[project @ 2004-11-19 18:00:29 by simonpj]
[ghc-hetmet.git] / ghc / rts / Linker.c
index 964f6fb..d8f1e43 100644 (file)
@@ -22,8 +22,8 @@
 #include "Linker.h"
 #include "LinkerInternals.h"
 #include "RtsUtils.h"
-#include "StoragePriv.h"
 #include "Schedule.h"
+#include "Storage.h"
 
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
@@ -96,6 +96,9 @@ ObjectCode *objects = NULL;   /* initially empty */
 static int ocVerifyImage_ELF    ( ObjectCode* oc );
 static int ocGetNames_ELF       ( ObjectCode* oc );
 static int ocResolve_ELF        ( ObjectCode* oc );
+#if defined(powerpc_TARGET_ARCH)
+static int ocAllocateJumpIslands_ELF ( ObjectCode* oc );
+#endif
 #elif defined(OBJFORMAT_PEi386)
 static int ocVerifyImage_PEi386 ( ObjectCode* oc );
 static int ocGetNames_PEi386    ( ObjectCode* oc );
@@ -293,6 +296,7 @@ typedef struct _RtsSymbolVal {
       SymX(log)                                 \
       SymX(sqrt)                                \
       SymX(memcpy)                              \
+      SymX(stg_InstallConsoleEvent)             \
       Sym(mktime)                               \
       Sym(_imp___timezone)                      \
       Sym(_imp___tzname)                        \
@@ -312,12 +316,34 @@ typedef struct _RtsSymbolVal {
 # define MAIN_CAP_SYM
 #endif
 
+#ifdef TABLES_NEXT_TO_CODE
+#define RTS_RET_SYMBOLS /* nothing */
+#else
+#define RTS_RET_SYMBOLS                        \
+      SymX(stg_enter_ret)                      \
+      SymX(stg_gc_fun_ret)                     \
+      SymX(stg_ap_0_ret)                       \
+      SymX(stg_ap_v_ret)                       \
+      SymX(stg_ap_f_ret)                       \
+      SymX(stg_ap_d_ret)                       \
+      SymX(stg_ap_l_ret)                       \
+      SymX(stg_ap_n_ret)                       \
+      SymX(stg_ap_p_ret)                       \
+      SymX(stg_ap_pv_ret)                      \
+      SymX(stg_ap_pp_ret)                      \
+      SymX(stg_ap_ppv_ret)                     \
+      SymX(stg_ap_ppp_ret)                     \
+      SymX(stg_ap_pppv_ret)                    \
+      SymX(stg_ap_pppp_ret)                    \
+      SymX(stg_ap_ppppp_ret)                   \
+      SymX(stg_ap_pppppp_ret)
+#endif
+
 #define RTS_SYMBOLS                            \
       Maybe_ForeignObj                         \
       Maybe_Stable_Names                       \
       Sym(StgReturn)                           \
       SymX(stg_enter_info)                     \
-      SymX(stg_enter_ret)                      \
       SymX(stg_gc_void_info)                   \
       SymX(__stg_gc_enter_1)                   \
       SymX(stg_gc_noregs)                      \
@@ -333,7 +359,6 @@ typedef struct _RtsSymbolVal {
       SymX(stg_gc_l1)                          \
       SymX(__stg_gc_fun)                       \
       SymX(stg_gc_fun_info)                    \
-      SymX(stg_gc_fun_ret)                     \
       SymX(stg_gc_gen)                         \
       SymX(stg_gc_gen_info)                    \
       SymX(stg_gc_gen_hp)                      \
@@ -354,6 +379,7 @@ typedef struct _RtsSymbolVal {
       SymX(StackOverflowHook)                  \
       SymX(__encodeDouble)                     \
       SymX(__encodeFloat)                      \
+      SymX(addDLL)                             \
       SymX(__gmpn_gcd_1)                       \
       SymX(__gmpz_cmp)                         \
       SymX(__gmpz_cmp_si)                      \
@@ -363,13 +389,17 @@ typedef struct _RtsSymbolVal {
       SymX(__int_encodeDouble)                 \
       SymX(__int_encodeFloat)                  \
       SymX(andIntegerzh_fast)                  \
+      SymX(atomicallyzh_fast)                  \
       SymX(barf)                               \
       SymX(blockAsyncExceptionszh_fast)                \
       SymX(catchzh_fast)                       \
+      SymX(catchRetryzh_fast)                  \
+      SymX(catchSTMzh_fast)                    \
+      SymX(closure_flags)                       \
       SymX(cmp_thread)                         \
-      SymX(complementIntegerzh_fast)           \
       SymX(cmpIntegerzh_fast)                  \
       SymX(cmpIntegerIntzh_fast)               \
+      SymX(complementIntegerzh_fast)           \
       SymX(createAdjustor)                     \
       SymX(decodeDoublezh_fast)                        \
       SymX(decodeFloatzh_fast)                 \
@@ -388,8 +418,10 @@ typedef struct _RtsSymbolVal {
       SymX(gcdIntegerIntzh_fast)               \
       SymX(gcdIntzh_fast)                      \
       SymX(genSymZh)                           \
+      SymX(genericRaise)                       \
       SymX(getProgArgv)                                \
       SymX(getStablePtr)                       \
+      SymX(initLinker)                         \
       SymX(int2Integerzh_fast)                 \
       SymX(integer2Intzh_fast)                 \
       SymX(integer2Wordzh_fast)                        \
@@ -404,6 +436,8 @@ typedef struct _RtsSymbolVal {
       SymX(isFloatNaN)                         \
       SymX(isFloatNegativeZero)                        \
       SymX(killThreadzh_fast)                  \
+      SymX(loadObj)                            \
+      SymX(lookupSymbol)                       \
       SymX(makeStablePtrzh_fast)               \
       SymX(minusIntegerzh_fast)                        \
       SymX(mkApUpd0zh_fast)                    \
@@ -415,6 +449,7 @@ typedef struct _RtsSymbolVal {
       SymX_redirect(newCAF, newDynCAF)         \
       SymX(newMVarzh_fast)                     \
       SymX(newMutVarzh_fast)                   \
+      SymX(newTVarzh_fast)                     \
       SymX(atomicModifyMutVarzh_fast)          \
       SymX(newPinnedByteArrayzh_fast)          \
       SymX(orIntegerzh_fast)                   \
@@ -428,9 +463,12 @@ typedef struct _RtsSymbolVal {
       SymX(quotRemIntegerzh_fast)              \
       SymX(raisezh_fast)                       \
       SymX(raiseIOzh_fast)                     \
+      SymX(readTVarzh_fast)                    \
       SymX(remIntegerzh_fast)                  \
       SymX(resetNonBlockingFd)                 \
       SymX(resumeThread)                       \
+      SymX(resolveObjs)                         \
+      SymX(retryzh_fast)                        \
       SymX(rts_apply)                          \
       SymX(rts_checkSchedStatus)               \
       SymX(rts_eval)                           \
@@ -489,6 +527,7 @@ typedef struct _RtsSymbolVal {
       SymX(stg_INTLIKE_closure)                        \
       SymX(stg_MUT_ARR_PTRS_FROZEN_info)       \
       SymX(stg_WEAK_info)                       \
+      SymX(stg_ap_0_info)                      \
       SymX(stg_ap_v_info)                      \
       SymX(stg_ap_f_info)                      \
       SymX(stg_ap_d_info)                      \
@@ -499,25 +538,10 @@ typedef struct _RtsSymbolVal {
       SymX(stg_ap_pp_info)                     \
       SymX(stg_ap_ppv_info)                    \
       SymX(stg_ap_ppp_info)                    \
+      SymX(stg_ap_pppv_info)                   \
       SymX(stg_ap_pppp_info)                   \
       SymX(stg_ap_ppppp_info)                  \
       SymX(stg_ap_pppppp_info)                 \
-      SymX(stg_ap_ppppppp_info)                        \
-      SymX(stg_ap_0_ret)                       \
-      SymX(stg_ap_v_ret)                       \
-      SymX(stg_ap_f_ret)                       \
-      SymX(stg_ap_d_ret)                       \
-      SymX(stg_ap_l_ret)                       \
-      SymX(stg_ap_n_ret)                       \
-      SymX(stg_ap_p_ret)                       \
-      SymX(stg_ap_pv_ret)                      \
-      SymX(stg_ap_pp_ret)                      \
-      SymX(stg_ap_ppv_ret)                     \
-      SymX(stg_ap_ppp_ret)                     \
-      SymX(stg_ap_pppp_ret)                    \
-      SymX(stg_ap_ppppp_ret)                   \
-      SymX(stg_ap_pppppp_ret)                  \
-      SymX(stg_ap_ppppppp_ret)                 \
       SymX(stg_ap_1_upd_info)                  \
       SymX(stg_ap_2_upd_info)                  \
       SymX(stg_ap_3_upd_info)                  \
@@ -525,7 +549,6 @@ typedef struct _RtsSymbolVal {
       SymX(stg_ap_5_upd_info)                  \
       SymX(stg_ap_6_upd_info)                  \
       SymX(stg_ap_7_upd_info)                  \
-      SymX(stg_ap_8_upd_info)                  \
       SymX(stg_exit)                           \
       SymX(stg_sel_0_upd_info)                 \
       SymX(stg_sel_10_upd_info)                        \
@@ -550,10 +573,12 @@ typedef struct _RtsSymbolVal {
       SymX(tryPutMVarzh_fast)                  \
       SymX(tryTakeMVarzh_fast)                 \
       SymX(unblockAsyncExceptionszh_fast)      \
+      SymX(unloadObj)                           \
       SymX(unsafeThawArrayzh_fast)             \
       SymX(waitReadzh_fast)                    \
       SymX(waitWritezh_fast)                   \
       SymX(word2Integerzh_fast)                        \
+      SymX(writeTVarzh_fast)                   \
       SymX(xorIntegerzh_fast)                  \
       SymX(yieldzh_fast)
 
