Zephyr System Requirements

Type	Level	UID	REFS	Title	Statement
Text					SPDX-License-Identifier: Apache-2.0
Requirement	1	ZEP-SYRS-1	Children: ZEP-SRS-19-1 Atomic Operations ZEP-SRS-19-2 Thread Context Switching ZEP-SRS-19-3 Software Exceptions ZEP-SRS-19-4 Processor Mode Support ZEP-SYRS-2 Support multiprocessor management	Architecture Layer Interface	The Zephyr RTOS shall provide a framework to communicate with a set of hardware architectural services.
Requirement	2	ZEP-SYRS-2	Parents: ZEP-SYRS-1 Architecture Layer Interface	Support multiprocessor management	The Zephyr RTOS shall support symmetric multiprocessing on multiple cores.
Requirement	3	ZEP-SYRS-3	Children: ZEP-SRS-18-1 Formatted output ZEP-SRS-18-2 Floating Point Math Support ZEP-SRS-18-3 Boolean Primitives Support ZEP-SRS-18-4 Standard Unix time interface ZEP-SRS-18-5 Strings support ZEP-SRS-18-6 Moving/copying regions of memory ZEP-SRS-18-7 I/O based interface ZEP-SRS-18-8 C99 integer types ZEP-SRS-18-9 Standard System Error Numbers (IEEE Std 1003.1-2017) ZEP-SRS-18-10 Document set of Zephyr OS required C library functions in Safety Manual ZEP-SRS-18-11 Support external C libraries documentation in Zephyr Safety Manual	Support Subset of Standard C Library	The Zephyr RTOS shall support a subset of the standard C library.
Requirement	4	ZEP-SYRS-4		Device Driver Abstraction	The Zephyr RTOS shall provide a framework for managing device drivers and peripherals.
Requirement	5	ZEP-SYRS-5		Fatal error and exception handling	The Zephyr RTOS shall provide a framework for error and exception handling.
Requirement	6	ZEP-SYRS-6		Common File system operation support	The Zephyr RTOS shall provide a framework for managing file system access.
Requirement	7	ZEP-SYRS-7	Children: ZEP-SRS-7-1 Installing static IRQ service routines (ISR). ZEP-SRS-7-2 Static IRQ initial status. ZEP-SRS-7-3 Installing direct IRQ service routines (ISR). ZEP-SRS-7-4 Direct IRQ initial status. ZEP-SRS-7-5 Installing dynamic IRQ service routines (ISR). ZEP-SRS-7-6 Dynamic IRQ initial status. ZEP-SRS-7-7 Uninstalling dynamic IRQ service routines (ISR). ZEP-SRS-7-8 Global IRQ disable ZEP-SRS-7-9 Global IRQ enable ZEP-SRS-7-10 Specific IRQ disable ZEP-SRS-7-11 Specific IRQ enable ZEP-SRS-7-12 IRQ Enabled status ZEP-SRS-7-13 ISR Context status ZEP-SRS-7-14 Multi-level interrupts ZEP-SYRS-20 Direct ISR, Platform Specific helpers.	Interrupt Management	The Zephyr RTOS shall provide a framework for interrupt and interrupt service routine management.
Requirement	8	ZEP-SYRS-20	Parents: ZEP-SYRS-7 Interrupt Management Children: ZEP-SRS-21-1 Dynamic initialization of condition variables ZEP-SRS-21-2 Static initialization of condition variables ZEP-SRS-21-3 Signal one waiting thread ZEP-SRS-21-4 Signal multiple waiting threads ZEP-SRS-21-5 Wait on a condition variable ZEP-SRS-21-6 Wait timeout on a condition variable ZEP-SRS-21-7 Wait timeout occurence ZEP-SRS-21-8 Release mutex on wait ZEP-SRS-21-9 Unblock a waiting thread	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.
Requirement	9	ZEP-SYRS-8		Logging	The Zephyr RTOS shall provide a framework for logging events.
Requirement	10	ZEP-SYRS-9		Memory Management framework	The Zephyr RTOS shall support a memory management framework.
Requirement	11	ZEP-SYRS-10		Power Management	The Zephyr RTOS shall provide an interface to control hardware power states.
Requirement	12			Multi core and SMP
Requirement	12.1	ZEP-SYRS-11		Multiple CPU scheduling	The Zephyr RTOS shall support scheduling of threads on multiple hardware CPUs.
Requirement	12.2	ZEP-SYRS-12		Scheduling	The Zephyr RTOS shall provide an interface to assign a thread to a specific CPU.
Requirement	13			Thread Synchronization
Requirement	13.1	ZEP-SYRS-13		Mutex	The Zephyr RTOS shall provide an interface for managing communication between threads.
Requirement	13.2	ZEP-SYRS-14	Children: ZEP-SRS-5-1 Counting Semaphore Definition At Compile Time ZEP-SRS-5-2 Counting Semaphore Definition At Run Time ZEP-SRS-5-4 Initialialization with maximum count value ZEP-SRS-5-5 Initial semaphore value ZEP-SRS-5-6 Semaphore acquisition mechanism ZEP-SRS-5-7 Semaphore acquisition with count greater than zero ZEP-SRS-5-8 Semaphore acquisition with zero count ZEP-SRS-5-9 Semaphore acquisition timeout ZEP-SRS-5-10 Semaphore acquisition timeout error handling ZEP-SRS-5-11 Semaphore acquisition no wait error handling ZEP-SRS-5-12 Semaphore release ZEP-SRS-5-13 Semaphore release ZEP-SRS-5-14 Semaphore release with priority inheritance ZEP-SRS-5-15 Checking semaphore count ZEP-SRS-5-16 Semaphore reset ZEP-SRS-5-17 Semaphore acquisitions abort after reset ZEP-SRS-5-18 Semaphore Initialization Option Validation	Counting Semaphore	The system shall implement a semaphore synchronization primitive for coordinating access to shared resources among multiple threads.
