I received this bug report from a Debian user. It seems that something is
wrong with tt mode in 2.4.26-2um; I can reproduce a similar (though not
identical) hang by trying to boot with mode=tt (my host kernel is 2.6.6 with
skas3). In my case, it hangs after init has started. Booting in skas mode
works fine (which is why I didn't notice this in the first place).