Developers Call On Intel To Open-Source PSE Firmware As Their Newest Binary Headache

[Old Grouch]

with OpenPOWER we maybe get some alternative hardware not directly from IBM... some people say IBM first makes POWER10 and 1-2years later they do POWER10-Opensource... it was the same with power9 the first power9 products where in fact not opensource.

The issue is not the Power10 processor/ISA, the issue is with the memory access architecture. By going from a parallel bus to a high-speed serial bus to access the memory, you need a microcontroller to act as the interface/translator between the high-speed serial connection and the physical connections to the memory. The firmware for this microcontroller is not open.
The are reasonable technical arguments for changing the approach to accessing the memory - so it likely is not just IBM deciding to be difficult. IBM get the 'intellectual property' (I hate that phrase) that mediates the memory access from a third party, and that third party is not known for being libre software friendly.
A 'quick fix' would be for the POWER10 processor to fall back to using an older (and slower) memory access approach that did not require third-party firmware, or uses libre firmware. This would compromise overall system performance, so is unlikely to be favoured.
Libre software is fairly well established, but libre hardware/firmware is not. It will take a long time, if ever, to get to a point where all the executable code on a system is libre - keyboard controllers, GPUs, LCD display controllers, HDMI/HDCP interfaces, USB3 interfaces: all can contain non-libre firmware, and we can add memory modules and SSD and hard disk controllers. It is not just Intel's ME and AMD's PSP we need to think about.