Mark Furneaux | Finally Installing a Proper SAS HBA in My File Server @TheUbuntuGuy | Uploaded June 2016 | Updated October 2024, 15 hours ago.
I've finally gotten me one of those fancy server cards.
You can skip my ramble and see the install from 17:11 onwards.
I should also mention that these cards are PowerPC, not ARM.

Cross-flashing instructions here:
servethehome.com/ibm-serveraid-m1015-part-4

Lexi's Tek: youtube.com/channel/UCr6YQHk1n2cBS0-vKC7XM3A

I have a second channel:
youtube.com/channel/UCN3Dgu6CVBcecDkc5DmIIqw