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/*
* gemu main
*
* Copyright (c) 2003 Fabrice Bellard
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <errno.h>
#include <unistd.h>
#include "gemu.h"
#include "cpu-i386.h"
#define DEBUG_LOGFILE "/tmp/gemu.log"
FILE *logfile = NULL;
int loglevel;
unsigned long x86_stack_size;
unsigned long stktop;
void gemu_log(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
/***********************************************************/
/* CPUX86 core interface */
void cpu_x86_outb(int addr, int val)
{
fprintf(stderr, "outb: port=0x%04x, data=%02x\n", addr, val);
}
void cpu_x86_outw(int addr, int val)
{
fprintf(stderr, "outw: port=0x%04x, data=%04x\n", addr, val);
}
void cpu_x86_outl(int addr, int val)
{
fprintf(stderr, "outl: port=0x%04x, data=%08x\n", addr, val);
}
int cpu_x86_inb(int addr)
{
fprintf(stderr, "inb: port=0x%04x\n", addr);
return 0;
}
int cpu_x86_inw(int addr)
{
fprintf(stderr, "inw: port=0x%04x\n", addr);
return 0;
}
int cpu_x86_inl(int addr)
{
fprintf(stderr, "inl: port=0x%04x\n", addr);
return 0;
}
/* default linux values for the selectors */
#define __USER_CS (0x23)
#define __USER_DS (0x2B)
void write_dt(void *ptr, unsigned long addr, unsigned long limit,
int seg32_bit)
{
unsigned int e1, e2, limit_in_pages;
limit_in_pages = 0;
if (limit > 0xffff) {
limit = limit >> 12;
limit_in_pages = 1;
}
e1 = (addr << 16) | (limit & 0xffff);
e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
e2 |= limit_in_pages << 23; /* byte granularity */
e2 |= seg32_bit << 22; /* 32 bit segment */
stl((uint8_t *)ptr, e1);
stl((uint8_t *)ptr + 4, e2);
}
uint64_t gdt_table[6];
void usage(void)
{
printf("gemu version " GEMU_VERSION ", Copyright (c) 2003 Fabrice Bellard\n"
"usage: gemu [-d] program [arguments...]\n"
"Linux x86 emulator\n"
);
exit(1);
}
int main(int argc, char **argv)
{
const char *filename;
struct target_pt_regs regs1, *regs = ®s1;
struct image_info info1, *info = &info1;
CPUX86State *env;
int optind;
if (argc <= 1)
usage();
loglevel = 0;
optind = 1;
if (argv[optind] && !strcmp(argv[optind], "-d")) {
loglevel = 1;
optind++;
}
filename = argv[optind];
/* init debug */
if (loglevel) {
logfile = fopen(DEBUG_LOGFILE, "w");
if (!logfile) {
perror(DEBUG_LOGFILE);
exit(1);
}
setvbuf(logfile, NULL, _IOLBF, 0);
}
/* Zero out regs */
memset(regs, 0, sizeof(struct target_pt_regs));
/* Zero out image_info */
memset(info, 0, sizeof(struct image_info));
if(elf_exec(filename, argv+optind, environ, regs, info) != 0) {
printf("Error loading %s\n", filename);
exit(1);
}
if (loglevel) {
fprintf(logfile, "start_brk 0x%08lx\n" , info->start_brk);
fprintf(logfile, "end_code 0x%08lx\n" , info->end_code);
fprintf(logfile, "start_code 0x%08lx\n" , info->start_code);
fprintf(logfile, "end_data 0x%08lx\n" , info->end_data);
fprintf(logfile, "start_stack 0x%08lx\n" , info->start_stack);
fprintf(logfile, "brk 0x%08lx\n" , info->brk);
fprintf(logfile, "esp 0x%08lx\n" , regs->esp);
fprintf(logfile, "eip 0x%08lx\n" , regs->eip);
}
target_set_brk((char *)info->brk);
syscall_init();
env = cpu_x86_init();
/* linux register setup */
env->regs[R_EAX] = regs->eax;
env->regs[R_EBX] = regs->ebx;
env->regs[R_ECX] = regs->ecx;
env->regs[R_EDX] = regs->edx;
env->regs[R_ESI] = regs->esi;
env->regs[R_EDI] = regs->edi;
env->regs[R_EBP] = regs->ebp;
env->regs[R_ESP] = regs->esp;
env->pc = regs->eip;
/* linux segment setup */
env->gdt.base = (void *)gdt_table;
env->gdt.limit = sizeof(gdt_table) - 1;
write_dt(&gdt_table[__USER_CS >> 3], 0, 0xffffffff, 1);
write_dt(&gdt_table[__USER_DS >> 3], 0, 0xffffffff, 1);
cpu_x86_load_seg(env, R_CS, __USER_CS);
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
cpu_x86_load_seg(env, R_SS, __USER_DS);
cpu_x86_load_seg(env, R_FS, __USER_DS);
cpu_x86_load_seg(env, R_GS, __USER_DS);
for(;;) {
int err;
uint8_t *pc;
err = cpu_x86_exec(env);
switch(err) {
case EXCP0D_GPF:
pc = (uint8_t *)env->pc;
if (pc[0] == 0xcd && pc[1] == 0x80) {
/* syscall */
env->pc += 2;
env->regs[R_EAX] = do_syscall(env,
env->regs[R_EAX],
env->regs[R_EBX],
env->regs[R_ECX],
env->regs[R_EDX],
env->regs[R_ESI],
env->regs[R_EDI],
env->regs[R_EBP]);
} else {
goto trap_error;
}
break;
default:
trap_error:
fprintf(stderr, "0x%08lx: Unknown exception %d, aborting\n",
(long)env->pc, err);
abort();
}
}
return 0;
}
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