# Particle Device OS Updates Thread **URL:** \ **Category:** Particle Updates\ **Created:** [August 14, 2015, 12:07am UTC](https://community.particle.io/t/particle-device-os-updates-thread/14378 "2015-08-14T00:07:33Z")\ **Posts on this page:** 1\ **Showing post:** 112
**Author:** ![avtolstoy](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/avtolstoy/32/8126_2.png) [@avtolstoy](https://community.particle.io/u/avtolstoy)\ **Post date:** [June 29, 2020, 4:44pm UTC](https://community.particle.io/t/particle-device-os-updates-thread/14378/112 "2020-06-29T16:44:37Z")
## Device OS 1.5.4-rc.1 Release Candidate is out on the [Web IDE](https://build.particle.io) for (Photon/P1/Electron/Argon/Boron/Xenon/B SoM/B5 SoM/Tracker) _released on June 29th, 2020_ * * * ✅ This 1.5.4-rc.1 **Release Candidate** will be defaulted to 1.5.4 on July 10th, 2020 unless there are regressions found that require further patches. ✏ Testing on your applications is encouraged and appreciated, thank you! 🙇 * * * > **Note:** This is a **Release Candidate (RC)** and is not intended for production yet. We've tested this RC to the best of our ability and we want to know what you think now! Please understand that some _care and attention_ is necessary when testing this RC, and be sure to upgrade to the final release when it's available. This RC will not be available by default. To use you must select the version dropdown from the **devices** drawer. _Downgrading back to the current release info is at the bottom of this post._ > > **Note:** OTA or YModem transfer on Electron (sequence required) > > 1. First Update to 0.5.5 (if the current version is less than that) > 2. Then update to 0.6.4 (if the current version is less than that) > 3. Then update to 0.7.0 (if the current version is less than that) > 4. Then update to 1.2.1 (if the current version is less than that) > 5. Then update to 1.5.4-rc.1 > > **Note:** DFU over USB on Electron/Photon/P1 (sequence not required) > > - You may update to 1.5.4-rc.1 directly first, flash the system firmware (attached above) in order 1,2(,3) to the device using `particle flash --usb `. See the next note about the bootloader if you are offline! > > **Note:** P1/Photon Bootloader > The Cloud will automatically update the bootloader on P1/Photon devices if your device is online. If your device does not connect to the cloud and it is offline, you should flash the bootloader to the device using `particle flash --serial `. This should be done _after_ upgrading system firmware. The Electron bootloader is applied automatically from it's own system parts. > > **Note:** Argon/Boron/Xenon/B SoM/B5 SoM > If your device is offline, the bootloader must be manually updated using `particle flash --serial `. This can be done _before_ or _after_ upgrading system firmware. > > **Note:** Argon/Boron/Xenon/B SoM/B5 SoM SoftDevice > If your device is offline, the SoftDevice must be manually updated using the CLI. See the instructions below. > > **Note:** Downgrading [Electron/Photon/P1] OTA or YModem transfer: > If you need to downgrade, you must downgrade to 1.2.1, then 0.7.0, then 0.6.3(Photon/P1), 0.6.4(Electron) to ensure that the bootloader downgrades automatically. When downgrading to older versions, downgrade to 1.2.1, then 0.7.0 first, then 0.6.3(Photon/P1), 0.6.4(Electron), then to an older version such as 0.5.5. ## 1.5.4-rc.1 > **Note:** If your Gen 2 Photon/P1 or Gen 3 device does not have a Cloud connection, it is recommended to update system firmware, and then the bootloader via CLI with `particle flash --serial bootloader.bin` (bootloaders found in Github release). Electron bootloaders are still contained in system firmware and will update automatically as needed. > **Note:** If your Gen 3 device does not have a Cloud connection, this release will also require manually updating the SoftDevice via CLI. The instructions are available in the release notes and the SoftDevice binaries are available in the Github release. > This release contains v502 bootloaders. ### BUGFIXES - [Electron] Fixes buffer overrun in modem HAL [#2115](https://github.com/particle-iot/device-os/pull/2115) - [Electron] Process 'CEREG: 0' URCs on R410M [#2119](https://github.com/particle-iot/device-os/pull/2119) - [Photon] Fix WPA Enterprise X509 certificate parsing [428940879f5fd1d5a3bdd658260ee45a9f7aca90](https://github.com/particle-iot/device-os/commit/428940879f5fd1d5a3bdd658260ee45a9f7aca90) ## System Binaries (all devices) [https://github.com/particle-iot/device-os/releases/download/v1.5.4-rc.1/particle\_device-os@1.5.4-rc.1.zip](https://github.com/particle-iot/device-os/releases/download/v1.5.4-rc.1/particle_device-os@1.5.4-rc.1.zip) * * * ## Programming and Debugging You can view specific [programming and debugging notes for this version of firmware here](https://prerelease-docs.particle.io/reference/device-os/firmware/photon/?fw_ver=1.5.4-rc.1&cli_ver=2.6.0&electron_parts=3#programming-and-debugging-notes). ## SoftDevice update This Device OS release will automatically update the SoftDevice for devices connected to the cloud. ### Prerequisites [particle-cli](https://docs.particle.io/tutorials/developer-tools/cli/) version 2.6.0. ### Upgrading OTA 1. Upgrade to 1.5.4-rc.1 2. Manually flash 1.5.4-rc.1 bootloader: `particle flash boron-bootloader@1.5.4-rc.1.bin` 3. Flash SoftDevice: `particle flash boron-softdevice@1.5.4-rc.1.bin` ### Upgrading using YModem 1. Upgrade to 1.5.4-rc.1 2. Put the device into listening mode (blinking blue) by holding MODE button 3. Manually flash 1.5.4-rc.1 bootloader: `particle flash --serial boron-bootloader@1.5.4-rc.1.bin` 4. Flash SoftDevice: `particle flash --serial boron-softdevice@1.5.4-rc.1.bin` ### Upgrading using DFU (--usb only works for SoftDevice, not bootloader yet) 1. Upgrade Device OS to 1.5.4-rc.1 2. Update the bootloader to 1.5.4-rc.1 with the OTA or YModem process above 3. Put the device into DFU mode (blinking yellow) 4. Flash the SoftDevice: `particle flash --usb boron-softdevice@1.5.4-rc.1.bin` ## QA Report Summary for Particle Device OS You can view [results of tests run this release here](https://docs.google.com/spreadsheets/d/e/2PACX-1vSYwlKFO9HNGiwxGD4KtBrBOHDGzJZoLehiEiZ7G8BA0bfsR2EoUOUrGn3jQ97coTWe3kHfXP0Z_Dhi/pubhtml). --- _[View the full topic](https://community.particle.io/t/particle-device-os-updates-thread/14378)._