Part V: Kernel Configuration

This chapter details the available configuration options, covering system parameters, scheduling settings, memory protection, interrupt handling, and enabled services. QuantumRT settings are defined at compile-time and must be adjusted before building the kernel. Developers can:

Enable or disable kernel features (e.g., FPU support, caching).
Adjust system parameters (e.g., thread limits, total memory allocated for thread stacks).
Define memory protection settings (e.g., MPU regions).

Configuration Options

Configuration options for generic ARM Cortex-M3 microcontrollers.

Allows configuring processor core, MPU, FPU, System Timer, scheduler, interrupt handling, IPC and kernel.

Copyright: Copyright (c) 2025 TNX Software Ltd. All rights reserved. Licensed under the terms of the QuantumRT Kernel License. the LICENSE file in the root of this package for details.

Defines

QRT_CFG_CPU_CORE

Options:

QRT_CPU_CORTEX_M0P
QRT_CPU_CORTEX_M3
QRT_CPU_CORTEX_M4
QRT_CPU_CORTEX_M7
QRT_CPU_CORTEX_M23
QRT_CPU_CORTEX_M33
QRT_CPU_CORTEX_M35P
QRT_CPU_CORTEX_M52
QRT_CPU_CORTEX_M55
QRT_CPU_CORTEX_M85

QRT_CFG_ICACHE_ENABLE

Enable instruction cache (if supported by CPU core)

Options:

0: Instruction cache disabled
1: Instruction cache enabled

QRT_CFG_DCACHE_ENABLE

Enable data cache (if supported by CPU core)

Options:

0: Data cache disabled
1: Data cache enabled

QRT_CFG_THREAD_LIMIT: Maximum number of threads.

QRT_CFG_CLEANUP_LIMIT: Maximum cleanup handlers per thread.

QRT_CFG_STACK_POOL_SIZE: Total stack pool size in bytes.

QRT_CFG_THREAD_STACK_DEFAULT: Default thread stack size in bytes.

QRT_CFG_THREAD_STACK_LIMIT_CHECK

Enable stack limit checking for threads (ARMv8-M only)

Options:

0: Stack limit checking disabled
1: Stack limit checking enabled

QRT_CFG_THREAD_NAME_ENABLE

Enable thread naming support.

Options:

0: Thread naming disabled
1: Thread naming enabled

QRT_CFG_SCHED_TIME_SLICE: Default time slice in milliseconds.

QRT_CFG_IDLE_STACK_SIZE: Idle thread stack size in bytes.

QRT_CFG_IDLE_SLEEP_ENABLE

Enable sleep mode in idle thread.

Options:

0: Sleep disabled (most clock signals stopped)
1: Sleep enabled (CPU enters sleep mode when idle)

QRT_CFG_IDLE_DEEP_SLEEP_ENABLE

Enable deep sleep mode in idle thread. Overrides configuration option QRT_CFG_IDLE_SLEEP_ENABLE.

Options:

0: Deep sleep disabled (all clock signals stopped)
1: Deep sleep enabled (CPU enters deep sleep mode when idle)

QRT_CFG_ATOMIC_DISABLE_IRQ

Atomic operation method.

Options:

0: Use LDREX/STREX instructions for atomic operations
1: Disable interrupts for atomic operations

QRT_CFG_MPU_ENABLE

Enable Memory Protection Unit support.

Options:

0: MPU disabled (all memory accessible)
1: MPU enabled (enforces memory access restrictions)

QRT_CFG_MPU_ENTRIES: Number of MPU regions to configure.

QRT_CFG_TZ_SECURE_WORLD

TrustZone configuration (ARMv8-M only)

Options:

0: Running in Non-Secure World
1: Running in Secure World

QRT_CFG_SEMAPHORE_ENABLE

Enable semaphore support.

Options:

0: Semaphores disabled
1: Semaphores enabled

QRT_CFG_MUTEX_ENABLE

Enable mutex support.

Options:

0: Mutexes disabled
1: Mutexes enabled

QRT_CFG_MUTEX_LIST_SIZE: Maximum mutexes a thread can hold simultaneously.

QRT_CFG_MESSAGE_QUEUE_ENABLE

Enable message queue support.

Options:

0: Message queues disabled
1: Message queues enabled

QRT_CFG_MESSAGE_QUEUE_LIMIT: Maximum number of message queues.

QRT_CFG_MESSAGE_QUEUE_NAME_LIMIT: Maximum message queue name length.

QRT_CFG_TIMER_ENABLE

Enable software timer support.

Options:

0: Software timers disabled
1: Software timers enabled

QRT_CFG_TIMER_LIMIT: Maximum number of software timers.

QRT_CFG_ERRNO_ENABLE

Enable errno support.

Options:

0: errno disabled
1: errno enabled

QRT_CFG_DEFER_ENABLE

Enable deferred calls.

Options:

0: Deferred calls disabled
1: Deferred calls enabled

QRT_CFG_DEFER_LIMIT: Maximum number of deferred interrupt calls.

QRT_CFG_SYSCALL_EXT_ENABLE

Enable System Call Extension support (requires MPU)

Options:

0: System Call Extensions disabled
1: System Call Extensions enabled

QRT_CFG_SYSCALL_EXT_LIMIT: Maximum number of registered System Call Extensions.

QRT_CFG_KERNEL_HEAP_SIZE: Kernel heap size in bytes.

QRT_CFG_FPU_ENABLE

Enable Floating-Point Unit support.

Options:

0: FPU disabled (no floating-point support)
1: FPU enabled (floating-point operations supported)

QRT_CFG_FPU_STACK_ENABLE

Enable FPU context stacking.

Options:

0: Never save FPU context (single-thread FPU use only)
1: Save FPU context on context switches (multi-thread FPU support)