Architecture
Contents
Introduction
Ultibo core is, by design, intended to be a development environment for embedded devices which currently includes all models of the Raspberry Pi but this will most likely expand to include other popular development boards as time and resources permit. Because it is not an operating system and is not derived from an existing operating system, the design decisions made reflect the needs of the environment and intentionally leave out certain general purpose operating system concepts.
The unit of execution in Ultibo core is the thread, there is no concept of a process but multi threading is fundamental to the design and cannot be removed. There is also no concept of a user space or kernel space, all threads run within a single address space and all threads have equal privileges.
All elements are intended to be dynamic in their implementation, for example devices are intended to be added and removed dynamically with notifications used to signal interested parties about the addition or removal. Only a few internal items have a fixed limit, a specific example being TLS index slots which are statically allocated during boot.
The design is also intended to be modular so that only the required elements are included in any given application, a small number of mandatory elements are included in every application such as memory management, threading and scheduling, interrupt handling, device management and the core functionality of the FPC run time library. Most other features such as the filesystem and network interfaces, USB, MMC/SD and hardware specific drivers can be omitted if they are not required.
Platform support
Memory Management
Threads and Scheduling
Multiple CPUs
Global Configuration
Boot process
Initialization process
