# SMP version merged to main, but getting build errors for using single core version

**URL:** <https://forums.freertos.org/t/smp-version-merged-to-main-but-getting-build-errors-for-using-single-core-version/19106>\
**Category:** Kernel\
**Created:** [February 2, 2024, 1:47pm UTC](https://forums.freertos.org/t/smp-version-merged-to-main-but-getting-build-errors-for-using-single-core-version/19106 "2024-02-02T13:47:45Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![ObligedTester](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/obligedtester/32/3863_2.png) [@ObligedTester](https://forums.freertos.org/u/ObligedTester)\
**Post date:** [February 2, 2024, 1:47pm UTC](https://forums.freertos.org/t/smp-version-merged-to-main-but-getting-build-errors-for-using-single-core-version/19106/1 "2024-02-02T13:47:45Z")

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Hello,

I have been using this repository to as a base for my freertos projects with the Rpi Pico: [GitHub - Evlers/pico-freertos: FreeRTOS SMP Template for Raspberry Pi Pico Board (RP2040)](https://github.com/Evlers/pico-freertos).  
It is working great, but I saw it was some versions behind and just wanted to see if I could update the kernel to the latest one.

Since I saw that the SMP version was now merged to the main branch, I downloaded the latest zip file, which is 11.0.1.  
Coincidentally, for some reason cloning main will result in 10.4.4. I have no clue why, but I have next to no experience with GitHub. So needed to “manually” select the zip file release that returned the latest. Not sure why?

When trying to compile this I get following build error:

> **error** configUSE\_CORE\_AFFINITY is not supported in single core FreeRTOS

So I have probably misinterpreted the meaning of “SMP version merged in to main”  
There is still another version to use SMP, or should this config not be set anymore?

There are so many versions and examples lately that is hard to follow what is the “new” way.

If anyone has any pointers of what needs to be done to move away from SMP version that seem to be very old and deprecated when reading the descriptions, it would be very much appreciated!

Thanks

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<div class="post-metadata">

**Author:** ![rtel](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/rtel/32/31_2.png) [@rtel](https://forums.freertos.org/u/rtel)\
**Post date:** [February 2, 2024, 6:47pm UTC](https://forums.freertos.org/t/smp-version-merged-to-main-but-getting-build-errors-for-using-single-core-version/19106/2 "2024-02-02T18:47:28Z")

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Do you have configNUM\_CORES set greater than 1? If not, it assumes a single core build.

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<div class="post-metadata">

**Author:** ![ObligedTester](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/obligedtester/32/3863_2.png) [@ObligedTester](https://forums.freertos.org/u/ObligedTester)\
**Post date:** [February 2, 2024, 7:47pm UTC](https://forums.freertos.org/t/smp-version-merged-to-main-but-getting-build-errors-for-using-single-core-version/19106/3 "2024-02-02T19:47:17Z")

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Thanks for your reply.

Yes it is set to 2.  
For reference, config is lifted straight from this one:[pico-freertos/include/FreeRTOSConfig.h at master · Evlers/pico-freertos · GitHub](https://github.com/Evlers/pico-freertos/blob/master/include/FreeRTOSConfig.h)

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**Author:** ![PaulB-AWS](https://avatars.discourse-cdn.com/v4/letter/p/a183cd/32.png) [@PaulB-AWS](https://forums.freertos.org/u/PaulB-AWS)\
**Post date:** [February 2, 2024, 9:42pm UTC](https://forums.freertos.org/t/smp-version-merged-to-main-but-getting-build-errors-for-using-single-core-version/19106/4 "2024-02-02T21:42:50Z")

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@ObligedTester I was able to successfully build by adding the following two definitions to the FreeRTOSConfig.h you pointed to:

```auto
#define configNUMBER_OF_CORES 2
#define configUSE_PASSIVE_IDLE_HOOK 0

```

It seems that configNUM\_CORES was replaced with configNUMBER\_OF\_CORES at some point.

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<div class="post-metadata">

**Author:** ![ObligedTester](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/obligedtester/32/3863_2.png) [@ObligedTester](https://forums.freertos.org/u/ObligedTester)\
**Post date:** [February 2, 2024, 9:48pm UTC](https://forums.freertos.org/t/smp-version-merged-to-main-but-getting-build-errors-for-using-single-core-version/19106/5 "2024-02-02T21:48:07Z")

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Thank you very much!

That solved it and I was able to build successfully also!

Difficult to keep track of the changes over the versions 🙂