@@ -602,6 +627,7 @@ typedef struct _RtsSymbolVal {
 #define SymX(vvv) /**/
 #define SymX_redirect(vvv,xxx) /**/
 RTS_SYMBOLS
+RTS_RET_SYMBOLS
 RTS_LONG_LONG_SYMS
 RTS_POSIX_ONLY_SYMBOLS
 RTS_MINGW_ONLY_SYMBOLS
@@ -629,6 +655,7 @@ RTS_LIBGCC_SYMBOLS
 
 static RtsSymbolVal rtsSyms[] = {
       RTS_SYMBOLS
+      RTS_RET_SYMBOLS
       RTS_LONG_LONG_SYMS
       RTS_POSIX_ONLY_SYMBOLS
       RTS_MINGW_ONLY_SYMBOLS
@@ -651,7 +678,7 @@ static void ghciInsertStrHashTable ( char* obj_name,
       insertStrHashTable(table, (StgWord)key, data);
       return;
    }
-   fprintf(stderr,
+   debugBelch(
       "\n\n"
       "GHCi runtime linker: fatal error: I found a duplicate definition for symbol\n"
       "   %s\n"
@@ -788,7 +815,7 @@ addDLL( char *dll_name )
 
    initLinker();
 
-   /* fprintf(stderr, "\naddDLL; dll_name = `%s'\n", dll_name); */
+   /* debugBelch("\naddDLL; dll_name = `%s'\n", dll_name); */
 
    /* See if we've already got it, and ignore if so. */
    for (o_dll = opened_dlls; o_dll != NULL; o_dll = o_dll->next) {
@@ -865,7 +892,7 @@ lookupSymbol( char *lbl )
         OpenedDLL* o_dll;
         void* sym;
         for (o_dll = opened_dlls; o_dll != NULL; o_dll = o_dll->next) {
-         /* fprintf(stderr, "look in %s for %s\n", o_dll->name, lbl); */
+         /* debugBelch("look in %s for %s\n", o_dll->name, lbl); */
            if (lbl[0] == '_') {
               /* HACK: if the name has an initial underscore, try stripping
                  it off & look that up first. I've yet to verify whether there's
@@ -874,13 +901,13 @@ lookupSymbol( char *lbl )
               */
               sym = GetProcAddress(o_dll->instance, (lbl+1));
               if (sym != NULL) {
-               /*fprintf(stderr, "found %s in %s\n", lbl+1,o_dll->name); fflush(stderr);*/
+               /*debugBelch("found %s in %s\n", lbl+1,o_dll->name);*/
                return sym;
              }
            }
            sym = GetProcAddress(o_dll->instance, lbl);
            if (sym != NULL) {
-            /*fprintf(stderr, "found %s in %s\n", lbl,o_dll->name); fflush(stderr);*/
+            /*debugBelch("found %s in %s\n", lbl,o_dll->name);*/
             return sym;
           }
         }
@@ -932,7 +959,7 @@ void ghci_enquire ( char* addr )
       for (i = 0; i < oc->n_symbols; i++) {
          sym = oc->symbols[i];
          if (sym == NULL) continue;
-         // fprintf(stderr, "enquire %p %p\n", sym, oc->lochash);
+         // debugBelch("enquire %p %p\n", sym, oc->lochash);
          a = NULL;
          if (oc->lochash != NULL) {
             a = lookupStrHashTable(oc->lochash, sym);
@@ -941,10 +968,10 @@ void ghci_enquire ( char* addr )
             a = lookupStrHashTable(symhash, sym);
         }
          if (a == NULL) {
-            // fprintf(stderr, "ghci_enquire: can't find %s\n", sym);
+            // debugBelch("ghci_enquire: can't find %s\n", sym);
          }
          else if (addr-DELTA <= a && a <= addr+DELTA) {
-            fprintf(stderr, "%p + %3d  ==  `%s'\n", addr, a - addr, sym);
+            debugBelch("%p + %3d  ==  `%s'\n", addr, a - addr, sym);
          }
       }
    }
@@ -975,26 +1002,27 @@ loadObj( char *path )
 
    initLinker();
 
-   /* fprintf(stderr, "loadObj %s\n", path ); */
+   /* debugBelch("loadObj %s\n", path ); */
 
-   /* Check that we haven't already loaded this object.  Don't give up
-      at this stage; ocGetNames_* will barf later. */
+   /* Check that we haven't already loaded this object. 
+      Ignore requests to load multiple times */
    {
        ObjectCode *o;
        int is_dup = 0;
        for (o = objects; o; o = o->next) {
-          if (0 == strcmp(o->fileName, path))
+          if (0 == strcmp(o->fileName, path)) {
              is_dup = 1;
+             break; /* don't need to search further */
+          }
        }
        if (is_dup) {
-        fprintf(stderr,
-            "\n\n"
+          IF_DEBUG(linker, debugBelch(
             "GHCi runtime linker: warning: looks like you're trying to load the\n"
             "same object file twice:\n"
             "   %s\n"
-            "GHCi will continue, but a duplicate-symbol error may shortly follow.\n"
-            "\n"
-            , path);
+            "GHCi will ignore this, but be warned.\n"
+            , path));
+          return 1; /* success */
        }
    }
 
@@ -1081,6 +1109,9 @@ loadObj( char *path )
 #  if defined(OBJFORMAT_MACHO)
    r = ocAllocateJumpIslands_MachO ( oc );
    if (!r) { return r; }
+#  elif defined(OBJFORMAT_ELF) && defined(powerpc_TARGET_ARCH)
+   r = ocAllocateJumpIslands_ELF ( oc );
+   if (!r) { return r; }
 #endif
 
    /* verify the in-memory image */
@@ -1193,7 +1224,7 @@ unloadObj( char *path )
        }
     }
 
-    belch("unloadObj: can't find `%s' to unload", path);
+    errorBelch("unloadObj: can't find `%s' to unload", path);
     return 0;
 }
 
@@ -1206,7 +1237,7 @@ static void addProddableBlock ( ObjectCode* oc, void* start, int size )
 {
    ProddableBlock* pb
       = stgMallocBytes(sizeof(ProddableBlock), "addProddableBlock");
-   /* fprintf(stderr, "aPB %p %p %d\n", oc, start, size); */
+   /* debugBelch("aPB %p %p %d\n", oc, start, size); */
    ASSERT(size > 0);
    pb->start      = start;
    pb->size       = size;
@@ -1242,12 +1273,118 @@ static void addSection ( ObjectCode* oc, SectionKind kind,
    s->next      = oc->sections;
    oc->sections = s;
    /*
-   fprintf(stderr, "addSection: %p-%p (size %d), kind %d\n",
+   debugBelch("addSection: %p-%p (size %d), kind %d\n",
                    start, ((char*)end)-1, end - start + 1, kind );
    */
 }
 
 
+/* --------------------------------------------------------------------------
+ * PowerPC specifics (jump islands)
+ * ------------------------------------------------------------------------*/
+
+#if defined(powerpc_TARGET_ARCH)
+
+/*
+  ocAllocateJumpIslands
+  
+  Allocate additional space at the end of the object file image to make room
+  for jump islands.
+  
+  PowerPC relative branch instructions have a 24 bit displacement field.
+  As PPC code is always 4-byte-aligned, this yields a +-32MB range.
+  If a particular imported symbol is outside this range, we have to redirect
+  the jump to a short piece of new code that just loads the 32bit absolute
+  address and jumps there.
+  This function just allocates space for one 16 byte ppcJumpIsland for every
+  undefined symbol in the object file. The code for the islands is filled in by
+  makeJumpIsland below.
+*/
+
+static int ocAllocateJumpIslands( ObjectCode* oc, int count, int first )
+{
+  int aligned;
+
+  if( count > 0 )
+  {
+#ifdef USE_MMAP
+    #error ocAllocateJumpIslands doesnt want USE_MMAP to be defined
+#endif
+    // round up to the nearest 4
+    aligned = (oc->fileSize + 3) & ~3;
+
+    oc->image = stgReallocBytes( oc->image,
+                                 aligned + sizeof( ppcJumpIsland ) * count,
+                                 "ocAllocateJumpIslands" );
+    oc->jump_islands = (ppcJumpIsland *) (((char *) oc->image) + aligned);
+    memset( oc->jump_islands, 0, sizeof( ppcJumpIsland ) * count );
+  }
+  else
+    oc->jump_islands = NULL;
+
+  oc->island_start_symbol = first;
+  oc->n_islands = count;
+
+  return 1;
+}
+
+static unsigned long makeJumpIsland( ObjectCode* oc,
+                                     unsigned long symbolNumber,
+                                     unsigned long target )
+{
+  ppcJumpIsland *island;
+
+  if( symbolNumber < oc->island_start_symbol ||
+      symbolNumber - oc->island_start_symbol > oc->n_islands)
+    return 0;
+
+  island = &oc->jump_islands[symbolNumber - oc->island_start_symbol];
+
+  // lis r12, hi16(target)
+  island->lis_r12     = 0x3d80;
+  island->hi_addr     = target >> 16;
+
+  // ori r12, r12, lo16(target)
+  island->ori_r12_r12 = 0x618c;
+  island->lo_addr     = target & 0xffff;
+
+  // mtctr r12
+  island->mtctr_r12   = 0x7d8903a6;
+
+  // bctr
+  island->bctr        = 0x4e800420;
+    
+  return (unsigned long) island;
+}
+
+/*
+   ocFlushInstructionCache
+
+   Flush the data & instruction caches.
+   Because the PPC has split data/instruction caches, we have to
+   do that whenever we modify code at runtime.
+ */
+
+static void ocFlushInstructionCache( ObjectCode *oc )
+{
+    int n = (oc->fileSize + sizeof( ppcJumpIsland ) * oc->n_islands + 3) / 4;
+    unsigned long *p = (unsigned long *) oc->image;
+
+    while( n-- )
+    {
+        __asm__ volatile ( "dcbf 0,%0\n\t"
+                           "sync\n\t"
+                           "icbi 0,%0"
+                           :
+                           : "r" (p)
+                         );
+        p++;
+    }
+    __asm__ volatile ( "sync\n\t"
+                       "isync"
+                     );
+}
+#endif
 
