Compile and then link the application code with the particular pieces of the toolkits that you needed and with the provided kernel into a single download image, and either embed or boot or network boot the target box using it. Remote debugging was available, as well as a relational database, etc.
One example of this general design is VAX ELN.
The following is a brochure from the V2.2 release, from 1986:
http://bitsavers.trailing-edge.com/pdf/dec/vax/vaxeln/2.0/VA...
Compile and then link the application code with the particular pieces of the toolkits that you needed and with the provided kernel into a single download image, and either embed or boot or network boot the target box using it. Remote debugging was available, as well as a relational database, etc.