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, 903 insertions, 0 deletions

diff --git a/darwin-user/machload.c b/darwin-user/machload.c
new file mode 100644
index 0000000..3ba417e
--- /dev/null
+++ b/darwin-user/machload.c
@@ -0,0 +1,903 @@
+/*
+ *  Mach-O object file loading
+ *
+ *  Copyright (c) 2006 Pierre d'Herbemont
+ *
+ * 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 <stdio.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "qemu.h"
+#include "disas.h"
+
+#include <mach-o/loader.h>
+#include <mach-o/fat.h>
+#include <mach-o/nlist.h>
+#include <mach-o/reloc.h>
+#include <mach-o/ppc/reloc.h>
+
+//#define DEBUG_MACHLOAD
+
+#ifdef DEBUG_MACHLOAD
+# define DPRINTF(...) do { if(loglevel) fprintf(logfile, __VA_ARGS__); printf(__VA_ARGS__); } while(0)
+#else
+# define DPRINTF(...) do { if(loglevel) fprintf(logfile, __VA_ARGS__); } while(0)
+#endif
+
+# define check_mach_header(x) (x.magic == MH_CIGAM)
+
+extern const char *interp_prefix;
+
+/* we don't have a good implementation for this */
+#define DONT_USE_DYLD_SHARED_MAP
+
+/* Pass extra arg to DYLD for debug */
+//#define ACTIVATE_DYLD_TRACE
+
+//#define OVERRIDE_DYLINKER
+
+#ifdef OVERRIDE_DYLINKER
+# ifdef TARGET_I386
+#  define DYLINKER_NAME "/Users/steg/qemu/tests/i386-darwin-env/usr/lib/dyld"
+# else
+#  define DYLINKER_NAME "/usr/lib/dyld"
+# endif
+#endif
+
+/* XXX: in an include */
+struct nlist_extended
+{
+    union {
+        char *n_name;
+        long  n_strx;
+    } n_un;
+    unsigned char n_type;
+    unsigned char n_sect;
+    short st_desc;
+    unsigned long st_value;
+    unsigned long st_size;
+};
+
+/* Print symbols in gdb */
+void *macho_text_sect = 0;
+int   macho_offset = 0;
+
+int load_object(const char *filename, struct target_pt_regs * regs, void ** mh);
+void qerror(const char *format, ...);
+#ifdef TARGET_I386
+typedef struct mach_i386_thread_state {
+    unsigned int    eax;
+    unsigned int    ebx;
+    unsigned int    ecx;
+    unsigned int    edx;
+    unsigned int    edi;
+    unsigned int    esi;
+    unsigned int    ebp;
+    unsigned int    esp;
+    unsigned int    ss;
+    unsigned int    eflags;
+    unsigned int    eip;
+    unsigned int    cs;
+    unsigned int    ds;
+    unsigned int    es;
+    unsigned int    fs;
+    unsigned int    gs;
+} mach_i386_thread_state_t;
+
+void bswap_i386_thread_state(struct mach_i386_thread_state *ts)
+{
+    bswap32s((uint32_t*)&ts->eax);
+    bswap32s((uint32_t*)&ts->ebx);
+    bswap32s((uint32_t*)&ts->ecx);
+    bswap32s((uint32_t*)&ts->edx);
+    bswap32s((uint32_t*)&ts->edi);
+    bswap32s((uint32_t*)&ts->esi);
+    bswap32s((uint32_t*)&ts->ebp);
+    bswap32s((uint32_t*)&ts->esp);
+    bswap32s((uint32_t*)&ts->ss);
+    bswap32s((uint32_t*)&ts->eflags);
+    bswap32s((uint32_t*)&ts->eip);
+    bswap32s((uint32_t*)&ts->cs);
+    bswap32s((uint32_t*)&ts->ds);
+    bswap32s((uint32_t*)&ts->es);
+    bswap32s((uint32_t*)&ts->fs);
+    bswap32s((uint32_t*)&ts->gs);
+}
+#define target_thread_state mach_i386_thread_state
+#define TARGET_CPU_TYPE CPU_TYPE_I386
+#define TARGET_CPU_NAME "i386"
+#endif
+
+#ifdef TARGET_PPC
+struct mach_ppc_thread_state {
+    unsigned int srr0;      /* Instruction address register (PC) */
+    unsigned int srr1;    /* Machine state register (supervisor) */
+    unsigned int r0;
+    unsigned int r1;
+    unsigned int r2;
+    unsigned int r3;
