topic Re: LPC5536 SDK: FreeRTOS config file outdated? in LPC Microcontrollers

LPC5536 SDK: FreeRTOS config file outdated?

danielholala — Tue, 24 Jun 2025 14:15:06 GMT

Dear reader,

I'm using MCUXpresso IDE V24.12 with the latest LPC5536 SDK.

Using the New Project Wizard, I created a FreeRTOS based project.

I checked FreeRTOS related files in this new project and noticed that they bear the version number V11.1.0 ("FreeRTOS Kernel V11.1.0"). This is quite recent.

However, the template for the FreeRTOSConfig.h bears version number V10.4.3.

Obviously, this configuration file is outdated and needs to be upgraded to match the version number of the source code.

Further, FreeRTOSConfig.h includes another configuration file, FreeRTOSConfig_Gen.h, which bears version number V10.5.1.

This is very confusing.

Why are there two FreeRTOS configuration files?
Has NXP adapted the configuration files and where?
If so, why hasn't NXP defined configENABLE_FPU in the first place? This bug has been reported in 2020, see here, and it is still not fixed.
Where does NXP want me to enter my FreeRTOS configuration?
Why doesn't NXP provide the config file that matches the version of the FreeRTOS source code?

For completeness sake, the config file for V11.1.0 is readily available here:

https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/V11.1.0/examples/template_configuration/FreeRTOSConfig.h

It appears to me that the FreeRTOS support from NXP is lacking.

If you use FreeRTOS, how do you handle this configuration file issue?

Thanks!

Best regards,
Daniel

Re: LPC5536 SDK: FreeRTOS config file outdated?

Omar_Anguiano — Tue, 24 Jun 2025 20:53:04 GMT

The SDK release is designed so it adapts to a specific device from NXP.
Since the Freertos release is very generic you would need to make some modifications so you take more advantage of the OS on your specific device.|
So some files present on the SDK can be from previous freertos releases.

Best regards,
Omar

Re: LPC5536 SDK: FreeRTOS config file outdated?

danielholala — Fri, 27 Jun 2025 08:28:25 GMT

Hello @Omar_Anguiano ,

Thank you for replying to my request.

You probably know that par of the FreeRTOS implementation is also quite specific to the device. Therefore FreeRTOS provides different ports and the SDK only includes the port relevant to the specific device.

Regarding FreeRTOS support in the SDK, I provided several bullet points in my first posting pointing to possible and crucial (enable configENABLE_FPU) improvements. Could you please forward them to the management that is responsible for handling FreeRTOS support in the SDK?

I'd highly appreciate if NXP would put more love into the SDK and also provide up-to-date versions of the FreeRTOS configuration file and add some documentation.

Thanks.
Dan

Re: LPC5536 SDK: FreeRTOS config file outdated?

danielholala — Thu, 03 Jul 2025 09:44:06 GMT

Just a couple of days ago, MCUXpresso IDE 25.06 was released. I installed it with matching SDK 25.06. Then I created a FreeRTOS based project again.

Now FreeRTOSConfig.h bears version number V11.1.0. However, this file does not contain the definitions. It contains some fallback #if clauses and includes FreeRTOSConfig_Gen.h. The latter contains the majority of defines and bears version V10.5.1.

So I still think FreeRTOSConfig_Gen.h should be compared against the template included in the official repository:

https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/V11.1.0/examples/template_configuration/FreeRTOSConfig.h

to check if any new or existing configuration options need to be added or migrated. Then bump the version number to V11.1.0.

I hope that makes sense to you , too.

Best regards,
Daniel