Archipelago » qemu

/*

 *  i386 emulator main execution loop

 * 

 *  Copyright (c) 2003-2005 Fabrice Bellard

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#include "config.h"

#include "exec.h"

#include "disas.h"

#if !defined(CONFIG_SOFTMMU)

#undef EAX

#undef ECX

#undef EDX

#undef EBX

#undef ESP

#undef EBP

#undef ESI

#undef EDI

#undef EIP

#include <signal.h>

#include <sys/ucontext.h>

#endif

int tb_invalidated_flag;

//#define DEBUG_EXEC

//#define DEBUG_SIGNAL

void cpu_loop_exit(void)

{

    /* NOTE: the register at this point must be saved by hand because

       longjmp restore them */

    regs_to_env();

    longjmp(env->jmp_env, 1);

}

#if !(defined(TARGET_SPARC) || defined(TARGET_SH4) || defined(TARGET_M68K))

#define reg_T2

#endif

/* exit the current TB from a signal handler. The host registers are

   restored in a state compatible with the CPU emulator

 */

void cpu_resume_from_signal(CPUState *env1, void *puc) 

{

#if !defined(CONFIG_SOFTMMU)

    struct ucontext *uc = puc;

#endif

    env = env1;

    /* XXX: restore cpu registers saved in host registers */

#if !defined(CONFIG_SOFTMMU)

    if (puc) {

        /* XXX: use siglongjmp ? */

        sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);

    }

#endif

    longjmp(env->jmp_env, 1);

}

static TranslationBlock *tb_find_slow(target_ulong pc,

                                      target_ulong cs_base,

                                      unsigned int flags)

{

    TranslationBlock *tb, **ptb1;

    int code_gen_size;

    unsigned int h;

    target_ulong phys_pc, phys_page1, phys_page2, virt_page2;

    uint8_t *tc_ptr;

    spin_lock(&tb_lock);

    tb_invalidated_flag = 0;

    regs_to_env(); /* XXX: do it just before cpu_gen_code() */

    /* find translated block using physical mappings */

    phys_pc = get_phys_addr_code(env, pc);

    phys_page1 = phys_pc & TARGET_PAGE_MASK;

    phys_page2 = -1;

    h = tb_phys_hash_func(phys_pc);

    ptb1 = &tb_phys_hash[h];

    for(;;) {

        tb = *ptb1;

        if (!tb)

            goto not_found;

        if (tb->pc == pc && 

            tb->page_addr[0] == phys_page1 &&

            tb->cs_base == cs_base && 

            tb->flags == flags) {

            /* check next page if needed */

            if (tb->page_addr[1] != -1) {

                virt_page2 = (pc & TARGET_PAGE_MASK) + 

                    TARGET_PAGE_SIZE;

                phys_page2 = get_phys_addr_code(env, virt_page2);

                if (tb->page_addr[1] == phys_page2)

                    goto found;

            } else {

                goto found;

            }

        }

        ptb1 = &tb->phys_hash_next;

    }

 not_found:

    /* if no translated code available, then translate it now */

    tb = tb_alloc(pc);

    if (!tb) {

        /* flush must be done */

        tb_flush(env);

        /* cannot fail at this point */

        tb = tb_alloc(pc);

        /* don't forget to invalidate previous TB info */

        tb_invalidated_flag = 1;

    }

    tc_ptr = code_gen_ptr;

    tb->tc_ptr = tc_ptr;

    tb->cs_base = cs_base;

    tb->flags = flags;

    cpu_gen_code(env, tb, CODE_GEN_MAX_SIZE, &code_gen_size);

    code_gen_ptr = (void *)(((unsigned long)code_gen_ptr + code_gen_size + CODE_GEN_ALIGN - 1) & ~(CODE_GEN_ALIGN - 1));

    /* check next page if needed */

    virt_page2 = (pc + tb->size - 1) & TARGET_PAGE_MASK;

    phys_page2 = -1;

    if ((pc & TARGET_PAGE_MASK) != virt_page2) {

        phys_page2 = get_phys_addr_code(env, virt_page2);

