main.c

qemu虚拟机代码

/*
 *  qemu user 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 <string.h>
#include <errno.h>
#include <unistd.h>

#include "qemu.h"

#define DEBUG_LOGFILE "/tmp/qemu.log"

#ifdef __APPLE__
#include <crt_externs.h>
# define environ  (*_NSGetEnviron())
#endif

static const char *interp_prefix = CONFIG_QEMU_PREFIX;

#if defined(__i386__) && !defined(CONFIG_STATIC)
/* Force usage of an ELF interpreter even if it is an ELF shared
   object ! */
const char interp[] __attribute__((section(".interp"))) = "/lib/ld-linux.so.2";
#endif

/* for recent libc, we add these dummy symbols which are not declared
   when generating a linked object (bug in ld ?) */
#if (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) && !defined(CONFIG_STATIC)
long __preinit_array_start[0];
long __preinit_array_end[0];
long __init_array_start[0];
long __init_array_end[0];
long __fini_array_start[0];
long __fini_array_end[0];
#endif

/* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
   we allocate a bigger stack. Need a better solution, for example
   by remapping the process stack directly at the right place */
unsigned long x86_stack_size = 512 * 1024;

void gemu_log(const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    vfprintf(stderr, fmt, ap);
    va_end(ap);
}

void cpu_outb(CPUState *env, int addr, int val)
{
    fprintf(stderr, "outb: port=0x%04x, data=%02x\n", addr, val);
}

void cpu_outw(CPUState *env, int addr, int val)
{
    fprintf(stderr, "outw: port=0x%04x, data=%04x\n", addr, val);
}

void cpu_outl(CPUState *env, int addr, int val)
{
    fprintf(stderr, "outl: port=0x%04x, data=%08x\n", addr, val);
}

int cpu_inb(CPUState *env, int addr)
{
    fprintf(stderr, "inb: port=0x%04x\n", addr);
    return 0;
}

int cpu_inw(CPUState *env, int addr)
{
    fprintf(stderr, "inw: port=0x%04x\n", addr);
    return 0;
}

int cpu_inl(CPUState *env, int addr)
{
    fprintf(stderr, "inl: port=0x%04x\n", addr);
    return 0;
}

int cpu_get_pic_interrupt(CPUState *env)
{
    return -1;
}

/* timers for rdtsc */

#if defined(__i386__)

int64_t cpu_get_real_ticks(void)
{
    int64_t val;
    asm volatile ("rdtsc" : "=A" (val));
    return val;
}

#elif defined(__x86_64__)

int64_t cpu_get_real_ticks(void)
{
    uint32_t low,high;
    int64_t val;
    asm volatile("rdtsc" : "=a" (low), "=d" (high));
    val = high;
    val <<= 32;
    val |= low;
    return val;
}

#else

static uint64_t emu_time;

int64_t cpu_get_real_ticks(void)
{
    return emu_time++;
}

#endif

#ifdef TARGET_I386
/***********************************************************/
/* CPUX86 core interface */

uint64_t cpu_get_tsc(CPUX86State *env)
{
    return cpu_get_real_ticks();
}

static void write_dt(void *ptr, unsigned long addr, unsigned long limit, 
                     int flags)
{
    unsigned int e1, e2;
    uint32_t *p;
    e1 = (addr << 16) | (limit & 0xffff);
    e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
    e2 |= flags;
    p = ptr;
    p[0] = tswapl(e1);
    p[1] = tswapl(e2);
}

static void set_gate(void *ptr, unsigned int type, unsigned int dpl, 
                     unsigned long addr, unsigned int sel)
{
    unsigned int e1, e2;
    uint32_t *p;
    e1 = (addr & 0xffff) | (sel << 16);
    e2 = (addr & 0xffff0000) | 0x8000 | (dpl << 13) | (type << 8);
    p = ptr;
    p[0] = tswapl(e1);
    p[1] = tswapl(e2);
}

uint64_t gdt_table[6];
uint64_t idt_table[256];

