Difference between revisions of "FreeRTOS"

Latest revision as of 18:14, 19 September 2022

Overview

Ted starting a wiki page to hold notes and findings from working through demos and tutorials on FreeRTOS operating system. First goals include:

• Learning what target CPUs, dev boards and systems run FreeRTOS
• Learning what emulators run and support testing of FreeRTOS instances

^ First Topics Explored

RTOS fundamentals covered in pages of FreeRTOS site:

• https://www.freertos.org/implementation/a00002.html

These initial links will likely be moved or removed, they're just first places Ted checked out at FreeRTOS site:

• https://www.freertos.org/rtos-trace-macros.html
• https://freertos.org/a00110.html#configASSERT

- 2017-12-27 WED - FreeRTOS demo applications described in overview fashion at https://www.freertos.org/a00102.html.

• https://www.freertos.org/a00017.html . . . source code organization,
• https://www.freertos.org/a00090.html . . . FreeRTOS ports, each its own web page,

- 2018-05-11 FRI - Quick-start page and configAssert():

• https://www.freertos.org/a00110.html#configASSERT

^ FreeRTOS Ported To Microcontroller Families

- 2017-12-15 FRI -

FreeRTOS ports to various microcontroller families:

• https://www.freertos.org/a00090.html
• https://www.freertos.org/FreeRTOS-for-Cortex-M0-LPC1114-LPCXpresso.html NXP LPC1114 ARM Cortex-M0 Demo
• https://www.freertos.org/FreeRTOS-for-STM32F4xx-Cortex-M4F-IAR.html

^ Specific Boards Usable with FreeRTOS

2018-04-10

Singleton Pattern mentioned in section named "Basics" in the following wiki document about San Jose State University LPC1758 dev board:

• http://socialledge.com/sjsu/index.php/SJ_One_Board
  • http://socialledge.com/sjsu/index.php/Main_Page
  • http://socialledge.com/sjsu/images/d/de/2012SJOneBoardSchematic.pdf

• https://www.freertos.org/FreeRTOS-Plus/BSP_Solutions/ST/index.html
  • https://www.freertos.org/FreeRTOS-Plus/BSP_Solutions/ST/STM32Cube.html#examples

• https://www.freertos.org/FreeRTOS_Support_Forum_Archive/April_2010/freertos_STM32F10X-128k-Eval_freeRTOS_V6.0.4_OK_3669009.html
• https://github.com/atgreen/FreeRTOS/tree/master/Demo/CORTEX_STM32F100_Atollic

# # # Trouble-shooting Related Notes Follow # # #

^ FreeRTOS Architecture

Context switchting, how context switched between tasks in FreeRTOS . . .

• https://www.freertos.org/implementation/a00003.html
• https://www.freertos.org/implementation/a00011.html

Task Control Block (TCB) memory allocation . . .

• https://www.freertos.org/FreeRTOS_Support_Forum_Archive/January_2018/freertos_Task_control_block_memory_allocation_55c3c1a5j.html

Task priorities assignable defined in tasks.h:

~/Downloads/freertos/FreeRTOSv10.0.1/FreeRTOS/Source$ grep -nr tskIDLE_PRIORITY ./*
./include/task.h:154:#define tskIDLE_PRIORITY			( ( UBaseType_t ) 0U )
./include/task.h:307:	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, &ucParameterToPass, tskIDLE_PRIORITY, &xHandle );
./include/task.h:423:                      tskIDLE_PRIORITY,// Priority at which the task is created.
./include/task.h:688:	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
./include/task.h:856:	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
./include/task.h:861:	 // It was created with tskIDLE_PRIORITY, but may have changed
./include/task.h:863:	 if( uxTaskPriorityGet( xHandle ) != tskIDLE_PRIORITY )
./include/task.h:988:	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
./include/task.h:993:	 vTaskPrioritySet( xHandle, tskIDLE_PRIORITY + 1 );
./include/task.h:998:	 vTaskPrioritySet( NULL, tskIDLE_PRIORITY + 1 );
./include/task.h:1030:	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
./include/task.h:1079:	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
./include/task.h:1154:	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
./include/task.h:1208:	 xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
./queue.c:2031:			uxHighestPriorityOfWaitingTasks = tskIDLE_PRIORITY;

^ Task Control Block - TCB

Exploring the Task Control Block and stack implementations of FreeRTOS. Following forum post mentions stack checking as a feature of FreeRTOS 7.1 which can be enabled. This post also mentions interrupt priorities which range from 1 to 15:

• https://www.freertos.org/FreeRTOS_Support_Forum_Archive/December_2012/freertos_pxCurrentTCB_corrupted_6477695.html

^ Memory Management and Heap

https://stackoverflow.com/questions/58746081/how-do-i-select-a-memory-allocation-implementation-heap-c-file-in-freertos

^ Software Timers

• https://www.freertos.org/RTOS-software-timer.html
• https://mcuoneclipse.com/2018/05/27/tutorial-understanding-and-using-freertos-software-timers/

Useful forum post regarding xTaskGetTickCount(): 2020-07-20

• https://www.freertos.org/FreeRTOS_Support_Forum_Archive/September_2018/freertos_Measure_Time_within_a_Task_with_xTaskGetTickCount_6d2307a0j.html

^ References

• https://www.freertos.org/History.txt . . . change history in text format gives a list of FreeRTOS stable releases
• https://www.freertos.org/a00104.html . . . source code download instructions

2018-06-08 - Friday

• http://www.aosabook.org/en/freertos.html