# FirmfareUpdate. File reading failed

**URL:** <https://forum.opencyphal.org/t/firmfareupdate-file-reading-failed/595>\
**Category:** Libcanard\
**Created:** [August 17, 2019, 7:57am UTC](https://forum.opencyphal.org/t/firmfareupdate-file-reading-failed/595 "2019-08-17T07:57:21Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Sergey\_Frolov](https://forum.opencyphal.org/letter_avatar_proxy/v4/letter/s/b19c9b/32.png) [@Sergey\_Frolov](https://forum.opencyphal.org/u/Sergey_Frolov)\
**Post date:** [August 17, 2019, 7:57am UTC](https://forum.opencyphal.org/t/firmfareupdate-file-reading-failed/595/1 "2019-08-17T07:57:21Z")

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Hello. I have a trouble in firmware updating through GUI tool. I get request for firmware updating with OK, get File Info with OK. Then file reading begins. In bus monitor I see, that first 1024 bytes (4 packets with 256 bytes) read with Ok. And EOT error happens at 5th packet File Read request. I need retrying Begin FW update request again with last offset value. Is its true? I cannot read file full at one BeginFWupdate request. Why?

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**Author:** ![pavel.kirienko](https://forum.opencyphal.org/user_avatar/forum.opencyphal.org/pavel.kirienko/32/9_2.png) [@pavel.kirienko](https://forum.opencyphal.org/u/pavel.kirienko)\
**Post date:** [August 17, 2019, 4:04pm UTC](https://forum.opencyphal.org/t/firmfareupdate-file-reading-failed/595/2 "2019-08-17T16:04:56Z")

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> [@Sergey\_Frolov](#):
>
> EOT error happens at 5th packet File Read request.

> [@Sergey\_Frolov](#):
>
> I cannot read file full at one BeginFWupdate request. Why?

This could be caused by the CAN hardware being unable to keep up with the traffic. What USB-CAN bridge are you using?

> [@Sergey\_Frolov](#):
>
> I need retrying Begin FW update request again with last offset value. Is its true?

The firmware update process is designed to be atomic and non-recoverable. Once failed, you can’t continue from the same point later, you have to start from scratch.

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<div class="post-metadata">

**Author:** ![Sergey\_Frolov](https://forum.opencyphal.org/letter_avatar_proxy/v4/letter/s/b19c9b/32.png) [@Sergey\_Frolov](https://forum.opencyphal.org/u/Sergey_Frolov)\
**Post date:** [August 19, 2019, 5:03am UTC](https://forum.opencyphal.org/t/firmfareupdate-file-reading-failed/595/3 "2019-08-19T05:03:51Z")

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Hello, I use 1000000 kbps speed. Maybe its causes troubles. Hmm… Contrary to your words, i can to initiate BeginFW operation again from my code, and complete file reading starting from last valid offset value. This trick works, but this way is not nice.  
I control each reading iteration, and if it will be fail, I save last success offset value. Then I initiate BFWU request again (starting from last valid offset address), while full file is not read.