# v18.9.0

We are pleased to announce the release of TT Zephyr Platforms firmware version 18.9.0 🥳🎉.

Major enhancements with this release include:

## Performance Improvements

* Load spi flash images using temporary buffer rather than large statically allocated SRAM buffer

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## Stability Improvements

* Update Blackhole ERISC FW to v1.5.0
  * Updated some eth training sequencing to help with Galaxy UBB products
  * Added CALL_ACK postcode in eth msg mailboxes to show message has been read and is being processed
  * Added fence instructions in eth msg mailboxes to invalidate L1 cache when polling
  * Changed default training mode to AUTO mode from ANLT, will result in manual eq on Galaxy QSFP ports
  * ETH msg FEATURE_ENABLE: allows for enable/disablement of eth fw features

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## Drivers

* Added Tenstorrent Blackhole PVT driver based on Zephyr's sensor API.

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## Migration guide

An overview of required and recommended changes to make when migrating from the previous v18.8.0 release can be found in [v18.9 Migration Guide](https://github.com/tenstorrent/tt-zephyr-platforms/tree/main/doc/release/migration-guide-18.9.md).

## Full ChangeLog

The full ChangeLog from the previous v18.8.0 release can be found at the link below.

https://github.com/tenstorrent/tt-zephyr-platforms/compare/v18.8.0...v18.9.0