Darwin userspace emulation, by Pierre d'Herbemont.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2332 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 922 insertions, 0 deletions

diff --git a/darwin-user/main.c b/darwin-user/main.c
new file mode 100644
index 0000000..259aab3
--- /dev/null
+++ b/darwin-user/main.c
@@ -0,0 +1,922 @@
+/*
+ *  qemu user main
+ *
+ *  Copyright (c) 2003 Fabrice Bellard
+ *  Copyright (c) 2006 Pierre d'Herbemont
+ *
+ *  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 <sys/syscall.h>
+#include <sys/mman.h>
+
+#include "qemu.h"
+
+#define DEBUG_LOGFILE "/tmp/qemu.log"
+
+#ifdef __APPLE__
+#include <crt_externs.h>
+# define environ  (*_NSGetEnviron())
+#endif
+
+#include <mach/mach_init.h>
+#include <mach/vm_map.h>
+
+const char *interp_prefix = "";
+
+asm(".zerofill __STD_PROG_ZONE, __STD_PROG_ZONE, __std_prog_zone, 0x0dfff000");
+
+/* 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 stack_size = 512 * 1024;
+
+void qerror(const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    vfprintf(stderr, fmt, ap);
+    va_end(ap);
+    fprintf(stderr, "\n");
+    exit(1);
+}
+
+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;
+}
+#ifdef TARGET_PPC
+
+static inline uint64_t cpu_ppc_get_tb (CPUState *env)
+{
+    /* TO FIX */
+    return 0;
+}
+
+uint32_t cpu_ppc_load_tbl (CPUState *env)
+{
+    return cpu_ppc_get_tb(env) & 0xFFFFFFFF;
+}
+
+uint32_t cpu_ppc_load_tbu (CPUState *env)
+{
+    return cpu_ppc_get_tb(env) >> 32;
+}
+
+static void cpu_ppc_store_tb (CPUState *env, uint64_t value)
+{
+    /* TO FIX */
+}
+
+void cpu_ppc_store_tbu (CPUState *env, uint32_t value)
+{
+    cpu_ppc_store_tb(env, ((uint64_t)value << 32) | cpu_ppc_load_tbl(env));
+}
+
+void cpu_ppc_store_tbl (CPUState *env, uint32_t value)
+{
+    cpu_ppc_store_tb(env, ((uint64_t)cpu_ppc_load_tbl(env) << 32) | value);
+}
+
+uint32_t cpu_ppc_load_decr (CPUState *env)
+{
+    /* TO FIX */
+    return -1;
+}
+
+void cpu_ppc_store_decr (CPUState *env, uint32_t value)
+{
+    /* TO FIX */
+}
+
+void cpu_loop(CPUPPCState *env)
+{
+    int trapnr;
+    uint32_t ret;
+    target_siginfo_t info;
+
+    for(;;) {
+        trapnr = cpu_ppc_exec(env);
+        if (trapnr != EXCP_SYSCALL_USER && trapnr != EXCP_BRANCH &&
+            trapnr != EXCP_TRACE) {
+            if (loglevel > 0) {
+                cpu_dump_state(env, logfile, fprintf, 0);
+            }
+        }
+        switch(trapnr) {
+        case EXCP_NONE:
+            break;
+        case EXCP_SYSCALL_USER:
+            /* system call */
+            if(((int)env->gpr[0]) <= SYS_MAXSYSCALL && ((int)env->gpr[0])>0)
+                ret = do_unix_syscall(env, env->gpr[0]/*, env->gpr[3], env->gpr[4],
+                                      env->gpr[5], env->gpr[6], env->gpr[7],
+                                      env->gpr[8], env->gpr[9], env->gpr[10]*/);
+            else if(((int)env->gpr[0])<0)
+                ret = do_mach_syscall(env, env->gpr[0], env->gpr[3], env->gpr[4],
+                                      env->gpr[5], env->gpr[6], env->gpr[7],
+                                      env->gpr[8], env->gpr[9], env->gpr[10]);
+            else
+                ret = do_thread_syscall(env, env->gpr[0], env->gpr[3], env->gpr[4],
+                                        env->gpr[5], env->gpr[6], env->gpr[7],
+                                        env->gpr[8], env->gpr[9], env->gpr[10]);
+
+            /* Unix syscall error signaling */
+            if(((int)env->gpr[0]) <= SYS_MAXSYSCALL && ((int)env->gpr[0])>0)
+            {
+                if( (int)ret < 0 )
+                    env->nip += 0;
+                else
+                    env->nip += 4;
+            }
+
+            /* Return value */
+            env->gpr[3] = ret;
+            break;
+        case EXCP_RESET:
+            /* Should not happen ! */
+            fprintf(stderr, "RESET asked... Stop emulation\n");
+            if (loglevel)
+                fprintf(logfile, "RESET asked... Stop emulation\n");
+                abort();
+        case EXCP_MACHINE_CHECK:
+            fprintf(stderr, "Machine check exeption...  Stop emulation\n");
+            if (loglevel)
+                fprintf(logfile, "RESET asked... Stop emulation\n");