    }

    tb_link_phys(tb, phys_pc, phys_page2);

 found:

    /* we add the TB in the virtual pc hash table */

    env->tb_jmp_cache[tb_jmp_cache_hash_func(pc)] = tb;

    spin_unlock(&tb_lock);

    return tb;

}

static inline TranslationBlock *tb_find_fast(void)

{

    TranslationBlock *tb;

    target_ulong cs_base, pc;

    unsigned int flags;

    /* we record a subset of the CPU state. It will

       always be the same before a given translated block

       is executed. */

#if defined(TARGET_I386)

    flags = env->hflags;

    flags |= (env->eflags & (IOPL_MASK | TF_MASK | VM_MASK));

    cs_base = env->segs[R_CS].base;

    pc = cs_base + env->eip;

#elif defined(TARGET_ARM)

    flags = env->thumb | (env->vfp.vec_len << 1)

            | (env->vfp.vec_stride << 4);

    if ((env->uncached_cpsr & CPSR_M) != ARM_CPU_MODE_USR)

        flags |= (1 << 6);

    if (env->vfp.xregs[ARM_VFP_FPEXC] & (1 << 30))

        flags |= (1 << 7);

    cs_base = 0;

    pc = env->regs[15];

#elif defined(TARGET_SPARC)

#ifdef TARGET_SPARC64

    // Combined FPU enable bits . PRIV . DMMU enabled . IMMU enabled

    flags = (((env->pstate & PS_PEF) >> 1) | ((env->fprs & FPRS_FEF) << 2))

        | (env->pstate & PS_PRIV) | ((env->lsu & (DMMU_E | IMMU_E)) >> 2);

#else

    // FPU enable . MMU enabled . MMU no-fault . Supervisor

    flags = (env->psref << 3) | ((env->mmuregs[0] & (MMU_E | MMU_NF)) << 1)

        | env->psrs;

#endif

    cs_base = env->npc;

    pc = env->pc;

#elif defined(TARGET_PPC)

    flags = (msr_pr << MSR_PR) | (msr_fp << MSR_FP) |

        (msr_se << MSR_SE) | (msr_le << MSR_LE);

    cs_base = 0;

    pc = env->nip;

#elif defined(TARGET_MIPS)

    flags = env->hflags & (MIPS_HFLAG_TMASK | MIPS_HFLAG_BMASK);

    cs_base = 0;

    pc = env->PC;

#elif defined(TARGET_M68K)

    flags = (env->fpcr & M68K_FPCR_PREC)  /* Bit  6 */

            | (env->sr & SR_S)            /* Bit  13 */

            | ((env->macsr >> 4) & 0xf);  /* Bits 0-3 */

    cs_base = 0;

    pc = env->pc;

#elif defined(TARGET_SH4)

    flags = env->sr & (SR_MD | SR_RB);

    cs_base = 0;         /* XXXXX */

    pc = env->pc;

#elif defined(TARGET_ALPHA)

    flags = env->ps;

    cs_base = 0;

    pc = env->pc;

#else

#error unsupported CPU

#endif

    tb = env->tb_jmp_cache[tb_jmp_cache_hash_func(pc)];

    if (__builtin_expect(!tb || tb->pc != pc || tb->cs_base != cs_base ||

                         tb->flags != flags, 0)) {

        tb = tb_find_slow(pc, cs_base, flags);

        /* Note: we do it here to avoid a gcc bug on Mac OS X when

           doing it in tb_find_slow */

        if (tb_invalidated_flag) {

            /* as some TB could have been invalidated because

               of memory exceptions while generating the code, we

               must recompute the hash index here */

            T0 = 0;

        }

    }

    return tb;

}

/* main execution loop */

int cpu_exec(CPUState *env1)

{

#define DECLARE_HOST_REGS 1

#include "hostregs_helper.h"

#if defined(TARGET_SPARC)

#if defined(reg_REGWPTR)

    uint32_t *saved_regwptr;