/* only dpl matters as we do only user space emulation */
static void set_idt(int n, unsigned int dpl)
{
    set_gate(idt_table + n, 0, dpl, 0, 0);
}

void cpu_loop(CPUX86State *env)
{
    int trapnr;
    target_ulong pc;
    target_siginfo_t info;

    for(;;) {
        trapnr = cpu_x86_exec(env);
        switch(trapnr) {
        case 0x80:
            /* linux syscall */
            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]);
            break;
        case EXCP0B_NOSEG:
        case EXCP0C_STACK:
            info.si_signo = SIGBUS;
            info.si_errno = 0;
            info.si_code = TARGET_SI_KERNEL;
            info._sifields._sigfault._addr = 0;
            queue_signal(info.si_signo, &info);
            break;
        case EXCP0D_GPF:
            if (env->eflags & VM_MASK) {
                handle_vm86_fault(env);
            } else {
                info.si_signo = SIGSEGV;
                info.si_errno = 0;
                info.si_code = TARGET_SI_KERNEL;
                info._sifields._sigfault._addr = 0;
                queue_signal(info.si_signo, &info);
            }
            break;
        case EXCP0E_PAGE:
            info.si_signo = SIGSEGV;
            info.si_errno = 0;
            if (!(env->error_code & 1))
                info.si_code = TARGET_SEGV_MAPERR;
            else
                info.si_code = TARGET_SEGV_ACCERR;
            info._sifields._sigfault._addr = env->cr[2];
            queue_signal(info.si_signo, &info);
            break;
        case EXCP00_DIVZ:
            if (env->eflags & VM_MASK) {
                handle_vm86_trap(env, trapnr);
            } else {
                /* division by zero */
                info.si_signo = SIGFPE;
                info.si_errno = 0;
                info.si_code = TARGET_FPE_INTDIV;
                info._sifields._sigfault._addr = env->eip;
                queue_signal(info.si_signo, &info);
            }
            break;
        case EXCP01_SSTP:
        case EXCP03_INT3:
            if (env->eflags & VM_MASK) {
                handle_vm86_trap(env, trapnr);
            } else {
                info.si_signo = SIGTRAP;
                info.si_errno = 0;
                if (trapnr == EXCP01_SSTP) {
                    info.si_code = TARGET_TRAP_BRKPT;
                    info._sifields._sigfault._addr = env->eip;
                } else {
                    info.si_code = TARGET_SI_KERNEL;
                    info._sifields._sigfault._addr = 0;
                }
                queue_signal(info.si_signo, &info);
            }
            break;
        case EXCP04_INTO:
        case EXCP05_BOUND:
            if (env->eflags & VM_MASK) {
                handle_vm86_trap(env, trapnr);
            } else {
                info.si_signo = SIGSEGV;
                info.si_errno = 0;
                info.si_code = TARGET_SI_KERNEL;
                info._sifields._sigfault._addr = 0;
                queue_signal(info.si_signo, &info);
            }
            break;
        case EXCP06_ILLOP:
            info.si_signo = SIGILL;
            info.si_errno = 0;
            info.si_code = TARGET_ILL_ILLOPN;
            info._sifields._sigfault._addr = env->eip;
            queue_signal(info.si_signo, &info);
            break;
        case EXCP_INTERRUPT:
            /* just indicate that signals should be handled asap */
            break;
        case EXCP_DEBUG:
            {
                int sig;

                sig = gdb_handlesig (env, TARGET_SIGTRAP);
                if (sig)
                  {
                    info.si_signo = sig;
                    info.si_errno = 0;
                    info.si_code = TARGET_TRAP_BRKPT;
                    queue_signal(info.si_signo, &info);
                  }
            }
            break;
        default:
            pc = env->segs[R_CS].base + env->eip;
            fprintf(stderr, "qemu: 0x%08lx: unhandled CPU exception 0x%x - aborting\n", 
                    (long)pc, trapnr);
            abort();
        }
        process_pending_signals(env);
    }
}
#endif

