System Object Model (file format)

In computing, the System Object Model (SOM) is a proprietary executable file format developed by Hewlett-Packard for it's HP-UX and MPE/ix operating systems. In particular, SOM is the native format used for 32-bit application executables, object code, and shared libraries running under the PA-RISC family of processors.

With the introduction of 64-bit processors, Hewlett Packard adopted the Executable and Linkable Format (ELF) format to represent the wider 64-bit program code, while still using SOM for applications running in 32-bit mode. Later, with the introduction of the Itanium processor family, HP-UX has abandoned the SOM format in favor of ELF for both 32-bit and 64-bit application code.

References

• http://devrsrc1.external.hp.com/STK/gloss.html#S - HP glossary
• The 32-bit PA-RISC Run-time Architecture Document, HP-UX 11.0 Version 1.0, Hewlett-Packard, 1997.
  Available at [1] (hp.com).
• The 32-bit PA-RISC Run-time Architecture Document, HP-UX 10.20 version 3.0, Hewlett-Packard, 1997.
  Available at [2] (hp.com) and [3] (parisc-linux.org)
• http://www.parisc-linux.org/documentation/index.html#pa11