+                info.si_signo = SIGBUS;
+            info.si_errno = 0;
+            info.si_code = BUS_OBJERR;
+            info.si_addr = (void*)(env->nip - 4);
+            queue_signal(info.si_signo, &info);
+        case EXCP_DSI:
+#ifndef DAR
+/* To deal with multiple qemu header version as host for the darwin-user code */
+# define DAR SPR_DAR
+#endif
+            fprintf(stderr, "Invalid data memory access: 0x%08x\n", env->spr[DAR]);
+            if (loglevel) {
+                fprintf(logfile, "Invalid data memory access: 0x%08x\n",
+                        env->spr[DAR]);
+            }
+            /* Handle this via the gdb */
+            gdb_handlesig (env, SIGSEGV);
+
+            info.si_addr = (void*)env->nip;
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP_ISI:
+            fprintf(stderr, "Invalid instruction fetch\n");
+            if (loglevel)
+                fprintf(logfile, "Invalid instruction fetch\n");
+            /* Handle this via the gdb */
+            gdb_handlesig (env, SIGSEGV);
+
+            info.si_addr = (void*)(env->nip - 4);
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP_EXTERNAL:
+            /* Should not happen ! */
+            fprintf(stderr, "External interruption... Stop emulation\n");
+            if (loglevel)
+                fprintf(logfile, "External interruption... Stop emulation\n");
+                abort();
+        case EXCP_ALIGN:
+            fprintf(stderr, "Invalid unaligned memory access\n");
+            if (loglevel)
+                fprintf(logfile, "Invalid unaligned memory access\n");
+                info.si_signo = SIGBUS;
+            info.si_errno = 0;
+            info.si_code = BUS_ADRALN;
+            info.si_addr = (void*)(env->nip - 4);
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP_PROGRAM:
+            switch (env->error_code & ~0xF) {
+                case EXCP_FP:
+                    fprintf(stderr, "Program exception\n");
+                    if (loglevel)
+                        fprintf(logfile, "Program exception\n");
+                        /* Set FX */
+                        env->fpscr[7] |= 0x8;
+                    /* Finally, update FEX */
+                    if ((((env->fpscr[7] & 0x3) << 3) | (env->fpscr[6] >> 1)) &
+                        ((env->fpscr[1] << 1) | (env->fpscr[0] >> 3)))
+                        env->fpscr[7] |= 0x4;
+                        info.si_signo = SIGFPE;
+                    info.si_errno = 0;
+                    switch (env->error_code & 0xF) {
+                        case EXCP_FP_OX:
+                            info.si_code = FPE_FLTOVF;
+                            break;
+                        case EXCP_FP_UX:
+                            info.si_code = FPE_FLTUND;
+                            break;
+                        case EXCP_FP_ZX:
+                        case EXCP_FP_VXZDZ:
+                            info.si_code = FPE_FLTDIV;
+                            break;
+                        case EXCP_FP_XX:
+                            info.si_code = FPE_FLTRES;
+                            break;
+                        case EXCP_FP_VXSOFT:
+                            info.si_code = FPE_FLTINV;
+                            break;
+                        case EXCP_FP_VXNAN:
+                        case EXCP_FP_VXISI:
+                        case EXCP_FP_VXIDI:
+                        case EXCP_FP_VXIMZ:
+                        case EXCP_FP_VXVC:
+                        case EXCP_FP_VXSQRT:
+                        case EXCP_FP_VXCVI:
+                            info.si_code = FPE_FLTSUB;
+                            break;
+                        default:
+                            fprintf(stderr, "Unknown floating point exception "
+                                    "(%02x)\n", env->error_code);
+                            if (loglevel) {
+                                fprintf(logfile, "Unknown floating point exception "
+                                        "(%02x)\n", env->error_code & 0xF);
+                            }
+                    }
+                        break;
+                case EXCP_INVAL:
+                    fprintf(stderr, "Invalid instruction\n");