 /* --------------------------------------------------------------------------
  * PEi386 specifics (Win32 targets)
@@ -1404,12 +1541,12 @@ printName ( UChar* name, UChar* strtab )
 {
    if (name[0]==0 && name[1]==0 && name[2]==0 && name[3]==0) {
       UInt32 strtab_offset = * (UInt32*)(name+4);
-      fprintf ( stderr, "%s", strtab + strtab_offset );
+      debugBelch("%s", strtab + strtab_offset );
    } else {
       int i;
       for (i = 0; i < 8; i++) {
          if (name[i] == 0) break;
-         fprintf ( stderr, "%c", name[i] );
+         debugBelch("%c", name[i] );
       }
    }
 }
@@ -1516,7 +1653,7 @@ ocVerifyImage_PEi386 ( ObjectCode* oc )
    COFF_section* sectab;
    COFF_symbol*  symtab;
    UChar*        strtab;
-   /* fprintf(stderr, "\nLOADING %s\n", oc->fileName); */
+   /* debugBelch("\nLOADING %s\n", oc->fileName); */
    hdr = (COFF_header*)(oc->image);
    sectab = (COFF_section*) (
                ((UChar*)(oc->image))
@@ -1530,36 +1667,36 @@ ocVerifyImage_PEi386 ( ObjectCode* oc )
             + hdr->NumberOfSymbols * sizeof_COFF_symbol;
 
    if (hdr->Machine != 0x14c) {
-      belch("Not x86 PEi386");
+      errorBelch("Not x86 PEi386");
       return 0;
    }
    if (hdr->SizeOfOptionalHeader != 0) {
-      belch("PEi386 with nonempty optional header");
+      errorBelch("PEi386 with nonempty optional header");
       return 0;
    }
    if ( /* (hdr->Characteristics & MYIMAGE_FILE_RELOCS_STRIPPED) || */
         (hdr->Characteristics & MYIMAGE_FILE_EXECUTABLE_IMAGE) ||
         (hdr->Characteristics & MYIMAGE_FILE_DLL) ||
         (hdr->Characteristics & MYIMAGE_FILE_SYSTEM) ) {
-      belch("Not a PEi386 object file");
+      errorBelch("Not a PEi386 object file");
       return 0;
    }
    if ( (hdr->Characteristics & MYIMAGE_FILE_BYTES_REVERSED_HI)
         /* || !(hdr->Characteristics & MYIMAGE_FILE_32BIT_MACHINE) */ ) {
-      belch("Invalid PEi386 word size or endiannness: %d",
+      errorBelch("Invalid PEi386 word size or endiannness: %d",
             (int)(hdr->Characteristics));
       return 0;
    }
    /* If the string table size is way crazy, this might indicate that
       there are more than 64k relocations, despite claims to the
       contrary.  Hence this test. */
-   /* fprintf(stderr, "strtab size %d\n", * (UInt32*)strtab); */
+   /* debugBelch("strtab size %d\n", * (UInt32*)strtab); */
 #if 0
    if ( (*(UInt32*)strtab) > 600000 ) {
       /* Note that 600k has no special significance other than being
          big enough to handle the almost-2MB-sized lumps that
          constitute HSwin32*.o. */
-      belch("PEi386 object has suspiciously large string table; > 64k relocs?");
+      debugBelch("PEi386 object has suspiciously large string table; > 64k relocs?");
       return 0;
    }
 #endif
@@ -1569,44 +1706,34 @@ ocVerifyImage_PEi386 ( ObjectCode* oc )
    IF_DEBUG(linker, i=1);
    if (i == 0) return 1;
 
-   fprintf ( stderr,
-             "sectab offset = %d\n", ((UChar*)sectab) - ((UChar*)hdr) );
-   fprintf ( stderr,
-             "symtab offset = %d\n", ((UChar*)symtab) - ((UChar*)hdr) );
-   fprintf ( stderr,
-             "strtab offset = %d\n", ((UChar*)strtab) - ((UChar*)hdr) );
-
-   fprintf ( stderr, "\n" );
-   fprintf ( stderr,
-             "Machine:           0x%x\n", (UInt32)(hdr->Machine) );
-   fprintf ( stderr,
-             "# sections:        %d\n",   (UInt32)(hdr->NumberOfSections) );
-   fprintf ( stderr,
-             "time/date:         0x%x\n", (UInt32)(hdr->TimeDateStamp) );
-   fprintf ( stderr,
-             "symtab offset:     %d\n",   (UInt32)(hdr->PointerToSymbolTable) );
-   fprintf ( stderr,
-             "# symbols:         %d\n",   (UInt32)(hdr->NumberOfSymbols) );
-   fprintf ( stderr,
-             "sz of opt hdr:     %d\n",   (UInt32)(hdr->SizeOfOptionalHeader) );
-   fprintf ( stderr,
-             "characteristics:   0x%x\n", (UInt32)(hdr->Characteristics) );
+   debugBelch( "sectab offset = %d\n", ((UChar*)sectab) - ((UChar*)hdr) );
+   debugBelch( "symtab offset = %d\n", ((UChar*)symtab) - ((UChar*)hdr) );
+   debugBelch( "strtab offset = %d\n", ((UChar*)strtab) - ((UChar*)hdr) );
+
+   debugBelch("\n" );
+   debugBelch( "Machine:           0x%x\n", (UInt32)(hdr->Machine) );
+   debugBelch( "# sections:        %d\n",   (UInt32)(hdr->NumberOfSections) );
+   debugBelch( "time/date:         0x%x\n", (UInt32)(hdr->TimeDateStamp) );
+   debugBelch( "symtab offset:     %d\n",   (UInt32)(hdr->PointerToSymbolTable) );
+   debugBelch( "# symbols:         %d\n",   (UInt32)(hdr->NumberOfSymbols) );
+   debugBelch( "sz of opt hdr:     %d\n",   (UInt32)(hdr->SizeOfOptionalHeader) );
+   debugBelch( "characteristics:   0x%x\n", (UInt32)(hdr->Characteristics) );
 
    /* Print the section table. */
-   fprintf ( stderr, "\n" );
+   debugBelch("\n" );
    for (i = 0; i < hdr->NumberOfSections; i++) {
       COFF_reloc* reltab;
       COFF_section* sectab_i
          = (COFF_section*)
            myindex ( sizeof_COFF_section, sectab, i );
-      fprintf ( stderr,
+      debugBelch(
                 "\n"
                 "section %d\n"
                 "     name `",
                 i
               );
       printName ( sectab_i->Name, strtab );
-      fprintf ( stderr,
+      debugBelch(
                 "'\n"
                 "    vsize %d\n"
                 "    vaddr %d\n"
@@ -1646,7 +1773,7 @@ ocVerifyImage_PEi386 ( ObjectCode* oc )
          COFF_symbol* sym;
          COFF_reloc* rel = (COFF_reloc*)
                            myindex ( sizeof_COFF_reloc, reltab, j );
-         fprintf ( stderr,
+         debugBelch(
                    "        type 0x%-4x   vaddr 0x%-8x   name `",
                    (UInt32)rel->Type,
                    rel->VirtualAddress );
@@ -1654,35 +1781,35 @@ ocVerifyImage_PEi386 ( ObjectCode* oc )
                myindex ( sizeof_COFF_symbol, symtab, rel->SymbolTableIndex );
         /* Hmm..mysterious looking offset - what's it for? SOF */
          printName ( sym->Name, strtab -10 );
-         fprintf ( stderr, "'\n" );
+         debugBelch("'\n" );
       }
 
-      fprintf ( stderr, "\n" );
+      debugBelch("\n" );
    }
-   fprintf ( stderr, "\n" );
-   fprintf ( stderr, "string table has size 0x%x\n", * (UInt32*)strtab );
-   fprintf ( stderr, "---START of string table---\n");
+   debugBelch("\n" );
+   debugBelch("string table has size 0x%x\n", * (UInt32*)strtab );
+   debugBelch("---START of string table---\n");
    for (i = 4; i < *(Int32*)strtab; i++) {
       if (strtab[i] == 0)
-         fprintf ( stderr, "\n"); else
-         fprintf( stderr, "%c", strtab[i] );
+         debugBelch("\n"); else
+         debugBelch("%c", strtab[i] );
    }
-   fprintf ( stderr, "--- END  of string table---\n");
+   debugBelch("--- END  of string table---\n");
 
-   fprintf ( stderr, "\n" );
+   debugBelch("\n" );
    i = 0;
    while (1) {
       COFF_symbol* symtab_i;
       if (i >= (Int32)(hdr->NumberOfSymbols)) break;
       symtab_i = (COFF_symbol*)
                  myindex ( sizeof_COFF_symbol, symtab, i );
-      fprintf ( stderr,
+      debugBelch(
                 "symbol %d\n"
                 "     name `",
                 i
               );
       printName ( symtab_i->Name, strtab );
-      fprintf ( stderr,
+      debugBelch(
                 "'\n"
                 "    value 0x%x\n"
                 "   1+sec# %d\n"
@@ -1699,7 +1826,7 @@ ocVerifyImage_PEi386 ( ObjectCode* oc )
       i++;
    }
 
-   fprintf ( stderr, "\n" );
+   debugBelch("\n" );
    return 1;
 }
 
@@ -1745,7 +1872,7 @@ ocGetNames_PEi386 ( ObjectCode* oc )
                               "ocGetNames_PEi386(anonymous bss)");
       sectab_i->PointerToRawData = ((UChar*)zspace) - ((UChar*)(oc->image));
       addProddableBlock(oc, zspace, sectab_i->VirtualSize);
-      /* fprintf(stderr, "BSS anon section at 0x%x\n", zspace); */
+      /* debugBelch("BSS anon section at 0x%x\n", zspace); */
    }
 
