[int_19h]

In an embedded scenario where the complete set of processes that are going to be running at the same time is known in advance, I would imagine that you could even just build the binaries with the correct base address in advance.

[actionfromafar]

A common trick to decrease code size in RAM, is to link everything to a single program, then have the program check its argv[0] to know which program to call.

With the right filesystem (certain kinds of read-only), the code (text segment) can even be mapped directly, and no loading into RAM need occur at all.

These approaches saves memory even on regular MMU platforms.