+                    if (loglevel)
+                        fprintf(logfile, "Invalid instruction\n");
+                        info.si_signo = SIGILL;
+                    info.si_errno = 0;
+                    switch (env->error_code & 0xF) {
+                        case EXCP_INVAL_INVAL:
+                            info.si_code = ILL_ILLOPC;
+                            break;
+                        case EXCP_INVAL_LSWX:
+                            info.si_code = ILL_ILLOPN;
+                            break;
+                        case EXCP_INVAL_SPR:
+                            info.si_code = ILL_PRVREG;
+                            break;
+                        case EXCP_INVAL_FP:
+                            info.si_code = ILL_COPROC;
+                            break;
+                        default:
+                            fprintf(stderr, "Unknown invalid operation (%02x)\n",
+                                    env->error_code & 0xF);
+                            if (loglevel) {
+                                fprintf(logfile, "Unknown invalid operation (%02x)\n",
+                                        env->error_code & 0xF);
+                            }
+                                info.si_code = ILL_ILLADR;
+                            break;
+                    }
+                        /* Handle this via the gdb */
+                        gdb_handlesig (env, SIGSEGV);
+                    break;
+                case EXCP_PRIV:
+                    fprintf(stderr, "Privilege violation\n");
+                    if (loglevel)
+                        fprintf(logfile, "Privilege violation\n");
+                        info.si_signo = SIGILL;
+                    info.si_errno = 0;
+                    switch (env->error_code & 0xF) {
+                        case EXCP_PRIV_OPC:
+                            info.si_code = ILL_PRVOPC;
+                            break;
+                        case EXCP_PRIV_REG:
+                            info.si_code = ILL_PRVREG;
+                            break;
+                        default:
+                            fprintf(stderr, "Unknown privilege violation (%02x)\n",
+                                    env->error_code & 0xF);
+                            info.si_code = ILL_PRVOPC;
+                            break;
+                    }
+                        break;
+                case EXCP_TRAP:
+                    fprintf(stderr, "Tried to call a TRAP\n");
+                    if (loglevel)
+                        fprintf(logfile, "Tried to call a TRAP\n");
+                        abort();
+                default:
+                    /* Should not happen ! */
+                    fprintf(stderr, "Unknown program exception (%02x)\n",
+                            env->error_code);
+                    if (loglevel) {
+                        fprintf(logfile, "Unknwon program exception (%02x)\n",
+                                env->error_code);
+                    }
+                        abort();
+            }
+            info.si_addr = (void*)(env->nip - 4);
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP_NO_FP:
+            fprintf(stderr, "No floating point allowed\n");
+            if (loglevel)
+                fprintf(logfile, "No floating point allowed\n");
+                info.si_signo = SIGILL;
+            info.si_errno = 0;
+            info.si_code = ILL_COPROC;
+            info.si_addr = (void*)(env->nip - 4);
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP_DECR:
+            /* Should not happen ! */
+            fprintf(stderr, "Decrementer exception\n");
+            if (loglevel)
+                fprintf(logfile, "Decrementer exception\n");
+            abort();
+        case EXCP_TRACE:
+            /* Pass to gdb: we use this to trace execution */
+            gdb_handlesig (env, SIGTRAP);
+            break;
+        case EXCP_FP_ASSIST:
+            /* Should not happen ! */
+            fprintf(stderr, "Floating point assist exception\n");
+            if (loglevel)
+                fprintf(logfile, "Floating point assist exception\n");
+            abort();
+        case EXCP_MTMSR:
+            /* We reloaded the msr, just go on */