    /* Copy section information into the ObjectCode. */
@@ -1760,7 +1887,7 @@ ocGetNames_PEi386 ( ObjectCode* oc )
       COFF_section* sectab_i
          = (COFF_section*)
            myindex ( sizeof_COFF_section, sectab, i );
-      IF_DEBUG(linker, belch("section name = %s\n", sectab_i->Name ));
+      IF_DEBUG(linker, debugBelch("section name = %s\n", sectab_i->Name ));
 
 #     if 0
       /* I'm sure this is the Right Way to do it.  However, the
@@ -1792,7 +1919,7 @@ ocGetNames_PEi386 ( ObjectCode* oc )
           && 0 != strcmp(".stab", sectab_i->Name)
           && 0 != strcmp(".stabstr", sectab_i->Name)
          ) {
-         belch("Unknown PEi386 section name `%s'", sectab_i->Name);
+         errorBelch("Unknown PEi386 section name `%s'", sectab_i->Name);
          return 0;
       }
 
@@ -1846,26 +1973,26 @@ ocGetNames_PEi386 ( ObjectCode* oc )
          addSection(oc, SECTIONKIND_RWDATA, addr,
                         ((UChar*)addr) + symtab_i->Value - 1);
          addProddableBlock(oc, addr, symtab_i->Value);
-         /* fprintf(stderr, "BSS      section at 0x%x\n", addr); */
+         /* debugBelch("BSS      section at 0x%x\n", addr); */
       }
 
       if (addr != NULL ) {
          sname = cstring_from_COFF_symbol_name ( symtab_i->Name, strtab );
-         /* fprintf(stderr,"addSymbol %p `%s \n", addr,sname);  */
-         IF_DEBUG(linker, belch("addSymbol %p `%s'\n", addr,sname);)
+         /* debugBelch("addSymbol %p `%s \n", addr,sname);  */
+         IF_DEBUG(linker, debugBelch("addSymbol %p `%s'\n", addr,sname);)
          ASSERT(i >= 0 && i < oc->n_symbols);
          /* cstring_from_COFF_symbol_name always succeeds. */
          oc->symbols[i] = sname;
          ghciInsertStrHashTable(oc->fileName, symhash, sname, addr);
       } else {
 #        if 0
-         fprintf ( stderr,
+         debugBelch(
                    "IGNORING symbol %d\n"
                    "     name `",
                    i
                  );
          printName ( symtab_i->Name, strtab );
-         fprintf ( stderr,
+         debugBelch(
                    "'\n"
                    "    value 0x%x\n"
                    "   1+sec# %d\n"
@@ -1907,7 +2034,7 @@ ocResolve_PEi386 ( ObjectCode* oc )
    /* ToDo: should be variable-sized?  But is at least safe in the
       sense of buffer-overrun-proof. */
    char symbol[1000];
-   /* fprintf(stderr, "resolving for %s\n", oc->fileName); */
+   /* debugBelch("resolving for %s\n", oc->fileName); */
 
    hdr = (COFF_header*)(oc->image);
    sectab = (COFF_section*) (
@@ -1951,7 +2078,8 @@ ocResolve_PEi386 ( ObjectCode* oc )
         COFF_reloc* rel = (COFF_reloc*)
                            myindex ( sizeof_COFF_reloc, reltab, 0 );
        noRelocs = rel->VirtualAddress;
-       fprintf(stderr, "WARNING: Overflown relocation field (# relocs found: %u)\n", noRelocs); fflush(stderr);
+       debugBelch("WARNING: Overflown relocation field (# relocs found: %u)\n",
+                  noRelocs);
        j = 1;
       } else {
        noRelocs = sectab_i->NumberOfRelocations;
@@ -1979,20 +2107,20 @@ ocResolve_PEi386 ( ObjectCode* oc )
                myindex ( sizeof_COFF_symbol,
                          symtab, reltab_j->SymbolTableIndex );
          IF_DEBUG(linker,
-                  fprintf ( stderr,
+                  debugBelch(
                             "reloc sec %2d num %3d:  type 0x%-4x   "
                             "vaddr 0x%-8x   name `",
                             i, j,
                             (UInt32)reltab_j->Type,
                             reltab_j->VirtualAddress );
                             printName ( sym->Name, strtab );
-                            fprintf ( stderr, "'\n" ));
+                            debugBelch("'\n" ));
 
          if (sym->StorageClass == MYIMAGE_SYM_CLASS_STATIC) {
             COFF_section* section_sym
                = findPEi386SectionCalled ( oc, sym->Name );
             if (!section_sym) {
-               belch("%s: can't find section `%s'", oc->fileName, sym->Name);
+               errorBelch("%s: can't find section `%s'", oc->fileName, sym->Name);
                return 0;
             }
             S = ((UInt32)(oc->image))
@@ -2010,7 +2138,7 @@ ocResolve_PEi386 ( ObjectCode* oc )
             (void*)S = lookupSymbol( symbol );
             if ((void*)S != NULL) goto foundit;
            /* Newline first because the interactive linker has printed "linking..." */
-            belch("\n%s: unknown symbol `%s'", oc->fileName, symbol);
+            errorBelch("\n%s: unknown symbol `%s'", oc->fileName, symbol);
             return 0;
            foundit:
          }
@@ -2035,7 +2163,7 @@ ocResolve_PEi386 ( ObjectCode* oc )
                *pP = S - ((UInt32)pP) - 4;
                break;
             default:
-               belch("%s: unhandled PEi386 relocation type %d",
+               debugBelch("%s: unhandled PEi386 relocation type %d",
                     oc->fileName, reltab_j->Type);
                return 0;
          }
@@ -2043,7 +2171,7 @@ ocResolve_PEi386 ( ObjectCode* oc )
       }
    }
 
-   IF_DEBUG(linker, belch("completed %s", oc->fileName));
+   IF_DEBUG(linker, debugBelch("completed %s", oc->fileName));
    return 1;
 }
 
@@ -2312,44 +2440,45 @@ ocVerifyImage_ELF ( ObjectCode* oc )
        ehdr->e_ident[EI_MAG1] != ELFMAG1 ||
        ehdr->e_ident[EI_MAG2] != ELFMAG2 ||
        ehdr->e_ident[EI_MAG3] != ELFMAG3) {
-      belch("%s: not an ELF object", oc->fileName);
+      errorBelch("%s: not an ELF object", oc->fileName);
       return 0;
    }
 
    if (ehdr->e_ident[EI_CLASS] != ELFCLASS) {
-      belch("%s: unsupported ELF format", oc->fileName);
+      errorBelch("%s: unsupported ELF format", oc->fileName);
       return 0;
    }
 
    if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB) {
-       IF_DEBUG(linker,belch( "Is little-endian" ));
+       IF_DEBUG(linker,debugBelch( "Is little-endian" ));
    } else
    if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB) {
-       IF_DEBUG(linker,belch( "Is big-endian" ));
+       IF_DEBUG(linker,debugBelch( "Is big-endian" ));
    } else {
-       belch("%s: unknown endiannness", oc->fileName);
+       errorBelch("%s: unknown endiannness", oc->fileName);
        return 0;
    }
 
    if (ehdr->e_type != ET_REL) {
-      belch("%s: not a relocatable object (.o) file", oc->fileName);
+      errorBelch("%s: not a relocatable object (.o) file", oc->fileName);
       return 0;
    }
-   IF_DEBUG(linker, belch( "Is a relocatable object (.o) file" ));
+   IF_DEBUG(linker, debugBelch( "Is a relocatable object (.o) file" ));
 
-   IF_DEBUG(linker,belch( "Architecture is " ));
+   IF_DEBUG(linker,debugBelch( "Architecture is " ));
    switch (ehdr->e_machine) {
-      case EM_386:   IF_DEBUG(linker,belch( "x86" )); break;
-      case EM_SPARC: IF_DEBUG(linker,belch( "sparc" )); break;
+      case EM_386:   IF_DEBUG(linker,debugBelch( "x86" )); break;
+      case EM_SPARC: IF_DEBUG(linker,debugBelch( "sparc" )); break;
 #ifdef EM_IA_64
-      case EM_IA_64: IF_DEBUG(linker,belch( "ia64" )); break;
+      case EM_IA_64: IF_DEBUG(linker,debugBelch( "ia64" )); break;
 #endif
-      default:       IF_DEBUG(linker,belch( "unknown" ));
-                     belch("%s: unknown architecture", oc->fileName);
+      case EM_PPC:   IF_DEBUG(linker,debugBelch( "powerpc32" )); break;
+      default:       IF_DEBUG(linker,debugBelch( "unknown" ));
+                     errorBelch("%s: unknown architecture", oc->fileName);
                      return 0;
    }
 
-   IF_DEBUG(linker,belch(
+   IF_DEBUG(linker,debugBelch(
              "\nSection header table: start %d, n_entries %d, ent_size %d",
              ehdr->e_shoff, ehdr->e_shnum, ehdr->e_shentsize  ));
 
