# What version of arm-none-eabi-gcc do you use to build OpenMV3 firmware?

**URL:** <https://forums.openmv.io/t/what-version-of-arm-none-eabi-gcc-do-you-use-to-build-openmv3-firmware/229>\
**Category:** OpenMV Boards\
**Created:** [April 8, 2017, 9:14am UTC](https://forums.openmv.io/t/what-version-of-arm-none-eabi-gcc-do-you-use-to-build-openmv3-firmware/229 "2017-04-08T09:14:22Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![RobotVision](https://avatars.discourse-cdn.com/v4/letter/r/8edcca/32.png) [@RobotVision](https://forums.openmv.io/u/RobotVision)\
**Post date:** [April 8, 2017, 9:14am UTC](https://forums.openmv.io/t/what-version-of-arm-none-eabi-gcc-do-you-use-to-build-openmv3-firmware/229/1 "2017-04-08T09:14:22Z")

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Hi, all  
I’ve tried gcc-arm-none-eabi\_5\_2-2015q4, gcc-arm-none-eabi\_5\_4-2016q2, gcc-arm-none-eabi\_5\_4-2016q3 to build OpenMV3 firmware but all failed.  
The compilers complained “src/st/startup\_stm32f765xx.s:47: Error: unknown cpu `cortex-m7’”.

So, What version of arm-none-eabi-gcc should I use and where can I get one ?

Thank you guys!

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**Author:** ![kwagyeman](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/kwagyeman/32/4_2.png) [@kwagyeman](https://forums.openmv.io/u/kwagyeman)\
**Post date:** [April 8, 2017, 4:36pm UTC](https://forums.openmv.io/t/what-version-of-arm-none-eabi-gcc-do-you-use-to-build-openmv3-firmware/229/2 "2017-04-08T16:36:15Z")

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Hi, I’ve not encountered that error. Did you follow this: [Home · openmv/openmv Wiki · GitHub](https://github.com/openmv/openmv/wiki/Firmware-Development)

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**Author:** ![iabdalkader](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/iabdalkader/32/1169_2.png) [@iabdalkader](https://forums.openmv.io/u/iabdalkader)\
**Post date:** [April 8, 2017, 5:00pm UTC](https://forums.openmv.io/t/what-version-of-arm-none-eabi-gcc-do-you-use-to-build-openmv3-firmware/229/3 "2017-04-08T17:00:39Z")

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I’m using 2016-q3 you can get it from here: [https://developer.arm.com/open-source/gnu-toolchain/gnu-rm/downloads](https://developer.arm.com/open-source/gnu-toolchain/gnu-rm/downloads)

Try this:

```python
arm-none-eabi-gcc -fsyntax-only -mcpu=cortex-m7 -mthumb -xc /dev/null

```

If your toolchain doesn’t support M7 you’ll get an error something like `unrecognized argument...` which means you have the wrong toolchain in path.

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<div class="post-metadata">

**Author:** ![RobotVision](https://avatars.discourse-cdn.com/v4/letter/r/8edcca/32.png) [@RobotVision](https://forums.openmv.io/u/RobotVision)\
**Post date:** [April 9, 2017, 9:17am UTC](https://forums.openmv.io/t/what-version-of-arm-none-eabi-gcc-do-you-use-to-build-openmv3-firmware/229/4 "2017-04-09T09:17:37Z")

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> [@](#):
>
> I’m using 2016-q3 you can get it from here: [Downloads | GNU Arm Embedded Toolchain Downloads – Arm Developer](https://developer.arm.com/open-source/gnu-toolchain/gnu-rm/downloads)
> 
> Try this:
> 
> ```python
> arm-none-eabi-gcc -fsyntax-only -mcpu=cortex-m7 -mthumb -xc /dev/null
> 
> ```
> 
> If your toolchain doesn’t support M7 you’ll get an error something like `unrecognized argument...` which means you have the wrong toolchain in path.

Hi, I think I made a mistake. The gcc-arm-none-eabi-5\_4-2016q3 toolchain is just OK.

Thanks to both of you.