Changes between FreeRTOS V11.0.0 and FreeRTOS V11.0.1 released December 21, 2023
Changes between FreeRTOS V10.6.2 and FreeRTOS V11.0.0 released December 18, 2023
+ SMP merged into the mainline: While FreeRTOS introduced Asymmetric
Multiprocessing (AMP) support in 2017, FreeRTOS Version 11.0.0 is the
first to merge Symmetric Multiprocessing (SMP) support into the mainline
release. SMP enables one instance of the FreeRTOS Kernel to schedule tasks
across multiple identical processor cores. We thank Mike Bruno and Jerry
McCarthy of XMOS and, Darian Liang, Sudeep Mohanty and Zim Kalinowski of
Espressif Systems for their contributions.
+ Switch MISRA compliance checking from PC Lint to Coverity, and update from
MISRA C:2004 to MISRA C:2012.
+ Add a template FreeRTOSConfig.h, inclusive of an abbreviated explanation of
each configuration item. Application writers can use this template as a
starting point to create the FreeRTOSConfig.h file for their application.
+ Add a template FreeRTOS port which can be used as a starting point for
developing a new FreeRTOS port.
+ Add bounds checking and obfuscation to internal heap block pointers in
heap_4.c and heap_5.c to help catch pointer corruptions. The application can
enable these checks by setting configENABLE_HEAP_PROTECTOR to 1 in their
FreeRTOSConfig.h. We thank @oliverlavery for their contribution.
+ Update vTaskList and vTaskGetRunTimeStats APIs to replace the use of sprintf
with snprintf.
+ Add trace macros to ports that enable tracing the interaction of ISRs with
scheduler events. We thank @conara for their contribution.
+ Add trace macros that enable tracing of entering and exiting all APIs. We
thank @Techcore123 for their contribution.
+ Add uxTaskBasePriorityGet and uxTaskBasePriorityGetFromISR APIs to get the
base priority of a task. The base priority of a task is the priority that
was last assigned to the task - which due to priority inheritance, may not
be the current priority of the task.
+ Add pdTICKS_TO_MS macro to convert time in FreeRTOS ticks to time in
milliseconds. We thank @Dazza0 for their contribution.
+ Add default implementations of vApplicationGetIdleTaskMemory and
vApplicationGetTimerTaskMemory. The application can enable these default
implementations by setting configKERNEL_PROVIDED_STATIC_MEMORY to 1 in their
FreeRTOSConfig.h. We thank @mdnr-g for their contribution.
+ Update vTaskGetInfo to include start and end of the stack whenever both
values are available. We thank @vinceburns for their contribution.
+ Prevent tasks waiting for a notification from being resumed by calls to
vTaskResume or vTaskResumeFromISR. We thank @Moral-Hao for their
contribution.
+ Add asserts to validate that the application has correctly installed
FreeRTOS handlers for PendSV and SVCall interrupts on Cortex-M devices.
We thank @jefftenney for their contribution.
+ Rename ARM_CA53_64_BIT and ARM_CA53_64_BIT_SRE ports to Arm_AARCH64 and
Arm_AARCH64_SRE respectively as these ports are applicable to all AArch64
architecture. We thank @urutva for their contribution.
+ Add CMake support to allow the application writer to select the RISC-V
chip extension. We thank @JoeBenczarski for their contribution.
+ Add CMake support to allow the application writer to build an application
with static allocation only. We thank @conara for their contribution.
+ Make taskYIELD available to unprivileged tasks for ARMv8-M ports.
+ Update Cortex-M23 ports to not use PSPLIM_NS. We thank @urutva for their
contribution.
+ Update the SysTick setup code for ARMv8-M ports to first configure the clock
source and then enable SysTick. This is needed to address a bug in QEMU
versions older than 7.0.0, which causes an emulation error if SysTick is
enabled without first selecting a valid clock source. We thank @jefftenney
for their contribution.
+ Add the port-optimized task selection algorithm optionally available for
ARMv7-M ports to the ARMv8-M ports. We thank @jefftenney for their
contribution.