@@ -2358,36 +2487,36 @@ ocVerifyImage_ELF ( ObjectCode* oc )
    shdr = (Elf_Shdr*) (ehdrC + ehdr->e_shoff);
 
    if (ehdr->e_shstrndx == SHN_UNDEF) {
-      belch("%s: no section header string table", oc->fileName);
+      errorBelch("%s: no section header string table", oc->fileName);
       return 0;
    } else {
-      IF_DEBUG(linker,belch( "Section header string table is section %d",
+      IF_DEBUG(linker,debugBelch( "Section header string table is section %d",
                           ehdr->e_shstrndx));
       sh_strtab = ehdrC + shdr[ehdr->e_shstrndx].sh_offset;
    }
 
    for (i = 0; i < ehdr->e_shnum; i++) {
-      IF_DEBUG(linker,fprintf(stderr, "%2d:  ", i ));
-      IF_DEBUG(linker,fprintf(stderr, "type=%2d  ", (int)shdr[i].sh_type ));
-      IF_DEBUG(linker,fprintf(stderr, "size=%4d  ", (int)shdr[i].sh_size ));
-      IF_DEBUG(linker,fprintf(stderr, "offs=%4d  ", (int)shdr[i].sh_offset ));
-      IF_DEBUG(linker,fprintf(stderr, "  (%p .. %p)  ",
+      IF_DEBUG(linker,debugBelch("%2d:  ", i ));
+      IF_DEBUG(linker,debugBelch("type=%2d  ", (int)shdr[i].sh_type ));
+      IF_DEBUG(linker,debugBelch("size=%4d  ", (int)shdr[i].sh_size ));
+      IF_DEBUG(linker,debugBelch("offs=%4d  ", (int)shdr[i].sh_offset ));
+      IF_DEBUG(linker,debugBelch("  (%p .. %p)  ",
                ehdrC + shdr[i].sh_offset,
                      ehdrC + shdr[i].sh_offset + shdr[i].sh_size - 1));
 
       if (shdr[i].sh_type == SHT_REL) {
-         IF_DEBUG(linker,fprintf(stderr, "Rel  " ));
+         IF_DEBUG(linker,debugBelch("Rel  " ));
       } else if (shdr[i].sh_type == SHT_RELA) {
-         IF_DEBUG(linker,fprintf(stderr, "RelA " ));
+         IF_DEBUG(linker,debugBelch("RelA " ));
       } else {
-         IF_DEBUG(linker,fprintf(stderr,"     "));
+         IF_DEBUG(linker,debugBelch("     "));
       }
       if (sh_strtab) {
-         IF_DEBUG(linker,fprintf(stderr, "sname=%s\n", sh_strtab + shdr[i].sh_name ));
+         IF_DEBUG(linker,debugBelch("sname=%s\n", sh_strtab + shdr[i].sh_name ));
       }
    }
 
-   IF_DEBUG(linker,belch( "\nString tables" ));
+   IF_DEBUG(linker,debugBelch( "\nString tables" ));
    strtab = NULL;
    nstrtab = 0;
    for (i = 0; i < ehdr->e_shnum; i++) {
@@ -2398,65 +2527,65 @@ ocVerifyImage_ELF ( ObjectCode* oc )
              debugging info. */
           && 0 != memcmp(".stabstr", sh_strtab + shdr[i].sh_name, 8)
          ) {
-         IF_DEBUG(linker,belch("   section %d is a normal string table", i ));
+         IF_DEBUG(linker,debugBelch("   section %d is a normal string table", i ));
          strtab = ehdrC + shdr[i].sh_offset;
          nstrtab++;
       }
    }
    if (nstrtab != 1) {
-      belch("%s: no string tables, or too many", oc->fileName);
+      errorBelch("%s: no string tables, or too many", oc->fileName);
       return 0;
    }
 
    nsymtabs = 0;
-   IF_DEBUG(linker,belch( "\nSymbol tables" ));
+   IF_DEBUG(linker,debugBelch( "\nSymbol tables" ));
    for (i = 0; i < ehdr->e_shnum; i++) {
       if (shdr[i].sh_type != SHT_SYMTAB) continue;
-      IF_DEBUG(linker,belch( "section %d is a symbol table", i ));
+      IF_DEBUG(linker,debugBelch( "section %d is a symbol table", i ));
       nsymtabs++;
       stab = (Elf_Sym*) (ehdrC + shdr[i].sh_offset);
       nent = shdr[i].sh_size / sizeof(Elf_Sym);
-      IF_DEBUG(linker,belch( "   number of entries is apparently %d (%d rem)",
+      IF_DEBUG(linker,debugBelch( "   number of entries is apparently %d (%d rem)",
                nent,
                shdr[i].sh_size % sizeof(Elf_Sym)
              ));
       if (0 != shdr[i].sh_size % sizeof(Elf_Sym)) {
-         belch("%s: non-integral number of symbol table entries", oc->fileName);
+         errorBelch("%s: non-integral number of symbol table entries", oc->fileName);
          return 0;
       }
       for (j = 0; j < nent; j++) {
-         IF_DEBUG(linker,fprintf(stderr, "   %2d  ", j ));
-         IF_DEBUG(linker,fprintf(stderr, "  sec=%-5d  size=%-3d  val=%5p  ",
+         IF_DEBUG(linker,debugBelch("   %2d  ", j ));
+         IF_DEBUG(linker,debugBelch("  sec=%-5d  size=%-3d  val=%5p  ",
                              (int)stab[j].st_shndx,
                              (int)stab[j].st_size,
                              (char*)stab[j].st_value ));
 
-         IF_DEBUG(linker,fprintf(stderr, "type=" ));
+         IF_DEBUG(linker,debugBelch("type=" ));
          switch (ELF_ST_TYPE(stab[j].st_info)) {
-            case STT_NOTYPE:  IF_DEBUG(linker,fprintf(stderr, "notype " )); break;
-            case STT_OBJECT:  IF_DEBUG(linker,fprintf(stderr, "object " )); break;
-            case STT_FUNC  :  IF_DEBUG(linker,fprintf(stderr, "func   " )); break;
-            case STT_SECTION: IF_DEBUG(linker,fprintf(stderr, "section" )); break;
-            case STT_FILE:    IF_DEBUG(linker,fprintf(stderr, "file   " )); break;
-            default:          IF_DEBUG(linker,fprintf(stderr, "?      " )); break;
+            case STT_NOTYPE:  IF_DEBUG(linker,debugBelch("notype " )); break;
+            case STT_OBJECT:  IF_DEBUG(linker,debugBelch("object " )); break;
+            case STT_FUNC  :  IF_DEBUG(linker,debugBelch("func   " )); break;
+            case STT_SECTION: IF_DEBUG(linker,debugBelch("section" )); break;
+            case STT_FILE:    IF_DEBUG(linker,debugBelch("file   " )); break;
+            default:          IF_DEBUG(linker,debugBelch("?      " )); break;
          }
-         IF_DEBUG(linker,fprintf(stderr, "  " ));
+         IF_DEBUG(linker,debugBelch("  " ));
 
-         IF_DEBUG(linker,fprintf(stderr, "bind=" ));
+         IF_DEBUG(linker,debugBelch("bind=" ));
          switch (ELF_ST_BIND(stab[j].st_info)) {
-            case STB_LOCAL :  IF_DEBUG(linker,fprintf(stderr, "local " )); break;
-            case STB_GLOBAL:  IF_DEBUG(linker,fprintf(stderr, "global" )); break;
-            case STB_WEAK  :  IF_DEBUG(linker,fprintf(stderr, "weak  " )); break;
-            default:          IF_DEBUG(linker,fprintf(stderr, "?     " )); break;
+            case STB_LOCAL :  IF_DEBUG(linker,debugBelch("local " )); break;
+            case STB_GLOBAL:  IF_DEBUG(linker,debugBelch("global" )); break;
+            case STB_WEAK  :  IF_DEBUG(linker,debugBelch("weak  " )); break;
+            default:          IF_DEBUG(linker,debugBelch("?     " )); break;
          }
-         IF_DEBUG(linker,fprintf(stderr, "  " ));
+         IF_DEBUG(linker,debugBelch("  " ));
 
-         IF_DEBUG(linker,fprintf(stderr, "name=%s\n", strtab + stab[j].st_name ));
+         IF_DEBUG(linker,debugBelch("name=%s\n", strtab + stab[j].st_name ));
       }
    }
 
    if (nsymtabs == 0) {
-      belch("%s: didn't find any symbol tables", oc->fileName);
+      errorBelch("%s: didn't find any symbol tables", oc->fileName);
       return 0;
    }
 
@@ -2478,7 +2607,7 @@ ocGetNames_ELF ( ObjectCode* oc )
    ASSERT(symhash != NULL);
 
    if (!strtab) {
-      belch("%s: no strtab", oc->fileName);
+      errorBelch("%s: no strtab", oc->fileName);
       return 0;
    }
 
@@ -2524,7 +2653,7 @@ ocGetNames_ELF ( ObjectCode* oc )
                                        "ocGetNames_ELF(BSS)");
          shdr[i].sh_offset = ((char*)zspace) - ((char*)ehdrC);
         /*
-         fprintf(stderr, "BSS section at 0x%x, size %d\n",
+         debugBelch("BSS section at 0x%x, size %d\n",
                          zspace, shdr[i].sh_size);
         */
       }
@@ -2560,7 +2689,7 @@ ocGetNames_ELF ( ObjectCode* oc )
             isLocal = FALSE;
             ad = stgCallocBytes(1, stab[j].st_size, "ocGetNames_ELF(COMMON)");
            /*
-            fprintf(stderr, "COMMON symbol, size %d name %s\n",
+            debugBelch("COMMON symbol, size %d name %s\n",
                             stab[j].st_size, nm);
            */
            /* Pointless to do addProddableBlock() for this area,
@@ -2585,7 +2714,7 @@ ocGetNames_ELF ( ObjectCode* oc )
             ASSERT(secno > 0 && secno < ehdr->e_shnum);
            /*
             if (shdr[secno].sh_type == SHT_NOBITS) {
-               fprintf(stderr, "   BSS symbol, size %d off %d name %s\n",
+               debugBelch("   BSS symbol, size %d off %d name %s\n",
                                stab[j].st_size, stab[j].st_value, nm);
             }
             */
@@ -2600,7 +2729,7 @@ ocGetNames_ELF ( ObjectCode* oc )
                if (ELF_ST_TYPE(stab[j].st_info) == STT_FUNC)
                    ad = (char *)allocateFunctionDesc((Elf_Addr)ad);
 #endif
-               IF_DEBUG(linker,belch( "addOTabName(GLOB): %10p  %s %s",
+               IF_DEBUG(linker,debugBelch( "addOTabName(GLOB): %10p  %s %s",
                                       ad, oc->fileName, nm ));
                isLocal = FALSE;
             }
@@ -2619,10 +2748,10 @@ ocGetNames_ELF ( ObjectCode* oc )
             }
          } else {
             /* Skip. */
-            IF_DEBUG(linker,belch( "skipping `%s'",
+            IF_DEBUG(linker,debugBelch( "skipping `%s'",
                                    strtab + stab[j].st_name ));
             /*
-            fprintf(stderr,
+            debugBelch(
                     "skipping   bind = %d,  type = %d,  shndx = %d   `%s'\n",
                     (int)ELF_ST_BIND(stab[j].st_info),
                     (int)ELF_ST_TYPE(stab[j].st_info),
@@ -2656,7 +2785,7 @@ do_Elf_Rel_relocations ( ObjectCode* oc, char* ehdrC,
 
    stab  = (Elf_Sym*) (ehdrC + shdr[ symtab_shndx ].sh_offset);
    targ  = (Elf_Word*)(ehdrC + shdr[ target_shndx ].sh_offset);
-   IF_DEBUG(linker,belch( "relocations for section %d using symtab %d",
+   IF_DEBUG(linker,debugBelch( "relocations for section %d using symtab %d",
                           target_shndx, symtab_shndx ));
 
    for (j = 0; j < nent; j++) {
@@ -2667,12 +2796,13 @@ do_Elf_Rel_relocations ( ObjectCode* oc, char* ehdrC,
       Elf_Word* pP = (Elf_Word*)P;
       Elf_Addr  A  = *pP;
       Elf_Addr  S;
+      void*     S_tmp;
       Elf_Addr  value;
 
