loadelflib.c

VXWORKS源代码

/* loadElfLib.c - UNIX elf object module loader */

/* Copyright 1996-2002 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
01x,09may02,fmk  use loadCommonManage() instead of loadElfCommonManage()
01w,23apr02,jn   SPR 75177 - correct inaccurate test for whether CPU is
                 SIMSPARCSOLARIS 
01v,26mar02,jn   fix alignment handling for COMMON's (SPR 74567)
01u,07mar02,jn   Add STT_ARM_16BIT to recognized types (SPR # 73992)
01t,07mar02,jn   Refix SPR# 30588 - load should return NULL when there are
                 unresolved symbols.
01s,14jan02,jn   Improve comments about setting SYM_THUMB
01r,25jan02,rec  Merge in coldfire changes
01q,12dec01,pad  Moved MIPS support code out in the ELF/MIPS relocation unit.
01p,28nov01,jn   Fix alignment of segments (SPR #28353).  Also removed 
                 declarations of unsupported relocation types for SH.
01o,19nov01,pch  Provide misalignment prevention based on _WRS_STRICT_ALIGNMENT
		 definition instead of testing a specific CPU type.
01n,08nov01,jn   Added support for ARM/THUMB architecture now using ELF
01m,17sep01,pad  Introduced usage of relocation unit's init routines. Added
		 support for I86 relocation unit. Symbols from a read-only data
 		 sections are now flagged as data, like in VxWorks AE, rather
		 than text. Made the determination of text sections more
		 flexible in loadElfSegSizeGet().
01l,28jun01,agf  add logic to MIPS that tests for attempted relative jumps
                 across a 26 bit boundary
01k,03mar00,zl   merged SH support from T1
01j,30nov98,dbt  no longer clear seg.flags<xxx> after loadSegmentAllocate()
                 call. (SPR #23553).
01i,05oct98,pcn  Initialize all the fields in the SEG_INFO structure.
01h,16sep98,pcn  Set to _ALLOC_ALIGN_SIZE the flags field in seg structure
                 (SPR #21836).
01g,17jul98,pcn  Fixed SPR #21836: alignment mismatch between sections and
                 target.
01f,18apr97,kkk  fixed printing of debug msgs for MIPS (spr# 8276)
01e,05dec96,dbt  fixed a bug in loadElfSizeGet() when loading an object file
                 with a data section null and a text and bss sections not
                 null.
01d,31oct96,elp  Replaced symAdd() call by symSAdd() call (symtbls synchro).
01c,22oct96,dbt  Zero out bss section (fixed SPR #7376).
01c,02oct96,dbt  Added support for SIMSPARCSOLARIS.
01b,02oct96,dbt  Unknown moduleformats are now correctly managed (SPR #7263).
01b,03aug96,kkk  throw away __gnu_compiled_c signatures.
01a,20jun96,dbt	 created from /host/src/tgtsvr/server/loadelf.c v01t
		 and /host/src/tgtsvr/server/elfppc.c v01e
		 and /host/src/tgtsvr/server/elfmips.c v01c
*/

/*
DESCRIPTION
This library provides an object module loading facility.  Any SYSV elf
format files may be loaded into memory, relocated properly, their
external references resolved, and their external definitions added to
the system symbol table for use by other modules and from the shell.
Modules may be loaded from any I/O stream.

EXAMPLE
.CS
    fdX = open ("/devX/objFile", O_RDONLY);
    loadModule (fdX, ALL_SYMBOLS);
    close (fdX);
.CE
This code fragment would load the ELF file "objFile" located on
device "/devX/" into memory which would be allocated from the system
memory pool.  All external and static definitions from the file would be
added to the system symbol table.

This could also have been accomplished from the shell, by typing:
.CS
    -> ld (1) </devX/objFile
.CE

INCLUDE FILE: loadElfLib.h

SEE ALSO: loadLib, usrLib, symLib, memLib,
.pG "Basic OS"
*/

/* defines */

#undef INCLUDE_SDA		/* SDA is not supported for the moment */
#define _CACHE_SUPPORT         	/* cache           */

/* includes */

#include "vxWorks.h"
#include "stdio.h"
#include "loadElfLib.h"
#include "elf.h"
#include "elftypes.h"
#include "ioLib.h"
#include "fioLib.h"
#include "bootLoadLib.h"
#include "loadLib.h"
#include "memLib.h"
#include "pathLib.h"
#include "string.h"
#include "symLib.h"
#include "sysSymTbl.h"
#ifdef  _CACHE_SUPPORT
#include "cacheLib.h"
#endif  /* _CACHE_SUPPORT */
#include "errnoLib.h"
#include "stdlib.h"
#include "symbol.h"     /* for SYM_TYPE typedef */
#include "moduleLib.h"
#include "private/vmLibP.h"