+ Improve the speed of pvPortMalloc in heap_4.c and heap_5.c by removing
unnecessary steps while splitting a large memory block into two. We thank
@Moral-Hao for their contribution.
+ Shorten the critical section in pvPortMalloc in heap_2.c, heap_4.c and
heap_5.c by moving the size calculation out of the critical section. We thank
@Moral-Hao for their contribution.
+ Update xTaskNotifyWait and ulTaskNotifyTake to remove the non-deterministic
operation of traversing a linked link from a critical section. We thank
@karver8 for their contribution.
+ Fix stack end and stack size computation in POSIX port to meet the stack
alignment requirements on MacOS. We thank @tegimeki for their contribution.
+ Update the vTaskPrioritySet implementation to use the new priority when the
task has inherited priority from a mutex it is holding, and the new priority
is bigger than the inherited priority. We thank @Moral-Hao for their
contribution.
+ Add stack alignment adjustment if stack grows upwards. We thank @ivq for
their contribution.
+ Fix pxTopOfStack calculation in configINIT_TLS_BLOCK when picolib C is
selected as the C library implementation to ensure that
pxPortInitialiseStack does not overwrite the data in the TLS block portion
of the stack. We thank @bebebib-rs for their contribution.
+ Fix vPortEndScheduler() for the MSVC port so that the function
prvProcessSimulatedInterrupts is not stuck in an infinite loop when the
scheduler is stopped. We thank @Ju1He1 for their contribution.
+ Add the Pull Request (PR) Process explaining the stages a PR goes through.
Changes between FreeRTOS V10.6.1 and FreeRTOS V10.6.2 released November 29, 2023
+ Add the following improvements to the new MPU wrapper (mpu_wrappers_v2.c)
introduced in version 10.6.0:
- Introduce Access Control List (ACL) feature to allow the application
writer to control an unprivileged task’s access to kernel objects.
- Update the system call entry mechanism to only require one Supervisor
Call (SVC) instruction.
- Wrap parameters for system calls with more than four parameters in a
struct to avoid special handling during system call entry.
- Fix 2 possible integer overflows.
- Convert some asserts to run time parameter checks.
Changes between FreeRTOS V10.6.0 and FreeRTOS V10.6.1 released August 17, 2023
+ Add runtime parameter checks to functions in mpu_wrappers_v2.c file.
The same checks are already performed in API implementations using
asserts.
We thank the following people for their inputs in these changes:
- Lan Luo, Zixia Liu of School of Computer Science and Technology,
Anhui University of Technology, China.
- Xinwen Fu of Department of Computer Science, University of
Massachusetts Lowell, USA.
- Xinhui Shao, Yumeng Wei, Huaiyu Yan, Zhen Ling of School of
Computer Science and Engineering, Southeast University, China.
Changes between FreeRTOS V10.5.1 and FreeRTOS 10.6.0 released July 13, 2023
+ Add a new MPU wrapper that places additional restrictions on unprivileged
tasks. The following is the list of changes introduced with the new MPU
wrapper:
1. Opaque and indirectly verifiable integers for kernel object handles:
All the kernel object handles (for example, queue handles) are now
opaque integers. Previously object handles were raw pointers.
2. Save the task context in Task Control Block (TCB): When a task is
swapped out by the scheduler, the task's context is now saved in its
TCB. Previously the task's context was saved on its stack.
3. Execute system calls on a separate privileged only stack: FreeRTOS
system calls, which execute with elevated privilege, now use a
separate privileged only stack. Previously system calls used the
calling task's stack. The application writer can control the size of
the system call stack using new configSYSTEM_CALL_STACK_SIZE config
macro.
4. Memory bounds checks: FreeRTOS system calls which accept a pointer
and de-reference it, now verify that the calling task has required
permissions to access the memory location referenced by the pointer.