+    unsigned int r4;
+    unsigned int r5;
+    unsigned int r6;
+    unsigned int r7;
+    unsigned int r8;
+    unsigned int r9;
+    unsigned int r10;
+    unsigned int r11;
+    unsigned int r12;
+    unsigned int r13;
+    unsigned int r14;
+    unsigned int r15;
+    unsigned int r16;
+    unsigned int r17;
+    unsigned int r18;
+    unsigned int r19;
+    unsigned int r20;
+    unsigned int r21;
+    unsigned int r22;
+    unsigned int r23;
+    unsigned int r24;
+    unsigned int r25;
+    unsigned int r26;
+    unsigned int r27;
+    unsigned int r28;
+    unsigned int r29;
+    unsigned int r30;
+    unsigned int r31;
+
+    unsigned int cr;        /* Condition register */
+    unsigned int xer;    /* User's integer exception register */
+    unsigned int lr;    /* Link register */
+    unsigned int ctr;    /* Count register */
+    unsigned int mq;    /* MQ register (601 only) */
+
+    unsigned int vrsave;    /* Vector Save Register */
+};
+
+void bswap_ppc_thread_state(struct mach_ppc_thread_state *ts)
+{
+    bswap32s((uint32_t*)&ts->srr0);
+    bswap32s((uint32_t*)&ts->srr1);
+    bswap32s((uint32_t*)&ts->r0);
+    bswap32s((uint32_t*)&ts->r1);
+    bswap32s((uint32_t*)&ts->r2);
+    bswap32s((uint32_t*)&ts->r3);
+    bswap32s((uint32_t*)&ts->r4);
+    bswap32s((uint32_t*)&ts->r5);
+    bswap32s((uint32_t*)&ts->r6);
+    bswap32s((uint32_t*)&ts->r7);
+    bswap32s((uint32_t*)&ts->r8);
+    bswap32s((uint32_t*)&ts->r9);
+    bswap32s((uint32_t*)&ts->r10);
+    bswap32s((uint32_t*)&ts->r11);
+    bswap32s((uint32_t*)&ts->r12);
+    bswap32s((uint32_t*)&ts->r13);
+    bswap32s((uint32_t*)&ts->r14);
+    bswap32s((uint32_t*)&ts->r15);
+    bswap32s((uint32_t*)&ts->r16);
+    bswap32s((uint32_t*)&ts->r17);
+    bswap32s((uint32_t*)&ts->r18);
+    bswap32s((uint32_t*)&ts->r19);
+    bswap32s((uint32_t*)&ts->r20);
+    bswap32s((uint32_t*)&ts->r21);
+    bswap32s((uint32_t*)&ts->r22);
+    bswap32s((uint32_t*)&ts->r23);
+    bswap32s((uint32_t*)&ts->r24);
+    bswap32s((uint32_t*)&ts->r25);
+    bswap32s((uint32_t*)&ts->r26);
+    bswap32s((uint32_t*)&ts->r27);
+    bswap32s((uint32_t*)&ts->r28);
+    bswap32s((uint32_t*)&ts->r29);
+    bswap32s((uint32_t*)&ts->r30);
+    bswap32s((uint32_t*)&ts->r31);
+
+    bswap32s((uint32_t*)&ts->cr);
+    bswap32s((uint32_t*)&ts->xer);
+    bswap32s((uint32_t*)&ts->lr);
+    bswap32s((uint32_t*)&ts->ctr);
+    bswap32s((uint32_t*)&ts->mq);
+
+    bswap32s((uint32_t*)&ts->vrsave);
+}
+
+#define target_thread_state mach_ppc_thread_state
+#define TARGET_CPU_TYPE CPU_TYPE_POWERPC
+#define TARGET_CPU_NAME "PowerPC"
+#endif
+
+struct target_thread_command {
+    unsigned long    cmd;    /* LC_THREAD or  LC_UNIXTHREAD */
+    unsigned long    cmdsize;    /* total size of this command */
+    unsigned long flavor;    /* flavor of thread state */
+    unsigned long count;        /* count of longs in thread state */
+    struct target_thread_state state;  /* thread state for this flavor */
+};
+
+void bswap_tc(struct target_thread_command *tc)
+{
+    bswap32s((uint32_t*)(&tc->flavor));
+    bswap32s((uint32_t*)&tc->count);
+#if defined(TARGET_I386)
+    bswap_i386_thread_state(&tc->state);
+#elif defined(TARGET_PPC)
+    bswap_ppc_thread_state(&tc->state);
+#else
+# error unknown TARGET_CPU_TYPE
+#endif
+}
+
+void bswap_mh(struct mach_header *mh)
+{
