Kernel panic in "early reservation" stage

[dunkirk]

My usual method of running Gentoo is to install the machine initially using genkernel, for the most part. The first time around, I'll let it configure, then I'll step in and tweak the build to my CPU with a menuconfig, and then I'll run `genkernel --no-clean all' to let it handle the image, initrd, and copying. As new kernels are released, I copy the .config from the old kernel tree to the new one, `make oldconfig', and then `genkernel --no-clean all'. I don't know how "proper" this method is, but it's worked well across a dozen machines for the 4 years I've been running Gentoo. I say all of that to set this up:

I've got an old PII which I use for a firewall/NAT box. It runs the hardened profile and toolchain. I just updated all of its software, and I can't get the gentoo-sources-2.6.28-r9 kernel to run on it. I tried and had to abandon my usual genkernel habit. I've let the kernel do a default config, and tweaked it from there. I've done the tweak, compile, reboot cycle about a dozen times now. (And on this old machine, that take a LONG time.) It always hangs right after it expands the kernel. I get the line "Booting the kernel", and then nothing.

I finally put `earlyprintk' on the grub boot line, and I can see that it's panic'ing with "overlapping early reservations". Specifically, I see "2000-5fff ACPI wakeup code to 1000-3fff BOOTMAP" are interfering. Thinking, aha!, it's ACPI, and this old machine doesn't even have it, I tried `noacpi' on the kernel boot line. That didn't work, so I removed ALL power management from the kernel, and THAT didn't work either.

So I'm at a loss, and I've never seen this sort of thing before. I don't see much about it on Google, and I don't know where to go from here. Is this an honest-to-goodness kernel bug? If so what's the procedure to try to get some help from the kernel mailing list. I've never been there before, and I've been around long enough to know by third-hand accounts that it's not a place to tread lightly... ;-)
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