#ifdef TARGET_ARM

/* XXX: find a better solution */
extern void tb_invalidate_page_range(target_ulong start, target_ulong end);

static void arm_cache_flush(target_ulong start, target_ulong last)
{
    target_ulong addr, last1;

    if (last < start)
        return;
    addr = start;
    for(;;) {
        last1 = ((addr + TARGET_PAGE_SIZE) & TARGET_PAGE_MASK) - 1;
        if (last1 > last)
            last1 = last;
        tb_invalidate_page_range(addr, last1 + 1);
        if (last1 == last)
            break;
        addr = last1 + 1;
    }
}

void cpu_loop(CPUARMState *env)
{
    int trapnr;
    unsigned int n, insn;
    target_siginfo_t info;
    uint32_t addr;
    
    for(;;) {
        trapnr = cpu_arm_exec(env);
        switch(trapnr) {
        case EXCP_UDEF:
            {
                TaskState *ts = env->opaque;
                uint32_t opcode;

                /* we handle the FPU emulation here, as Linux */
                /* we get the opcode */
                opcode = tget32(env->regs[15]);
                
                if (EmulateAll(opcode, &ts->fpa, env) == 0) {
                    info.si_signo = SIGILL;
                    info.si_errno = 0;
                    info.si_code = TARGET_ILL_ILLOPN;
                    info._sifields._sigfault._addr = env->regs[15];
                    queue_signal(info.si_signo, &info);
                } else {
                    /* increment PC */
                    env->regs[15] += 4;
                }
            }
            break;
        case EXCP_SWI:
        case EXCP_BKPT:
            {
                env->eabi = 1;
                /* system call */
                if (trapnr == EXCP_BKPT) {
                    if (env->thumb) {
                        insn = tget16(env->regs[15]);
                        n = insn & 0xff;
                        env->regs[15] += 2;
                    } else {
                        insn = tget32(env->regs[15]);
                        n = (insn & 0xf) | ((insn >> 4) & 0xff0);
                        env->regs[15] += 4;
                    }
                } else {
                    if (env->thumb) {
                        insn = tget16(env->regs[15] - 2);
                        n = insn & 0xff;
                    } else {
                        insn = tget32(env->regs[15] - 4);
                        n = insn & 0xffffff;
                    }
                }

                if (n == ARM_NR_cacheflush) {
                    arm_cache_flush(env->regs[0], env->regs[1]);
                } else if (n == ARM_NR_semihosting
                           || n == ARM_NR_thumb_semihosting) {
                    env->regs[0] = do_arm_semihosting (env);
                } else if (n == 0 || n >= ARM_SYSCALL_BASE
                           || (env->thumb && n == ARM_THUMB_SYSCALL)) {
                    /* linux syscall */
                    if (env->thumb || n == 0) {
                        n = env->regs[7];
                    } else {
                        n -= ARM_SYSCALL_BASE;
                        env->eabi = 0;
                    }
                    env->regs[0] = do_syscall(env, 
                                              n, 
                                              env->regs[0],
                                              env->regs[1],
                                              env->regs[2],
                                              env->regs[3],
                                              env->regs[4],
                                              env->regs[5]);
                } else {
                    goto error;
                }
            }
            break;
        case EXCP_INTERRUPT:
            /* just indicate that signals should be handled asap */
            break;
        case EXCP_PREFETCH_ABORT:
            addr = env->cp15.c6_data;
            goto do_segv;
        case EXCP_DATA_ABORT:
            addr = env->cp15.c6_insn;
            goto do_segv;
        do_segv:
            {
                info.si_signo = SIGSEGV;
                info.si_errno = 0;
                /* XXX: check env->error_code */
                info.si_code = TARGET_SEGV_MAPERR;
                info._sifields._sigfault._addr = addr;