The ssystem is an old eMachines desktop PC with a Cyrix MII/266 processor. Using the 7.0.91 Beta ISO images the machine loads kernel just fine but just after the memory information line I get the message: Checking if this processor honours the WP bit even in supervisor mode... and the system then hangs. This seems to come from the kernel source file arch/i386/mm/init.c but I do not profess to know any more than that; it's not a bit of the kernel I've ever looked at. Suffice it to say it looks like RedHat 7.1 will not boot on old Cyrix machines as it stands.
This problem manifested itself also for some 486's. It was caused by a fix for an SMP race in vmalloc which broke the "WP" test for several older CPU types. A fix for this breakage will be in the next kernel we build.