Ultra10 console problems

I need some help debugging this. A pointer on how to begin would be helpful....

I have a Sun Ultra 10, usually headless, running sid. Kernel 2.4.26-6 works fine. The boot completes normally, and the console is a functional and bland white characters on black background. Once the boot completes, I get a "login:" prompt, and I can type "root" and "********" and get logged in fine.

The available builds (apt-get) of kernels 2.6.8, 2.6.12, 2.6.14-1-sparc64, 2.6.14-2-sparc64, and 2.6.14-4-sparc64 fail to complete the boot process.

The last message I see is "Booting Linux" on the console. I do not have a serial console set up, so I don't know whether it locks at that point, but it appears to.

I have installed the 2.6.14 source, and if I build the kernel using the default configuration options, I get a kernel that will boot, and comes to a "login:" prompt without issue. After the boot, however, the console is unusable. In other words, I can type "root" and "********", but the system doesn't log me in, and an ssh from another system confirms that a) the system is up, and b) who shows that no one else is logged in.

One thing I notice with 2.6.14 is that the console has switched from white characters on black background to black characters on a white background.

One other thing I notice is that when "Booting Linux" comes up, the num lock, caps lock, scrool lock, and compose flash on then off, and nothing else happens as far as I can tell.

I am not running X, and as far as I know, there are no hardware problems.

Any suggestions?

Would setting up a serial console help debug this issue? [If so, I'll have to figure out how to do that....]

Thank you.

Cheers,
Dave