9650 / Jackhammer SCSI installation hang

[RobotsAreWe]

I've got this Workgroup Server 9650/350 sitting around my office that I can't get the gentoo install kernel to work properly on. I think it's a scsi problem. Here is how the drives are laid out:
Onboard scsi (bus 0):
1.2gb id 2 (1 partition, MacOS 8.6)
2.0gb id 3 (unpartitioned space, destined to be the boot device)
CD-Rom id 6
StreamLogic Jackhammer SCSI card (bus 2):
2x 4.5gb (currently both have separate 500mb HFS partitions and a joint 3.5gb RAID-1 HFS partition that I want to toast, and commit the entire thing to a 9gb RAID-0)

Since this is an old world mac, I had to use the BootX installer on the Gentoo 1.2 PPC CD. The install went fine. I rebooted the machine, watched linux attempt to bootstrap itself, but the last line printed on the console before it hangs indefinitely is:

Serial driver version 5.05c (2001-07-08) with MANY_PORTS SHARE_IRQ SERIAL_PCI enabled

Then, bam. Nothing more. Tux keeps smiling at me from the top of the framebuffer console :)

What is the likely cause of the problem? Is it choking on the jackhammer card? In any case I'm not very confident in the hardware of this machine because it was behaving a bit flakey during the drive setup / MacOS install: hanging occasionally on boot etc., but its behavior is consistant when trying to boot to the gentoo install image. It does the exact same thing, every time.

I thought there might be some boot arguments pertinant to this scsi controller (I mean, c'mon, this thing is stock!) so I went through the kernel parameters documentation but didn't see anything that helpful

I've got a few years experience using linux and have done a few gentoo installs, including on the G3 that I'm typing this on, but I think i'm in a little over my head.

Can anybody help me? I'd much rather see this thing running linux than MacOS since linux can do far more than just appleshare IP.

[Gerk]

Try turning off serial support in your kernel... it seems to be the last thing it loads at death, and I've seen these problems with other oldworld machines (such as umax clones).

[Gerk]

Actually I think I've narrowed it down to PNP support. Turning off PNP support seems to solve all these serial hangs (as it probably tries to PNP detect your serial when it shouldn't)