+    bswap32s((uint32_t*)(&mh->magic));
+    bswap32s((uint32_t*)&mh->cputype);
+    bswap32s((uint32_t*)&mh->cpusubtype);
+    bswap32s((uint32_t*)&mh->filetype);
+    bswap32s((uint32_t*)&mh->ncmds);
+    bswap32s((uint32_t*)&mh->sizeofcmds);
+    bswap32s((uint32_t*)&mh->flags);
+}
+
+void bswap_lc(struct load_command *lc)
+{
+    bswap32s((uint32_t*)&lc->cmd);
+    bswap32s((uint32_t*)&lc->cmdsize);
+}
+
+
+void bswap_fh(struct fat_header *fh)
+{
+    bswap32s((uint32_t*)&fh->magic);
+    bswap32s((uint32_t*)&fh->nfat_arch);
+}
+
+void bswap_fa(struct fat_arch *fa)
+{
+    bswap32s((uint32_t*)&fa->cputype);
+    bswap32s((uint32_t*)&fa->cpusubtype);
+    bswap32s((uint32_t*)&fa->offset);
+    bswap32s((uint32_t*)&fa->size);
+    bswap32s((uint32_t*)&fa->align);
+}
+
+void bswap_segcmd(struct segment_command *sc)
+{
+    bswap32s((uint32_t*)&sc->vmaddr);
+    bswap32s((uint32_t*)&sc->vmsize);
+    bswap32s((uint32_t*)&sc->fileoff);
+    bswap32s((uint32_t*)&sc->filesize);
+    bswap32s((uint32_t*)&sc->maxprot);
+    bswap32s((uint32_t*)&sc->initprot);
+    bswap32s((uint32_t*)&sc->nsects);
+    bswap32s((uint32_t*)&sc->flags);
+}
+
+void bswap_symtabcmd(struct symtab_command *stc)
+{
+    bswap32s((uint32_t*)&stc->cmd);
+    bswap32s((uint32_t*)&stc->cmdsize);
+    bswap32s((uint32_t*)&stc->symoff);
+    bswap32s((uint32_t*)&stc->nsyms);
+    bswap32s((uint32_t*)&stc->stroff);
+    bswap32s((uint32_t*)&stc->strsize);
+}
+
+void bswap_sym(struct nlist *n)
+{
+    bswap32s((uint32_t*)&n->n_un.n_strx);
+    bswap16s((uint16_t*)&n->n_desc);
+    bswap32s((uint32_t*)&n->n_value);
+}
+
+int load_thread(struct mach_header *mh, struct target_thread_command *tc, struct target_pt_regs * regs, int fd, int mh_pos, int need_bswap)
+{
+    int entry;
+    if(need_bswap)
+        bswap_tc(tc);
+#if defined(TARGET_I386)
+    entry = tc->state.eip;
+    DPRINTF(" eax 0x%.8x\n ebx 0x%.8x\n ecx 0x%.8x\n edx 0x%.8x\n edi 0x%.8x\n esi 0x%.8x\n ebp 0x%.8x\n esp 0x%.8x\n ss 0x%.8x\n eflags 0x%.8x\n eip 0x%.8x\n cs 0x%.8x\n ds 0x%.8x\n es 0x%.8x\n fs 0x%.8x\n gs 0x%.8x\n",
+            tc->state.eax, tc->state.ebx, tc->state.ecx, tc->state.edx, tc->state.edi, tc->state.esi, tc->state.ebp,
+            tc->state.esp, tc->state.ss, tc->state.eflags, tc->state.eip, tc->state.cs, tc->state.ds, tc->state.es,
+            tc->state.fs, tc->state.gs );
+#define reg_copy(reg)   regs->reg = tc->state.reg
+    if(regs)
+    {
+        reg_copy(eax);
+        reg_copy(ebx);
+        reg_copy(ecx);
+        reg_copy(edx);
+
+        reg_copy(edi);
+        reg_copy(esi);
+
+        reg_copy(ebp);
+        reg_copy(esp);
+
+        reg_copy(eflags);
+        reg_copy(eip);
+    /*
+        reg_copy(ss);
+        reg_copy(cs);
+        reg_copy(ds);
+        reg_copy(es);
+        reg_copy(fs);
+        reg_copy(gs);*/
+    }
+#undef reg_copy
+#elif defined(TARGET_PPC)
+    entry =  tc->state.srr0;
+#endif
+    DPRINTF("load_thread: entry 0x%x\n", entry);
+    return entry;
+}
+
+int load_dylinker(struct mach_header *mh, struct dylinker_command *dc, int fd, int mh_pos, int need_bswap)
+{
+    int size;
+    char * dylinker_name;
+    size = dc->cmdsize - sizeof(struct dylinker_command);
+
+    if(need_bswap)
+        dylinker_name = (char*)(bswap_32(dc->name.offset)+(int)dc);
+    else
+        dylinker_name = (char*)((dc->name.offset)+(int)dc);
+
+#ifdef OVERRIDE_DYLINKER
