1 /* 2 * gemu 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 "gemu.h" 28 29 #include "cpu-i386.h" 30 31 #define DEBUG_LOGFILE "/tmp/gemu.log" 32 33 FILE *logfile = NULL; 34 int loglevel; 35 36 /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so 37 we allocate a bigger stack. Need a better solution, for example 38 by remapping the process stack directly at the right place */ 39 unsigned long x86_stack_size = 512 * 1024; 40 unsigned long stktop; 41 42 void gemu_log(const char *fmt, ...) 43 { 44 va_list ap; 45 46 va_start(ap, fmt); 47 vfprintf(stderr, fmt, ap); 48 va_end(ap); 49 } 50 51 /***********************************************************/ 52 /* CPUX86 core interface */ 53 54 void cpu_x86_outb(int addr, int val) 55 { 56 fprintf(stderr, "outb: port=0x%04x, data=%02x\n", addr, val); 57 } 58 59 void cpu_x86_outw(int addr, int val) 60 { 61 fprintf(stderr, "outw: port=0x%04x, data=%04x\n", addr, val); 62 } 63 64 void cpu_x86_outl(int addr, int val) 65 { 66 fprintf(stderr, "outl: port=0x%04x, data=%08x\n", addr, val); 67 } 68 69 int cpu_x86_inb(int addr) 70 { 71 fprintf(stderr, "inb: port=0x%04x\n", addr); 72 return 0; 73 } 74 75 int cpu_x86_inw(int addr) 76 { 77 fprintf(stderr, "inw: port=0x%04x\n", addr); 78 return 0; 79 } 80 81 int cpu_x86_inl(int addr) 82 { 83 fprintf(stderr, "inl: port=0x%04x\n", addr); 84 return 0; 85 } 86 87 void write_dt(void *ptr, unsigned long addr, unsigned long limit, 88 int seg32_bit) 89 { 90 unsigned int e1, e2, limit_in_pages; 91 limit_in_pages = 0; 92 if (limit > 0xffff) { 93 limit = limit >> 12; 94 limit_in_pages = 1; 95 } 96 e1 = (addr << 16) | (limit & 0xffff); 97 e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000); 98 e2 |= limit_in_pages << 23; /* byte granularity */ 99 e2 |= seg32_bit << 22; /* 32 bit segment */ 100 stl((uint8_t *)ptr, e1); 101 stl((uint8_t *)ptr + 4, e2); 102 } 103 104 uint64_t gdt_table[6]; 105 106 void cpu_loop(struct CPUX86State *env) 107 { 108 int err; 109 uint8_t *pc; 110 target_siginfo_t info; 111 112 for(;;) { 113 err = cpu_x86_exec(env); 114 pc = env->seg_cache[R_CS].base + env->eip; 115 switch(err) { 116 case EXCP0D_GPF: 117 if (pc[0] == 0xcd && pc[1] == 0x80) { 118 /* syscall */ 119 env->eip += 2; 120 env->regs[R_EAX] = do_syscall(env, 121 env->regs[R_EAX], 122 env->regs[R_EBX], 123 env->regs[R_ECX], 124 env->regs[R_EDX], 125 env->regs[R_ESI], 126 env->regs[R_EDI], 127 env->regs[R_EBP]); 128 } else { 129 /* XXX: more precise info */ 130 info.si_signo = SIGSEGV; 131 info.si_errno = 0; 132 info.si_code = 0; 133 info._sifields._sigfault._addr = 0; 134 queue_signal(info.si_signo, &info); 135 } 136 break; 137 case EXCP00_DIVZ: 138 /* division by zero */ 139 info.si_signo = SIGFPE; 140 info.si_errno = 0; 141 info.si_code = TARGET_FPE_INTDIV; 142 info._sifields._sigfault._addr = env->eip; 143 queue_signal(info.si_signo, &info); 144 break; 145 case EXCP04_INTO: 146 case EXCP05_BOUND: 147 info.si_signo = SIGSEGV; 148 info.si_errno = 0; 149 info.si_code = 0; 150 info._sifields._sigfault._addr = 0; 151 queue_signal(info.si_signo, &info); 152 break; 153 case EXCP06_ILLOP: 154 info.si_signo = SIGILL; 155 info.si_errno = 0; 156 info.si_code = TARGET_ILL_ILLOPN; 157 info._sifields._sigfault._addr = env->eip; 158 queue_signal(info.si_signo, &info); 159 break; 160 case EXCP_INTERRUPT: 161 /* just indicate that signals should be handled asap */ 162 break; 163 default: 164 fprintf(stderr, "0x%08lx: Unknown exception CPU %d, aborting\n", 165 (long)pc, err); 166 abort(); 167 } 168 process_pending_signals(env); 169 } 170 } 171 172 void usage(void) 173 { 174 printf("gemu version " GEMU_VERSION ", Copyright (c) 2003 Fabrice Bellard\n" 175 "usage: gemu [-d] program [arguments...]\n" 176 "Linux x86 emulator\n" 177 ); 178 exit(1); 179 } 180 181 /* XXX: currently only used for async signals (see signal.c) */ 182 CPUX86State *global_env; 183 184 int main(int argc, char **argv) 185 { 186 const char *filename; 187 struct target_pt_regs regs1, *regs = ®s1; 188 struct image_info info1, *info = &info1; 189 CPUX86State *env; 190 int optind; 191 192 if (argc <= 1) 193 usage(); 194 loglevel = 0; 195 optind = 1; 196 if (argv[optind] && !strcmp(argv[optind], "-d")) { 197 loglevel = 1; 198 optind++; 199 } 200 filename = argv[optind]; 201 202 /* init debug */ 203 if (loglevel) { 204 logfile = fopen(DEBUG_LOGFILE, "w"); 205 if (!logfile) { 206 perror(DEBUG_LOGFILE); 207 exit(1); 208 } 209 setvbuf(logfile, NULL, _IOLBF, 0); 210 } 211 212 /* Zero out regs */ 213 memset(regs, 0, sizeof(struct target_pt_regs)); 214 215 /* Zero out image_info */ 216 memset(info, 0, sizeof(struct image_info)); 217 218 if(elf_exec(filename, argv+optind, environ, regs, info) != 0) { 219 printf("Error loading %s\n", filename); 220 exit(1); 221 } 222 223 if (loglevel) { 224 fprintf(logfile, "start_brk 0x%08lx\n" , info->start_brk); 225 fprintf(logfile, "end_code 0x%08lx\n" , info->end_code); 226 fprintf(logfile, "start_code 0x%08lx\n" , info->start_code); 227 fprintf(logfile, "end_data 0x%08lx\n" , info->end_data); 228 fprintf(logfile, "start_stack 0x%08lx\n" , info->start_stack); 229 fprintf(logfile, "brk 0x%08lx\n" , info->brk); 230 fprintf(logfile, "esp 0x%08lx\n" , regs->esp); 231 fprintf(logfile, "eip 0x%08lx\n" , regs->eip); 232 } 233 234 target_set_brk((char *)info->brk); 235 syscall_init(); 236 signal_init(); 237 238 env = cpu_x86_init(); 239 global_env = env; 240 241 /* linux register setup */ 242 env->regs[R_EAX] = regs->eax; 243 env->regs[R_EBX] = regs->ebx; 244 env->regs[R_ECX] = regs->ecx; 245 env->regs[R_EDX] = regs->edx; 246 env->regs[R_ESI] = regs->esi; 247 env->regs[R_EDI] = regs->edi; 248 env->regs[R_EBP] = regs->ebp; 249 env->regs[R_ESP] = regs->esp; 250 env->eip = regs->eip; 251 252 /* linux segment setup */ 253 env->gdt.base = (void *)gdt_table; 254 env->gdt.limit = sizeof(gdt_table) - 1; 255 write_dt(&gdt_table[__USER_CS >> 3], 0, 0xffffffff, 1); 256 write_dt(&gdt_table[__USER_DS >> 3], 0, 0xffffffff, 1); 257 cpu_x86_load_seg(env, R_CS, __USER_CS); 258 cpu_x86_load_seg(env, R_DS, __USER_DS); 259 cpu_x86_load_seg(env, R_ES, __USER_DS); 260 cpu_x86_load_seg(env, R_SS, __USER_DS); 261 cpu_x86_load_seg(env, R_FS, __USER_DS); 262 cpu_x86_load_seg(env, R_GS, __USER_DS); 263 264 cpu_loop(env); 265 /* never exits */ 266 return 0; 267 } 268