There seem to be a fully free software OS for the ti89 calculators.
It might be possible to flash it with fully free software if we manage to build tigcc on recent GNU/Linux distributions.
This way we would be able to build it, then sign it with the factorized keys, and flash it with the free flasher without relying on any nonfree software.
Note that this has not been tested yet because we need to refresh tigcc (and potentially upstream) patches.
|Free software compiler||tigcc||Strongly outdated, no more packages for recent GNU/Linux distributions|
|ti83c||Unknown if it works for the TI89 or not.|
|Free software OS||Pedrom||To use it you need:
|Free software flasher||RabbitSign||Package available for several GNU/Linux distributions, require private keys to flash an OS.|
|Signing keys||Signing keys||Factorized|