#endif

#endif

#if defined(__sparc__) && !defined(HOST_SOLARIS)

    int saved_i7;

    target_ulong tmp_T0;

#endif

    int ret, interrupt_request;

    void (*gen_func)(void);

    TranslationBlock *tb;

    uint8_t *tc_ptr;

    if (cpu_halted(env1) == EXCP_HALTED)

        return EXCP_HALTED;

    cpu_single_env = env1; 

    /* first we save global registers */

#define SAVE_HOST_REGS 1

#include "hostregs_helper.h"

    env = env1;

#if defined(__sparc__) && !defined(HOST_SOLARIS)

    /* we also save i7 because longjmp may not restore it */

    asm volatile ("mov %%i7, %0" : "=r" (saved_i7));

#endif

    env_to_regs();

#if defined(TARGET_I386)

    /* put eflags in CPU temporary format */

    CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);

    DF = 1 - (2 * ((env->eflags >> 10) & 1));

    CC_OP = CC_OP_EFLAGS;

    env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);

#elif defined(TARGET_SPARC)

#if defined(reg_REGWPTR)

    saved_regwptr = REGWPTR;

#endif

#elif defined(TARGET_M68K)

    env->cc_op = CC_OP_FLAGS;

    env->cc_dest = env->sr & 0xf;

    env->cc_x = (env->sr >> 4) & 1;

#elif defined(TARGET_ALPHA)

#elif defined(TARGET_ARM)

#elif defined(TARGET_PPC)

#elif defined(TARGET_MIPS)

#elif defined(TARGET_SH4)

    /* XXXXX */

#else

#error unsupported target CPU

#endif

    env->exception_index = -1;

    /* prepare setjmp context for exception handling */

    for(;;) {

        if (setjmp(env->jmp_env) == 0) {

            env->current_tb = NULL;

            /* if an exception is pending, we execute it here */

            if (env->exception_index >= 0) {

                if (env->exception_index >= EXCP_INTERRUPT) {

                    /* exit request from the cpu execution loop */

                    ret = env->exception_index;

                    break;

                } else if (env->user_mode_only) {

                    /* if user mode only, we simulate a fake exception

                       which will be handled outside the cpu execution

                       loop */

#if defined(TARGET_I386)

                    do_interrupt_user(env->exception_index, 

                                      env->exception_is_int, 

                                      env->error_code, 

                                      env->exception_next_eip);

#endif

                    ret = env->exception_index;

                    break;

                } else {

#if defined(TARGET_I386)

                    /* simulate a real cpu exception. On i386, it can

                       trigger new exceptions, but we do not handle

                       double or triple faults yet. */

                    do_interrupt(env->exception_index, 

                                 env->exception_is_int, 

                                 env->error_code, 

                                 env->exception_next_eip, 0);

                    /* successfully delivered */

                    env->old_exception = -1;

#elif defined(TARGET_PPC)

                    do_interrupt(env);

#elif defined(TARGET_MIPS)

                    do_interrupt(env);

#elif defined(TARGET_SPARC)

                    do_interrupt(env->exception_index);

#elif defined(TARGET_ARM)

                    do_interrupt(env);

#elif defined(TARGET_SH4)

                    do_interrupt(env);

#elif defined(TARGET_ALPHA)

                    do_interrupt(env);

#elif defined(TARGET_M68K)

                    do_interrupt(0);

#endif

                }

                env->exception_index = -1;

            } 

#ifdef USE_KQEMU

            if (kqemu_is_ok(env) && env->interrupt_request == 0) {

                int ret;

                env->eflags = env->eflags | cc_table[CC_OP].compute_all() | (DF & DF_MASK);

                ret = kqemu_cpu_exec(env);

                /* put eflags in CPU temporary format */

                CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);

                DF = 1 - (2 * ((env->eflags >> 10) & 1));

                CC_OP = CC_OP_EFLAGS;

                env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);

                if (ret == 1) {

                    /* exception */

                    longjmp(env->jmp_env, 1);

