kernel 2.6.5 hangs on boot

Hi list,

On booting into a newly compiled kernel 2.6.5, my Sparc20 hangs:

SILO boot: kernel2.6.5
PROMLIB: obio_ranges 5
Booting Linux...

And that's as far as it gets. gcc-3.3.3 was built on the same machine
specifically for compiling the kernel. The kernel build went relatively
trouble free, other than dying once with this error:

drivers/serial/8250.c:103:24: asm/serial.h: No such file or directory

A make menuconfig later, disabling support for the 8250 driver, and the
kernel then built cleanly.

Any clues would be much appreciated - or pointers to prebuilt 2.4+
series kernels.

Thanks