For any Amiga 4000 hobbyists running a Linux m68k operating system, a PCI driver was finally published three decades later for Linux. Patches posted for mainline Linux kernel review today enable the Mediator 4000 PCI bridge available for the Amiga 4000 computer from the early 90’s.
Commodore’s Amiga 4000 computer powered by a Motorola CPU, PATA-based storage, up to 18MB of RAM, and later on came the ability to have PCI adapters via replacement expansion boards. The Mediator PCI 4000 by Elbox is one such expansion board for providing five PCI slots that are PCI 2.1 compliant with a 33MHz PCI clock.
Daniel Palmer wrote a PCI driver and today posted it for review. He explained:
“This series adds a driver for the Mediator 4000 PCI bridge for the Amiga 4000.
Since this is my first PCI driver it’s probably awful so this is an RFC and also there is one interesting unsolved bit:
As far as I can tell the Mediator 4000 cannot do DMA between the normal memory and the PCI cards but PCI cards can DMA between themselves. In the AmigaOS drivers a bounce buffer is allocated on one of the cards that contains memory, like a graphics card, and that is used for PCI DMA. I’m not sure if that’s even possible to do in Linux?
I’ve managed to use a network card that doesn’t need DMA so far, but I’m having trouble getting a Voodoo 3000 or Radeon 9250 graphics card to come up properly. I guess no one tests their cutting edge graphics drivers on non-x86 machines. ;)”
Should any Amiga 4000 owners be interested, the code is now out for review on the mailing list.
