start_stack);
 263         fprintf(logfile, "brk         0x%08lx\n" , info->brk);
 264         fprintf(logfile, "esp         0x%08lx\n" , regs->esp);
 265         fprintf(logfile, "eip         0x%08lx\n" , regs->eip);
 266     }
 267
 268     target_set_brk((char *)info->brk);
 269     syscall_init();
 270     signal_init();
 271
 272     env = cpu_x86_init();
 273     global_env = env;
 274
 275     /* linux register setup */
 276     env->regs[R_EAX] = regs->eax;
 277     env->regs[R_EBX] = regs->ebx;
 278     env->regs[R_ECX] = regs->ecx;
 279     env->regs[R_EDX] = regs->edx;
 280     env->regs[R_ESI] = regs->esi;
 281     env->regs[R_EDI] = regs->edi;
 282     env->regs[R_EBP] = regs->ebp;
 283     env->regs[R_ESP] = regs->esp;
 284     env->eip = regs->eip;
 285
 286     /* linux segment setup */
 287     env->gdt.base = (void *)gdt_table;
 288     env->gdt.limit = sizeof(gdt_table) - 1;
 289     write_dt(&gdt_table[__USER_CS >> 3], 0, 0xffffffff, 1);
 290     write_dt(&gdt_table[__USER_DS >> 3], 0, 0xffffffff, 1);
 291     cpu_x86_load_seg(env, R_CS, __USER_CS);
 292     cpu_x86_load_seg(env, R_DS, __USER_DS);
 293     cpu_x86_load_seg(env, R_ES, __USER_DS);
 294     cpu_x86_load_seg(env, R_SS, __USER_DS);
 295     cpu_x86_load_seg(env, R_FS, __USER_DS);
 296     cpu_x86_load_seg(env, R_GS, __USER_DS);
 297
 298     cpu_loop(env);
 299     /* never exits */
 300     return 0;
 301 }