                } else if (ret == 2) {

                    /* softmmu execution needed */

                } else {

                    if (env->interrupt_request != 0) {

                        /* hardware interrupt will be executed just after */

                    } else {

                        /* otherwise, we restart */

                        longjmp(env->jmp_env, 1);

                    }

                }

            }

#endif

            T0 = 0; /* force lookup of first TB */

            for(;;) {

#if defined(__sparc__) && !defined(HOST_SOLARIS)

                /* g1 can be modified by some libc? functions */ 

                tmp_T0 = T0;

#endif            

                interrupt_request = env->interrupt_request;

                if (__builtin_expect(interrupt_request, 0)) {

                    if (interrupt_request & CPU_INTERRUPT_DEBUG) {

                        env->interrupt_request &= ~CPU_INTERRUPT_DEBUG;

                        env->exception_index = EXCP_DEBUG;

                        cpu_loop_exit();

                    }

#if defined(TARGET_ARM) || defined(TARGET_SPARC) || defined(TARGET_MIPS) || \

    defined(TARGET_PPC) || defined(TARGET_ALPHA)

                    if (interrupt_request & CPU_INTERRUPT_HALT) {

                        env->interrupt_request &= ~CPU_INTERRUPT_HALT;

                        env->halted = 1;

                        env->exception_index = EXCP_HLT;

                        cpu_loop_exit();

                    }

#endif

#if defined(TARGET_I386)

                    if ((interrupt_request & CPU_INTERRUPT_SMI) &&

                        !(env->hflags & HF_SMM_MASK)) {

                        env->interrupt_request &= ~CPU_INTERRUPT_SMI;

                        do_smm_enter();

#if defined(__sparc__) && !defined(HOST_SOLARIS)

                        tmp_T0 = 0;

#else

                        T0 = 0;

#endif

                    } else if ((interrupt_request & CPU_INTERRUPT_HARD) &&

                        (env->eflags & IF_MASK) && 

                        !(env->hflags & HF_INHIBIT_IRQ_MASK)) {

                        int intno;

                        env->interrupt_request &= ~CPU_INTERRUPT_HARD;

                        intno = cpu_get_pic_interrupt(env);

                        if (loglevel & CPU_LOG_TB_IN_ASM) {

                            fprintf(logfile, "Servicing hardware INT=0x%02x\n", intno);

                        }

                        do_interrupt(intno, 0, 0, 0, 1);

                        /* ensure that no TB jump will be modified as

                           the program flow was changed */

#if defined(__sparc__) && !defined(HOST_SOLARIS)

                        tmp_T0 = 0;

#else

                        T0 = 0;

#endif

                    }

#elif defined(TARGET_PPC)

#if 0

                    if ((interrupt_request & CPU_INTERRUPT_RESET)) {

                        cpu_ppc_reset(env);

                    }

#endif

                    if (interrupt_request & CPU_INTERRUPT_HARD) {

                        ppc_hw_interrupt(env);

                        if (env->pending_interrupts == 0)

                            env->interrupt_request &= ~CPU_INTERRUPT_HARD;

#if defined(__sparc__) && !defined(HOST_SOLARIS)

                        tmp_T0 = 0;

#else

                        T0 = 0;

#endif

                    }

#elif defined(TARGET_MIPS)

                    if ((interrupt_request & CPU_INTERRUPT_HARD) &&

                        (env->CP0_Status & env->CP0_Cause & CP0Ca_IP_mask) &&

                        (env->CP0_Status & (1 << CP0St_IE)) &&

                        !(env->CP0_Status & (1 << CP0St_EXL)) &&

                        !(env->CP0_Status & (1 << CP0St_ERL)) &&

                        !(env->hflags & MIPS_HFLAG_DM)) {

                        /* Raise it */

                        env->exception_index = EXCP_EXT_INTERRUPT;

                        env->error_code = 0;

                        do_interrupt(env);

#if defined(__sparc__) && !defined(HOST_SOLARIS)

                        tmp_T0 = 0;

#else

                        T0 = 0;