#if   ((CPU_FAMILY == MIPS) || (CPU_FAMILY == PPC) || \
       (CPU_FAMILY == SIMSPARCSOLARIS) || (CPU_FAMILY == SH) || \
       (CPU_FAMILY == I80X86) || (CPU_FAMILY == ARM) || \
       (CPU_FAMILY==COLDFIRE))

/* define */

#ifndef EM_ARCH_MACHINE
#define EM_ARCH_MACHINE -1              /* default */
#endif /* EM_ARCH_MACHINE */

#undef DEBUGG
#ifdef DEBUGG
int elfDebug=1;
#define DSMINST(x)
#define DBG(x) if (elfDebug) { printf x; fflush(stdout); }
#else
#define DSMINST(x)
#define DBG(x)
#endif /* DEBUG */

#ifdef	_WRS_STRICT_ALIGNMENT
#define ELFOUTMSBU32(b,w) \
  ((b)[0] = (w >> 24), \
   (b)[1] = (w >> 16), \
   (b)[2] = (w >> 8), \
   (b)[3]  = w)
#endif /* _WRS_STRICT_ALIGNMENT */

/* globals */

/* externals */
	
#ifdef INCLUDE_SDA
IMPORT char SDA_BASE[];		/* Base address of SDA Area */
IMPORT char SDA2_BASE[];	/* Base address of SDA2 Area */
IMPORT int SDA_SIZE;		/* size of SDA area */
IMPORT int SDA2_SIZE;		/* size of SDA2 area */
#endif /* INCLUDE_SDA */

/* locals */

#ifdef INCLUDE_SDA
LOCAL STATUS moduleElfSegAdd (MODULE_ID moduleId, int type, void * location,
    				int length, int flags, PART_ID memPartId);

LOCAL BOOL segElfFindByType (SEGMENT_ID segmentId, MODULE_ID moduleId,
    				int type);
#endif /* INCLUDE_SDA */

LOCAL UINT32 loadElfAlignGet (UINT32 alignment, void * pAddrOrSize);

LOCAL BOOL (* pElfModuleVerifyRtn) (UINT32 machType,
				    BOOL * sda) = NULL; /* verif rtn ptr */

LOCAL STATUS (* pElfSegRelRtn) (int fd, MODULE_ID moduleId, int loadFlag,
		    		int posCurRelocCmd, Elf32_Shdr * pScnHdrTbl,
			    	Elf32_Shdr * pRelHdr, SCN_ADRS * pScnAddr,
	    			SYM_INFO_TBL symInfoTbl,
			       	Elf32_Sym * pSymsArray, SYMTAB_ID symTbl,
				SEG_INFO * pSeg) = NULL; /* seg reloc rtn ptr */

#if     (CPU_FAMILY == PPC)

LOCAL STATUS elfPpcSegReloc (int fd, MODULE_ID moduleId, int loadFlag,
		    		int posCurRelocCmd, Elf32_Shdr * pScnHdrTbl,
			    	Elf32_Shdr * pRelHdr, SCN_ADRS * pScnAddr,
	    			SYM_INFO_TBL symInfoTbl,
				Elf32_Sym *  pSymsArray,
			    	SYMTAB_ID    symTbl,
				SEG_INFO *   pSeg);
LOCAL STATUS elfPpcAddr32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl, MODULE_ID moduleId);
LOCAL STATUS elfPpcAddr24Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcAddr16Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcAddr16LoReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcAddr16HiReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcAddr16HaReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcAddr14Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcRel24Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcRel14Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcUaddr32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcUaddr16Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcRel32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcEmbNaddr32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcEmbNaddr16Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcEmbNaddr16LoReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcEmbNaddr16HiReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfPpcEmbNaddr16HaReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
#ifdef INCLUDE_SDA
LOCAL STATUS elfPpcSdaRel16Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl, SEG_INFO * pSeg);
LOCAL STATUS elfPpcEmbSda21Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl, SEG_INFO * pSeg);
LOCAL STATUS elfPpcEmbSda2RelReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl, SEG_INFO * pSeg);
LOCAL STATUS elfPpcEmbRelSdaReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl, SEG_INFO * pSeg);
#endif /* INCLUDE_SDA */
#endif     /* CPU_FAMILY == PPC */

#if	(CPU_FAMILY == SIMSPARCSOLARIS)

LOCAL STATUS elfSparcSegReloc (int fd, MODULE_ID moduleId, int loadFlag, 
			      int posCurRelocCmd, Elf32_Shdr * pScnHdrTbl,
    			      Elf32_Shdr * pRelHdr, SCN_ADRS * pScnAddr,
    			      SYM_INFO_TBL symInfoTbl, Elf32_Sym * pSymsArray,
    			      SYMTAB_ID symTbl, SEG_INFO * pSeg);
LOCAL STATUS elfSparc32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparc16Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparc8Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcDisp32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd,
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcDisp16Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcDisp8Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcWDisp30Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcWDisp22Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcHi22Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparc22Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparc13Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcLo10Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcPc10Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcPc22Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfSparcUa32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
#endif	/* (CPU_FAMILY == SIMSPARCSOLARIS) */