+    dylinker_name = DYLINKER_NAME;
+#else
+    if(asprintf(&dylinker_name, "%s%s", interp_prefix, dylinker_name) == -1)
+        qerror("can't allocate the new dylinker name\n");
+#endif
+
+    DPRINTF("dylinker_name %s\n", dylinker_name);
+    return load_object(dylinker_name, NULL, NULL);
+}
+
+int load_segment(struct mach_header *mh, struct segment_command *sc, int fd, int mh_pos, int need_bswap, int fixed, int slide)
+{
+    unsigned long addr = sc->vmaddr;
+    unsigned long size = sc->filesize;
+    unsigned long error = 0;
+
+    if(need_bswap)
+        bswap_segcmd(sc);
+
+    if(sc->vmaddr == 0)
+    {
+        DPRINTF("load_segment: sc->vmaddr == 0 returning\n");
+        return -1;
+    }
+
+    if (strcmp(sc->segname, "__PAGEZERO") == 0)
+    {
+        DPRINTF("load_segment: __PAGEZERO returning\n");
+        return -1;
+    }
+
+    /* Right now mmap memory */
+    /* XXX: should check to see that the space is free, because MAP_FIXED is dangerous */
+    DPRINTF("load_segment: mmaping %s to 0x%x-(0x%x|0x%x) + 0x%x\n", sc->segname, sc->vmaddr, sc->filesize, sc->vmsize, slide);
+
+    if(sc->filesize > 0)
+    {
+        int opt = 0;
+
+        if(fixed)
+            opt |= MAP_FIXED;
+
+        DPRINTF("sc->vmaddr 0x%x slide 0x%x add 0x%x\n", slide, sc->vmaddr, sc->vmaddr+slide);
+
+        addr = target_mmap(sc->vmaddr+slide, sc->filesize,  sc->initprot, opt, fd, mh_pos + sc->fileoff);
+
+        if(addr==-1)
+            qerror("load_segment: can't mmap at 0x%x\n", sc->vmaddr+slide);
+
+        error = addr-sc->vmaddr;
+    }
+    else
+    {
+        addr = sc->vmaddr+slide;
+        error = slide;
+    }
+
+    if(sc->vmsize > sc->filesize)
+    {
+        addr += sc->filesize;
+        size = sc->vmsize-sc->filesize;
+        addr = target_mmap(addr, size, sc->initprot, MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+        if(addr==-1)
+            qerror("load_segment: can't mmap at 0x%x\n", sc->vmaddr+slide);
+    }
+
+    return error;
+}
+
+void *load_data(int fd, long offset, unsigned int size)
+{
+    char *data;
+
+    data = malloc(size);
+    if (!data)
+        return NULL;
+    lseek(fd, offset, SEEK_SET);
+    if (read(fd, data, size) != size) {
+        free(data);
+        return NULL;
+    }
+    return data;
+}
+
+/* load a mach-o object file */
+int load_object(const char *filename, struct target_pt_regs * regs, void ** mh)
+{
+    int need_bswap = 0;
+    int entry_point = 0;
+    int dyld_entry_point = 0;
+    int slide, mmapfixed;
+    int fd;
+    struct load_command *lcmds, *lc;
+    int is_fat = 0;
+    unsigned int i, magic;
+    int mach_hdr_pos = 0;
+    struct mach_header mach_hdr;
+
+    /* for symbol lookup whith -d flag. */
+    struct symtab_command *    symtabcmd = 0;
+    struct nlist_extended *symtab, *sym;
+    struct nlist     *symtab_std, *syment;
+    char            *strtab;
+
+    fd = open(filename, O_RDONLY);
+    if (fd < 0)
+        qerror("can't open file '%s'", filename);
+
+    /* Read magic header.  */
+    if (read(fd, &magic, sizeof (magic)) != sizeof (magic))
+        qerror("unable to read Magic of '%s'", filename);
+
+    /* Check Mach identification.  */
+    if(magic == MH_MAGIC)
+    {
+        is_fat = 0;
+        need_bswap = 0;
+    } else if (magic == MH_CIGAM)
+    {
+        is_fat = 0;
+        need_bswap = 1;
