Zephyr System Requirements

ZEP-SYRS-1: Architecture Layer Interface

The Zephyr RTOS shall provide a framework to communicate with a set of hardware architectural services.

Status:: Draft
Type:: Functional
Component:: Hardware Architecture Interface
User Story:: As a Zephyr RTOS user I want to be able to easily switch my application to a different MCU architecture (x86, ARM Cortex-M/A, RISCV etc.).

ZEP-SYRS-2: Support multiprocessor management

The Zephyr RTOS shall support symmetric multiprocessing on multiple cores.

Status:: Draft
Type:: Functional
Component:: Hardware Architecture Interface
User Story:: As a Zephyr RTOS user I want to use Zephyr OS on multi core (SMP-)MCUs/MPUs.
Parents:: ZEP-SYRS-1

ZEP-SYRS-3: Support Subset of Standard C Library

The Zephyr RTOS shall support a subset of the standard C library.

Status:: Draft
Type:: Functional
Component:: C Library
User Story:: As a Zephyr RTOS user I want to have a selection of standard C library implementations e.g. a full extend and a minimal with a smaller footprint or a particular fast executing implementation.

ZEP-SYRS-4: Device Driver Abstraction

The Zephyr RTOS shall provide a framework for managing device drivers and peripherals.

Status:: Draft
Type:: Functional
Component:: Device Drivers
User Story:: As a Zephyr RTOS user I want my application to be portable between different MCU architectures (ARM Cortex-M/A, Intel x86, RISCV etc.) and MCU vendors (STM, NXP, Intel, etc.) without having to change the MCU peripherals access.

ZEP-SYRS-5: Fatal error and exception handling

The Zephyr RTOS shall provide a framework for error and exception handling.

Status:: Draft
Type:: Functional
Component:: Exception and Error Handling
User Story:: As a Zephyr RTOS user I want errors and exceptions to handled and react according to my applications requirements (e.g. reach/establish the applications safety state).

ZEP-SYRS-6: Common File system operation support

The Zephyr RTOS shall provide a framework for managing file system access.

Status:: Draft
Type:: Functional
Component:: File Systems
User Story:: As a Zephyr RTOS user I want a posix / c like file system access to store data.

ZEP-SYRS-7: Interrupt Management

The Zephyr RTOS shall provide a framework for interrupt and interrupt service routine management.

Status:: Draft
Type:: Functional
Component:: Interrupts
User Story:: As the Zephyr RTOS user I want the Kernel to provide abstracted interfaces to the platform enabling me to implement standard interrupts interrupt service routines without detailed knowledge of the platform architecture and programming model.

ZEP-SYRS-20: Direct ISR, Platform Specific helpers.

Zephyr RTOS shall support development of direct ISRs by providing platform specific code fragments and factory functions including, minimal header instructions, minimal footer instructions, low power termination, and ISR construction.

Status:: Draft
Type:: Functional
Component:: Interrupts
User Story:: As the Zephyr RTOS user I want the Kernel to provide support for implementing standard low latency and low power interrupt service routines without detailed knowledge of the platform architecture and programming model.
Parents:: ZEP-SYRS-7

ZEP-SYRS-8: Logging

The Zephyr RTOS shall provide a framework for logging events.

Status:: Draft
Type:: Functional
Component:: Logging
User Story:: As a Zephyr RTOS user I want to be able to log application defined events as well as framework exceptions.

ZEP-SYRS-9: Memory Management framework

The Zephyr RTOS shall support a memory management framework.

Status:: Draft
Type:: Functional
Component:: Memory Management
User Story:: As a Zephyr RTOS user I want memory to be allocated and protected to my application threads preventing mistakenly access to foreign memory as far as the hardware allows.

ZEP-SYRS-10: Power Management

The Zephyr RTOS shall provide an interface to control hardware power states.

Status:: Draft
Type:: Functional
Component:: Power Management
User Story:: As a Zephyr RTOS user I want to be able to control the power mode of the MCU and its peripherals to take advantage of the hardware features and to be able to implement low power or battery driven long life applications.