-      IF_DEBUG(linker,belch( "Rel entry %3d is raw(%6p %6p)",
+      IF_DEBUG(linker,debugBelch( "Rel entry %3d is raw(%6p %6p)",
                              j, (void*)offset, (void*)info ));
       if (!info) {
-         IF_DEBUG(linker,belch( " ZERO" ));
+         IF_DEBUG(linker,debugBelch( " ZERO" ));
          S = 0;
       } else {
          Elf_Sym sym = stab[ELF_R_SYM(info)];
@@ -2688,16 +2818,17 @@ do_Elf_Rel_relocations ( ObjectCode* oc, char* ehdrC,
         } else {
             /* No, so look up the name in our global table. */
             symbol = strtab + sym.st_name;
-            (void*)S = lookupSymbol( symbol );
+            S_tmp = lookupSymbol( symbol );
+            S = (Elf_Addr)S_tmp;
         }
          if (!S) {
-            belch("%s: unknown symbol `%s'", oc->fileName, symbol);
+            errorBelch("%s: unknown symbol `%s'", oc->fileName, symbol);
            return 0;
          }
-         IF_DEBUG(linker,belch( "`%s' resolves to %p", symbol, (void*)S ));
+         IF_DEBUG(linker,debugBelch( "`%s' resolves to %p", symbol, (void*)S ));
       }
 
-      IF_DEBUG(linker,belch( "Reloc: P = %p   S = %p   A = %p",
+      IF_DEBUG(linker,debugBelch( "Reloc: P = %p   S = %p   A = %p",
                             (void*)P, (void*)S, (void*)A ));
       checkProddableBlock ( oc, pP );
 
@@ -2709,7 +2840,7 @@ do_Elf_Rel_relocations ( ObjectCode* oc, char* ehdrC,
          case R_386_PC32: *pP = value - P; break;
 #        endif
          default:
-            belch("%s: unhandled ELF relocation(Rel) type %d\n",
+            errorBelch("%s: unhandled ELF relocation(Rel) type %d\n",
                  oc->fileName, ELF_R_TYPE(info));
             return 0;
       }
@@ -2735,11 +2866,11 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
 
    stab  = (Elf_Sym*) (ehdrC + shdr[ symtab_shndx ].sh_offset);
    targ  = (Elf_Addr) (ehdrC + shdr[ target_shndx ].sh_offset);
-   IF_DEBUG(linker,belch( "relocations for section %d using symtab %d",
+   IF_DEBUG(linker,debugBelch( "relocations for section %d using symtab %d",
                           target_shndx, symtab_shndx ));
 
    for (j = 0; j < nent; j++) {
-#if defined(DEBUG) || defined(sparc_TARGET_ARCH) || defined(ia64_TARGET_ARCH)
+#if defined(DEBUG) || defined(sparc_TARGET_ARCH) || defined(ia64_TARGET_ARCH) || defined(powerpc_TARGET_ARCH)
       /* This #ifdef only serves to avoid unused-var warnings. */
       Elf_Addr  offset = rtab[j].r_offset;
       Elf_Addr  P      = targ + offset;
@@ -2747,6 +2878,7 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
       Elf_Addr  info   = rtab[j].r_info;
       Elf_Addr  A      = rtab[j].r_addend;
       Elf_Addr  S;
+      void*     S_tmp;
       Elf_Addr  value;
 #     if defined(sparc_TARGET_ARCH)
       Elf_Word* pP = (Elf_Word*)P;
@@ -2754,13 +2886,15 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
 #     elif defined(ia64_TARGET_ARCH)
       Elf64_Xword *pP = (Elf64_Xword *)P;
       Elf_Addr addr;
+#     elif defined(powerpc_TARGET_ARCH)
+      Elf_Sword delta;
 #     endif
 
-      IF_DEBUG(linker,belch( "Rel entry %3d is raw(%6p %6p %6p)   ",
+      IF_DEBUG(linker,debugBelch( "Rel entry %3d is raw(%6p %6p %6p)   ",
                              j, (void*)offset, (void*)info,
                                 (void*)A ));
       if (!info) {
-         IF_DEBUG(linker,belch( " ZERO" ));
+         IF_DEBUG(linker,debugBelch( " ZERO" ));
          S = 0;
       } else {
          Elf_Sym sym = stab[ELF_R_SYM(info)];
@@ -2782,23 +2916,24 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
         } else {
             /* No, so look up the name in our global table. */
             symbol = strtab + sym.st_name;
-            (void*)S = lookupSymbol( symbol );
+            S_tmp = lookupSymbol( symbol );
+            S = (Elf_Addr)S_tmp;
 
 #ifdef ELF_FUNCTION_DESC
            /* If a function, already a function descriptor - we would
               have to copy it to add an offset. */
             if (S && (ELF_ST_TYPE(sym.st_info) == STT_FUNC) && (A != 0))
-               belch("%s: function %s with addend %p", oc->fileName, symbol, (void *)A);
+               errorBelch("%s: function %s with addend %p", oc->fileName, symbol, (void *)A);
 #endif
         }
          if (!S) {
-          belch("%s: unknown symbol `%s'", oc->fileName, symbol);
+          errorBelch("%s: unknown symbol `%s'", oc->fileName, symbol);
           return 0;
          }
-         IF_DEBUG(linker,belch( "`%s' resolves to %p", symbol, (void*)S ));
+         IF_DEBUG(linker,debugBelch( "`%s' resolves to %p", symbol, (void*)S ));
       }
 
-      IF_DEBUG(linker,fprintf ( stderr, "Reloc: P = %p   S = %p   A = %p\n",
+      IF_DEBUG(linker,debugBelch("Reloc: P = %p   S = %p   A = %p\n",
                                         (void*)P, (void*)S, (void*)A ));
       /* checkProddableBlock ( oc, (void*)P ); */
 
@@ -2870,9 +3005,49 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
            /* This goes with R_IA64_LTOFF22X and points to the load to
             * convert into a move.  We don't implement relaxation. */
            break;
+#        elif defined(powerpc_TARGET_ARCH)
+         case R_PPC_ADDR16_LO:
+            *(Elf32_Half*) P = value;
+            break;
+
+         case R_PPC_ADDR16_HI:
+            *(Elf32_Half*) P = value >> 16;
+            break;
+         case R_PPC_ADDR16_HA:
+            *(Elf32_Half*) P = (value + 0x8000) >> 16;
+            break;
+
+         case R_PPC_ADDR32:
+            *(Elf32_Word *) P = value;
+            break;
+
+         case R_PPC_REL32:
+            *(Elf32_Word *) P = value - P;
+            break;
+
+         case R_PPC_REL24:
+            delta = value - P;
+
+            if( delta << 6 >> 6 != delta )
+            {
+               value = makeJumpIsland( oc, ELF_R_SYM(info), value );
+               delta = value - P;
+
+               if( value == 0 || delta << 6 >> 6 != delta )
+               {
+                  barf( "Unable to make ppcJumpIsland for #%d",
+                        ELF_R_SYM(info) );
+                  return 0;
+               }
+            }
+
+            *(Elf_Word *) P = (*(Elf_Word *) P & 0xfc000003)
+                                          | (delta & 0x3fffffc);
+            break;
 #        endif
          default:
-            belch("%s: unhandled ELF relocation(RelA) type %d\n",
+            errorBelch("%s: unhandled ELF relocation(RelA) type %d\n",
                  oc->fileName, ELF_R_TYPE(info));
             return 0;
       }
@@ -2899,7 +3074,7 @@ ocResolve_ELF ( ObjectCode* oc )
    strtab = findElfSection ( ehdrC, SHT_STRTAB );
 
    if (stab == NULL || strtab == NULL) {
-      belch("%s: can't find string or symbol table", oc->fileName);
+      errorBelch("%s: can't find string or symbol table", oc->fileName);
       return 0;
    }
 
@@ -2930,6 +3105,10 @@ ocResolve_ELF ( ObjectCode* oc )
    freeHashTable(oc->lochash, NULL);
    oc->lochash = NULL;
 
+#if defined(powerpc_TARGET_ARCH)
+   ocFlushInstructionCache( oc );
+#endif
+
    return 1;
 }
 
@@ -3025,6 +3204,44 @@ ia64_reloc_pcrel21(Elf_Addr target, Elf_Addr value, ObjectCode *oc)
 
 #endif /* ia64 */
 
+/*
+ * PowerPC ELF specifics
+ */
+
+#ifdef powerpc_TARGET_ARCH
+
+static int ocAllocateJumpIslands_ELF( ObjectCode *oc )
+{
+  Elf_Ehdr *ehdr;
+  Elf_Shdr* shdr;
+  int i;
+
+  ehdr = (Elf_Ehdr *) oc->image;
+  shdr = (Elf_Shdr *) ( ((char *)oc->image) + ehdr->e_shoff );
+
+  for( i = 0; i < ehdr->e_shnum; i++ )
+    if( shdr[i].sh_type == SHT_SYMTAB )
+      break;
+
+  if( i == ehdr->e_shnum )
+  {
+    errorBelch( "This ELF file contains no symtab" );
+    return 0;
+  }
+
+  if( shdr[i].sh_entsize != sizeof( Elf_Sym ) )
+  {
+    errorBelch( "The entry size (%d) of the symtab isn't %d\n",
+      shdr[i].sh_entsize, sizeof( Elf_Sym ) );
+    
+    return 0;
+  }
+
+  return ocAllocateJumpIslands( oc, shdr[i].sh_size / sizeof( Elf_Sym ), 0 );
+}
+
+#endif /* powerpc */
+
 #endif /* ELF */
 