Requirement	14			Threads
Requirement	14.1	ZEP-SYRS-15	Children: ZEP-SRS-2-4 Scheduling a thread based on an event ZEP-SRS-1-1 Creating threads ZEP-SRS-1-3 Suspending a thread ZEP-SRS-1-4 Resuming a suspended thread ZEP-SRS-1-5 Resuming a suspended thread after a timeout ZEP-SRS-1-6 Deleting a thread ZEP-SRS-1-7 Thread states ZEP-SRS-1-8 Thread stack objects ZEP-SRS-1-9 Thread privileges ZEP-SRS-1-11 Thread Options ZEP-SRS-1-12 Thread Custom Data	Thread support	The Zephyr RTOS shall support threads.
Requirement	14.2	ZEP-SYRS-16	Children: ZEP-SRS-1-1 Creating threads ZEP-SRS-1-3 Suspending a thread ZEP-SRS-1-4 Resuming a suspended thread ZEP-SRS-1-5 Resuming a suspended thread after a timeout ZEP-SRS-1-6 Deleting a thread ZEP-SRS-1-7 Thread states ZEP-SRS-1-8 Thread stack objects ZEP-SRS-1-9 Thread privileges ZEP-SRS-1-10 Scheduling multiple threads ZEP-SRS-1-11 Thread Options ZEP-SRS-1-12 Thread Custom Data	Thread management	The Zephyr RTOS shall provide a framework for managing multiple threads of execution.
Requirement	14.3	ZEP-SYRS-17	Children: ZEP-SRS-1-2 Setting thread priority	Thread priority	Threads shall have a priority.
Requirement	15	ZEP-SYRS-18	Children: ZEP-SRS-4-1 Timer definition at compile time ZEP-SRS-4-2 Timer expiry function ZEP-SRS-4-3 Timer stop function ZEP-SRS-4-4 Timer definition at run time ZEP-SRS-4-5 Timer start ZEP-SRS-4-6 Timer stop ZEP-SRS-4-7 Timer status ZEP-SRS-4-8 Timer status reinitialization ZEP-SRS-4-9 Timer thread synchronization ZEP-SRS-4-10 Timer next expiration time in system ticks ZEP-SRS-4-11 Timer remaining time until expiration in system ticks ZEP-SRS-4-12 Timer remaining time until expiration in milliseconds ZEP-SRS-4-13 Timer set user data ZEP-SRS-4-14 Timer get user data ZEP-SRS-4-15 Timer expire functions in interrupt context	Timers	The Zephyr RTOS shall provide a framework for managing time-based events.
Requirement	16	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.).
Requirement	17			Condition Variables
Requirement	17.1	ZEP-SYRS-21	Children: ZEP-SRS-24-11 Queue definition at compile time ZEP-SRS-20-1 Queue definition at compile time ZEP-SRS-20-2 Queue definition at run time. ZEP-SRS-20-3 Queue enqueue item to the back ZEP-SRS-20-4 Queue enqueue item to the front ZEP-SRS-20-5 Queue remove item ZEP-SRS-20-6 Queue get and dequeue item from front ZEP-SRS-20-7 Queue empty check ZEP-SRS-20-8 Queue peek item at back ZEP-SRS-20-9 Queue peek item at front ZEP-SRS-20-10 Queue insert ZEP-SRS-20-11 Queue append item list to the back ZEP-SRS-20-12 Queue append and empty item list to the back ZEP-SRS-20-13 Queue append unique data item ZEP-SRS-20-14 Queue implicit memory allocation	Condition Variables	The Zephyr RTOS shall provide a framework to synchronize threads based on a condition variable.
Requirement	18			Queues
Requirement	18.1	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.
Requirement	19			LIFOs
Requirement	19.1	ZEP-SYRS-23	Children: ZEP-SRS-23-1 LIFO definition at compile time ZEP-SRS-23-2 LIFO enqueue item to the back ZEP-SRS-23-3 LIFO implicit memory allocation ZEP-SRS-23-4 LIFO get and dequeue item from front ZEP-SRS-23-5 Queue definition at compile time	LIFOs data passing	The Zephyr RTOS shall implement a LIFOs which can be used to pass data between threads and interrupt service routines.
Requirement	20			FIFOs
Requirement	20.1	ZEP-SYRS-24	Children: ZEP-SRS-24-1 FIFO definition at compile time ZEP-SRS-24-2 FIFO cancel waiting thread ZEP-SRS-24-3 FIFO enqueue item to the back ZEP-SRS-24-4 FIFO implicit memory allocation ZEP-SRS-24-5 FIFO append item list to the back ZEP-SRS-24-6 FIFO append and empty item list to the back ZEP-SRS-24-7 FIFO get and dequeue item from front ZEP-SRS-24-8 FIFO empty check ZEP-SRS-24-9 FIFO peek item at front ZEP-SRS-24-10 FIFO peek item at back	FIFOs data passing	The Zephyr RTOS shall implement FIFOs which can be used to pass data between threads and interrupt service routines.