Tutorial: GNU gcov Coverage with the NXP i.MX RT1064

This tutorial shows how to use and collect coverage data using the GNU gcov tool. As board and hardaware I’m using the NXP i.MX RT1064 EVK:

MIMXRT1064-EVK running ThreadX
MIMXRT1064-EVK

While this tutorial uses this specific board, things are pretty generic and should be applicable for any other board or MCU.

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New MCU-Link Debug Probe from NXP

The NXP MCUXpressso IDE Release V11.2.1 gave a hint about a coming new debug probe, the MCU-Link which is available now:

MCU-Link debugging the LPC845-BRK Board

MCU-Link in 3D printed enclosure debugging the LPC845-BRK Board

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Steps to use FreeRTOS with newlib reentrant Memory Allocation

Reentrancy is an attribute of a piece of code and basically means it can re-entered by another execution flow, for example by an interrupt or by another task or thread. This is an important concept and still a lot of code ‘in the wild’ does violate reentrancy. As a result the application crashes immediately in the best case. Worse it crashes randomly or even worse it behaves incorrectly 😦 .

Reentrancy is always a concern if using standard library functions, including printf() or malloc(). FreeRTOS offers a reentrant wrapper to the standard malloc() and free() (Memory Scheme 3)

Running FreeRTOS with reentrant newlib

Running FreeRTOS with reentrant newlib

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FreeRTOS Task Runtime Statistics for NXP i.MX RT1064

FreeRTOS has many cool features, and one is that it can report the CPU percentage spent in each task. The downside is that to get this kind of information some extra work is needed. In this article I show how to do this for the NXP i.MX1064.

FreeRTOS Runtime Information

FreeRTOS Runtime Information

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SWO with NXP i.MX RT1064-EVK Board

With the cost of an single pin, many ARM Cortex-M boards including the NXP i.MX RT1064 can produde SWO data: think about a pin able to stream data out of the chip in realtime. For example interrupt activity which otherwise might be hard to capture:

SWO Interrupt Trace

SWO Interrupt Trace

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Tutorial: Transforming the NXP LPC845-BRK into a CMSIS-DAP Debug Probe

The NXP LPC845-BRK board is a tiny an inexpensive (sub $6) breakout board. The board includes a CMSIS-DAP (LPC11U35) on-board debug probe which can be used as a debug probe to debug any NXP LPC, Kinetis or i.MX RT device 🙂

LPC845-BRK used to debug robot

LPC845-BRK used to debug a Sumo Battle Robot

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First Steps with the NXP i.MX RT1064-EVK Board

I always reserve time between Christmas and New Year to get my hands on technology pieces which I might not have any time otherwise. Among different things I ordered the NXP i.MX RT1064-EVK board from Mouser.com, and it arrived right before Christmas. Time to have it unboxed and started….

i.MX RT1064 Processor

i.MX RT1064 Processor

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