#endif

                    }

#elif defined(TARGET_SPARC)

                    if ((interrupt_request & CPU_INTERRUPT_HARD) &&

                        (env->psret != 0)) {

                        int pil = env->interrupt_index & 15;

                        int type = env->interrupt_index & 0xf0;

                        if (((type == TT_EXTINT) &&

                             (pil == 15 || pil > env->psrpil)) ||

                            type != TT_EXTINT) {

                            env->interrupt_request &= ~CPU_INTERRUPT_HARD;

                            do_interrupt(env->interrupt_index);

                            env->interrupt_index = 0;

#if defined(__sparc__) && !defined(HOST_SOLARIS)

                            tmp_T0 = 0;

#else

                            T0 = 0;

#endif

                        }

                    } else if (interrupt_request & CPU_INTERRUPT_TIMER) {

                        //do_interrupt(0, 0, 0, 0, 0);

                        env->interrupt_request &= ~CPU_INTERRUPT_TIMER;

                    }

#elif defined(TARGET_ARM)

                    if (interrupt_request & CPU_INTERRUPT_FIQ

                        && !(env->uncached_cpsr & CPSR_F)) {

                        env->exception_index = EXCP_FIQ;

                        do_interrupt(env);

                    }

                    if (interrupt_request & CPU_INTERRUPT_HARD

                        && !(env->uncached_cpsr & CPSR_I)) {

                        env->exception_index = EXCP_IRQ;

                        do_interrupt(env);

                    }

#elif defined(TARGET_SH4)

                    /* XXXXX */

#elif defined(TARGET_ALPHA)

                    if (interrupt_request & CPU_INTERRUPT_HARD) {

                        do_interrupt(env);

                    }

#elif defined(TARGET_M68K)

                    if (interrupt_request & CPU_INTERRUPT_HARD

                        && ((env->sr & SR_I) >> SR_I_SHIFT)

                            < env->pending_level) {

                        /* Real hardware gets the interrupt vector via an

                           IACK cycle at this point.  Current emulated

                           hardware doesn't rely on this, so we

                           provide/save the vector when the interrupt is

                           first signalled.  */

                        env->exception_index = env->pending_vector;

                        do_interrupt(1);

                    }

#endif

                   /* Don't use the cached interupt_request value,

                      do_interrupt may have updated the EXITTB flag. */

                    if (env->interrupt_request & CPU_INTERRUPT_EXITTB) {

                        env->interrupt_request &= ~CPU_INTERRUPT_EXITTB;

                        /* ensure that no TB jump will be modified as

                           the program flow was changed */

#if defined(__sparc__) && !defined(HOST_SOLARIS)

                        tmp_T0 = 0;

#else

                        T0 = 0;

#endif

                    }

                    if (interrupt_request & CPU_INTERRUPT_EXIT) {

                        env->interrupt_request &= ~CPU_INTERRUPT_EXIT;

                        env->exception_index = EXCP_INTERRUPT;

                        cpu_loop_exit();

                    }

                }

#ifdef DEBUG_EXEC

                if ((loglevel & CPU_LOG_TB_CPU)) {

                    /* restore flags in standard format */

                    regs_to_env();

#if defined(TARGET_I386)

                    env->eflags = env->eflags | cc_table[CC_OP].compute_all() | (DF & DF_MASK);

                    cpu_dump_state(env, logfile, fprintf, X86_DUMP_CCOP);

                    env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);

#elif defined(TARGET_ARM)

                    cpu_dump_state(env, logfile, fprintf, 0);

#elif defined(TARGET_SPARC)

                    REGWPTR = env->regbase + (env->cwp * 16);

                    env->regwptr = REGWPTR;

                    cpu_dump_state(env, logfile, fprintf, 0);

#elif defined(TARGET_PPC)

                    cpu_dump_state(env, logfile, fprintf, 0);

#elif defined(TARGET_M68K)

                    cpu_m68k_flush_flags(env, env->cc_op);

                    env->cc_op = CC_OP_FLAGS;

                    env->sr = (env->sr & 0xffe0)

