# Adding Custom Accelerators - Passing Device Tree from freedom to freedom-u-sdk

**URL:** <https://forums.sifive.com/t/adding-custom-accelerators-passing-device-tree-from-freedom-to-freedom-u-sdk/2341>\
**Category:** Freedom U500\
**Created:** [May 17, 2019, 3:04pm UTC](https://forums.sifive.com/t/adding-custom-accelerators-passing-device-tree-from-freedom-to-freedom-u-sdk/2341 "2019-05-17T15:04:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![bchetwynd](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@bchetwynd](https://forums.sifive.com/u/bchetwynd)\
**Post date:** [May 17, 2019, 3:04pm UTC](https://forums.sifive.com/t/adding-custom-accelerators-passing-device-tree-from-freedom-to-freedom-u-sdk/2341/1 "2019-05-17T15:04:38Z")

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I am looking to add some custom accelerators to the the Freedom U500 and are wondering how the device tree is passed to freedom-u-sdk? Many .dts files in the repo… but it is not clear which are used…

Thanks,  
Brendon

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**Author:** ![bchetwynd](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@bchetwynd](https://forums.sifive.com/u/bchetwynd)\
**Post date:** [May 21, 2019, 11:55am UTC](https://forums.sifive.com/t/adding-custom-accelerators-passing-device-tree-from-freedom-to-freedom-u-sdk/2341/2 "2019-05-21T11:55:27Z")

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Answered my own question: Device-tree is included as part of the Bootroom build and pass to the BBL.