5. System calls restrictions: The following system calls are no longer
available to unprivileged tasks:
- vQueueDelete
- xQueueCreateMutex
- xQueueCreateMutexStatic
- xQueueCreateCountingSemaphore
- xQueueCreateCountingSemaphoreStatic
- xQueueGenericCreate
- xQueueGenericCreateStatic
- xQueueCreateSet
- xQueueRemoveFromSet
- xQueueGenericReset
- xTaskCreate
- xTaskCreateStatic
- vTaskDelete
- vTaskPrioritySet
- vTaskSuspendAll
- xTaskResumeAll
- xTaskGetHandle
- xTaskCallApplicationTaskHook
- vTaskList
- vTaskGetRunTimeStats
- xTaskCatchUpTicks
- xEventGroupCreate
- xEventGroupCreateStatic
- vEventGroupDelete
- xStreamBufferGenericCreate
- xStreamBufferGenericCreateStatic
- vStreamBufferDelete
- xStreamBufferReset
Also, an unprivileged task can no longer use vTaskSuspend to suspend
any task other than itself.
We thank the following people for their inputs in these enhancements:
- David Reiss of Meta Platforms, Inc.
- Lan Luo, Xinhui Shao, Yumeng Wei, Zixia Liu, Huaiyu Yan and Zhen Ling
of School of Computer Science and Engineering, Southeast University,
China.
- Xinwen Fu of Department of Computer Science, University of
Massachusetts Lowell, USA.
- Yueqi Chen, Zicheng Wang, Minghao Lin, Jiahe Wang of University of
Colorado Boulder, USA.
+ Add Cortex-M35P port. Contributed by @urutva.
+ Add embedded extension (RV32E) support to the IAR RISC-V port.
+ Add ulTaskGetRunTimeCounter and ulTaskGetRunTimePercent APIs. Contributed by
@chrisnc.
+ Add APIs to get the application supplied buffers from statically
created kernel objects. The following new APIs are added:
- xTaskGetStaticBuffers
- xQueueGetStaticBuffers
- xQueueGenericGetStaticBuffers
- xSemaphoreGetStaticBuffer
- xEventGroupGetStaticBuffer
- xStreamBufferGetStaticBuffers
- xMessageBufferGetStaticBuffers
These APIs enable the application writer to obtain static buffers from
the kernel object and free/reuse them at the time of deletion. Earlier
the application writer had to maintain the association of static buffers
and the kernel object in the application. Contributed by @Dazza0.
+ Add Thread Local Storage (TLS) support using picolibc function. Contributed
by @keith-packard.
+ Add configTICK_TYPE_WIDTH_IN_BITS to configure TickType_t data type. As a result,
the number of bits in an event group also increases with big data type. Contributed
by @Hadatko.
+ Update eTaskGetState and uxTaskGetSystemState to return eReady for pending ready
tasks. Contributed by @Dazza0.
+ Update heap_4 and heap_5 to add padding only if the resulting block is not
already aligned.
+ Fix the scheduler logic in a couple of places to not preempt a task when an
equal priority task becomes ready.
+ Add macros used in FreeRTOS-Plus libraries. Contributed by @Holden.
+ Fix clang compiler warnings. Contributed by @phelter.
+ Add assertions to ARMv8-M ports to detect when FreeRTOS APIs are called from
interrupts with priority higher than the configMAX_SYSCALL_INTERRUPT_PRIORITY.
Contributed by @urutva.
+ Add xPortIsInsideInterrupt API to ARM_CM0 ports.
+ Fix build warning in MSP430X port when large data model is used.
+ Add the ability to use Cortex-R5 port on the parts without FPU.
+ Fix build warning in heap implementations on PIC24/dsPIC.
+ Update interrupt priority asserts for Cortex-M ports so that these do not fire
on QEMU which does not implement PRIO bits.
+ Update ARMv7-M ports to ensure that kernel interrupts run at the lowest priority.
configKERNEL_INTERRUPT_PRIORITY is now obsolete for ARMv7-M ports and brings
these ports inline with the newer ARMv8-M ports. Contributed by @chrisnc.
+ Fix build issue in POSIX GCC port on Windows Subsystem for Linux (WSL). Contributed
by @jacky309.
+ Add portMEMORY_BARRIER to Microblaze port. Contributed by @bbain.
+ Add portPOINTER_SIZE_TYPE definition for ATmega port. Contributed by @jputcu.
+ Multiple improvements in the CMake support. Contributed by @phelte and @cookpate.