                              | env->cc_dest | (env->cc_x << 4);

                    cpu_dump_state(env, logfile, fprintf, 0);

#elif defined(TARGET_MIPS)

                    cpu_dump_state(env, logfile, fprintf, 0);

#elif defined(TARGET_SH4)

                    cpu_dump_state(env, logfile, fprintf, 0);

#elif defined(TARGET_ALPHA)

                    cpu_dump_state(env, logfile, fprintf, 0);

#else

#error unsupported target CPU 

#endif

                }

#endif

                tb = tb_find_fast();

#ifdef DEBUG_EXEC

                if ((loglevel & CPU_LOG_EXEC)) {

                    fprintf(logfile, "Trace 0x%08lx [" TARGET_FMT_lx "] %s\n",

                            (long)tb->tc_ptr, tb->pc,

                            lookup_symbol(tb->pc));

                }

#endif

#if defined(__sparc__) && !defined(HOST_SOLARIS)

                T0 = tmp_T0;

#endif            

                /* see if we can patch the calling TB. When the TB

                   spans two pages, we cannot safely do a direct

                   jump. */

                {

                    if (T0 != 0 &&

#if USE_KQEMU

                        (env->kqemu_enabled != 2) &&

#endif

                        tb->page_addr[1] == -1

#if defined(TARGET_I386) && defined(USE_CODE_COPY)

                    && (tb->cflags & CF_CODE_COPY) == 

                    (((TranslationBlock *)(T0 & ~3))->cflags & CF_CODE_COPY)

#endif

                    ) {

                    spin_lock(&tb_lock);

                    tb_add_jump((TranslationBlock *)(long)(T0 & ~3), T0 & 3, tb);

#if defined(USE_CODE_COPY)

                    /* propagates the FP use info */

                    ((TranslationBlock *)(T0 & ~3))->cflags |= 

                        (tb->cflags & CF_FP_USED);

#endif

                    spin_unlock(&tb_lock);

                }

                }

                tc_ptr = tb->tc_ptr;

                env->current_tb = tb;

                /* execute the generated code */

                gen_func = (void *)tc_ptr;

#if defined(__sparc__)

                __asm__ __volatile__("call        %0\n\t"

                                     "mov        %%o7,%%i0"

                                     : /* no outputs */

                                     : "r" (gen_func) 

                                     : "i0", "i1", "i2", "i3", "i4", "i5",

                                       "o0", "o1", "o2", "o3", "o4", "o5",

                                       "l0", "l1", "l2", "l3", "l4", "l5",

                                       "l6", "l7");

#elif defined(__arm__)

                asm volatile ("mov pc, %0\n\t"

                              ".global exec_loop\n\t"

                              "exec_loop:\n\t"

                              : /* no outputs */

                              : "r" (gen_func)

                              : "r1", "r2", "r3", "r8", "r9", "r10", "r12", "r14");

#elif defined(TARGET_I386) && defined(USE_CODE_COPY)

{

    if (!(tb->cflags & CF_CODE_COPY)) {

        if ((tb->cflags & CF_FP_USED) && env->native_fp_regs) {

            save_native_fp_state(env);

        }

        gen_func();

    } else {

        if ((tb->cflags & CF_FP_USED) && !env->native_fp_regs) {

            restore_native_fp_state(env);

        }

        /* we work with native eflags */

        CC_SRC = cc_table[CC_OP].compute_all();

        CC_OP = CC_OP_EFLAGS;

        asm(".globl exec_loop\n"

            "\n"

            "debug1:\n"

            "    pushl %%ebp\n"

            "    fs movl %10, %9\n"

            "    fs movl %11, %%eax\n"

            "    andl $0x400, %%eax\n"

            "    fs orl %8, %%eax\n"

            "    pushl %%eax\n"

            "    popf\n"

            "    fs movl %%esp, %12\n"

            "    fs movl %0, %%eax\n"

            "    fs movl %1, %%ecx\n"

            "    fs movl %2, %%edx\n"