ZEP-SYRS-11: Multiple CPU scheduling

The Zephyr RTOS shall support scheduling of threads on multiple hardware CPUs.

Status:: Draft
Type:: Functional
Component:: SMP and Multi core
User Story:: As a Zephyr RTOS user I want Zephyr OS to run on MCUs/CPUs with one or more CPU cores.

ZEP-SYRS-12: Scheduling

The Zephyr RTOS shall provide an interface to assign a thread to a specific CPU.

Status:: Draft
Type:: Functional
Component:: SMP and Multi core
User Story:: As a Zephyr RTOS user, I want to be able to control which thread will run on which CPU.

ZEP-SYRS-13: Mutex

The Zephyr RTOS shall provide an interface for managing communication between threads.

Status:: Draft
Type:: Functional
Component:: Mutex
User Story:: As a Zephyr RTOS user I want to able to exchange information between threads in a thread-safe manner guaranteeing data consistence.

ZEP-SYRS-14: Counting Semaphore

The system shall implement a semaphore synchronization primitive for coordinating access to shared resources among multiple threads.

Status:: Draft
Type:: Functional
Component:: Semaphore

ZEP-SYRS-15: Thread support

The Zephyr RTOS shall support threads.

Status:: Draft
Type:: Functional
Component:: Threads
User Story:: As a Zephyr RTOS user, I want to be able to have support for the kernel objects named threads for processing work.

ZEP-SYRS-16: Thread management

The Zephyr RTOS shall provide a framework for managing multiple threads of execution.

Status:: Draft
Type:: Functional
Component:: Threads
User Story:: As a Zephyr RTOS user, I want to be able to manage the execute of multiple threads with different priorities.

ZEP-SYRS-17: Thread priority

Threads shall have a priority.

Status:: Draft
Type:: Functional
Component:: Threads
User Story:: As a Zephyr RTOS user, I want to be able to give my threads different priorities for execution.

ZEP-SYRS-18: Timers

The Zephyr RTOS shall provide a framework for managing time-based events.

Status:: Draft
Type:: Functional
Component:: Timers
User Story:: As a Zephyr RTOS user, I want to start, suspend, resume and stop timers which shall trigger an event on a set expiration time.

ZEP-SYRS-19: Tracing

Zepyhr shall provide a framework mechanism for tracing low level system operations (NOTE: system calls, interrupts, kernel calls, thread, synchronization, etc.).

Status:: Draft
Type:: Functional
Component:: Tracing
User Story:: As a Zephyr RTOS user, I want to be able to trace different OS operations.

ZEP-SYRS-21: Condition Variables

The Zephyr RTOS shall provide a framework to synchronize threads based on a condition variable.

Status:: Draft
Type:: Non-Functional
Component:: Condition Variables

ZEP-SYRS-22: Queues data passing

The Zephyr RTOS shall implement a queue which can be used to pass data between threads and interrupt service routines.

Status:: Draft
Type:: Functional
Component:: Queues

ZEP-SYRS-23: LIFOs data passing

The Zephyr RTOS shall implement a LIFOs which can be used to pass data between threads and interrupt service routines.

Status:: Draft
Type:: Functional
Component:: LIFOs

ZEP-SYRS-24: FIFOs data passing

The Zephyr RTOS shall implement FIFOs which can be used to pass data between threads and interrupt service routines.

Status:: Draft
Type:: Functional
Component:: FIFOs

ZEP-SYRS-25: Mailboxes

The Zephyr RTOS shall provide a framework to pass messages of arbitrary size between threads.

Status:: Draft
Type:: Functional
Component:: Mailboxes

ZEP-SYRS-26: Atomic Service

The Zephyr RTOS shall provide an interface to perform atomic operations on variables, guaranteeing that all reads and writes are free from tearing across all processors.

Status:: Draft
Type:: Functional
Component:: Atomic Service

ZEP-SYRS-30: Stacks

The Zephyr RTOS shall implement a stack which can be used to pass data between threads and interrupt service routines.

Status:: Draft
Type:: Functional
Component:: Stacks