+    } else if (magic == FAT_MAGIC)
+    {
+        is_fat = 1;
+        need_bswap = 0;
+    } else if (magic == FAT_CIGAM)
+    {
+        is_fat = 1;
+        need_bswap = 1;
+    }
+    else
+        qerror("Not a Mach-O file.", filename);
+
+    DPRINTF("loading %s %s...\n", filename, is_fat ? "[FAT]": "[REGULAR]");
+    if(is_fat)
+    {
+        int found = 0;
+        struct fat_header fh;
+        struct fat_arch *fa;
+
+        lseek(fd, 0, SEEK_SET);
+
+        /* Read Fat header.  */
+        if (read(fd, &fh, sizeof (fh)) != sizeof (fh))
+            qerror("unable to read file header");
+
+        if(need_bswap)
+            bswap_fh(&fh);
+
+        /* Read Fat Arch.  */
+        fa = malloc(sizeof(struct fat_arch)*fh.nfat_arch);
+
+        if (read(fd, fa, sizeof(struct fat_arch)*fh.nfat_arch) != sizeof(struct fat_arch)*fh.nfat_arch)
+            qerror("unable to read file header");
+
+        for( i = 0; i < fh.nfat_arch; i++, fa++)
+        {
+            if(need_bswap)
+                bswap_fa(fa);
+            if(fa->cputype == TARGET_CPU_TYPE)
+            {
+                mach_hdr_pos = fa->offset;
+                lseek(fd, mach_hdr_pos, SEEK_SET);
+
+                /* Read Mach header.  */
+
+                if (read(fd, &mach_hdr, sizeof(struct mach_header)) != sizeof (struct mach_header))
+                    qerror("unable to read file header");
+
+                if(mach_hdr.magic == MH_MAGIC)
+                    need_bswap = 0;
+                else if (mach_hdr.magic == MH_CIGAM)
+                    need_bswap = 1;
+                else
+                    qerror("Invalid mach header in Fat Mach-O File");
+                found = 1;
+                break;
+            }
+        }
+        if(!found)
+            qerror("%s: No %s CPU found in FAT Header", filename, TARGET_CPU_NAME);
+    }
+    else
+    {
+        lseek(fd, 0, SEEK_SET);
+        /* Read Mach header */
+        if (read(fd, &mach_hdr, sizeof (mach_hdr)) != sizeof (mach_hdr))
+            qerror("%s: unable to read file header", filename);
+    }
+
+    if(need_bswap)
+        bswap_mh(&mach_hdr);
+
+    if ((mach_hdr.cputype) != TARGET_CPU_TYPE)
+        qerror("%s: Unsupported CPU 0x%x (only 0x%x(%s) supported)", filename, mach_hdr.cputype, TARGET_CPU_TYPE, TARGET_CPU_NAME);
+
+
+    switch(mach_hdr.filetype)
+    {
+        case MH_EXECUTE:  break;
+        case MH_FVMLIB:
+        case MH_DYLIB:
+        case MH_DYLINKER: break;
+        default:
+            qerror("%s: Unsupported Mach type (0x%x)", filename, mach_hdr.filetype);
+    }
+
+    /* read segment headers */
+    lcmds = malloc(mach_hdr.sizeofcmds);
+
+    if(read(fd, lcmds, mach_hdr.sizeofcmds) != mach_hdr.sizeofcmds)
+            qerror("%s: unable to read load_command", filename);
+    slide = 0;
+    mmapfixed = 0;
+    for(i=0, lc = lcmds; i < (mach_hdr.ncmds) ; i++)
+    {
+
+        if(need_bswap)
+            bswap_lc(lc);
+        switch(lc->cmd)
+        {
+            case LC_SEGMENT:
+                /* The main_exe can't be relocated */
+                if(mach_hdr.filetype == MH_EXECUTE)
+                    mmapfixed = 1;
+
+                slide = load_segment(&mach_hdr, (struct segment_command*)lc, fd, mach_hdr_pos, need_bswap, mmapfixed, slide);
+
+                /* other segment must be mapped according to slide exactly, if load_segment did something */