            "    fs movl %3, %%ebx\n"

            "    fs movl %4, %%esp\n"

            "    fs movl %5, %%ebp\n"

            "    fs movl %6, %%esi\n"

            "    fs movl %7, %%edi\n"

            "    fs jmp *%9\n"

            "exec_loop:\n"

            "    fs movl %%esp, %4\n"

            "    fs movl %12, %%esp\n"

            "    fs movl %%eax, %0\n"

            "    fs movl %%ecx, %1\n"

            "    fs movl %%edx, %2\n"

            "    fs movl %%ebx, %3\n"

            "    fs movl %%ebp, %5\n"

            "    fs movl %%esi, %6\n"

            "    fs movl %%edi, %7\n"

            "    pushf\n"

            "    popl %%eax\n"

            "    movl %%eax, %%ecx\n"

            "    andl $0x400, %%ecx\n"

            "    shrl $9, %%ecx\n"

            "    andl $0x8d5, %%eax\n"

            "    fs movl %%eax, %8\n"

            "    movl $1, %%eax\n"

            "    subl %%ecx, %%eax\n"

            "    fs movl %%eax, %11\n"

            "    fs movl %9, %%ebx\n" /* get T0 value */

            "    popl %%ebp\n"

            :

            : "m" (*(uint8_t *)offsetof(CPUState, regs[0])),

            "m" (*(uint8_t *)offsetof(CPUState, regs[1])),

            "m" (*(uint8_t *)offsetof(CPUState, regs[2])),

            "m" (*(uint8_t *)offsetof(CPUState, regs[3])),

            "m" (*(uint8_t *)offsetof(CPUState, regs[4])),

            "m" (*(uint8_t *)offsetof(CPUState, regs[5])),

            "m" (*(uint8_t *)offsetof(CPUState, regs[6])),

            "m" (*(uint8_t *)offsetof(CPUState, regs[7])),

            "m" (*(uint8_t *)offsetof(CPUState, cc_src)),

            "m" (*(uint8_t *)offsetof(CPUState, tmp0)),

            "a" (gen_func),

            "m" (*(uint8_t *)offsetof(CPUState, df)),

            "m" (*(uint8_t *)offsetof(CPUState, saved_esp))

            : "%ecx", "%edx"

            );

    }

}

#elif defined(__ia64)

                struct fptr {

                        void *ip;

                        void *gp;

                } fp;

                fp.ip = tc_ptr;

                fp.gp = code_gen_buffer + 2 * (1 << 20);

                (*(void (*)(void)) &fp)();

#else

                gen_func();

#endif

                env->current_tb = NULL;

                /* reset soft MMU for next block (it can currently

                   only be set by a memory fault) */

#if defined(TARGET_I386) && !defined(CONFIG_SOFTMMU)

                if (env->hflags & HF_SOFTMMU_MASK) {

                    env->hflags &= ~HF_SOFTMMU_MASK;

                    /* do not allow linking to another block */

                    T0 = 0;

                }

#endif

#if defined(USE_KQEMU)

#define MIN_CYCLE_BEFORE_SWITCH (100 * 1000)

                if (kqemu_is_ok(env) &&

                    (cpu_get_time_fast() - env->last_io_time) >= MIN_CYCLE_BEFORE_SWITCH) {

                    cpu_loop_exit();

                }

#endif

            } /* for(;;) */

        } else {

            env_to_regs();

        }

    } /* for(;;) */

#if defined(TARGET_I386)

#if defined(USE_CODE_COPY)

    if (env->native_fp_regs) {

        save_native_fp_state(env);

    }

#endif

    /* restore flags in standard format */

    env->eflags = env->eflags | cc_table[CC_OP].compute_all() | (DF & DF_MASK);

#elif defined(TARGET_ARM)

    /* XXX: Save/restore host fpu exception state?.  */

#elif defined(TARGET_SPARC)

#if defined(reg_REGWPTR)

    REGWPTR = saved_regwptr;

#endif

#elif defined(TARGET_PPC)

