I used make localyesconfig to strip the kernel down to just what's necessary for my hardware.

Unfortunately, when I boot up I get a purple screen (Ubuntu) and then the screen goes black. From the bottom of the screen white appears and 'spreads' (as if a slow liquid) across the screen. I then hold the power button and shut down.

This is with the lastest stable 3.11.5 kernel.

Wondering if this sounds like something in particular. I figured GPU, but in my config I do see that Radeon is *'d.

Thoughts?

Here's my config. You may be tempted to point out the grsec stuff, that's almost certainly not the issue as I've used every other kernel with grsec and the only thing that's changed is the make localyesconfig

http://pastebin.com/Q24yVTKA

I'm running a Sony VAIO VPCEC290X. intel CPU, Radeon GPU, samsung SSD. EXT4 drive with NTFS partition.

You've not given us much to work on - is this you (re-)compiling a "Ubuntu kernel", or a stock upstream kernel ?.
What efforts have you made to accommodate Ubuntus somewhat unique build ?.

As a side comment I never found Ubuntu a good environment on which to build a customised kernel. Although in my case it was before the new make targets were introduced (so my experience on Ubuntu is many years out of date).
I found Arch best fitted the way I work.

Stock upstream kernel.

'What efforts have you made to accommodate Ubuntus somewhat unique build ?.'

0. But I've built from upstream for a long time now just downloading kernel source. I just unpack the kernel, patch with grsecurity, set up a few things, and compile it/ install it.

Hmmm - seems like things have changed a bit.
What are you doing about plymouth ?. Are you using an initrd at all.
First step would be to get rid of the splash and see the boot messages.

Where does Plymouth factor in? And doesn't the system use initrd at boot? I checked to see if it still had ramdisk decompression support and it did. Is there somethign else I should check.

I had the splash disabled before, no boot messages. Just purple screen, then black.

Plymouth.
I don't use an initrd at all on my custom kernels.

Try removing "quiet" as well as "splash" from the boot line.

I didn't have Radeon configured as a framebuffer device. That may have been the issue. Recompiling now, I'll know in a couple of minutes. If it's something else I'll look into Plymouth.

So I removed splash/quiet. On my normal kernel it doesn't show purple and I see the output.

With this kernel it's still just purple and then black, so perhaps the kernel is not even managing to load at all?

I added in firmware for radeon. Still not working.