+            if (msr_pr == 0) {
+                fprintf(stderr, "Tried to go into supervisor mode !\n");
+                if (loglevel)
+                    fprintf(logfile, "Tried to go into supervisor mode !\n");
+                abort();
+            }
+            break;
+        case EXCP_BRANCH:
+            /* We stopped because of a jump... */
+            break;
+        case EXCP_INTERRUPT:
+            /* Don't know why this should ever happen... */
+            fprintf(stderr, "EXCP_INTERRUPT\n");
+            break;
+        case EXCP_DEBUG:
+            gdb_handlesig (env, SIGTRAP);
+            break;
+        default:
+            fprintf(stderr, "qemu: unhandled CPU exception 0x%x - aborting\n",
+                    trapnr);
+            if (loglevel) {
+                fprintf(logfile, "qemu: unhandled CPU exception 0x%02x - "
+                        "0x%02x - aborting\n", trapnr, env->error_code);
+            }
+                abort();
+        }
+        process_pending_signals(env);
+    }
+}
+#endif
+
+
+#ifdef TARGET_I386
+
+/***********************************************************/
+/* CPUX86 core interface */
+
+uint64_t cpu_get_tsc(CPUX86State *env)
+{
+    return cpu_get_real_ticks();
+}
+
+void
+write_dt(void *ptr, unsigned long addr, unsigned long limit,
+                     int flags)
+{
+    unsigned int e1, e2;
+    e1 = (addr << 16) | (limit & 0xffff);
+    e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
+    e2 |= flags;
+    stl((uint8_t *)ptr, e1);
+    stl((uint8_t *)ptr + 4, e2);
+}
+
+static void set_gate(void *ptr, unsigned int type, unsigned int dpl,
+                     unsigned long addr, unsigned int sel)
+{
+    unsigned int e1, e2;
+    e1 = (addr & 0xffff) | (sel << 16);
+    e2 = (addr & 0xffff0000) | 0x8000 | (dpl << 13) | (type << 8);
+    stl((uint8_t *)ptr, e1);
+    stl((uint8_t *)ptr + 4, e2);
+}
+
+#define GDT_TABLE_SIZE 14
+#define LDT_TABLE_SIZE 15
+#define IDT_TABLE_SIZE 256
+#define TSS_SIZE 104
+uint64_t gdt_table[GDT_TABLE_SIZE];
+uint64_t ldt_table[LDT_TABLE_SIZE];
+uint64_t idt_table[IDT_TABLE_SIZE];
+uint32_t tss[TSS_SIZE];
+
+/* 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);
+}
+
+/* ABI convention: after a syscall if there was an error the CF flag is set */
+static inline set_error(CPUX86State *env, int ret)
+{
+    if(ret<0)
+        env->eflags = env->eflags | 0x1;
+    else
+        env->eflags &= ~0x1;
+    env->regs[R_EAX] = ret;
+}
+
+void cpu_loop(CPUX86State *env)
+{
+    int trapnr;
+    int ret;
+    uint8_t *pc;
+    target_siginfo_t info;
+
+    for(;;) {
+        trapnr = cpu_x86_exec(env);
+        uint32_t *params = (uint32_t *)env->regs[R_ESP];
+        switch(trapnr) {
+        case 0x79: /* Our commpage hack back door exit is here */
+            do_commpage(env,  env->eip,   *(params + 1), *(params + 2),
+                                          *(params + 3), *(params + 4),
+                                          *(params + 5), *(params + 6),
+                                          *(params + 7), *(params + 8));
+            break;
+        case 0x81: /* mach syscall */
+        {
+            ret = do_mach_syscall(env,  env->regs[R_EAX],
+                                          *(params + 1), *(params + 2),
+                                          *(params + 3), *(params + 4),
+                                          *(params + 5), *(params + 6),
+                                          *(params + 7), *(params + 8));
+            set_error(env, ret);
+            break;
+        }
+        case 0x90: /* unix backdoor */
+        {
+            /* after sysenter, stack is in R_ECX, new eip in R_EDX (sysexit will flip them back)*/
+            int saved_stack = env->regs[R_ESP];
+            env->regs[R_ESP] = env->regs[R_ECX];
+
+            ret = do_unix_syscall(env, env->regs[R_EAX]);
+
+            env->regs[R_ECX] = env->regs[R_ESP];
+            env->regs[R_ESP] = saved_stack;
+
+            set_error(env, ret);
+            break;
+        }
+        case 0x80: /* unix syscall */
+        {
+            ret = do_unix_syscall(env, env->regs[R_EAX]/*,
+                                          *(params + 1), *(params + 2),