#elif defined(TARGET_M68K)

    cpu_m68k_flush_flags(env, env->cc_op);

    env->cc_op = CC_OP_FLAGS;

    env->sr = (env->sr & 0xffe0)

              | env->cc_dest | (env->cc_x << 4);

#elif defined(TARGET_MIPS)

#elif defined(TARGET_SH4)

#elif defined(TARGET_ALPHA)

    /* XXXXX */

#else

#error unsupported target CPU

#endif

    /* restore global registers */

#if defined(__sparc__) && !defined(HOST_SOLARIS)

    asm volatile ("mov %0, %%i7" : : "r" (saved_i7));

#endif

#include "hostregs_helper.h"

    /* fail safe : never use cpu_single_env outside cpu_exec() */

    cpu_single_env = NULL; 

    return ret;

}

/* must only be called from the generated code as an exception can be

   generated */

void tb_invalidate_page_range(target_ulong start, target_ulong end)

{

    /* XXX: cannot enable it yet because it yields to MMU exception

       where NIP != read address on PowerPC */

#if 0

    target_ulong phys_addr;

    phys_addr = get_phys_addr_code(env, start);

    tb_invalidate_phys_page_range(phys_addr, phys_addr + end - start, 0);

#endif

}

#if defined(TARGET_I386) && defined(CONFIG_USER_ONLY)

void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector)

{

    CPUX86State *saved_env;

    saved_env = env;

    env = s;

    if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) {

        selector &= 0xffff;

        cpu_x86_load_seg_cache(env, seg_reg, selector, 

                               (selector << 4), 0xffff, 0);

    } else {

        load_seg(seg_reg, selector);

    }

    env = saved_env;

}

void cpu_x86_fsave(CPUX86State *s, uint8_t *ptr, int data32)

{

    CPUX86State *saved_env;

    saved_env = env;

    env = s;

    helper_fsave((target_ulong)ptr, data32);

    env = saved_env;

}

void cpu_x86_frstor(CPUX86State *s, uint8_t *ptr, int data32)

{

    CPUX86State *saved_env;

    saved_env = env;

    env = s;

    helper_frstor((target_ulong)ptr, data32);

    env = saved_env;

}

#endif /* TARGET_I386 */

#if !defined(CONFIG_SOFTMMU)

#if defined(TARGET_I386)

/* 'pc' is the host PC at which the exception was raised. 'address' is

   the effective address of the memory exception. 'is_write' is 1 if a

   write caused the exception and otherwise 0'. 'old_set' is the

   signal set which should be restored */

static inline int handle_cpu_signal(unsigned long pc, unsigned long address,

                                    int is_write, sigset_t *old_set, 

                                    void *puc)

{

    TranslationBlock *tb;

    int ret;

    if (cpu_single_env)

        env = cpu_single_env; /* XXX: find a correct solution for multithread */

#if defined(DEBUG_SIGNAL)

    qemu_printf("qemu: SIGSEGV pc=0x%08lx address=%08lx w=%d oldset=0x%08lx\n", 

                pc, address, is_write, *(unsigned long *)old_set);

#endif

    /* XXX: locking issue */

    if (is_write && page_unprotect(h2g(address), pc, puc)) {

        return 1;

    }

    /* see if it is an MMU fault */

    ret = cpu_x86_handle_mmu_fault(env, address, is_write, 

                                   ((env->hflags & HF_CPL_MASK) == 3), 0);

    if (ret < 0)

        return 0; /* not an MMU fault */

    if (ret == 0)

        return 1; /* the MMU fault was handled without causing real CPU fault */

    /* now we have a real cpu fault */

    tb = tb_find_pc(pc);

    if (tb) {

        /* the PC is inside the translated code. It means that we have

           a virtual CPU fault */

        cpu_restore_state(tb, env, pc, puc);

    }

    if (ret == 1) {

#if 0

        printf("PF exception: EIP=0x%08x CR2=0x%08x error=0x%x\n", 

               env->eip, env->cr[2], env->error_code);