ELFWRAP(1) User Commands ELFWRAP(1)


elfwrap - wrap data in an ELF file


elfwrap [-64] [-o relobj-file] [-z target=sparc | x86]


The elfwrap utility creates an ELF relocatable object file from one or
more data files. The relocatable object encapsulates each data file
within an individual section, together with symbols that can be used to
reference the section. The relocatable object is appropriate for
inclusion with a subsequent link-edit. Users can reference the
encapsulated data using the associated symbols.

By default, a 32-bit ELF relocatable object is created that is
appropriate for the machine on which elfwrap is executed. The -64 option
can be used to create a 64-bit ELF relocatable object. The -z target
option can be used to create a relocatable object for a specific machine

Note -

Any data encapsulated with elfwrap must be in a format appropriate for
the destination target.

By default, the relocatable object a.wrap.o is created. The -o option can
be used to specify an alternative relocatable object name.

The basename(1) of each data file is used to create various pieces of ELF
information. For example, if the input data file is ISV/isv-data, the
following ELF information is created within the relocatable object.

An ELF section named .isv-data

This section contains the entire contents of the input data file.

An ELF symbol named isv-data_start

This symbol reflects the starting address of the .isv-data section.

An ELF symbol named isv-data_end

This symbol reflects the address of the first location after the
.isv-data section.


The following options are supported:


Create a 64-bit ELF relocatable object.

-o relobj-file

Produce a relocatable object that is named relobj-file.

-z target=sparc | x86

Specifies the machine type for the output relocatable object.
Supported targets are sparc and x86. The 32-bit machine type for the
specified target is used unless the -64 option is also present, in
which case the corresponding 64-bit machine type is used. By default,
the relocatable object that is generated is 32-bit for the machine
one which elfwrap is executed.


The following example encapsulates the system passwd file and the system
group file within a relocatable object passgroup.o.

example% elfwrap -o passgroup.o /etc/passwd /etc/group
example% elfdump -s passgroup.o | egrep "passwd|group"
[2] 0x00000000 0x00000000 SECT LOCL D 0 .passwd
[3] 0x00000000 0x00000000 SECT LOCL D 0 .group
[7] 0x00000000 0x000002f0 OBJT GLOB D 0 .passwd passwd_start
[8] 0x000002f0 0x00000000 OBJT GLOB D 0 .passwd passwd_end
[9] 0x00000000 0x00000121 OBJT GLOB D 0 .group group_start
[10] 0x00000121 0x00000000 OBJT GLOB D 0 .group group_end
example% strings -N.passwd passgroup.o | head -1
example% strings -N.group passgroup.o | head -1

This relocatable object can be referenced from the following user code.

example% cat main.c
#include <stdio.h>

extern char passwd_start, passwd_end;

void main()
char *pstart = &passwd_start, *pend = &passwd_end;
char *str, *lstr;

for (lstr = str = pstart; str < pend; str++) {
if ((*str == '\n') && (str != (pend - 1))) {
(void) printf("%.*s", (++str - lstr), lstr);
lstr = str;
example% cc -o main main.c passgroup.o
example% ./main
nobody4:x:65534:65534:SunOS 4.x NFS Anonymous Access User:/:


The default relocatable object file created.


See attributes(7) for descriptions of the following attributes:

|Interface Stability | Committed |


elfdump(1), ld(1), strings(1), elf(3ELF), attributes(7), ddi_modopen(9F)

Linker and Libraries Guide

September 10, 2013 ELFWRAP(1)