 /* --------------------------------------------------------------------------
@@ -3043,57 +3260,25 @@ ia64_reloc_pcrel21(Elf_Addr target, Elf_Addr value, ObjectCode *oc)
   *) add still more sanity checks.
 */
 
-
-/*
-  ocAllocateJumpIslands_MachO
-
-  Allocate additional space at the end of the object file image to make room
-  for jump islands.
-
-  PowerPC relative branch instructions have a 24 bit displacement field.
-  As PPC code is always 4-byte-aligned, this yields a +-32MB range.
-  If a particular imported symbol is outside this range, we have to redirect
-  the jump to a short piece of new code that just loads the 32bit absolute
-  address and jumps there.
-  This function just allocates space for one 16 byte jump island for every
-  undefined symbol in the object file. The code for the islands is filled in by
-  makeJumpIsland below.
-*/
-
-static const int islandSize = 16;
-
 static int ocAllocateJumpIslands_MachO(ObjectCode* oc)
 {
-    char *image = (char*) oc->image;
-    struct mach_header *header = (struct mach_header*) image;
-    struct load_command *lc = (struct load_command*) (image + sizeof(struct mach_header));
+    struct mach_header *header = (struct mach_header *) oc->image;
+    struct load_command *lc = (struct load_command *) (header + 1);
     unsigned i;
 
-    for(i=0;i<header->ncmds;i++)
+    for( i = 0; i < header->ncmds; i++ )
     {
-       if(lc->cmd == LC_DYSYMTAB)
+        if( lc->cmd == LC_DYSYMTAB )
         {
-           struct dysymtab_command *dsymLC = (struct dysymtab_command*) lc;
-            unsigned long nundefsym = dsymLC->nundefsym;
-            oc->island_start_symbol = dsymLC->iundefsym;
-            oc->n_islands = nundefsym;
+            struct dysymtab_command *dsymLC = (struct dysymtab_command *) lc;
 
-            if(nundefsym > 0)
-            {
-#ifdef USE_MMAP
-                #error ocAllocateJumpIslands_MachO doesnt want USE_MMAP to be defined
-#else
-                oc->image = stgReallocBytes(
-                    image, oc->fileSize + islandSize * nundefsym,
-                    "ocAllocateJumpIslands_MachO");
-#endif
-                oc->jump_islands = oc->image + oc->fileSize;
-                memset(oc->jump_islands, 0, islandSize * nundefsym);
-            }
+            if( !ocAllocateJumpIslands( oc, dsymLC->nundefsym,
+                                            dsymLC->iundefsym ) )
+              return 0;
 
             break;  // there can be only one LC_DSYMTAB
         }
-       lc = (struct load_command *) ( ((char*)lc) + lc->cmdsize );
+        lc = (struct load_command *) ( ((char *)lc) + lc->cmdsize );
     }
     return 1;
 }
@@ -3130,7 +3315,7 @@ static int resolveImports(
            addr = lookupSymbol(nm);
        if(!addr)
        {
-           belch("\n%s: unknown symbol `%s'", oc->fileName, nm);
+           errorBelch("\n%s: unknown symbol `%s'", oc->fileName, nm);
            return 0;
        }
        ASSERT(addr);
@@ -3141,31 +3326,6 @@ static int resolveImports(
     return 1;
 }
 
-static void* makeJumpIsland(
-    ObjectCode* oc,
-    unsigned long symbolNumber,
-    void* target)
-{
-    if(symbolNumber < oc->island_start_symbol ||
-        symbolNumber - oc->island_start_symbol > oc->n_islands)
-        return NULL;
-    symbolNumber -= oc->island_start_symbol;
-
-    void *island = (void*) ((char*)oc->jump_islands + islandSize * symbolNumber);
-    unsigned long *p = (unsigned long*) island;
-
-        // lis r12, hi16(target)
-    *p++ = 0x3d800000 | ( ((unsigned long) target) >> 16 );
-        // ori r12, r12, lo16(target)
-    *p++ = 0x618c0000 | ( ((unsigned long) target) & 0xFFFF );
-        // mtctr r12
-    *p++ = 0x7d8903a6;
-        // bctr
-    *p++ = 0x4e800420;
-
-    return (void*) island;
-}
-
 static char* relocateAddress(
     ObjectCode* oc,
     int nSections,
@@ -3221,7 +3381,12 @@ static int relocateSection(
                    // Step 1: Figure out what the relocated value should be
                    if(scat->r_type == GENERIC_RELOC_VANILLA)
                    {
-                       word = scat->r_value + sect->offset + ((long) image);
+                        word = *wordPtr + (unsigned long) relocateAddress(
+                                                                oc,
+                                                                nSections,
+                                                                sections,
+                                                                scat->r_value)
+                                        - scat->r_value;
                    }
                    else if(scat->r_type == PPC_RELOC_SECTDIFF
                        || scat->r_type == PPC_RELOC_LO16_SECTDIFF
@@ -3240,7 +3405,45 @@ static int relocateSection(
                              - relocateAddress(oc, nSections, sections, pair->r_value));
                        i++;
                    }
-                   else
+                   else if(scat->r_type == PPC_RELOC_HI16
+                         || scat->r_type == PPC_RELOC_LO16
+                         || scat->r_type == PPC_RELOC_HA16
+                         || scat->r_type == PPC_RELOC_LO14)
+                    {   // these are generated by label+offset things
+                       struct relocation_info *pair = &relocs[i+1];
+                        if((pair->r_address & R_SCATTERED) || pair->r_type != PPC_RELOC_PAIR)
+                           barf("Invalid Mach-O file: "
+                                "PPC_RELOC_* not followed by PPC_RELOC_PAIR");
+                        
+                        if(scat->r_type == PPC_RELOC_LO16)
+                        {
+                            word = ((unsigned short*) wordPtr)[1];
+                            word |= ((unsigned long) relocs[i+1].r_address & 0xFFFF) << 16;
+                        }
+                        else if(scat->r_type == PPC_RELOC_LO14)
+                        {
+                            barf("Unsupported Relocation: PPC_RELOC_LO14");
+                            word = ((unsigned short*) wordPtr)[1] & 0xFFFC;
+                            word |= ((unsigned long) relocs[i+1].r_address & 0xFFFF) << 16;
+                        }
+                        else if(scat->r_type == PPC_RELOC_HI16)
+                        {
+                            word = ((unsigned short*) wordPtr)[1] << 16;
+                            word |= ((unsigned long) relocs[i+1].r_address & 0xFFFF);
+                        }
+                        else if(scat->r_type == PPC_RELOC_HA16)
+                        {
+                            word = ((unsigned short*) wordPtr)[1] << 16;
+                            word += ((short)relocs[i+1].r_address & (short)0xFFFF);
+                        }
+                       
+                        
+                        word += (unsigned long) relocateAddress(oc, nSections, sections, scat->r_value)
+                                                - scat->r_value;
+                        
+                        i++;
+                    }
+                    else
                        continue;  // ignore the others
 
                     if(scat->r_type == GENERIC_RELOC_VANILLA
@@ -3248,15 +3451,15 @@ static int relocateSection(
                     {
                         *wordPtr = word;
                     }
-                    else if(scat->r_type == PPC_RELOC_LO16_SECTDIFF)
+                    else if(scat->r_type == PPC_RELOC_LO16_SECTDIFF || scat->r_type == PPC_RELOC_LO16)
                     {
                         ((unsigned short*) wordPtr)[1] = word & 0xFFFF;
                     }
-                    else if(scat->r_type == PPC_RELOC_HI16_SECTDIFF)
+                    else if(scat->r_type == PPC_RELOC_HI16_SECTDIFF || scat->r_type == PPC_RELOC_HI16)
                     {
                         ((unsigned short*) wordPtr)[1] = (word >> 16) & 0xFFFF;
                     }
-                    else if(scat->r_type == PPC_RELOC_HA16_SECTDIFF)
+                    else if(scat->r_type == PPC_RELOC_HA16_SECTDIFF || scat->r_type == PPC_RELOC_HA16)
                     {
                         ((unsigned short*) wordPtr)[1] = ((word >> 16) & 0xFFFF)
                             + ((word & (1<<15)) ? 1 : 0);
@@ -3303,7 +3506,7 @@ static int relocateSection(
                else if(reloc->r_type == PPC_RELOC_BR24)
                {
                    word = *wordPtr;
-                   word = (word & 0x03FFFFFC) | (word & 0x02000000) ? 0xFC000000 : 0;
+                   word = (word & 0x03FFFFFC) | ((word & 0x02000000) ? 0xFC000000 : 0);
                }
 
 
@@ -3320,16 +3523,20 @@ static int relocateSection(
                {
                    struct nlist *symbol = &nlist[reloc->r_symbolnum];
                    char *nm = image + symLC->stroff + symbol->n_un.n_strx;
-                   word = (unsigned long) (lookupSymbol(nm));
-                   if(!word)
+                   unsigned long symbolAddress = (unsigned long) (lookupSymbol(nm));
+                   if(!symbolAddress)
                    {
-                       belch("\nunknown symbol `%s'", nm);
+                       errorBelch("\nunknown symbol `%s'", nm);
                        return 0;
                    }
 
                    if(reloc->r_pcrel)
-                    {
-                        jumpIsland = (long) makeJumpIsland(oc,reloc->r_symbolnum,(void*)word);
+                    {  
+                            // In the .o file, this should be a relative jump to NULL
+                            // and we'll change it to a jump to a relative jump to the symbol
+                        ASSERT(-word == reloc->r_address);
+                        word = symbolAddress;
+                        jumpIsland = makeJumpIsland(oc,reloc->r_symbolnum,word);
                        word -= ((long)image) + sect->offset + reloc->r_address;
                         if(jumpIsland != 0)
                         {
@@ -3337,6 +3544,10 @@ static int relocateSection(
                                 - (((long)image) + sect->offset + reloc->r_address);
                         }
                     }
+                    else
+                    {
+                        word += symbolAddress;
+                    }
                }
 
                if(reloc->r_type == GENERIC_RELOC_VANILLA)
@@ -3451,68 +3662,86 @@ static int ocGetNames_MachO(ObjectCode* oc)
 
