Solaris SPARC to Solaris x86 Porting Guide

Object files

The Solaris OS link editors work with files that conform to the executable and linking format,

otherwise referred to as ELF.

Link-editing takes a variety of input files, typically generated from compilers, assemblers, or ld(1). The

link-editor concatenates and interprets the data within these input files to form a single output file.

Although the link-editor provides numerous options, the output file that is produced is one of four basic

types:

• Relocatable object—A concatenation of input relocatable objects that can be used in subsequent

link-edit phases.

• Static executable—A concatenation of input relocatable objects that have all symbolic references

resolved. This executable represents a ready-to-run process.

• Dynamic executable—A concatenation of input relocatable objects that requires intervention by the

runtime linker to produce a runnable process. A dynamic executable might still need symbolic

references bound at runtime. Dynamic executables typically have one or more dependencies in the

form of shared objects.

• Shared object—A concatenation of input relocatable objects that provide services that might be

bound to a dynamic executable at runtime. The shared object can have dependencies on other

shared objects.

These output files, and the key link-editor options used in their creation, are shown in the following

figure.

Dynamic executables and shared objects are often referred to jointly as dynamic objects.

32–bit Environments and 64–bit environments

The link-editors are provided as 32–bit applications and 64–bit applications. Each link-editor can

operate on 32–bit objects and 64–bit objects. However, a link-edit cannot contain a mix of 32–bit

objects and 64–bit objects. On systems that are running a 64–bit environment, both versions of the

link-editor can be executed. On systems that are running a 32–bit environment, only the 32–bit

version of the link-editor can be executed. Although a 32–bit link-editor can generate a 64–bit object,

the size of the generated object, not including the .bss, is restricted to 2 Gbytes.