You could do it half-way, like the Transmeta chips, having an MMU for data only. Code doesn't need an MMU if it is relocatable, if it is installed as one big bl

You could do it half-way, like the Transmeta chips, having an MMU for data only. Code doesn't need an MMU if it is relocatable, if it is installed as one big blob like busybox, or if it is the result of a trusted JIT.