This example demonstrates integrating Memfault with FreeRTOS applications. The example uses the QEMU target, MPS2 Cortex M3 AN385, to run the application and is based on the MPS2 Cortex M3 AN385 FreeRTOS Demo. This file outlines various components of the example application. For more information on the MCU SDK, please see our documentation at docs.memfault.com.
The project requires the following:
- git
- GNU Make
- A version of the Arm GNU Toolchain
- Note: The project assumes the toolchain can be found via your environment's PATH, otherwise
you may specify by setting
ARM_CCwith the full path to the toolchain/bindirectory
- Note: The project assumes the toolchain can be found via your environment's PATH, otherwise
you may specify by setting
By default the project will clone FreeRTOS V10.4.6 into the project directory. If you would like to use a
different version, please set FREERTOS_DIR to an existing FreeRTOS directory.
To build, from the project directory run:
makeTo run, from the project directory run:
make runWith the console open you may test out various features using the demo CLI commands. A simple example of testing assert handling and data export:
MFLT:[INFO] GNU Build ID: 8a45620abae6842848670c379411d8b31846eadc
MFLT:[INFO] S/N: freertos-example
MFLT:[INFO] SW type: qemu-app
MFLT:[INFO] SW version: 1.0.0
MFLT:[INFO] HW version: qemu-mps2-an385
MFLT:[INFO] Memfault Initialized!
mflt> test_assert
MFLT:[INFO] GNU Build ID: 8a45620abae6842848670c379411d8b31846eadc
MFLT:[INFO] S/N: freertos-example
MFLT:[INFO] SW type: qemu-app
MFLT:[INFO] SW version: 1.0.0
MFLT:[INFO] HW version: qemu-mps2-an385
MFLT:[INFO] Memfault Initialized!
mflt> export
MFLT:[INFO] MC:SK8SgQlDT1JFAgYAAwwTFAABTAYAIwGAAAD//wAAe30AAEBmACB7fQwACKUHgFMAICilE3BTACA3WAAAhG8KABNhMP8/IHBTACAMDgABFAY=:
MFLT:[INFO] MC:wE0AKYpFYgq65oQoSGcMN5QR2LMYRurcAg4AARAGACFmcmVlcnRvcy1leGFtcGxlCg4AAQUGAAsxLjAuMAsOAAEIBgARcWVtdS1hcHAEDgA=:
MFLT:[INFO] MC:wJsBAQ8GAB9xZW11LW1wczItYW4zODUHDgABBAYAASgGAAEFDgABBAYACQGAAAABBgAJJO0A4BwSAAEBCAABQCAAAQEGAAkY7QDgDBoABP8=:
MFLT:[INFO] MC:wOgBAQEGAAkE4ADgEB4ACQcAAQABBgAJBO0A4AgGAAcD+AAECAABAQYACfztAOAEDgABAQgAB+EA4AQOAAEBCAAH4gDgBA4AAQEIAAfjAOA=:
MFLT:[INFO] MC:wLUCBA4AAQEIAAfkAOAgRgABAQYACUhlACAoBgAGARoAAakIACcCAADMWQAgzFkAIAACAABpvQAAAQYA4QLMWQAgAAIAAAE2R05VIEJ1aWw=:
# Output clippedThe exported output can be pasted into the Memfault web app for processing. See this page in our docs.
To debug, from the project directory run:
make debugQEMU will start the application and wait for a debugger to attach. From a separate terminal run:
make gdbThe application is built with the MCU SDK's demo CLI. This CLI includes commands to trigger faults;
collect data from logs, trace events, and metrics; and export data to Memfault's web application
for processing. For more info on the commands available use the "help" command in the console or
view the source code at memfault-firmware-sdk/components/demo.
Two simple tasks are used to illustrate creating metrics to measure your application's performance. The first task, Heap Task, allocates and deallocates memory periodically. A second tasks, Metrics Task, sets metrics based on the state of the system heap. The two metrics produced are:
FreeRTOS_HeapFreeBytes: Measures current total bytes free in the FreeRTOS heapFreeRTOS_HeapMinFreeBytes: Measures the lowest total bytes free in the FreeRTOS heap since bootFreeRTOS_Heap_pct_max: Measures the max percentage of the FreeRTOS heap used since boot
These metrics are collected every 60 seconds in this example. This can be changed by modifying
MEMFAULT_METRICS_HEARTBEAT_INTERVAL_SECS in memfault_platform_config.h.
The heap tracing capabilities of the MCU SDK are enabled by default. The SDK will collect a set of the most recent allocations with their location in code and size when a coredump is saved.
The application is configured to collect the most recent logs along whenever a coredump is collected.