        // count external symbols defined here
     oc->n_symbols = 0;
-    for(i=dsymLC->iextdefsym;i<dsymLC->iextdefsym+dsymLC->nextdefsym;i++)
+    if(dsymLC)
     {
-       if((nlist[i].n_type & N_TYPE) == N_SECT)
-           oc->n_symbols++;
+        for(i = dsymLC->iextdefsym;
+            i < dsymLC->iextdefsym + dsymLC->nextdefsym;
+            i++)
+        {
+            if((nlist[i].n_type & N_TYPE) == N_SECT)
+                oc->n_symbols++;
+        }
     }
-    for(i=0;i<symLC->nsyms;i++)
+    if(symLC)
     {
-       if((nlist[i].n_type & N_TYPE) == N_UNDF
+        for(i=0;i<symLC->nsyms;i++)
+        {
+           if((nlist[i].n_type & N_TYPE) == N_UNDF
                && (nlist[i].n_type & N_EXT) && (nlist[i].n_value != 0))
-       {
-           commonSize += nlist[i].n_value;
-           oc->n_symbols++;
-       }
+           {
+               commonSize += nlist[i].n_value;
+               oc->n_symbols++;
+           }
+        }
     }
     oc->symbols = stgMallocBytes(oc->n_symbols * sizeof(char*),
                                   "ocGetNames_MachO(oc->symbols)");
 
-       // insert symbols into hash table
-    for(i=dsymLC->iextdefsym,curSymbol=0;i<dsymLC->iextdefsym+dsymLC->nextdefsym;i++)
-    {
-       if((nlist[i].n_type & N_TYPE) == N_SECT)
-       {
-           char *nm = image + symLC->stroff + nlist[i].n_un.n_strx;
-           ghciInsertStrHashTable(oc->fileName, symhash, nm, image +
-               sections[nlist[i].n_sect-1].offset
-               - sections[nlist[i].n_sect-1].addr
-               + nlist[i].n_value);
-           oc->symbols[curSymbol++] = nm;
-       }
-    }
-
-       // insert local symbols into lochash
-    for(i=dsymLC->ilocalsym;i<dsymLC->ilocalsym+dsymLC->nlocalsym;i++)
+    if(dsymLC)
     {
-       if((nlist[i].n_type & N_TYPE) == N_SECT)
-       {
-           char *nm = image + symLC->stroff + nlist[i].n_un.n_strx;
-           ghciInsertStrHashTable(oc->fileName, oc->lochash, nm, image +
-               sections[nlist[i].n_sect-1].offset
-               - sections[nlist[i].n_sect-1].addr
-               + nlist[i].n_value);
-       }
+        // insert symbols into hash table
+        for(i = dsymLC->iextdefsym, curSymbol = 0;
+            i < dsymLC->iextdefsym + dsymLC->nextdefsym;
+            i++)
+        {
+            if((nlist[i].n_type & N_TYPE) == N_SECT)
+            {
+                char *nm = image + symLC->stroff + nlist[i].n_un.n_strx;
+                ghciInsertStrHashTable(oc->fileName, symhash, nm,
+                                        image
+                                        + sections[nlist[i].n_sect-1].offset
+                                        - sections[nlist[i].n_sect-1].addr
+                                        + nlist[i].n_value);
+                oc->symbols[curSymbol++] = nm;
+            }
+        }
+    
+        // insert local symbols into lochash
+        for(i=dsymLC->ilocalsym;i<dsymLC->ilocalsym+dsymLC->nlocalsym;i++)
+        {
+            if((nlist[i].n_type & N_TYPE) == N_SECT)
+            {
+                char *nm = image + symLC->stroff + nlist[i].n_un.n_strx;
+                ghciInsertStrHashTable(oc->fileName, oc->lochash, nm,
+                                        image
+                                        + sections[nlist[i].n_sect-1].offset
+                                        - sections[nlist[i].n_sect-1].addr
+                                        + nlist[i].n_value);
+            }
+        }
     }
 
-
     commonStorage = stgCallocBytes(1,commonSize,"ocGetNames_MachO(common symbols)");
     commonCounter = (unsigned long)commonStorage;
-    for(i=0;i<symLC->nsyms;i++)
+    if(symLC)
     {
-       if((nlist[i].n_type & N_TYPE) == N_UNDF
-               && (nlist[i].n_type & N_EXT) && (nlist[i].n_value != 0))
-       {
-           char *nm = image + symLC->stroff + nlist[i].n_un.n_strx;
-           unsigned long sz = nlist[i].n_value;
+        for(i=0;i<symLC->nsyms;i++)
+        {
+           if((nlist[i].n_type & N_TYPE) == N_UNDF
+                   && (nlist[i].n_type & N_EXT) && (nlist[i].n_value != 0))
+           {
+               char *nm = image + symLC->stroff + nlist[i].n_un.n_strx;
+               unsigned long sz = nlist[i].n_value;
 
-           nlist[i].n_value = commonCounter;
+               nlist[i].n_value = commonCounter;
 
-           ghciInsertStrHashTable(oc->fileName, symhash, nm, (void*)commonCounter);
-           oc->symbols[curSymbol++] = nm;
+               ghciInsertStrHashTable(oc->fileName, symhash, nm,
+                                      (void*)commonCounter);
+               oc->symbols[curSymbol++] = nm;
 
-           commonCounter += sz;
-       }
+               commonCounter += sz;
+           }
+        }
     }
     return 1;
 }
@@ -3528,7 +3757,6 @@ static int ocResolve_MachO(ObjectCode* oc)
     struct symtab_command *symLC = NULL;
     struct dysymtab_command *dsymLC = NULL;
     struct nlist *nlist;
-    unsigned long *indirectSyms;
 
     for(i=0;i<header->ncmds;i++)
     {
@@ -3542,7 +3770,8 @@ static int ocResolve_MachO(ObjectCode* oc)
     }
 
     sections = (struct section*) (segLC+1);
-    nlist = (struct nlist*) (image + symLC->symoff);
+    nlist = symLC ? (struct nlist*) (image + symLC->symoff)
+                  : NULL;
 
     for(i=0;i<segLC->nsects;i++)
     {
@@ -3552,15 +3781,19 @@ static int ocResolve_MachO(ObjectCode* oc)
            nl_ptrs = &sections[i];
     }
 
-    indirectSyms = (unsigned long*) (image + dsymLC->indirectsymoff);
-
-    if(la_ptrs)
-       if(!resolveImports(oc,image,symLC,la_ptrs,indirectSyms,nlist))
-           return 0;
-    if(nl_ptrs)
-       if(!resolveImports(oc,image,symLC,nl_ptrs,indirectSyms,nlist))
-           return 0;
-
+    if(dsymLC)
+    {
+        unsigned long *indirectSyms
+            = (unsigned long*) (image + dsymLC->indirectsymoff);
+
+        if(la_ptrs)
+            if(!resolveImports(oc,image,symLC,la_ptrs,indirectSyms,nlist))
+                return 0;
+        if(nl_ptrs)
+            if(!resolveImports(oc,image,symLC,nl_ptrs,indirectSyms,nlist))
+                return 0;
+    }
+    
     for(i=0;i<segLC->nsects;i++)
     {
        if(!relocateSection(oc,image,symLC,nlist,segLC->nsects,sections,&sections[i]))
@@ -3571,22 +3804,10 @@ static int ocResolve_MachO(ObjectCode* oc)
     freeHashTable(oc->lochash, NULL);
     oc->lochash = NULL;
 
-    /*
-        Flush the data & instruction caches.
-        Because the PPC has split data/instruction caches, we have to
-        do that whenever we modify code at runtime.
-    */
-    {
-        int n = (oc->fileSize + islandSize * oc->n_islands) / 4;
-        unsigned long *p = (unsigned long*)oc->image;
-        while(n--)
-        {
-            __asm__ volatile ("dcbf 0,%0\n\tsync\n\ticbi 0,%0"
-                                : : "r" (p));
-            p++;
-        }
-        __asm__ volatile ("sync\n\tisync");
-    }
+#if defined (powerpc_TARGET_ARCH)
+    ocFlushInstructionCache( oc );
+#endif
+
     return 1;
 }
 
@@ -3601,14 +3822,24 @@ static int ocResolve_MachO(ObjectCode* oc)
 
 static void machoInitSymbolsWithoutUnderscore()
 {
-    void *p;
+    extern void* symbolsWithoutUnderscore[];
+    void **p = symbolsWithoutUnderscore;
+    __asm__ volatile(".data\n_symbolsWithoutUnderscore:");
 
 #undef Sym
-#define Sym(x)                                         \
-    __asm__ ("lis %0,hi16(" #x ")\n\tori %0,%0,lo16(" #x ")" : "=r" (p));      \
-    ghciInsertStrHashTable("(GHCi built-in symbols)", symhash, #x, p);
+#define Sym(x)  \
+    __asm__ volatile(".long " # x);
 
     RTS_MACHO_NOUNDERLINE_SYMBOLS
 
+    __asm__ volatile(".text");
+    
+#undef Sym
+#define Sym(x)  \
+    ghciInsertStrHashTable("(GHCi built-in symbols)", symhash, #x, *p++);
+    
+    RTS_MACHO_NOUNDERLINE_SYMBOLS
+    
+#undef Sym
 }
 #endif