The Atari Jaguar is a video game console marketed from 1993 to 1996, with an active homebrew community. The original SDK provided by Atari was last updated in the mid-1990s and the source code for these programs was never released.

Over time, the homebrew community has developed modern reimplementations for some of these tools, but there are still extent use-cases for running the original ones. Keeping these ancient tools running as-is on modern systems is proving to be increasingly difficult as time goes on and requires an ever-increasing number of workarounds to pull off:

  • The default mmap() minimum address has been bumped to 65536, which is too low for a.out executables ; fixing this requires lowering vm.mmap_min_addr, a privileged operation.
  • The Linux kernel dropped support for the traditional a.out executable format in 2022, requiring a user-land utility to act as an a.out executable loader/shim.

In this series of articles, we’ll explore an application of the delinking reverse-engineering technique previously explained here: to make software ports of programs without having access to the original source code.

The files for this case study can be found here: case-study.tar.gz