+                                          *(params + 3), *(params + 4),
+                                          *(params + 5), *(params + 6),
+                                          *(params + 7), *(params + 8)*/);
+            set_error(env, ret);
+            break;
+        }
+        case 0x82: /* thread syscall */
+        {
+            ret = do_thread_syscall(env,  env->regs[R_EAX],
+                                          *(params + 1), *(params + 2),
+                                          *(params + 3), *(params + 4),
+                                          *(params + 5), *(params + 6),
+                                          *(params + 7), *(params + 8));
+            set_error(env, ret);
+            break;
+        }
+        case EXCP0B_NOSEG:
+        case EXCP0C_STACK:
+            info.si_signo = SIGBUS;
+            info.si_errno = 0;
+            info.si_code = BUS_NOOP;
+            info.si_addr = 0;
+            gdb_handlesig (env, SIGBUS);
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP0D_GPF:
+            info.si_signo = SIGSEGV;
+            info.si_errno = 0;
+            info.si_code = SEGV_NOOP;
+            info.si_addr = 0;
+            gdb_handlesig (env, SIGSEGV);
+            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 = SEGV_MAPERR;
+            else
+                info.si_code = SEGV_ACCERR;
+            info.si_addr = (void*)env->cr[2];
+            gdb_handlesig (env, SIGSEGV);
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP00_DIVZ:
+            /* division by zero */
+            info.si_signo = SIGFPE;
+            info.si_errno = 0;
+            info.si_code = FPE_INTDIV;
+            info.si_addr = (void*)env->eip;
+            gdb_handlesig (env, SIGFPE);
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP01_SSTP:
+        case EXCP03_INT3:
+            info.si_signo = SIGTRAP;
+            info.si_errno = 0;
+            info.si_code = TRAP_BRKPT;
+            info.si_addr = (void*)env->eip;
+            gdb_handlesig (env, SIGTRAP);
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP04_INTO:
+        case EXCP05_BOUND:
+            info.si_signo = SIGSEGV;
+            info.si_errno = 0;
+            info.si_code = SEGV_NOOP;
+            info.si_addr = 0;
+            gdb_handlesig (env, SIGSEGV);
+            queue_signal(info.si_signo, &info);
+            break;
+        case EXCP06_ILLOP:
+            info.si_signo = SIGILL;
+            info.si_errno = 0;
+            info.si_code = ILL_ILLOPN;
+            info.si_addr = (void*)env->eip;
+            gdb_handlesig (env, SIGILL);
+            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, SIGTRAP);
+                if (sig)
+                  {
+                    info.si_signo = sig;
+                    info.si_errno = 0;
+                    info.si_code = TRAP_BRKPT;
+                    queue_signal(info.si_signo, &info);
+                  }
+            }
+            break;
+        default:
+            pc = (void*)(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
+
+void usage(void)
+{
+    printf("qemu-" TARGET_ARCH " version " QEMU_VERSION ", Copyright (c) 2003-2004 Fabrice Bellard\n"
+           "usage: qemu-" TARGET_ARCH " [-h] [-d opts] [-L path] [-s size] program [arguments...]\n"
+           "Darwin CPU emulator (compiled for %s emulation)\n"
+           "\n"
+           "-h           print this help\n"
+           "-L path      set the elf interpreter prefix (default=%s)\n"
+           "-s size      set the stack size in bytes (default=%ld)\n"
+           "\n"
+           "debug options:\n"
+#ifdef USE_CODE_COPY
+           "-no-code-copy   disable code copy acceleration\n"
+#endif
+           "-d options   activate log (logfile=%s)\n"
+           "-g wait for gdb on port 1234\n"
+           "-p pagesize  set the host page size to 'pagesize'\n",
+           TARGET_ARCH,
+           interp_prefix,
+           stack_size,
+           DEBUG_LOGFILE);
+    _exit(1);
+}
+
+/* XXX: currently only used for async signals (see signal.c) */
+CPUState *global_env;
+/* used only if single thread */
+CPUState *cpu_single_env = NULL;
+
+/* used to free thread contexts */
+TaskState *first_task_state;
+