+                if(slide != -1)
+                    mmapfixed = 1;
+                else
+                    slide = 0; /* load_segment didn't map the segment */
+
+                if(mach_hdr.filetype == MH_EXECUTE && slide != 0)
+                    qerror("%s: Warning executable can't be mapped at the right address (offset: 0x%x)\n", filename, slide);
+
+                if(strcmp(((struct segment_command*)(lc))->segname, "__TEXT") == 0)
+                {
+                    /* Text section */
+                    if(mach_hdr.filetype == MH_EXECUTE)
+                    {
+                        /* return the mach_header */
+                        *mh = (void*)(((struct segment_command*)(lc))->vmaddr + slide);
+                    }
+                    else
+                    {
+                        /* it is dyld save the section for gdb, we will be interested in dyld symbol
+                           while debuging */
+                        macho_text_sect = (void*)(((struct segment_command*)(lc))->vmaddr + slide);
+                        macho_offset = slide;
+                    }
+                }
+                break;
+            case LC_LOAD_DYLINKER:
+                dyld_entry_point = load_dylinker( &mach_hdr, (struct dylinker_command*)lc, fd, mach_hdr_pos, need_bswap );
+                break;
+            case LC_LOAD_DYLIB:
+                /* dyld will do that for us */
+                break;
+            case LC_THREAD:
+            case LC_UNIXTHREAD:
+                {
+                struct target_pt_regs * _regs;
+                if(mach_hdr.filetype == MH_DYLINKER)
+                    _regs = regs;
+                else
+                    _regs = 0;
+                entry_point = load_thread( &mach_hdr, (struct target_thread_command*)lc, _regs, fd, mach_hdr_pos, need_bswap );
+                }
+                break;
+            case LC_SYMTAB:
+                /* Save the symtab and strtab */
+                symtabcmd = (struct symtab_command *)lc;
+                break;
+            case LC_ID_DYLINKER:
+            case LC_ID_DYLIB:
+            case LC_UUID:
+            case LC_DYSYMTAB:
+            case LC_TWOLEVEL_HINTS:
+            case LC_PREBIND_CKSUM:
+            case LC_SUB_LIBRARY:
+                break;
+            default: fprintf(stderr, "warning: unkown command 0x%x in '%s'\n", lc->cmd, filename);
+        }
+        lc = (struct load_command*)((int)(lc)+(lc->cmdsize));
+    }
+
+    if(symtabcmd)
+    {
+        if(need_bswap)
+            bswap_symtabcmd(symtabcmd);
+
+        symtab_std = load_data(fd, symtabcmd->symoff+mach_hdr_pos, symtabcmd->nsyms * sizeof(struct nlist));
+        strtab = load_data(fd, symtabcmd->stroff+mach_hdr_pos, symtabcmd->strsize);
+
+        symtab = malloc(sizeof(struct nlist_extended) * symtabcmd->nsyms);
+
+        if(need_bswap)
+        {
+            for(i = 0, syment = symtab_std; i < symtabcmd->nsyms; i++, syment++)
+                bswap_sym(syment);
+        }
+
+        for(i = 0, sym = symtab, syment = symtab_std; i < symtabcmd->nsyms; i++, sym++, syment++)
+        {
+            struct nlist *sym_follow, *sym_next = 0;
+            unsigned int j;
+            memset(sym, 0, sizeof(*sym));
+
+            sym->n_type = syment->n_type;
+            if ( syment->n_type & N_STAB ) /* Debug symbols are skipped */