#if 	(CPU_FAMILY == COLDFIRE)
LOCAL STATUS elfM68k32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
			     SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfM68k16Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
			     SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfM68kDisp32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				 SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfM68kDisp16Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				 SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfM68kSegReloc (int fd, MODULE_ID moduleId, int loadFlag, 
			      int posCurRelocCmd, Elf32_Shdr * pScnHdrTbl,
    			      Elf32_Shdr * pRelHdr, SCN_ADRS * pScnAddr,
    			      SYM_INFO_TBL symInfoTbl, Elf32_Sym * pSymsArray,
    			      SYMTAB_ID symTbl, SEG_INFO * pSeg);
#endif 	/* (CPU_FAMILY == COLDFIRE) */

#if	(CPU_FAMILY == SH)

LOCAL STATUS elfShSegReloc (int fd, MODULE_ID moduleId, int loadFlag,
		    		int posCurRelocCmd, Elf32_Shdr * pScnHdrTbl,
			    	Elf32_Shdr * pRelHdr, SCN_ADRS * pScnAddr,
	    			SYM_INFO_TBL symInfoTbl,
				Elf32_Sym *  pSymsArray,
			    	SYMTAB_ID    symTbl,
				SEG_INFO *   pSeg);
LOCAL STATUS elfShDir32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl, MODULE_ID moduleId);
#if FALSE /* Relocation types not currently supported. */
LOCAL STATUS elfShRel32Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfShDir8wpnReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfShInd12wReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfShDir8wplReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfShDir8bpReloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
LOCAL STATUS elfShSwitch16Reloc (void * pAdrs, Elf32_Rela * pRelocCmd, 
				SYM_INFO_TBL symInfoTbl);
#endif /* relocation types not currently supported. */