+int main(int argc, char **argv)
+{
+    const char *filename;
+    struct target_pt_regs regs1, *regs = &regs1;
+    TaskState ts1, *ts = &ts1;
+    CPUState *env;
+    int optind;
+    short use_gdbstub = 0;
+    const char *r;
+
+    if (argc <= 1)
+        usage();
+
+    /* init debug */
+    cpu_set_log_filename(DEBUG_LOGFILE);
+
+    optind = 1;
+    for(;;) {
+        if (optind >= argc)
+            break;
+        r = argv[optind];
+        if (r[0] != '-')
+            break;
+        optind++;
+        r++;
+        if (!strcmp(r, "-")) {
+            break;
+        } else if (!strcmp(r, "d")) {
+            int mask;
+            CPULogItem *item;
+
+        if (optind >= argc)
+        break;
+
+        r = argv[optind++];
+            mask = cpu_str_to_log_mask(r);
+            if (!mask) {
+                printf("Log items (comma separated):\n");
+                for(item = cpu_log_items; item->mask != 0; item++) {
+                    printf("%-10s %s\n", item->name, item->help);
+                }
+                exit(1);
+            }
+            cpu_set_log(mask);
+        } else if (!strcmp(r, "s")) {
+            r = argv[optind++];
+            stack_size = strtol(r, (char **)&r, 0);
+            if (stack_size <= 0)
+                usage();
+            if (*r == 'M')
+                stack_size *= 1024 * 1024;
+            else if (*r == 'k' || *r == 'K')
+                stack_size *= 1024;
+        } else if (!strcmp(r, "L")) {
+            interp_prefix = argv[optind++];
+        } else if (!strcmp(r, "p")) {
+            qemu_host_page_size = atoi(argv[optind++]);
+            if (qemu_host_page_size == 0 ||
+                (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
+                fprintf(stderr, "page size must be a power of two\n");
+                exit(1);
+            }
+        } else
+        if (!strcmp(r, "g")) {
+            use_gdbstub = 1;
+        } else
+#ifdef USE_CODE_COPY
+        if (!strcmp(r, "no-code-copy")) {
+            code_copy_enabled = 0;
+        } else
+#endif
+        {
+            usage();
+        }
+    }
+    if (optind >= argc)
+        usage();
+    filename = argv[optind];
+
+    /* Zero out regs */
+    memset(regs, 0, sizeof(struct target_pt_regs));
+
+#if 0
+    /* Scan interp_prefix dir for replacement files. */
+    init_paths(interp_prefix);
+#endif
+
+    /* NOTE: we need to init the CPU at this stage to get
+       qemu_host_page_size */
+    env = cpu_init();
+
+    printf("Starting %s with qemu\n----------------\n", filename);
+
+    commpage_init();
+
+    if (mach_exec(filename, argv+optind, environ, regs) != 0) {
+    printf("Error loading %s\n", filename);
+    _exit(1);
+    }
+
+    syscall_init();
+    signal_init();
+    global_env = env;
+
+    /* build Task State */
+    memset(ts, 0, sizeof(TaskState));
+    env->opaque = ts;
+    ts->used = 1;
+    env->user_mode_only = 1;
+
+#if defined(TARGET_I386)
+    cpu_x86_set_cpl(env, 3);
+
+    env->cr[0] = CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK;
+    env->hflags |= HF_PE_MASK;
+
+    if (env->cpuid_features & CPUID_SSE) {
+        env->cr[4] |= CR4_OSFXSR_MASK;
+        env->hflags |= HF_OSFXSR_MASK;
+    }
+
+    /* flags setup : we activate the IRQs by default as in user mode */
+    env->eflags |= IF_MASK;
+
+    /* darwin 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->eip = regs->eip;
+
+    /* Darwin LDT setup */
+    /* 2 - User code segment
+       3 - User data segment
+       4 - User cthread */
+    bzero(ldt_table, LDT_TABLE_SIZE * sizeof(ldt_table[0]));
+    env->ldt.base = (uint32_t) ldt_table;
+    env->ldt.limit = sizeof(ldt_table) - 1;
+
+    write_dt(ldt_table + 2, 0, 0xfffff,
+             DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
+             (3 << DESC_DPL_SHIFT) | (0xa << DESC_TYPE_SHIFT));
+    write_dt(ldt_table + 3, 0, 0xfffff,
+             DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
+             (3 << DESC_DPL_SHIFT) | (0x2 << DESC_TYPE_SHIFT));
+    write_dt(ldt_table + 4, 0, 0xfffff,
+             DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
+             (3 << DESC_DPL_SHIFT) | (0x2 << DESC_TYPE_SHIFT));
+
+    /* Darwin GDT setup.
