The PSoC is quite "bare", there is no operating system, so you are completely free in programming and you are only limited to the resources availlable. Programming is done in C-language (not C++). So you might implement your own OS-like environment if you like.
Components in the PSoC5 world are real hardware. The fixed-function versions are using pre-built blocks that can be configured to suit you needs. The UDB versions are more versatile: They are made out of blocks (there are 24 of them) looking all the same which contain registers, FIFOs, a programmable ALU, some PLD logic and some more stuff. You may program that blocks to define new components by using a HDL language as Verilog. The information on how to do that was installed with Creator in the documentation branch of the Cypress start menu entry.
Maybe i should have mentioned that i want to use a bootloadable project and want to use functions from the bootloader application without programming these into the bootloadable application except maybe the references...
There is an example concerning BLE Over The Air (OTA) upgrade. Since the BLE-stack is using quite a lot of resources there are methods shown how to use that in the project. Probably you can adapt that to your needs.
All the BLE examples use the BLE component which is only compatible with the PSoC 4 BLE.
However it is possible to place my code in de Bootloader application then create a library which is used in the bootloadable.
The components from the custom library will include (hardware) components and the functions will refer to the functions of the bootloader.
Solution was quite simple actually... just didn't think of it this way before.
Was struggling with the thought how to use the hardware components of the bootloader, why not just include the modified components in the bootloadable and use functions of the bootloader.