The portion of Tofino software that was released as open source is in this repository: GitHub - p4lang/open-p4studio
I believe it does NOT contain BSP software, though.
In Oct 2025 Intel announced that they would satisfy requests for the proprietary parts of the software for running Tofino hardware boards until Jan 1, 2026, but not afterwards [1]. I have not confirmed whether those plans have changed, but suspect they have not, as it has been almost 2 years since Intel stopped selling Tofino ASICs.
[1] Intel(r) Tofino(tm) Family, TNA, and P4Studio questions Note: Read all replies in that thread.