+     * has changed a lot between old Darwin/x86 (pre-Mac Intel) and Mac OS X/x86,
+       now everything is done via  int 0x81(mach) int 0x82 (thread) and sysenter/sysexit(unix) */
+    bzero(gdt_table, sizeof(gdt_table));
+    env->gdt.base = (uint32_t)gdt_table;
+    env->gdt.limit = sizeof(gdt_table) - 1;
+
+    /* Set up a back door to handle sysenter syscalls (unix) */
+    char * syscallbackdoor = malloc(64);
+    page_set_flags((int)syscallbackdoor, (int)syscallbackdoor + 64, PROT_EXEC | PROT_READ | PAGE_VALID);
+
+    int i = 0;
+    syscallbackdoor[i++] = 0xcd;
+    syscallbackdoor[i++] = 0x90; /* int 0x90 */
+    syscallbackdoor[i++] = 0x0F;
+    syscallbackdoor[i++] = 0x35; /* sysexit */
+
+    /* Darwin sysenter/sysexit setup */
+    env->sysenter_cs = 0x1; //XXX
+    env->sysenter_eip = (int)syscallbackdoor;
+    env->sysenter_esp = (int)malloc(64);
+
+    /* Darwin TSS setup
+       This must match up with GDT[4] */
+    env->tr.base = (uint32_t) tss;
+    env->tr.limit = sizeof(tss) - 1;
+    env->tr.flags = DESC_P_MASK | (0x9 << DESC_TYPE_SHIFT);
+    stw(tss + 2, 0x10);  // ss0 = 0x10 = GDT[2] = Kernel Data Segment
+
+    /* Darwin interrupt setup */
+    bzero(idt_table, sizeof(idt_table));
+    env->idt.base = (uint32_t) idt_table;
+    env->idt.limit = sizeof(idt_table) - 1;
+    set_idt(0, 0);
+    set_idt(1, 0);
+    set_idt(2, 0);
+    set_idt(3, 3);
+    set_idt(4, 3);
+    set_idt(5, 3);
+    set_idt(6, 0);
+    set_idt(7, 0);
+    set_idt(8, 0);
+    set_idt(9, 0);
+    set_idt(10, 0);
+    set_idt(11, 0);
+    set_idt(12, 0);
+    set_idt(13, 0);
+    set_idt(14, 0);
+    set_idt(15, 0);
+    set_idt(16, 0);
+    set_idt(17, 0);
+    set_idt(18, 0);
+    set_idt(19, 0);
+    /* Syscalls are done via
+        int 0x80 (unix) (rarely used)
+        int 0x81 (mach)
+        int 0x82 (thread)
+        int 0x83 (diag) (not handled here)
+        sysenter/sysexit (unix) -> we redirect that to int 0x90 */
+    set_idt(0x79, 3); /* Commpage hack, here is our backdoor interrupt */
+    set_idt(0x80, 3); /* Unix Syscall */
+    set_idt(0x81, 3); /* Mach Syscalls */
+    set_idt(0x82, 3); /* thread Syscalls */
+
+    set_idt(0x90, 3); /* Unix Syscall backdoor */
+
+
+    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);
+
+#elif defined(TARGET_PPC)
+    {
+        int i;
+        env->nip = regs->nip;
+        for(i = 0; i < 32; i++) {
+            env->gpr[i] = regs->gpr[i];
+        }
+    }
+#else
+#error unsupported target CPU
+#endif
+
+    if (use_gdbstub) {
+        printf("Waiting for gdb Connection on port 1234...\n");
+        gdbserver_start (1234);
+        gdb_handlesig(env, 0);
+    }
+
+    cpu_loop(env);
+    /* never exits */
+    return 0;
+}