+                continue;
+
+            memcpy(sym, syment, sizeof(*syment));
+
+            /* Find the following symbol in order to get the current symbol size */
+            for(j = 0, sym_follow = symtab_std; j < symtabcmd->nsyms; j++, sym_follow++) {
+                if ( sym_follow->n_type & N_STAB || !(sym_follow->n_value > sym->st_value))
+                    continue;
+                if(!sym_next) {
+                    sym_next = sym_follow;
+                    continue;
+                }
+                if(!(sym_next->n_value > sym_follow->n_value))
+                    continue;
+                sym_next = sym_follow;
+            }
+            if(sym_next)
+                sym->st_size = sym_next->n_value - sym->st_value;
+            else
+                sym->st_size = 10; /* XXX: text_sec_hdr->size + text_sec_hdr->offset - sym->st_value; */
+
+            sym->st_value += slide;
+        }
+
+        free((void*)symtab_std);
+
+        {
+            DPRINTF("saving symtab of %s (%d symbol(s))\n", filename, symtabcmd->nsyms);
+            struct syminfo *s;
+            s = malloc(sizeof(*s));
+            s->disas_symtab = symtab;
+            s->disas_strtab = strtab;
+            s->disas_num_syms = symtabcmd->nsyms;
+            s->next = syminfos;
+            syminfos = s;
+        }
+    }
+    close(fd);
+    if(mach_hdr.filetype == MH_EXECUTE && dyld_entry_point)
+        return dyld_entry_point;
+    else
+        return entry_point+slide;
+}
+
+extern unsigned long stack_size;
+
+unsigned long setup_arg_pages(void * mh, char ** argv, char ** env)
+{
+    unsigned long stack_base, error, size;
+    int i;
+    int * stack;
+    int argc, envc;
+
+    /* Create enough stack to hold everything.  If we don't use
+     * it for args, we'll use it for something else...
+     */
+    size = stack_size;
+
+    error = target_mmap(0,
+                        size + qemu_host_page_size,
+                        PROT_READ | PROT_WRITE,
+                        MAP_PRIVATE | MAP_ANONYMOUS,
+                        -1, 0);
+    if (error == -1)
+        qerror("stk mmap");
+
+    /* we reserve one extra page at the top of the stack as guard */
+    target_mprotect(error + size, qemu_host_page_size, PROT_NONE);
+
+    stack_base = error + size;
+    stack = (void*)stack_base;
+/*
+ *    | STRING AREA |
+ *    +-------------+
+ *    |      0      |
+*    +-------------+
+ *    |  apple[n]   |
+ *    +-------------+
+ *           :
+ *    +-------------+
+ *    |  apple[0]   |
+ *    +-------------+
+ *    |      0      |
+ *    +-------------+
+ *    |    env[n]   |
+ *    +-------------+
+ *           :
+ *           :
+ *    +-------------+
+ *    |    env[0]   |
+ *    +-------------+
+ *    |      0      |
+ *    +-------------+
+ *    | arg[argc-1] |
+ *    +-------------+
+ *           :
+ *           :
+ *    +-------------+
+ *    |    arg[0]   |
+ *    +-------------+
+ *    |     argc    |
+ *    +-------------+
+ * sp->    |      mh     | address of where the a.out's file offset 0 is in memory
+ *    +-------------+
+*/
+    /* Construct the stack Stack grows down */
+    stack--;
+
+    /* XXX: string should go up there */
+
+    *stack = 0;
+    stack--;
+
+    /* Push the absolute path of our executable */
+    DPRINTF("pushing apple %s (0x%x)\n", (char*)argv[0], (int)argv[0]);