#endif	/* (CPU_FAMILY == SH) */

LOCAL BOOL 	loadElfModuleIsOk (Elf32_Ehdr *pHdr);
LOCAL STATUS 	loadElfMdlHdrCheck (Elf32_Ehdr *pHdr);
LOCAL STATUS 	loadElfMdlHdrRd (int fd, Elf32_Ehdr *pHdr);
LOCAL STATUS 	loadElfProgHdrCheck (Elf32_Phdr *pProgHdr, int progHdrNum);
LOCAL STATUS 	loadElfProgHdrTblRd (int fd, int posProgHdrField,
				 Elf32_Phdr *pProgHdrTbl, int progHdrNumber);
LOCAL STATUS 	loadElfScnHdrCheck (Elf32_Shdr *pScnHdr, int scnHdrNum);
LOCAL STATUS 	loadElfScnHdrIdxDispatch (Elf32_Shdr *pScnHdrTbl, int scnHdrIdx,
				IDX_TBLS *pIndexTables);
LOCAL STATUS 	loadElfScnHdrRd (int fd, int posScnHdrField, 
				Elf32_Shdr * pScnHdrTbl,
    				int sectionNumber, IDX_TBLS * pIndexTables);
LOCAL void 	loadElfSegSizeGet (char * pScnStrTbl, 
				UINT32 *pLoadScnHdrIdxs, 
				Elf32_Shdr *pScnHdrTbl, SEG_INFO *pSeg);
LOCAL STATUS 	loadElfScnRd (int fd, char * pScnStrTbl, 
				UINT32 *pLoadScnHdrIdxs, Elf32_Shdr *pScnHdrTbl,
				SCN_ADRS_TBL sectionAdrsTbl, SEG_INFO *pSeg);
LOCAL int	loadElfSymEntryRd (int fd, int symEntry, Elf32_Sym *pSymbol);
LOCAL STATUS 	loadElfSymTabRd (int fd, int nextSym, UINT32 nSyms, 
				Elf32_Sym *pSymsArray);
LOCAL int 	loadElfSymTablesHandle (UINT32 *pSymTabScnHdrIdxs, 
				Elf32_Shdr *pScnHdrTbl, int fd,	
				SYMTBL_REFS *pSymTblRefs,
				SYMINFO_REFS * pSymsAdrsRefs);
LOCAL SYM_TYPE 	loadElfSymTypeGet (Elf32_Sym *pSymbol, Elf32_Shdr *pScnHdrTbl, 
				char * pScnStrTbl);
LOCAL BOOL 	loadElfSymIsVisible (UINT32	symAssoc, UINT32 symBinding, 
				int loadFlag);
LOCAL STATUS 	loadElfSymTabProcess (MODULE_ID moduleId, int loadFlag, 
				Elf32_Sym *pSymsArray, 
				SCN_ADRS_TBL sectionAdrsTbl,
				SYM_INFO_TBL symsAdrsTbl, char * pStringTable,
				SYMTAB_ID symTbl, UINT32 symNumber,
				Elf32_Shdr * pScnHdrTbl, char * pScnStrTbl,
				SEG_INFO * pSeg);
LOCAL STATUS 	loadElfSymTableBuild (MODULE_ID moduleId, int loadFlag,
				SYMTBL_REFS  symTblRefs, 
				SCN_ADRS_TBL sectionAdrsTbl,
				SYMINFO_REFS symsAdrsRefs, 
				IDX_TBLS *pIndexTables, SYMTAB_ID symTbl, 
				int fd, Elf32_Shdr * pScnHdrTbl,
				char * pScnStrTbl, SEG_INFO * pSeg);
LOCAL FUNCPTR 	loadElfRelSegRtnGet (void);
LOCAL STATUS 	loadElfSegReloc (int fd, int loadFlag, MODULE_ID moduleId, 
				Elf32_Ehdr * pHdr, IDX_TBLS *pIndexTables, 
				Elf32_Shdr *pScnHdrTbl,
			    	SCN_ADRS_TBL sectionAdrsTbl, 
				SYMTBL_REFS  symTblRefs,
				SYMINFO_REFS symsAdrsRefs, SYMTAB_ID symTbl,
				SEG_INFO * pSeg);
LOCAL STATUS 	loadElfTablesAlloc (Elf32_Ehdr *pHdr, Elf32_Phdr **ppProgHdrTbl,
				Elf32_Shdr **ppScnHdrTbl, 
				IDX_TBLS *pIndexTables);
LOCAL MODULE_ID loadElfFmtManage (FAST int fd, int loadFlag, void **ppText,
			  	void **ppData, void **ppBss, SYMTAB_ID symTbl);
LOCAL void 	loadElfBufferFree (void ** ppBuf);
LOCAL STATUS 	loadElfRelocMod (SEG_INFO * pSeg, int fd, char * pScnStrTbl,
				IDX_TBLS * pIndexTables, Elf32_Ehdr * pHdr,
    				Elf32_Shdr * pScnHdrTbl,
    				SCN_ADRS_TBL * pSectionAdrsTbl);
LOCAL STATUS 	loadElfSegStore (SEG_INFO * pSeg, int loadFlag, int fd,
				char * pScnStrTbl,
    				IDX_TBLS * pIndexTables, Elf32_Ehdr * pHdr,
    				Elf32_Shdr * pScnHdrTbl, 
				Elf32_Phdr * pProgHdrTbl,
    				SCN_ADRS_TBL * pSectionAdrsTbl);
LOCAL char * 	loadElfScnStrTblRd (int fd, Elf32_Shdr * pScnHdrTbl, 
				Elf32_Ehdr * pHdr);

#ifdef INCLUDE_SDA
LOCAL STATUS 	loadElfSdaAllocate (SDA_INFO * pSda);

LOCAL STATUS 	loadElfSdaCreate (void);

LOCAL SDA_SCN_TYPE loadElfSdaScnDetermine (char * pScnStrTbl, 
				Elf32_Shdr * pScnHdr, char * sectionName);

LOCAL BOOL      sdaIsRequired = FALSE;  /* TRUE if SDA are used by the arch */
LOCAL PART_ID   sdaMemPartId = NULL;    /* keeps SDA memory partition id */
LOCAL PART_ID   sda2MemPartId = NULL;   /* keeps SDA2 memory partition id */
LOCAL void *    sdaBaseAddr = NULL;     /* keeps SDA area base address */
LOCAL void *    sda2BaseAddr = NULL;    /* keeps SDA2 area base address */
LOCAL int     	sdaAreaSize = 0;     	/* keeps SDA area size */
LOCAL int     	sda2AreaSize = 0;     	/* keeps SDA area size */
#endif /* INCLUDE_SDA */

/*******************************************************************************
*
* elfRelocRelaEntryRd - read in ELF relocation entry for RELA relocation
* 
* This routine fills a relocation structure with information from the object
* module in memory.
*
* RETURNS : the address of the next relocation entry or ERROR if entry not read.
*/

int elfRelocRelaEntryRd
    (
    int 	 fd,		/* file to read in */
    int 	 posRelocEntry,	/* position of reloc. command in object file */
    Elf32_Rela * pReloc		/* ptr on relocation structure to fill */
    )
    {
    int nbytes;		/* number of bytes to copy */

    nbytes = sizeof (Elf32_Rela);

    if ((ioctl (fd, FIOSEEK, posRelocEntry)) == ERROR)
        return ERROR; 

    if ((fioRead (fd, (char *) pReloc, nbytes)) == ERROR)
        return ERROR;

    return (posRelocEntry + nbytes);