You can easily extend the firmware in your released, embedded system using ELF program provide via a file system. For example, an SD card or, perhaps, downloaded into on-board SPI FLASH.
There are two ways you can accomplish this:
- Partially linked. This describes building the partially linked, relocatable ELF program that depends on a symbol table provided by the base firmware in FLASH.
- Fully linked. This describes building a fully linked, relocatable ELF program that does not depend in any symbol table information.