+    stl(stack, (int) argv[0]);
+
+    stack--;
+
+    stl(stack, 0);
+    stack--;
+
+    /* Get envc */
+    for(envc = 0; env[envc]; envc++);
+
+    for(i = envc-1; i >= 0; i--)
+    {
+        DPRINTF("pushing env %s (0x%x)\n", (char*)env[i], (int)env[i]);
+        stl(stack, (int)env[i]);
+        stack--;
+
+        /* XXX: remove that when string will be on top of the stack */
+        page_set_flags((int)env[i], (int)(env[i]+strlen(env[i])), PROT_READ | PAGE_VALID);
+    }
+
+    /* Add on the stack the interp_prefix choosen if so */
+    if(interp_prefix[0])
+    {
+        char *dyld_root;
+        asprintf(&dyld_root, "DYLD_ROOT_PATH=%s", interp_prefix);
+        page_set_flags((int)dyld_root, (int)(dyld_root+strlen(interp_prefix)+1), PROT_READ | PAGE_VALID);
+
+        stl(stack, (int)dyld_root);
+        stack--;
+    }
+
+#ifdef DONT_USE_DYLD_SHARED_MAP
+    {
+        char *shared_map_mode;
+        asprintf(&shared_map_mode, "DYLD_SHARED_REGION=avoid");
+        page_set_flags((int)shared_map_mode, (int)(shared_map_mode+strlen(shared_map_mode)+1), PROT_READ | PAGE_VALID);
+
+        stl(stack, (int)shared_map_mode);
+        stack--;
+    }
+#endif
+
+#ifdef ACTIVATE_DYLD_TRACE
+    char * extra_env_static[] = {"DYLD_DEBUG_TRACE=yes",
+    "DYLD_PREBIND_DEBUG=3", "DYLD_UNKNOW_TRACE=yes",
+    "DYLD_PRINT_INITIALIZERS=yes",
+    "DYLD_PRINT_SEGMENTS=yes", "DYLD_PRINT_REBASINGS=yes", "DYLD_PRINT_BINDINGS=yes", "DYLD_PRINT_INITIALIZERS=yes", "DYLD_PRINT_WARNINGS=yes" };
+
+    char ** extra_env = malloc(sizeof(extra_env_static));
+    bcopy(extra_env_static, extra_env, sizeof(extra_env_static));
+    page_set_flags((int)extra_env, (int)((void*)extra_env+sizeof(extra_env_static)), PROT_READ | PAGE_VALID);
+
+    for(i = 0; i<9; i++)
+    {
+        DPRINTF("pushing (extra) env %s (0x%x)\n", (char*)extra_env[i], (int)extra_env[i]);
+        stl(stack, (int) extra_env[i]);
+        stack--;
+    }
+#endif
+
+    stl(stack, 0);
+    stack--;
+
+    /* Get argc */
+    for(argc = 0; argv[argc]; argc++);
+
+    for(i = argc-1; i >= 0; i--)
+    {
+        DPRINTF("pushing arg %s (0x%x)\n", (char*)argv[i], (int)argv[i]);
+        stl(stack, (int) argv[i]);
+        stack--;
+
+        /* XXX: remove that when string will be on top of the stack */
+        page_set_flags((int)argv[i], (int)(argv[i]+strlen(argv[i])), PROT_READ | PAGE_VALID);
+    }
+
+    DPRINTF("pushing argc %d \n", argc);
+    stl(stack, argc);
+    stack--;
+
+    DPRINTF("pushing mh 0x%x \n", (int)mh);
+    stl(stack, (int) mh);
+
+    /* Stack points on the mh */
+    return (unsigned long)stack;
+}
+
+int mach_exec(const char * filename, char ** argv, char ** envp,
+             struct target_pt_regs * regs)
+{
+    int entrypoint, stack;
+    void * mh; /* the Mach Header that will be  used by dyld */
+
+    DPRINTF("mach_exec at 0x%x\n", (int)mach_exec);
+
+    entrypoint = load_object(filename, regs, &mh);
+    stack = setup_arg_pages(mh, argv, envp);
+#if defined(TARGET_I386)
+    regs->eip = entrypoint;
+    regs->esp = stack;
+#elif defined(TARGET_PPC)
+    regs->nip = entrypoint;
+    regs->gpr[1] = stack;
+#endif
+    DPRINTF("mach_exec returns eip set to 0x%x esp 0x%x mh 0x%x\n", entrypoint, stack, (int)mh);
+
+    if(!entrypoint)
+        qerror("%s: no entry point!\n", filename);
+
+    return 0;
+}