I ported Linux to an embedded system that booted straight into ash (minimal shell). Other than ash, it only had custom applications. We didn't bother with a separate init app even - ash served that role sufficiently well.
Linux has very minimal requirements of userspace - pretty much you need to have a process that will act as your init process that knows to wait to clean up any zombine processes now and again. The rest is pretty much up to how you want to organize things.
Linux has very minimal requirements of userspace - pretty much you need to have a process that will act as your init process that knows to wait to clean up any zombine processes now and again. The rest is pretty much up to how you want to organize things.